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AUGENHEILKUNDE
212/1998 – ISSUE
5
Abstracts:
S. 252-256 (Art. 283)
Imaging in children with intraocular
lesions
Unknown Author
Background A certain diagnosis, as soon as possible, is indispensable
in children with intraocular lesions, the presence of retinoblastoma always
beeing a possibility.
Patients From our casuistic of 418 children since 1970 and from the
literatur, we currently adopt the following attitude. Where the media are
clear, a drawing and fundus photographs are made. Echography is performed
in all cases. Ultrasound biomicroscopic examination is carried out in all
lesions where involvement of the anterior segment is suspected.
Results Where echography shows no calcifications, computed tomography
(CT) is indicated. CT may also enable a possible lesion extension, particularly
to the optic nerve, to be studied.
Conclusions Magnetic resonance imaging (RMI) is the procedure of choice
for evaluating secondary retinal detachment, massive extension of retinoblastoma
and for detecting any early involvement of the pineal gland (pinealoblastoma),
or any other associated lesion. In case of unilateral unifocal sporadic
retinoblastoma, however, no CT or MRI is performed, except where there is
a suspected extension into the optic nerve or the orbit. Echography remains
the most economical, rapid and safest means of diagnosis even in difficult
cases.
Key words Imaging - fundus photography - echography - ultrasound
biomicroscopy - computed tomography - magnetic resonance imaging - retinoblastoma
- intraocular lesion in children
[ back ]
S. 257-258 (Art. 284)
Quantification of intrastromal micro-dot
deposits in the cornea of long-term contact lens wearers
Unknown Author
Background Some months ago we described morphological changes in the
stroma of the cornea of patients with a history of long term contact lens
wear. These degenerations consist of little highly reflective structures
called "micro-dotsÓ. For a more precise quantification of the micro-dots
we established a clinically practicable method for measuring and counting.
Material and methods The micro-dots can be visualized in optical sections
with the scanning slit confocal microscope. To get the real thickness of
a single optical section we had to develop a in vitro model, which consists
of a gel of agar with particles of latex of different size.
Results Some stereological methods made it possible to calculate the
thickness of an optical section as seen with the confocal microscope. We
found out that the thickness shows a variation depending on the reflectivity
and size of the particles as well as on the aperture of the objective used.
From the area of the frame and the thickness of the optical section we could
calculate the density of the highly reflective particles.
Discussion Up to now we could determine the morphological changes
(micro-dots) in the cornea of patients with a history of long term contact
lens wear in a semiquantitative manner only. With the presented method we
are able to make a quite precise numerical estimation of micro-dots. This
is very useful to follow up the progress of these stromal changes over many
years.
Key words confocal microscopy - contact lens wear - long term side
effects
[ back ]
S. 259-260 (Art. 285)
Endoscopy of the lacrymal
duct
Unknown Author
Summary The study presents a new technic for the examination of the
lacrymal duct; i.e the endoscopy. It demonstrates the advantages and permits
to open up new ways to act on the lacrymal duct.
Methods and patients The seventy two patients examined by means of
endoscopy between January 1997 and May 1997 have had all a clear pathology:
epiphora, chronic or acute dacryocystite in a remission phase. Some patients
were at the same time examined radiogically, by means of a
dacryocystorhinography.
Results In all the cases studied using both technics, the endoscopy
made it possible to put into evidence the origin of the epiphora or the
dacryocystite with a much higher precision than with radiographies.
Discussion and conclusion The endoscopy of the lacrymal duct is the
best examination technic in the lacrymal pathology and should in a near future
replace the dacryocystorhinography.
Key words Endoscopy - lacrymal duct - dacryocystorhinography
[ back ]
S. 261-263 (Art. 286)
Effect of aging on retinal nerve fiber
layer thickness using scanning laser polarimetry
Unknown Author
Purpose In glaucoma, visual field defects are a late sign of retinal
nerve fiber layer damage. Scanning laser polarimetry directly quantifies
nerve fiber layer thickness (NFLT) and may allow early detection of defects
and progression during follow-up.
Methods The NFLT of 54 healthy eyes of 54 subjects (age range from
14 to 83 years) was measured with a scanning laser polarimeter (Nerve Fiber
Analyzer II). Measurements were performed along an ellipse 1.75 disc diameters
away from the disc margin. For each subject an average image was calculated
from three measurements. The ellipse was divided into four sectors by the
internal software. All measurements were performed by the same examiner.
All examined eyes had a normal ophthalmological examination, normal eye pressure,
and a normal computerized perimetry.
Results The mean NFLT was thicker in the superior (91.3 mmB16.7 mm)
and inferior sector (90.8 mmB15.6 mm) as compared to the temporal (53.7 mmB15.4
mm) and nasal sector (60.0 mmB14.8 mm). There was an inverse linear correlation
between age and NFLT (Pearson's correlation-coefficient rpP0.30, p < 0.025).
On the average, the mean NFLT decreased by 2.5 mm for each decade of age.
The interindividual variation of the NFLT (mean standard deviation
(sø)=16.1 mm) was, even after correction for age, much larger than
the intraindividual variation (søp6.6 µm).
Conclusions In normal subjects the NFLT decreases with age. The
interindividual NFLT variation is, even after correction for age, much larger
than the intraindividual. Therefore, scanning laser polarymetry might be
especially useful for follow-up of NFLT.
Key words retinal nerve fiber layer - scanning laser polarimetry -
age - follow-up
[ back ]
S. 264-267 (Art. 287)
Digital internet-based ophthalmological
image database
Unknown Author
Objective To manage an ophthalmological image database easily and
rationally.
Materials and Methods Fundus, macro and simultaneously recorded
Fluorescein and ICG angiography images were digitized and archived using
personalcomputers and UNIX workstations. Image data were written to
CD-recordables. The CD-s with image information were stored in a jukebox-server.
On demand image information was converted to dynamic hypertext markup language
(html) with a WWW-server. Information stored on the servers could be observed
with browser programs running on client computers connected to local area
network. The communication with ophthalmologist working outside our hospital
was realized by electronic mail.
Results Different platforms (PC, Mac, workstations, etc.) and operating
systems (Windows 3.x, 95, NT, MacOS, UNIX, etc.) can be used as clients.
The communication with the system is accomplished by standard internet programs
(Internet Explorer, Netscape Navigator, etc.). Thanks to the intuitive graphical
user interface, no special computer knowledge is required to retrieve the
stored data.
Conclusion Our digital image database has many advantages over a
conventional image archive: it is round the clock available, images can be
stored and copied without loss of quality, digital images can be easily
integrated in other applications, it can be used without special computer
knowledge, it is expandable and compatible with all contemporary computer
platforms.
Key words indocyanine green angiography - fluorescein angiography
- digital angiography - digital image processing - internet - intranet
[ back ]
S. 268-269 (Art. 288)
The pressure lowering effect of Latanoprost
0.005%
Unknown Author
Background Earlier studies in monkeys have shown that latanoprost
0.005% lowers the IOP by improving the uveo-scleral Outflow. We wanted to
know if this is also the case in the human eye.
Patients and methods We used our new aqueous humor outflow test with
2 -nitrophenyl-acetate in 9 healthy human volunteers, mean age 32B8.3 years.
They were measured before and 12 h after receiving one drop of latanoprost
0,005% in one eye, randomly chosen. The ocular Photometer was used to quantify
the disappearance of the dye out of the anterior chamber.
Results The half-life time of the dye is shortened after latanoprost
0.005%. It is significantly correlated to the pressure lowering effect of
latanoprost 0.005% (r2p0.5968).
Conclusion The dye-dilution technique proves that latanoprost 0.005%
influences the outflow of the human eye. The better the outflow, the greater
the pressure drop in the eye. The experiment nicely shows that photometric
quantification of 2-nitrophenyl-acetate is a simple, reliable test for the
knowledge of the aqueous humor outflow.
Keywords aqueous humor outflow - dye dilution - nitro-phenyl-acetate
- latanoprost 0.005% - glaucoma
[ back ]
S. 270-274 (Art. 289)
Influence of mental and physical stress
on intraocular pressure - a pilot study
Unknown Author
Background The aim of the present study was to examine the influence
of phasic stressors on intraocular pressure (IOP).
