AUGENHEILKUNDE 213/1999 – ISSUE 4

Abstracts:

S. 191-196 (Art. 405)

Genetic and molecular diagnostics in retinoblastoma
Dietmar Lohmann, Bernhard Horsthemke

Retinoblastoma is a childhood malignancy of the eye. Almost all patients with familial or bilateral disease suffer from the hereditary form of the disease that is caused by germline mutations in one allele of the RB1 gene. Tumor development is initiated by the loss of the second RB allele in a retinal progenitor cell. Most patients with isolated unilateral disease have nonhereditary retinoblastoma and thus do not carry a mutant allele in their germline. In no patient, the presence of a germline mutation can be excluded clinically. Consequently, relatives are at an increased risk for retinoblastoma. Molecular testing, however, enables accurate risk prediction provided that samples are available. In some relatives an increased risk can be excluded by segregation analysis. Most often, however, identification of the disease causing mutation is necessary for accurate risk prediction. Mutation analysis, which is impeded by the size and complexity of the RB gene, is facilitated by use of efficient screening methods. Using these methods, the oncogenic mutation can be identified in most patients. Therefore, predictive testing has become an integral part of contemporary management of retinoblastoma.

Key words review - retinoblastoma - genetics - RB1 gene - genetic testing - mutation

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S. 197-200 (Art. 420)

Aqueous flare in acute retinal necrosis syndrome
Nhung X Nguyen, Thomas Amann, Michael Küchle und die Erlanger Arbeitsgruppe "Laser-Tyndallometrie"

Purpose Acute retinal necrosis syndrome (ARN) is a rapidly progressive viral necrotic retinitis. We used noninvasive measurement of aqueous flare to quantify blood-ocular barrier breakdown in eyes with ARN und to follow the inflammatory activity and treatment effects.

Patients and Methods We report on seven patients (5 males und 2 females, age: 16 to 57 years) with ARN that were treated in our institution between 1991 to 1996. Aqueous flare was quantified regularily during treatment using the laser flare-cell meter (Kowa, FC-1000) following pupillary dilation.

Results Aqueous flare was highly significantly increased in eyes with ARN (145.5±139.7, range 30 to 367 photon counts/ms). Contralateral, unaffected eyes showed normal flare values (3.6±0.8 photon counts/ms, p < 0.0001; normals: 4.1±1.1 photon counts/ms). Flare values correlated with inflammatory activity before and during antiviral treatment. In two patients with ARN caused by herpes simplex-virus aqueous flare values were extremly increased (367 and 316 photon counts/ms), and retinal necrosis was rapidly progressive despite antiviral therapy. One patient developed early ARN in his contralateral eye with flare values increasing from 3.5 to 22.0 photon counts/ms, which quickly normalized following antiviral treatment.

Conclusions Measurement with the laser flare-cell meter allows quantification of blood-ocular barrier breakdown in eyes with ARN und may be useful for monitoring inflammatory activity during treatment.

Key words Acute retinal necrosis syndrome - tyndallo-metry - laser flare meter - aqueous flare - blood-aqueous barrier

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S. 201-206 (Art. 419)

Outcome after penetrating keratoplasty in congenital hereditary corneal endothelial dystrophy (CHED)
Report on 13 eyes
Michael JM Groh, Gabriele Ch Gusek-Schneider, Berthold Seitz, Ulrich Schönherr, Gottfried OH Naumann

Background Congenital hereditary endothelial dystrophy (CHED) is a rare bilateral corneal disease. The stromal opacity is supposed to result from terminal misdifferentiation of the endothelial cells. In this study we present the morphological and functional results after penetrating keratoplasty in children with CHED who were operated in our department between 1981 and 1997.

Patients and Methods In a retrospective clinical cross-sectional study we looked up case histories of 13 eyes from 8 children (7 female, 1 male) with a mean age of 6.0B3.1 years (ranged from 3 to 14 years). In all children penetrating keratoplasty was performed by one surgeon (GOHN), in 3 eyes using nonmechanical excimer laser trephination. The graft-diameter was in 7 eyes 7.0/7.1 mm, in 2 eyes 7.0/7.2 mm, in 2 eyes 6.5/6.6 mm (resp. 6.8 mm), in 2 eyes 6.0/6.1 mm (resp. 6.2 mm). Fixation of grafts was achieved in 2 eyes by single running suture, in 8 eyes by double running suture and in 3 eyes by multiple interrupted sutures.

Results During a mean follow-up of 4.0B2.4 years visual acuity increased in all patients (from light perception to 6/20 preoperativaly to 2/200 to 14/20 postoperatively). In one patient corneal endothelial-epithelial-decompensation occurred (both eyes unterwent previous antiglaucomatous surgery elsewhere), and in 1 patient loosening of one suture happened after 10 month. No immunological graft reaction occurred during follow-up. After excimer laser trephination (3 eyes from 2 patients) visual acuity and corneal astigmatism after surgery was favorable in comparison to all other patients.