Subjects and methods We exposed 15 ophthalmologically and systemically
healthy non-smoking subjects (m : fp8 : 7; mean age 25.4 years) to both bicycle
ergometry physical stress and a computer-game psychological stress. IOP,
blood pressure, and subjective stress were measured. To adjust for
between-subject variance, we calculated intra-subject z-scores based on IOP
values. Because of the habituation occurring during repeated tonometric
measurements, we tested the significance of the difference between the observed
and expected IOP z-values for each of the stressors. The expected IOP value
was the mean of the pre- and post-stress relaxation-period values. Student's
t-tests were used to assess the impact of the stressors on blood pressure.
Results Both stressors increased the systolic blood pressure, but
only under mental stress was the intraocular-pressure increase statistically
significant (pp0.048).
Discussion The selective increase in intraocular pressure during mental
stress by similar reaction of blood pressure to both stressors is a hint
for possible different regulation circuits in the autonomic nerve system
for intraocular- and blood pressure, respectively. Additionally, it was possible
to demonstrate that mental stress could lead to a rise in intraocular pressure.
Key words glaucoma - intraocular pressure - blood pressure - stress
[ back ]
S. 275-277 (Art. 280)
Results of combined trabeculectomy and
lens implantation
Unknown Author
Background When trabeculectomy and cataract extraction with intraocular
lens insertion are combined, do the success and complication rates add.
Material and methods Follow-up of 47 eyes of 34 patients with combined
trabeculectomy and cataract extraction with intraocular lens implantation
after 12 to 42 months.
Results With a low periperative complication rate the intraocular
pressure after one year was below 22 mm Hg in 90% without any medication
and in 98% additional glaucoma therapy. After 2 and 3 years the intraocular
pressure was normal without any additional therapy in 83% of the eyes. The
visual acuity was better or equal to the preoperative value in 89% of the
cases.
Conclusions The combination of trabeculectomy and of cataract extraction
with intraocular lens implantation has a low complication rate and gives
good results regarding intraocular pressure and visual rehabilitation. When
a trabeculectomy is indicated, the indication for a simultaneous cataract
extraction with intraocular lens implantation should not be to restricted.
Key words Glaucoma - trabeculectomy - cataract - cataract extraction
- intraocular lens implantation
[ back ]
S. 278-279 (Art. 291)
Intracameral lidocaine as an addition
to topical tetracaine anesthesia in clear corneal
phacoemulsification
Unknown Author
Background We have been successfully using topical tetracaine 1%
anesthesia in clear corneal phacoemulsification since 1992. Adding intracameral
lidocaine to topical anesthesia in cataract surgery has been reported since
1996.
Patients and methods We examined the effectiveness of intracameral
lidocaine 1%, which we dyed with methylene blue 2% in 600 cases. During surgery
we merely inject 0.3 ccl lidocaine 1% twice over the iris under a shield
of a viscoelastic substance. After only a few seconds time of action we remove
it again from the anterior chamber.
Results With intracameral lidocaine 1% postoperative pain was totally
eliminated for one to two hours, and usually no pain was felt thereafter.
Non of our cases showed any negative signs of postoperative reaction of the
eye. With the use of intracameral lidocaine we were able to omit pre- and
postoperative systemic pain medication completely. This has proven to be
very advantageous in elderly outpatients. Staining the lidocaine with methylene
blue 2% helps prevent mix-ups and emphasizes its significance. Yet , an
intracameral blue flow was not visible enough to determine the spread of
lidocaine.
Conclusions Intracameral lidocaine represents an ideal addition to
topical tetracaine anesthesia in clear corneal phacoemulsification.
Key words intracameral lidocaine - intracameral methylene blue - topical
tetracain anasthesia - clear corneal phacoemulsification
[ back ]
S. 280-282 (Art. 292)
Clear Lens Extraction (CLE) in high
myopic eyes
Unknown Author
Purpose To evaluate the efficacy and safety of the clear lens removal
to compensate the myopic refractive error.
Methods Retrospective analysis of 40 myopic eyes with axial length
more than 27 mm, treated by phacoemulsification and posterior chamber lens
implantation. Mean follow-up 45.9 months (17 to 118). Analysed parameters:
postoperative uncorrected and bestcorrected visual acuity, comparison of
pre- and postoperative bestcorrected visual acuity, intra- and postoperative
complications, predictability of refraction, subjective satisfaction score.
Results Axial length 30.63B2.0 mm (min. 27, max. 36.8 mm). Preoperative
myopia P14.50B3.6 dpt. Bestcorrected preoperative visual acuity 0.40B0.19
(min. 0.1, max. 0.8). Bestcorrected postoperative visual acuity 0.71B0.25
(min. 0.16, max. 1.25). No loss of best corrected visual acuity. Posterior
capsule opacification requiring YAG-capsulotomy occurred in 50%. One eye
developed cystoid macular edema, no retinal detachment were observed
postoperatively. All patients were satisfayed or very satisfayed.
Conclusions Clear Lens Extraction for severe myopia is safe, for the
patient satisfying and is a valid alternative to corneal refractive
surgery.
Key words Clear Lens Extraction - high myopia
[ back ]
S. 283-285 (Art. 293)
Intraocular pressure variations after
peribulbar and retrobulbar anaesthesia for standard cataract
surgery
Unknown Author
Background To assess the effect on intraocular pressure of peribulbar
and retrobulbar anaesthesia before standard cataract surgery and to study
the efficacy of ocular compression.
Methods In study group 1, 29 eyes of 29 patients undergoing cataract
surgery each received peribulbar injections consisting of 9 ml of anaesthetic
from an inferotemporal site through the skin. IOP values were measured
immediately before and after the injections and then after 10 minutes of
external ocular compression. In study group 2, 30 eyes of 30 patients undergoing
cataract surgery received retrobulbar injections of local anaesthetic as
above but through the conjunctiva and a facialis blockade. IOP values were
measured immediately before and after the injections and then after 10 minutes
of external ocular compression.
Results The mean immediate increase in IOP induced by the injections
was 16,10 (95% confidence interval 11,58/20,62) mm Hg in study group 1 and
1,76 (CI: 0,76/2,76) in study group 2. After The mean variation in IOP after
10 minutes of ocular compression was c0,97 (CI: P1,06/c3) mm Hg in group
1 and P2,97 (CI: P3,98/P1,96) mm Hg in group 2.
Conclusions The peribulbar injection cause a very important increase
of the IOP immediately after the injection: the retrobulbar injection did
not. An ocular compression of 10 minutes is effective in reversing this rise.
The implications for clinical practice are discussed.
Key words Peribulbar - retrobulbar - anaesthesia - cata-ract - intraocular
pressure
[ back ]
S. 286-288 (Art. 294)
Is there a true primary and secondary
deviation in fourth cranial nerve palsies?
Unknown Author
Background An extraocular muscle palsy is conventionally characterized
by a deviation of the visual axes, this being greater when measured with
the affected eye fixing. By definition and illustrating Hering's law, this
secondary angle of deviation is greater than the primary one, measured with
the sound eye fixing. We present here a comparative study of the amount of
subjective excyclodeviation measured in patients suffering from IVth nerve
palsy, with the sound or affected eye fixing.
Methods Two groups of patients were entred into the study : Group
1 (Np54) for superior oblique palsies studied retrospectively and Group 2
(Np14), for a prospective study of those recently acquired (post-traumatic)
and followed over 6 months. In both groups, measurements were made at two
stages, early (1 to 7 weeks after onset) and late (4 to 6 months later).
Results In both groups, the majority of cases showed a greater secondary
torsional deviation, the difference between this and the primary deviation
lessening on late stage measurements.
Conclusion In both groups, the difference between primary and secondary
torsional deviation was not statistically significant.
Key words Superior oblique palsy - torsional deviation - Hering's
law - secondary torsional deviation
[ back ]
S. 289-290 (Art. 295)
Skew deviation and recovery
prognosis
Unknown Author
Background Skew deviation is a vertical ocular misalignement of prenuclear
origin. Although well described in the litterature, it is still probably
underdiagnosed. Natural history of skew deviation is not well described in
the literature.
Purpose To describe the clinical presentations, etiologies and follow-up
of skew deviation.
Methods Retrospective study of 29 patients diagnosed with skew deviation
between 1993 and 1996.
Results The commonest cause was cerebrovascular accident (12/29) and
the commonest localisation was mesencephalic (9/29). Other causes included
surgery (7/29), tumor (4/29), trauma (3/29), degeneration (3/29), inflammatory
(2/29), increased intracranial pressure (1/29). Other localisations included
cerebellum (5/29), ponto-mesencephalic (3/29), and medulla (2/29). Vertical
diplopia was always accompanied by other neuro-ophthalmologic abnormalities.
69.2% (18/26) patients were totally asymptomatic after 7.5 months. 30.8%
(8/26) were still symptomatic (diplopia). One patient required surgery, three
patients were relieved with prisms, one patient needed monocular occlusion.
One patient died during follow-up and precise data were lacking in two
symptomatic patients.
Conclusion Skew deviation is not so rare, 10% of the cases referred
to us for diplopia in 3 years. The diagnosis of skew deviation should be
entertained when vertical diplopia cannot be explained by pathology of
extraocular muscles, peripheral or central cranial nerve III or IV palsies,
myasthenia, or orbital pathology. Prognosis for recovery in patients with
skew deviation is good. 70% will recover, after a median time of 7.5 months.
Surgery should be postponed at least for 12 months.
Key words skew deviation - diplopia - brainstem - vestibular system
- prognosis - recovery
[ back ]
S. 291-293 (Art. 296)
Surgical management of convergence excess
esotropia: study of 50 operated cases
Unknown Author
Background Convergence excess esotropia (EC) can be an additional
component in all forms of strabismus. The most favourable prognosis is found
in those cases where EC is associated with microtropia or bifoveal fusion,
due to a better binocular potential.
Methods 50 non selected cases were entered into the study and divided
into two groups (Group A: EC with microtropia; Group B: EC with bifoveal
fusion). All the patients were followed at the Lausanne Strabismus Unit and
all cases underwent a bilateral medial rectus posterior fixation (Cüppers'
Faden operation) placed at 13 mm from the original insertion.
Results In Group A, the average reduction of angle of strabismus was
25D for near fixation, 20D in Group B. In both groups, the average decrease
in angle for distance fixation was 6D. In Group A, 75% of cases gained some
binocularity post-operatively, not only for distance but also for near fixation.
In Group B, all the patients showed a normal response on the Lang stereotest
post-operatively.
Conclusions In both groups of this study, a bilateral medial rectus
retroequatorial myopexy was a satisfactory alternative for those patients
who refused to wear bifocal glasses.
Key words Convergence excess esotropia - Posterior fixation -
Microesotropia
[ back ]
S. 294-295 (Art. 297)
Asthenopic symptoms in vertebral cervical
syndrome
Unknown Author
Summary The vertebral cervical syndrome is a clinical entity defined
as a dysfunction of the cranio-cervical junction of traumatic or non traumatic
cause. The authors report on asthenopic disorders occurring in such a syndrome.
The fusion amplitude and the accommodation power were reduced in all patients
and were a cause of delayed job reccurrence. The treatment of fusion was
long, painful and, in some cases, not successful. A depressive status associated
with a prolonged job interruption were bad prognosis factors. A differential
diagnosis has to be made with the so-called insurance neurotic reaction.
Key words Asthenopic disorders - Vertebral-cervical syndrome
[ back ]
S. 296-298 (Art. 298)
Strabismus surgery and anterior segment
ischemia
Unknown Author
Background First described in 1957, anterior segment ischemia (ASI)
following extraocular muscle surgery for non paralytic or paralytic strabismus
is a rare but serious complication. Systemic and anatomical risk factors
can be identified and vesselsparing surgical techniques used. The aim of
this study is to evaluate those changes in the anterior chamber that may
indicate the presence of post-operative subclinical ASI.
Methods Pre- and 1 day post-operative anterior chamber flare measurements
with the Laser flare cell meter (Kowa FC-1000) were made in 107 patients
(109 operations) undergoing strabismus surgery. Surgery was carried out by
the same surgeon in all cases and under general anaesthesia. Patients were
divided into different groups according to the muscles operated (horizontal
recti, vertical recti, obliques, or combinations thereof).
Results Global and selective analysis showed no significant statistical
difference between pre-and post-operative flare measurements in patients
undergoing strabismus surgery.
Conclusion No subclinical ASI was found in this study of 109 strabismus
operations (107 patients).
Key words Strabismus surgery - anterior segment ischemia - laser flare
cell meter
[ back ]
S. 299-300 (Art. 299)
Ocular mitochondrial myopathy: a spectrum
of clinical presentations
Unknown Author
Purpose To determine the spectrum of clinical presentations of patients
with chronic progressive external ophthalmoplegia (CPEO).
Methods Retrospective study of 13 cases with CPEO.
Results Eight patients presented an isolated CPEO, three patients
had an associated retinopathy (Kearns-Sayre syndrome), one case suffered
from retinopathy, deafness, diabetes mellitus and dysphagia, and one patient
had an associated dysphagia. Mitochondrial DNA deletions were found in two
cases.
Conclusions Our cases illustrate the wide spectrum of mitochondrial
ocular myopathies. As patients present mostly with ptosis and ophthalmoplegia,
ophthalmologists should be aware of these rare conditions.
Key words chronic progressive external ophthalmoplegia - CPEO -
Kearns-Sayre syndrome - oculopharyngeal dystrophy - 3243 point mutation
[ back ]
S. 301-304 (Art. 300)
Clinical and genetic description of
two families with dominant optic atrophy of Kjier (Locus
3q28)
Unknown Author
Dominant Optic Atrophy, type Kjer (OPA1), is an autosomal dominant
eye disease recently linked to 3q28.
Method We examined 20 patients from 2 unrelated Swiss families to
describe their clinical phenotype. In addition, a linkage analysis was performed
in an attempt to confirm the reported genetic homogeneity of this condition
as well as to refine its genomic localization.
Results Two point analysis provided a cumulative LODscore of 3.03
with marker D3S 2305 . The absence of recombination precluded further refinement
of the disease interval.
Conclusions Our data confirm the genetic homogeneity and the extreme
variability of expression, occasionally mimicking low tension glaucoma.
Key words dominant optic atrophy (Kjer type) - linkage analysis
[ back ]
S. 305-308 (Art. 301)
Mutational screening of peripherine/RDS,
rhodopsine and ROM-1 genes in 69 index patients with retinitis pigmentosa
and allied retinal dystrophies
Unknown Author
Purpose phenotypic, genetic and molecular characterization of 69 index
patients with retinitis pigmentosa (RP) and various inherited retinal
diseases.
Patients and method patients went through complete ocular examination
and blood samples were drawn for mutational screening of three candidate
genes: rhodopsin (RHO), peripherin/RDS, and ROM-1.
Results the most frequent type of RP among our population was the
autosomal dominant (43.6%). Three RHO mutations were found among the RP patients.
A RDS mutation was detected in three unrelated families segregating dominant
macular dystrophy.
Discussion and conclusions 18% of the autosomal dominant RP patients
presented a RHO mutation; RDS R172W mutation was present in 25% of the dominant
macular dystrophies.
Key words retinitis pigmentosa - rhodopsin - peripherin/RDS - macular
dystrophy - autosomal dominant inheritance
[ back ]
S. 309-310 (Art. 302)
Leber's congenital amaurosis: diagnosis,
course and differential diagnosis
Unknown Author
Aim of the study Leber's congenital amaurosis (LCA) had been diagnosed
on/in 42 children between 1968 and 1996 at the Deptm. of Ophthalmology,
University Hospital Zurich. We reexamined critically this rare diagnosis
in retrospect and with new examinations where possible.
Patients and methods Clinical and electroretinographic (ERG) results,
often obtaianed in general anesthesia, were re-evaluated and when possible
repeated in new examinations.
Results Thirtythree of the total 42 patients presented with an
extinguished, 35 with markedly reduced, and 6 with minimal ERGs. A profound
visual loss (from no light perception to 20/200), nystagmus and strabismus
were the principal symptoms. The heterogeneity of retinal findings ranged
from normal to salt and pepper or bone spicules pigmentation and pronounced
chorioretinal atrophy. Vascular attenuation and rarification were frequent.
Patients with nonocular findings such as mental retardation (np12), renal
(np3) and skeletal (np4) abnormalities revealed no differing ERG- or retinal
findings. The oculodigital sign (eye-poking) was found in 25%, and parental
consanguinity was evident in 10% of the cases. In 16 patients that were
reexamined, the progression of the disease was characterized by an increase
in retinal pigmentary changes, attenuation of retinal vessel, and further
diminuation of the visual acuity (np6).