Conclusion In children with CHED penetrating keratoplasty results not only in a clear cornea but also in a satisfactory functional outcome. Postoperatively periodical morphological controls and assessment of refraction as well as means to prevent amblyopia are indispensable before age 7.

Key words congenital hereditary corneal dystrophy - CHED - penetrating keratoplasty - amblyopia - binocular vision - nonmechanical trephination

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S. 207-212 (Art. 416)

Design and preliminary results of the Erlangen non-high-risk penetrating-keratoplasty study
Murat M Kus, Michael Küchle, Achim Langenbucher, Berthold Seitz, Nhung X Nguyen, Kerstin Blüthner, Peter Martus, Ralf Wassmuth, Gottfried OH Naumann

Purpose The purpose of this prospective study is to examine the non-high-risk penetrating keratoplasty clinically, tyndallometrically and immunological-serologically in order to learn more about the pathogenesis, early symptoms and therapy monitoring of corneal graft rejection.

Patients and Methods Since february 1997, patients undergoing non-high-risk-PK have been enrolled in this prospective study. Examinations are done preoperatively and in well-defined postoperative gates (6 weeks, 3 months, 6 months, etc.) and include clinical assessments, corneal topography, laser-tyndallometry, corneal endothelial cell count and corneal pachymetry. Preoperatively as well as at each postoperative examination, 10 ml serum and perioperatively corneoscleral donor tissue are collected and frozen (P80°C) to allow immunological and serological examinations in case of graft rejection later. A relational data base (MS Access) guarantees complete and homogenous standardized clinical and serological data. We randomised our patients with respect to duration of topical steroid therapy in standard situations (short-time vs. long-time) as well as for systemic steroid therapy (bolus group vs. tapering group) in case of a graft rejection in 2 treatment groups.

Results Up to March 1998, 99 patients have been enrolled in this prospective study. Our report includes the first consecutive 55 patients (25 female, 30 male, recipient age 56.9B19.4 years, donor age 57.0B19.9 years). Up to now (follow-up 2.5B2.1, maximum of 7.3 months) we did not observe immunologic graft rejections. In one patient a primary graft failure occurred. Laser tyndallometry showed a reduction of blood-aqueous barrier breakdown from 6 weeks postoperatively (9.3B5.7 photon counts/msec) to 3 months postoperatively (6.8B3.5 photon counts/msec).

Conclusion This prospective randomized clinical and immunological study after non-high-risk-PK is supposed to give more information about pathogenesis, early symptoms and therapy monitoring of graft rejection after elective PK. The concept and design of this study are described. Preliminary data may give significant results in a few years.

Keywords Immunologic graft rejection - non-high-risk-penetrating-keratoplasty - laser flare - corneal transplantation

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S. 213-219 (Art. 412)

Cyclocryotherapy in neovascular glaucoma and non-neovascular glaucoma
Alexander H Heuring, Werner W Hütz, Peter C Hoffmann, H Berthold Eckhardt

Background There are conflicting reports on the value of cyclocryotherapy and it seems that the success rate is depending on glaucoma conditions, the period of follow-up and the technique. This retrospective study was carried out to assess the efficacy and complication rate of cyclocryosurgery for advanced glaucoma with and without neovascularization.

Patients and methods We induced 76 eyes of 75 patients with inadequately controlled glaucoma, which underwent cyclocryotherapy during the period of 1993 and 1996 (treatment time 60 seconds with -80 °C, 6-12 applications (mean 9.8B2.3), 180-360 degree (median 270 degree), diameter of the probe tip 2.5 mm, 1-2 mm distance from the limbus). Depending on the etiology we distinguished between neovascular (NVG) and non-neovascular glaucoma (nNVG). Pre- and postoperative data from all patients were studied retrospectively, for follow-up after 12-36 months patients were examined.

Results Intraocular pressure (IOP) decreased in all patients from 44.7B12.6 mm Hg preoperatively to 15.6B6.5 mm Hg postoperatively after a follow-up of 12-36 months. In 88.2% IOP was lowered to ^25 mm Hg. NVG showed a mean IOP reduction from 49.1B12.5 mm Hg before cyclocryotherapy to 15.6B5.0 mm Hg at follow-up. In the nNVG group IOP was 40.5B11.3 mm Hg and 15.7B7.6 mm Hg after cyclocryotherapy. Pressure was controlled (^25 mm Hg) for 83.8% of NVG and 92.3% of nNVG. A cyclocryotherapy-induced intense inflammation was seen more frequent in NVG (43.2%) than in nNVG (17.9%). 2 patients with NVG and 3 with nNVG developed phthisis postoperatively (total 6.7%).

Conclusions Cyclocryosurgery is an effective method to reduce IOP in advanced, refractory glaucoma, when other methods have failed. The risk/success rate seems to be acceptable.

Key words glaucoma - intraocular pressure - cyclocryotherapy

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S. 220-229 (Art. 411)

Computer aided, examiner independent screening for inapparent eye misalignment among 590 infants and preschoolers - a pilot study with an orthoptic gold standard
Jean-Cyriaque Barry, Jens Uwe Piesold, Uwe Martin Pongs

Background The purpose of the study was to investigate the computer aided screening method using Purkinje image I and IV reflection patterns for the detection of inapparent eye misalignment and to compare this to an orthoptic examination.