Conclusion Upon review, the diagnosis had to be revised in 8 patients
as juvenile retinitis pigmentosa and in one as infantile Refsum syndrome.
Bilateral visual impairement in infants should be assessed clinically and
electroretinographically within the first year. Neuropediatric and metabolic
examinations meaningfully complement the diagnostic procedures.
Key words Leber's congenital amaurosis - juvenile retinitis pigmentosa
- electroretinogram (ERG) - infantile Refsum syndrome
[ back ]
S. 311-313 (Art. 303)
Determination of critical (foveal) flicker
fusion frequency (CFF) helps to separate organic disease from (orthoptic)
amblyopia
Unknown Author
Purpose To measure critical (foveal) flicker fusion frequencies (CFF)
in normal eyes, unilateral maculopathies and neuropathies and in orthoptic
amblyopias.
Methods A newly developed apparatus (4F) with LED's measured subjective
foveal CFF by ascending and descending mode in a group of normals and
patients.
Results The apparatus (4F) measures temporal resolution. Foveal CFF
ist more reduced in neuropathies than in maculopathies. In contrast, CFF
in amblyopic eyes is hardly reduced, in most cases equal or better than in
the dominant fellow eye. This is independent from the visual acuity of the
amblyopic eye.
Conclusion CFF testing is useful in the evaluation of unexplained
(unilateral) reduction of visual acuity. A dissociation between visual acuity
and CFF (within normal range) is present in cases of amblyopia.
Key words critical (foveal) flicker fusion frequency (CFF) - maculopathy
- neuropathy - amblyopia
[ back ]
S. 314-317 (Art. 304)
Episcleral buckle or vitrectomy for
the primary treatment of pseudophakic retinal detachment. A comparison of
the two techniques
Unknown Author
Objective For the primary treatment of pseudophakic retinal detachment,
vitrectomy could be preferred to episcleral buckle because it does not induce
myopia, it clears opacities of the posterior capsule and/or of the vitreous
and allows a good visualization of the fundus. This study was determined
to compare the anatomic and functional results of vitrectomy and episcleral
buckle.
Methods from 1990 to 1995, 93 pseudophakic eyes were operated on for
retinal detachment. 75 eyes were treated with episcleral buckle (group I)
and 18 eyes were treated with vitrectomy (group II). In the latter group,
4 eyes had a giant tear, and 4 other eyes had a macular hole associated with
high myopia. The anatomic and functional results were analyzed
retrospectively.
Results The retina was reattached with one operation in 67 eyes of
group I (89%) and 16 of group II (89%). More than one month after the first
operation, the retina redetached in 6 eyes of group I (8%) and one eye of
group II (6%). The causes of failure were a) new or missed retinal tears
[Group I: 10 eyes (13%), group II: 3 eyes (17%)] and b) vitreoretinal
proliferation (group I: 4 eyes, group II: 0). The number of subsequent
reoperations for failures or recurrences was higher in group I than in group
II. At the final examination, the retina was attached in 73 eyes of group
I (97%) and in 18 eyes of group II (100%). The Kruskal-Wallis test did not
detect any difference between the two groups concerning the pre- or postoperative
visual acuities.
Conclusion Vitrectomy seems as effective as episcleral buckle for
the treatment of pseudophakic retinal detachment and offers additional
advantages.
Key words Retinal detachment - pseudophakia - vitrectomy - episcleral
buckle
[ back ]
S. 318-320 (Art. 305)
Indocyanine green angiography in Multiple
evanescent white dot syndrome (MEWDS)
Unknown Author
Purpose Multiple evanescent white dot syndrome (MEWDS) is a benign
acquired chorioretinal disorder occurring mostly in young adults. Its
pathophysiology is unknown. To describe the results of indocyanine green
angiography (ICGA) in MEWDS.
Patients and Methods Four patients with MEWDS were investigated by
ICGA.
Results In all cases, ICGA revealed numerous choroidal hypofluorescent
lesions that largely outnumbered the lesions visible with either fundoscopy
or fluorescein angiography. Three cases showed a blind spot enlargement on
perimetry associated with the presence of a large peripapillary hypofluorescent
zone on ICGA. Three cases showed macular granularity on fundoscopy correlating
with a significant subfoveal hypofluorescent lesion on ICGA. Evolution was
always favorable with disappearance of the hypofluorescent choroidal
lesions.
Conclusions Our results confirm that MEWDS is primarily a choroidal
disorder. The blind spot enlargement and the macular granularity, frequently
detected in MEWDS, result from larger peripapillary and subfoveal choroidal
lesions.
Key words Multiple evanescent white dot syndrome - MEWDS - Indocyanine
green angiography - choroidopathy - blind spot enlargement
[ back ]
S. 321-323 (Art. 306)
Radiotherapy for treatment of occult
neovascularization in AMD
Unknown Author
Background AMD is the leading cause of legal blindness in people aged
of more than 50 in industrialized countries. Occult neovascularization accounts
for more than 70% of all exsudatives forms of AMD. Radiotherapy has been
proposed as a possible treatment for retrofoveal neovascularization. We present
the first results of a pilot study actually ongoing at the AMD Center in
Creteil.
Patients and methods 44 patients (46 eyes) presenting occult choroidal
neovascularization involving the fovea, aged of `50 years and with a minimal
visual acuity of at least 0.1 were included. They received a total dose of
16 Gy in 4 sessions of 4 Gy. All the patients were checked after 3 months.
Results Visual acuity was globally mantained (`0.1 in 93% of the eyes). Only
one eye suffered a significant loss of vision (`6 lines) and 11% suffered
a moderate loss of vision (`3 lines). Moreover 67% of eyes still had a near
vision of 0.5 or more with reading glasses. On fluorescein angiography 17.5%
of the eyes experienced an increase of the size of the occult neovascularization
of `0.5 Disk Area (DA), 76% showed no modification and 6.5% demonstrated
a decrease in size of `0.5 DA. Conclusion : As it has been shown that the
antimitotic action of radiotherapy is most effective after 3 months, the
present results suggest better evolution than natural history. However, as
occult choroidal neovascularization is a slow-evolving disease further folow-up
is needed to confirm it.
Key words Radiotherapy - Age Related Macular Degeneration - occult
neovascularization
[ back ]
S. 324-325 (Art. 307)
Decreased NO release is a worsening
factor in branch vein occlusion
Unknown Author
Purpose Following retinal branch vein occlusion (b.v.o.), the arteriole
crossing the occluded territories is often constricted. This constriction
persists up to several weeks and is correlated with the development of extended
territories of non-perfused capillaries. We present here results of an
investigation supporting the hypothesis that decrease in the production of
nitric oxide (NO) accounts for the observed arteriolar constriction.
Methods Preretinal [NO] was measured using an NO microprobe in the
anesthethized miniature pigs, before and within the first 4 hours following
experimental b.v.o.. Modifications of arteriolar diameter were correlated
to preretinal [NO] changes. The retinal arteriolar sensitivity to constitutive
NO was checked by performing preretinal puff injections of nitro-l-arginine
(L-NA) after both systemic hypoxia and b.v.o.
Results Two hours after b.v.o. there was 73.7 B 4% decrease in preretinal
[NO] and a simultaneous 25.4 B3.4 % decrease in the diameter of the arteriole
in the affected territory. Both persisted for at least 4 hours after b.v.o..
Puffing L-NA over an arteriole previously dilated by systemic hypoxia induced
a vasoconstriction. However no arteriolar constriction was observed when
puffing was performed on an arteriole after b.v.o.
Conclusions These results show that experimental b.v.o. induces in
the affected retina an impairment in the release of constitutive NO and an
arteriolar constriction, which in turn, contribute to the development of
tissue hypoxia and neuronal swelling and death in the inner retina.
Key words Nitric oxide - branch vein occlusion
[ back ]
S. 326-329 (Art. 308)
Diffuse luminance flicker increases
retinal vessel diameter in humans
Unknown Author
Background Previous studies have demonstrated, in the cat, a
vasodilatation of retinal vessels in response to neuronal activity induced
by diffuse luminance flicker. The aim of this study was to determine whether
a similar diameter variation is detectable in humans.
Materials and Methods Nine normal subjects were exposed to 1 min of
sinusoidally varying diffuse luminance flicker (10 Hz, 30¡ around optic
nerve head). Monochromatic fundus pictures before and after the stimulation
were taken. The diameter of retinal arteries and veins was measured on the
digitised photographs with the NIH-Image software and an own algorythm.
Results The diameter immediately after flicker was significantly larger
than the pre-stimulus diameter by 4.2 B2.2% (p ~0.014) (mean BSD) for the
retinal arteries and 2.7 B1.7% (p~0.001) for the retinal veins. Six seconds
after cessation of the flicker, arterial diameter was not significantly different
from that of pre-flicker value.
Conclusions Diffuse luminance flicker induces an increase in retinal
vessel diameter. This suggest that retinal blood flow is coupled with neuronal
activity as previously evidenced by the blue field simulation technique in
the macula.
Key words Retinal vessel diameter - flicker - neuronal activity -
retinal blood flow
[ back ]
S. 330-333 (Art. 309)
Current strategies in the laboratory
diagnosis of ocular toxoplasmosis
Unknown Author
Background The diagnosis of ocular toxoplasmosis has remained a merely
clinical one, because the low sensitivity of established methods does not
allow clinical consequences. The underlying open prospective study was undertaken
to analyse the sensitivity of a combination including the newly available
tests for the diagnosis of the disease.
Methods From 27 patients included until now, aqueous humor and serum
samples were collected and sent to one of two reference laboratories according
to their actual availability. From all samples, total IgG and anti-Toxoplasma
IgG as well as specific IgM and IgA were quantified, and from the results,
the antibody ratio was calculated according to the formula of Goldmann and
Witmer. From the samples sent to laboratory 2, antibody avidity was determined
and Toxoplasma DNA amplified using PCR.
Results A confirmation of the clinical diagnosis was achieved in 5/9
cases (56%) from samples sent to laboratory 1, and from 14/18 samples (78%)
sent to laboratory 2. Calculation of the antibody ratio was confirmed to
be the most sensitive method with a confirmation rate of 41%, followed by
PCR (28%), determination of specific IgA (22%) and finally antibody avidity
(15%). A confirmation with two independent tests was achieved in 28% of
cases.
Conclusion None of the methods analysed was sensitive enough to establish
the diagnosis in a given case. The combination of all four methods, however,
achieved a sensitivity, which is high enough to justify a clinical routine
analysis of aqueous humor samples.
Key words Ocular toxoplasmosis - antibody ratio - antibody avidity
- anti-Toxoplasma-IgA - DNA amplification - PCR - Toxoplasma gondii
[ back ]
S. 334-338 (Art. 310)
Surgical removal of subfoveal choroidal
neovascularization
Unknown Author
Background to present the functionnal, angiographic and electron
microscopic results of 3 patients who underwent surgical removal of a subfoveolar
neovascularisation. These patients are representative of the most common
indications for subfoveolar surgery.
Material and method in one case, the neovascularization originated
from an old chorioretinal scar close to the macula; in another case, it was
associated with high myopia; in the last case the neovascularization was
coupled with an age-related macular degeneration (ARMD). The 3 removed
neovascular membranes were examined by electron microscopy. Indocyanine green
and fluorescein angiographies were performed in all 3 cases before and after
surgery.
Results visual recovery was excellent in the case of neovascularization
and old chorioretinitis scar; it was minimal in the case of high myopia;
no objective improvement was found in the case of ARMD. Electron microscopic
examination did not always allow to determine accurately if the
neovascularization was located in the subretinal space or under the pigment
epthelium.
Conclusions these results match those already published: surgical
prognosis is the best when neovascularization is in the subretinal space
and when the pigment epithelium has not been damaged by the underlying disease
or by the surgical maneuvers. Electron microscopic examination is not easy
to interprete.
Key words vitrectomy - choroidal neovascularization - electron microscopy
[ back ]
S. 339-342 (Art. 311)
Vitrectomy for diabetic retinopathy:
results, risk factors, complications
Unknown Author
Background Functional results, risk factors and complications of
vitrectomy for diabetic retinopathy were studied to improve our estimation
for benefits and risks of vitreous surgery with current techniques.
Materials and Methods The course of 389 consecutive eyes, who had
undergone vitreous surgery for complications of diabetic retinopathy within
a four year period, was retrospectively reviewed. The minimum follow-up was
6 months, the median 26 months. Risk factors were studied using multivariate
logistic regression analysis.
Results Six months postoperatively 25% of the eyes had a visual acuity
of 20/60 or better, a vision of less than 5/200 was found in 25% of the eyes.
The most important risk factors were detachment of the macula and iris rubeosis.
Only 16% of the eyes with tractional detachment of the macula had a postoperative
vision of 20/200 or better, although in 86% the macula was anatomically
succesfully reattached. Postoperative retinal detachment was observed in
18% of all eyes. The incidence of this serious complication was only 5% after
surgery for vitreous hemorrhage, but 54% after vitrectomy for tractional
detachment of the macula.
Conclusions In eyes with advanced stages of long-standing tractional
detachment of the macula, the functional prognosis is very poor due to the
underlying microvascular disease. In less advanced stages with vitreous
hemorrhage and flat retina the risk of vitreous surgery is low.
Key words diabetic retinopathy - vitrectomy - results - risk factors
- complications
[ back ]
S. 343-344 (Art. 312)
ZCentral serous chorioretinopathy and
endogenous hypercortisolism
Unknown Author
Background The exact pathogenic mechanism of the accumulation of
subretinal fluid at the posterior pole of the fundus in cases of central
serous chorioretinopathy (CSC) is not well established. Recently, it was
reported that CSC is more frequent among patients with endogenous Cushing's
syndrome. Thus, it has been suggested that glucocorticoids might be involved
in the pathogenesis of CSC. Subsequently, additional observations, have confirmed
the relationship between glucocorticoids and CSC. We present preliminary
data on the endogenous cortisol secretion in patients with CSC.
Patients and Method Sixteen patients (14 men and 2 women, 35-65 years
of age) suffering from CSC, not exposed to exogenous glucocorticoids and
without clinical and/or biological stigmata of endogenous Cushing's syndrome,
have been examined. Twenty four hour urinary free cortisol (24 h-UFC) secretion
was measured within one week of their CSC episode. Twenty four hour urinary
free cortisol of age and sex matched controls were also measured.
Results Twenty four hour urinary free cortisol was 188.20 nmol/l B34.1
for the patients suffering from CSC and 115.3 nmol/l B63.4 for the control
group (p~0.05).
Conclusion These results give additional evidence that glucocorticoids
may play a role in the pathogenesis of CSC. However, given the substantial
variability of urinary free cortisol levels, as indicated by the increased
SD, additional number of patients should be examined.
Key words Central serous chorioretinopathy - endogenous hypercortisolism
- glucocorticoids
[ back ]
S. 345-349 (Art. 313)
The uveovascular barrier in HIV-associated
retinal microangiopathy
Unknown Author
Background HIV-associated retinal microangiopathy is understood as
a sign of uveovascular barrier breakdown and associated with an increasing
risk to develop opportunistic infections. Hence no controled studies have
been available, the underlying study was undertaken to validate this clinical
impression.
Patients and Methods HIV-positive patients with or without clinical
signs of retinal angiopathy were included into this study and followed up
longitudinally with fotodocumentation, laser-flare and, sporadically, fluorescein
angiography to quantify the disturbance of their uveovascular barrier. The
data were correlated to the CD4 cell counts and the development of opportunistic
infections.
Results 104 patients have been included into one of four groups: patients
without signs of ocular vascular disease (group 1, np46), with newly diagnosed
HIV-associated microangiopathy (group 2, np37), with angiopathy for more
than six months (group 3, np16), and with viral retinitis (group 4, np5).
We found no difference in the flare between patients with and without angiopathy
(pp0.3), but a significant increase after the development of retinitis (p
< 0.001). In contrast, the presence and duration of angiopathy were associated
with a reduction in CD4 cell counts (pp0.03). Using fluorescein angiography,
we found vascular occlusions on the capillary level without leakages
corresponding to a not relevant disruption of the retinovascular barrier.
Conclusions In HIV-associated retinal microangiopathy, there exists
no relevant disturbance of the uveovascular barrier. The association of
angiopathy with a reduction of CD4 cells is more likely a sign of
immuncomplex-associated rather than infectious etiology. The analysis of
drug effects on the course of angiopathy during a recovery of the cellular
immunity will provide further etiological information in the progress of
this study.
Key words HIV infection - retinal microangiopathy - CD4 cells - laser
flare - fluorescein angiography - clinical study
[ back ]
S. 350-352 (Art. 314)
Blood flow in the human optic nerve
head (ONH) during isometric exercises
Unknown Author
Purpose Authoregulation of optic nerve head blood flow (Fonh) in response
to decreases in perfusion pressure has been demonstrated in animals and humans.
The aim of this study was to determine change in Fonh when systemic blood
pressure is increased.
Methods Blood flow parameters, i.e. relative mean velocity, number,
and flux of red blood cells in the ONH tissue (Velonh, Volonh and Fonh,
respectively) were measured by laser Doppler flowmetry in one eye of 13 normal
subjects (aged 16 to 58 years), at baseline, during, and after isometric
exercises consisting of squatting. Brachial artery blood pressure was measured
by sphygmomanometry. IOP was mesured at baseline and at the end of
squatting.
Results During squatting mean arterial presure increased from 103
B6 mm Hg to 139 B58 mm Hg (average B95% confidence interval), IOP increased
from 13 B0.5 to 17 B1 mm Hg. An average increase in PPm from 56 B4 to 80
b 7 mm Hg induced no significant (p`0.05) change in the blood flow parameters.
The sensitivity (detection threshold) of the blood flow changes was 8%.
Conclusion This study shows for the first time in human Authoregulation
of Fonh when PPm is increased by increasing the systemic blood pressure.
Key words Laser Doppler flowmetry - blood flow - optic nerve head
- intraocular pressure - isometric exercise - Authoregulation
[ back ]
S. 353-355 (Art. 315)
Varicella-zoster-virus and atypical
necrotizing retinopathies HIV-positive and AIDS patients
Unknown Author
Background Necrotizing retinopathies of suspected viral origin, but
which do not meet the criteria for either CMV-retinitis or acute retinal
necrosis syndrome, have been grouped together under the term atypical necrotizing
retinopathies. Nothing is known about their etiology.
Patients and Methods Aqueous humor samples were drawn from two
HIV-positive and eight patients with AIDS presenting with an atypical necrotizing
retinopathy, additionally from six patients with acute retinal necrosis syndrome
and 28 patients with active CMV-retinitis at the time of diagnosis as well
as from thirty healthy controls at surgery. All samples underwent DNA extraction
and amplification for viral DNA of HSV-1, VZV and CMV.
Results VZV-DNA was detected in seven of nine aqueous humor samples
derived from patients with atypical necrotizing retinopathies and in four
of six samples from patients with acute retinal necrosis syndrome, but not
in any one from the 28 patients with CMV retinitis. In the latter group,
CMV DNA was detectable in 23 samples, in two of these additionally HSV-1
DNA. No viral DNA was amplified from any of the samples from healthy controls.
Conclusions Varicella zoster virus ist the leading cause of atypical
necrotizing retinopathies. This should be considered in the antiviral
chemotherapy. Moreover, we were able to establish the diagnosis using DNA
amplification for the viruses of the herpes family irrespective of the etiology
in 80% of necrotizing retinopathies.
Key words Atypical necrotizing retinopathies - HSV-1 - VZV - CMV -
Viral Retinitis - HIV-infection - AIDS
[ back ]
S. 356-358 (Art. 316)
Myofibroblasts and epiretinal
membranes
Unknown Author
Introduction Epiretinal tissue proliferations occurring during the
evolution of ischemic microangiopathies or preretinal diseases are tough
to cause retinal detachment by traction mechanisms. Cellular migration /
proliferations and finally contraction are tough to be the pathogenic element.
Myofibroblasts are contractile cells having features intermediate between
those of the fibroblasts and smooth muscle. We conducted a study to explore
wheter such cells are present in preretinal membranes.
Materials and methods 8 membranes, prelevated during vitrectomy for
proliferative vitreoretinopathy or diabetic proliferative vitreoretinopathy,
were analysed with immunostainig technique searching for alpha-actine smooth
muscle, desmine, which are specific markers for myofibroblasts and TGF-beta1,
that is considered as the mean factor promoting the transformation of fibroblasts
into myofibroblasts.
Results All the histological preparation showed aboundant staining
with antibody against alpha-actine smooth muscle, desmine and TGF-beta1.
Conclusions Myofibroblasts are one of the major cellular element of
preretinal membranes. They are scattered throughout the membrane and seem
to account for their contractile properties.
Key words Myofibroblasts - epiretinal membranes
[ back ]
S. 359-362 (Art. 317)
The laboratory diagnosis of granulomatous
anterior uveitis and keratouveitis of suspected viral origin
Unknown Author
Background In epithelial viral keratitis as in viral retinitis, the
diagnosis is made on the basis of typical clinical findings. A laboratory
confirmation is achieved in over 80% using routine laboratory methods. In
contrast, it is almost impossible to confirm the diagnosis of stromal herpetic
keratitis in vivo using the currently available laboratory methods. Nothing
is known about the situation in cases of viral anterior uveitis.
Methods Of 52 patients with granulomatous anterior uveitis, 31 were
diagnosed on the basis of clinical findings as active herpetic uveitis (group
1), 14 as active granulomatous uveitis of unknown origin (group 2), and 7
had inactive disease after quietening down of herpetic uveitis (group 3).
From all patients, aqueous humor was collected at the time of diagnosis and
processed for viral culture, Herpes antigen ELISA, and amplification of viral
DNA of HSV-1 and VZV.
Results Viral growth in culture was found in only one case in group
3. In this group, viral antigen or viral DNA were detected in no case. Herpes
antigen was found in 5/31 cases (16%) in group 1 and in 1/11 cases (9%) in
group 2, and viral DNA was found in 8/31 cases from group 1 (5x HSV-1 and
3x VZV) and in 5/14 cases (31%) from group 2. After combination of antigen
detection and DNA amplification, the presence of virus was confirmed in 14/45
cases (29%).
Conclusion Virus culture has not proven useful in the diagnosis of
viral anterior segment disease. Despite their high overall sensitivity, neither
antigen ELISA nor the amplification of viral DNA prooved sensitive enough
to establish a viral etiology. Nevertheless, a laboratory confirmation should
be attempted in granulomatous uveitis of unknown origin after preclusion
of an underlying systemic disease because of the consequences of a diagnosis
of viral anterior segment disease for treatment and prognosis.
Key words Herpetic uveitis - HSV-1 - herpes antigen - DNA amplification
- ELISA - viral culture - PCR
[ back ]
S. 363-366 (Art. 318)
Learning curve in refractive surgery:
criteria for evaluation
Unknown Author
Background We wanted to analyse and compare the results of our first
100 cases of refractive surgery using the commonly accepted refractive parameters
and using more subjective data.
Materials and Methods Retrospective analysis of the first 100 consecutive
cases of refractive surgery using objective and subjective criteria.
Results Our objective refractive results are comparable to the results
of many other authors.
The subjective evaluation reveals a large discrepancy compared to the objective
data.
Conclusions The evaluation of the results in refractive surgery should
include more subjective parameters. This will allow to better correlate the
quality-parameters of the surgery to the patient's expectations.
Key words refractive surgery - photorefractive keratectomy - lasik
- learning curve
[ back ]
S. 367-371 (Art. 319)
Measurement of corneal thickness by
low coherence reflectometry
Unknown Author
Purpose To integrate a newly developed OLCR instrument into the optical
system of the excimer laser. The instrument is designed to perform corneal
pachymetry before, during, and after corneal photoablation and thus allow
for a precise and continous on-line measurement of the corneal photoablation
process.
Methods The conditions required to integrate the OLCR instrument into
the excimer laser optics were investigated. With a technical setting providing
on-line data of corneal thickness, three groups of 8-10 corneae received
central keratectomies of 27 (group 1), 82 (group 2) and 163 (group 3) mm
calculated central depth and 7.38 mm diameter. All measurements were performed
with OLCR and ultrasound.
Results The OLCR instrument was coupled into the optical system of
the excimer laser and a useful signal obtained at SLD power levels of 40
mW incident on the cornea. Individual corneal thickness measurements were
obtained before, during and after the photoablation procedure. In group 1,
the ablation was 50.3 (40-68) mm measured with ultrasound and 30.2 (27-38)
mm measured with OLCR. In group 2, the ablation was 101.1 (80-113) mm measured
with ultrasound and 93.3 (76-109) mm measured with OLCR. In group 3, the
ablation was 210.6 (190-227) mm measured with ultrasound and 188.4 (181-197)
mm measured with OLCR. The precision (standard deviation) for measurements
of individual corneas was 1-2 mm with OLCR and up to 12 mm in Ultrasound
measurements.
Conclusion With this interferometric method, continuous, non-contact
measurement of corneal thickness before, during and after excimer laser
photoablation were performed. By establishing a feed-back control between
the pachymetric measurements and the photoablation process, the precision
of excimer ablation may possibly be further increased.
Key words Excimer laser - photorefractive keratectomy - corneal pachymetry
- optical low-coherence reflectometry - corneal photoablation
[ back ]
S. 372-375 (Art. 320)
Taking care of low vision
children
Unknown Author
Presentation of the Lausanne school for blind and visually impaired children.
38 children were admitted in the school in 1996-1997. 16 have a visual acuity
of less than 3/60. Ocular malformations of various origins are the main reason
of the handicap, followed by visual lesions of central origin. Comparing
the study with those of 1992 and 1993, it seems that the number of retrolental
fibroplasia and cataracts (operated or not) is decreasing.
The authors present the educational care of these children. At present, the
goal is to maintain the children in their own family. Most of them are day
pupils and the transportation organisation is therefore very important. In
special cases, it is possible to leave the children in a non-specialized
school, provided the children receive a good educational support by one of
our specialized low-vision teachers.
Key words Basse vision
[ back ]
S. 376-378 (Art. 321)
Ocular trauma induced by
airbag
Unknown Author
Background Since the introduction of Airbag several reports about
airbag-associated ocular injuries where published.
Patients and Methods Here we report about four patients who were seen
and treated in the university eye clinic Bern the last two years.
Results The injuries included alkali burns, mechanical erosions and
contusion of the globe associated with ruptures of the choroid and retinal
detachment. Injuries were strictly unilateral in all cases, two affecting
the right eye, two the left eye. Two cases healed without any residual lesions,
while the other two showed a persistent reduction of visual acuity.
Conclusions The airbag is certainly a lifesaving device in modern
passenger vehicles. Nevertheless severe eye injuries can be caused by these
devices. Further research and development concerning the volume of the inflating
gas, the size of the airbag as well as the speed of the vehicle at which
the airbag is activated, should be continued.
Key words Airbag - ocular injuries - trauma
[ back ]
S. 379-381 (Art. 322)
Visual perception of motion. A normative
study
Unknown Author
Background A battery of tests has been developed to better define
the variety of defects which can occur in the process of visual perception
of motion.
Methods The tests assessed the perception of 1) coherent motion, in
each of the four cardinal directions; (2) form from motion; (3) flow in depth;
and (4) motion of a target moving in depth, within or without an optic flow
surround.
A normative study was conducted with 34 subjects, 21 to 69 years of age.
Results Recognition of form from motion was better with upwards than
with downwards motion. Perception of motion in depth was better with backward
than forwards motion. The presence of an optic flow altered the perception
of a motion in depth.
Conclusion The recognition of form from motion demonstrated an asymmetry
in threshold between the upward and downward movements. This asymmetry did
not occur with global coherent motion, thus reflecting the variety of mechanisms
involved in the visual process of motion. Moreover, alteration of perception
of motion in depth within an optic flow reflected background effect.
Key words Coherence motion - motion in depth - visual perception
[ back ]
S. 382-384 (Art. 323)
Influence of presbyopia on vergence,
loss of ciliary innervation with age
Unknown Author
Background Due to accommodation -vergence cross -link we can expect
that presbyopia will affect vergence as well. From investigations of cross
-link as function of age one may assess strain of visual system due to
presbyopia. Furthermore, this observation will give hints on innervation
of ciliary muscle.
Material and method Vergence is assessed as function of stimulus of
accommodation in 27 subjects (24-65 years).
Results Presbyops tend to be exophoric for near vision. Vergence is
linked to accommodation by means of a quadratic polynome rather than by a
linear function.
Conclusions We may expect, that missing vergence strains visual system
of presbyops. Results support Hess-Gullstrand theory of presbyopia and indicate
a loss of innervation of ciliary muscle with increasing age.
Key words presbyopia - accommodation -vergence cross-link - innervation
ciliary muscle - phoria
[ back ]
S. 385-387 (Art. 324)
The diurnal, axial eye growth rhythm
in chicks is influenced by the diurnal light/dark illumination
cycle
Unknown Author
Background In chicks, the distance from the cornea to the posterior
sclera (defined as axial eye length) grows in a diurnal rhythm: growth during
the day is greater than during the night. The purpose of this study was to
investigate whether this diurnal, axial eye growth rhythm is influenced by
the diurnal light/dark illumination cycle.
Methods One day after hatching, 18 White Leghorn chicks were reared
under a 12 hour light/dark illumination cycle. After seven days, 12 chicks
were switched to continuous light; the other 6 chicks remained under the
12 hour light/dark cycle and served as controls. Every 12 hours, at times
corresponding to the onset of former light and dark phases over a period
of 2 days, axial eye length was measured in the right eyes by laser Doppler
interferometry with a precision of 20 µm.
Results In group 1, axial eye growth during time intervals corresponding
to former light phases (0.063B0.024 mm; mean B95% confidence limit) and dark
phases (0.040B 0.017 mm) were not significantly different (one-factor ANOVA).
In group 2, axial eye growth during light phases (0.065B0.028 mm) was
significantly greater than during dark phases (0.015B0.023 mm; pp0.015).
Significantly, total axial eye growth during the two-day period was greater
in group 1 (0.206B0.015 mm) than in group 2 (0.160B0.021 mm; pp0.02; unpaired,
two-tailed Student's t-test).
Conclusion The diurnal, axial eye growth rhythm is strongly attenuated
following an acute switch from a 12 hour light/dark cycle to continuous light.
Control chicks exhibit the normal rhythm. This observation demonstrates that
the diurnal, axial eye growth rhythm is influenced by the light/dark illumination
cycle. Whether the alteration of the rhythm and the increased axial growth
during continuous light is caused by the increased amount of light alone
or by increased light-induced form vision remains to be investigated.
Key words axial eye length - eye growth - chick - laser Doppler
interferometry
[ back ]
S. 388-391 (Art. 325)
Clinical evaluation of impression cytology
for the diagnosis of superficial viral eye diseases
Unknown Author
Background Impression cytology is a non invasive technique for the
diagnosis of external eye disease. As infected epithelial cells are losing
their adhesion to neighbouring cells they are an ideal target for impression
cytology. Despite its diagnostic potential impression cytology has not yet
become a routine diagnostic tool because of technical inconvenience in use
of conventional membranes. The aim of this study was to evaluate a practicable
technique of impression cytology for the rapid diagnosis of superficial viral
eye disease.
Material and Methods 52 patients with suspected viral conjunctivitis
or keratitis underwent impression cytology with a Biopore membrane device.
After air fixation immunologic detection tests using either peroxidase
antiperoxidase or fluorescent techniques were performed directly on the
membrane.
Results and Conclusions 21 of 38 patients with suspected
Herpes-simplex-virus (HSV), 3 of 4 patients with suspected Varicella-Zoster-virus
(VZV) and 2 of 10 patients with suspected Adenovirus infection had a positive
result on the impression cytology membrane. These results were confirmed
by virus cultures or polymerase chain reactions (PCR) a few days later. No
patient with a negative impression cytology had a positive culture result.
Using impression cytology and an immunodetection test results became available
within 1 to 4 hours.
Conclusions Impression cytology combined with immunologic detection
tests is a rapid, sensitive and practicable diagnostic test for superficial
viral eye diseases.
Key words impression cytology - diagnosis - virus
[ back ]
S. 392-393 (Art. 326)
Unilateral spasm of accommodation: a
diagnostic pitfall!
Unknown Author
Background Accommodation-convergence spasm (spasm of the near reflex)
is usually bilateral, resulting in increased myopia, convergence, and miosis.
Unilateral spasm of accommodation has rarely been reported.
Patients We investigated three females (age range 10-19 years) referred
for investigations of retrobulbar optic neuritis (2 cases) and decompensated
esophoria (1 case).
Results They all presented unilateral spasm of accommodation with
visual loss due to increased myopia (P3.5 to P11.75 diopters). Apart from
that, results of neuro-ophthalmological examination were normal.
Conclusions Unilateral accommodation spasm is rare and can mimic
retrobulbar optic neuritis and convergent strabismus. The three components
of the accommodation-convergence spasm may not always be present simultaneously.
Recognizing such an entity is important to prevent the patient from useless,
costful and potentially harmful investigations.
Key words accommodation spasm - spasm of the near reflex - pseudomyopia,
convergence
[ back ]
S. 394-396 (Art. 327)
Photopsias: underdiagnosed symptom and
help of electroretinography
Unknown Author
Background Photopsias are unformed luminous spontaneous visual
hallucinations, often described as flickering or wiggling lights, sometimes
like a glare. Phosphenes are more intense and of shorter duration whereas
migraine fortifications have a specific time course and succesion of events.
Recognition of this symptom is often poor, hence patients are wrongly
investigated.
Purpose To describe the clinical presentation and electroretinographic
characteristics of patients with photopsias.
Methods 4 patients were worked-up with clinical, psychophysical,
angiographic and electroretinographic examinations.
Results Despite normal fundus and angiographic examinations, full-field
electroretinogram was diagnostic in all cases. Retinal dysfunction involved
either inner or outer retina. Paraneoplastic, and probable
autoimmune/inflammatory retinopathies were found in our cases.
Conclusion Photopsias are often secondary to sick retinal cells. In
the presence of photopsias, investigations should be directed towards the
retina and electroretinography is the gold standard. Recognition of the symptom
should prevent useless and potentially harmful investigations for the
patient.
Key words photopsia - ERG - night blindness - paraneoplasic retinopathy
- CAR - AZOOR - AIBSE
[ back ]
S. 397-399 (Art. 328)
Silent sinus syndrome: an unusual cause
of transient vertical diplopia
Unknown Author
Background Causes of transient vertical diplopia include myasthenia,
dysthyroid orbitopathy, multiple sclerosis, decompensation of a pre-existing
state.
Purpose To describe an unusual cause of transient diplopia, silent
sinus syndrom.
Methods Clinical, radiological and pathology findings from a 55-year-old
man with acquired transient vertical diplopia are reported.
Results Eight months after onset of symptoms, vertical diplopia was
constant. Hypoglobus and enophthalmos were present. On CT scan, orbital floor
was thinned and lowered by 8 mm. Maxillary sinus was filled with material
compatible with the histological diagnosis of mucocele. Sinus surgery and
orbital floor reconstruction resulted in resolution of diplopia.
Conclusion Sinus disorders can produce diplopia and/or visual loss,
when invading the orbit. Usually, an acute orbitopathy is obvious. Our case
shows that chronic sinus disorders can produce "silentÓ oculomotor
disturbances and, at least in the beginning, transient diplopia.
Key words silent sinus syndrome - transient vertical diplopia - mucocele
[ back ]
S. 400-402 (Art. 329)
Infantile myofibromatosis - case
report
Unknown Author
A four months old child was referred for a rapidly growing recurrency of
a tumor of the left eyebrow. The tumor was excised completely. The pathologic
examination revealed an infantile myofibromatosis, most probably of the solitary
type.
The term "infantile myofibromatosisÓ summarizes a heterogenous group
of rare fibromatoses in childhood, characterized by the proliferation of
myofibroblasts. Isolated tumors have a fair prognosis after complete
excision.
Key words Infantile myofibromatosis - orbital tumor
[ back ]
S. 403-404 (Art. 330)
The Susac syndrom - a case
report
Unknown Author
Background The Susac syndrom is often misdiagnosed as Multiple Sclerosis.
In the absence of an early diagnosis of the disease, both the doctors and
patients concerned are left in an uncertainly regarding the interpretation,
diagnosis and prognosis of the discovered illness.
Patient The following case report focuses on this syndrome.
Conclusion The disease mainly affects young women and appears in the
triple form of retinal arterial occlusion, hearing impairment and
Encephalopathy.
Key words Susac syndrom - retinal arterial occlusion - encephalopathy
- hearing impairment
[ back ]
S. 405-406 (Art. 331)
Excimer laser phototherapeutic keratectomy
in treating Schnyder cristalline corneal dystrophy
Unknown Author
Purpose To evaluate the efficacy of excimer laser phototherapeutic
keratectomy (PTK) in treating the Schnyder cristalline corneal dystrophy.
Methods We examined the members of three generations of a family affected
by Schnyder crystalline dystrophy.
Two patients with disabling visual acuity were treated with PTK.
Results The best corrected visual acuity (BCVA) of the patient with
the cristalline form of the dystrophy progressed from 20/70 to 20/25. The
BCVA of the other patient affected by the sine crystals form of the Schnyder
dystrophy progressed from 20/70 to 20/30.
Conclusions Excimer laser photokeratectomy is a valuable tool in treating
the Schnyder cristalline form of corneal dystrophy.
Key words Excimer laser - phototherapeutic keratec- tomy - Schnyder
cristalline corneal dystrophy
[ back ]
S. 407-409 (Art. 332)
Non Hodgkin lymphoma of the
conjunctiva
Unknown Author
Background Lymphoid tumors of the conjunctiva are extremely rare.
Primarily such tumors can appear as isolated neoplasm or secondarily within
a systemic disease.
Patients The difficulties relating to dignity of the clinical diagnosis
and the histological examination of the biopsies are presented. Both patients
received orbital radiation therapy.
Results The therapeutically success and clinical course are
reported.
Key words Non Hodgkin lymphoma - MALT lymphoma - conjunctiva
[ back ]
S. 410-412 (Art. 333)
Cüppers' Faden operation (posterior
fixation) in the management of pseudoptosis: two cases
Unknown Author
Background According to Hering's law, the induced palsy of an extraocular
muscle will result in an increased innervational flow to this muscle as well
as to its contralateral synergist. A retroequatorial myopexy (Cüppers
Faden Operation), with or without muscle recession, can be considered as
an iatrogenic palsy.
Methods Two patients, aged 16 and 5 years respectively, presented
with hypotropia, the deviated eye showing limited ocular movements in elevation
and pseudoptosis of the upper eye lid. Both patients underwent surgery, this
consisting of a posterior fixation and recession of the superior rectus of
the sound eye.
Results After surgery, both cases showed a stable improvement of the
opening of the palpebral fissure and of the vertical deviation.
Conclusions This surgical procedure was already described by Cüppers
and, although rarely performed, does represent a useful surgical alternative
in cases of partial ptosis of the upper eye lid together with hypotropia.
Key words Pseudoptosis - Cüpper's Fadenoperation - posterior
fixation - counter-palsy
[ back ]
S. 413-415 (Art. 334)
Rhino-orbito-cŽrŽbral mucormycosis
: clinical presentations
Unknown Author
Background Rhino-orbito-cerebral mucormycosis is an opportunistic
rapidly progressive infection affecting almost exclusively diabetic or
immunocompromised patients.
Case reports Three cases are reported. For one patient mucormycosis
was the first manifestation of juvenile diabetes and the evolution was favorable.
In the second case the infection affected a known diabetic patient and the
clinical course was fatal.The third patient was immunocompromised, showed
mild clinical features and a rapidly fatal evolution, the diagnosis being
made only postmortem.
Conclusion These three cases illustrate the wide clinical spectrum
of rhino-orbito-cerebral mucormycosis, its serious nature and difficult
diagnosis.
Key words rhino-orbito-cerebral mucormycosis - diabetes - immunodeficiency
- palatal necrosis
[ back ]
S. 416-417 (Art. 335)
Interleukin - 10 Found in the vitreous,
in uveitis associated to cerebral lymphom
Unknown Author
The authors report on a 46 year-old patient who presented with a chronic
unilateral vitritis. A diagnosis of cerebral lymphoma was made 4 years earlier
and a maxillary sinus recurrence was treated with chemotherapy and radiotherapy.
A vitrectomy was performed and the level of Interleukin-10, a lymphoma cells
growth factor, was found very high, giving a clue for the lymphomatous cause
of the vitritis.
Key words Interleukin-10 - vitritis - cerebral lymphoma
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