Materials and Methods 590 subjects up to 72 months of age with inapparent eye misalignment were recruited from the orthoptic outpatient department and externally. The computer aided screening consisted of taking a series of still video pictures with Purkinje reflection patterns. These were evaluated in an examiner independent way to reach a recommendation whether the child needed an ophthalmological referral or not. As gold standard, an orthoptic examination was performed. For analysis, the data were split by age groups. The orthoptic results were tested for certainty and repeatability.

Results The computer aided examination had the highest sensitivity of 0.82 in the age group up to 2.5 years of age, and a specificity of 0.90. With an estimated prevalence for microtropia of 0.01, the extrapolated positive predictive value was 0.08, and the negative predictive value was 0.998. In the age group up to 2.5 years of age, the percentage of orthoptic examinations without clear result (neither non-referral, nor strabismic) was 22.4%, and 6.1% in the screening examination. Among the cases which were examined repeatedly, some were classified as "strabismic" in the beginning, and as "non-referral" in the end in the orthoptic examinations.

Conclusions The examiner independent, computer aided screening method is a cost effective option for the screening for inapparent eye misalignment, especially in the age group up to 2.5 years of age. If an orthoptic examination was carried out for screening, one should expect a higher rate of false positives, which entails more costly ophthalmological checks. Future studies should assess the validity of the single ortoptic examination as the gold standard in this age group.

Key words screening - computer aided - objective meth-ods - microtropia - Purkinje I and IV reflection pattern evaluation - amblyopia

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S. 230-237 (Art. 403)

Immunhistochemical markers for cytoplasmic antigens in acquired melanoses, malignant melanoses, and nevi of the conjunctiva
Stephanie Hitzer, Alexander A Bialasiewicz, Gisbert Richard

Background Benign and malignant melanocytic lesions of the conjunctiva are difficult to differentiate histologically. At present in the ophthalmologic literature there is not known a high specific and simply applicable histological feature (tumor marker) of differentiation to identify melanocytic lesions of the conjunctiva.

Methods In this study 55 nevi, 15 primary acquired melanoses (stage Ia) and 54 melanomas of the conjunctiva were examined retrospectively immunhistochemically by antibodies vs. S-100 protein, and the melanoma-associated antigens HMB-45 and NKI/C3 using the labelled avidin-biotin method. 45 patients (25 female, 20 male) with malignant melanomas of the conjunctiva have been followed up clinically.

Results S-100, HMB-45 and NKI/C3 are highly significant markers to identify malignant melanomas of the conjunctiva (sensitivity: S-100: 96.4%, HMB-45: 96.3%, NKI/C3: 98.1%), whereas markers in acquired melanoses (sensitivity: 93.3%, 78.6% and 92.9%), and nevi (sensitivity: 92.9% 40.7%, 98.2%) are not. Positive tumor markers do not correlate with local recurrences or metastasis. The localization of malignant melanomas and the lymphocytic infiltration are not prognostically significant. The only significant risk factor (p=0.0485) predicting the development of recurrence or metastasis is tumor thickness >1.5 mm.

Conclusions The tumor markers S-100, HMB-45 and NKI/C3 cannot differentiate reliably between benign and malignant melanocytic lesions of the conjunctiva, and positive tumor markers do not correlate with local recurrences or metastasis. The only significant risk factor (p=0.0485) predicting the development of metastasis is tumor thickness (> 1.5 mm).

Key-words melanocytic lesions of the conjunctiva - S-100 - HMB-45 - NKI/C3 - tumor thickness - metastasis

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S. 238-240 (Art. 395)

Ritleng-lacrimal intubation system for injured canaliculi
Klaus Müllner

Background Intubation of the lacrimal pathway is used to restore the canaliculi. This procedure is often complicated by the so called accordion-phenomen.

Patients and Methods During the last 4 years we used a new system for lacrimal intubation: the Silicon intubationset designed by Ritleng. It consists of a silkon tube which is connected to a polypropylene tube and a stainless probe for lacrimal insertion. We used this set in 24 lacrimal lacerations of the lacrimal pathway.

Results With this lacrimal intubation set lacerated canalicula in 24 patients could be quickly reapproximated in 20 minutes under general anesthesia without complications.

Conclusion The silicon intubation set allows quick and safe silikon tubing of injured canalicula. The new intubation set is a great advantage in operating of lacerated canalicula and suitable even for surgeons in training.

Key words lacrimal laceration - Ritleng Intubationset - silicone tube intubation

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S. 241-244 (Art. 389)

Ocular pulse amplitude during manipulation of systemic perfusion parameters
Karl-Georg Schmidt, Andrea v. Rückmann, Volker Klingmüller, Ralph Becker, Lutz E Pillunat, Thomas W Mittag

Background The mechanism for the control of choroidal perfusion is unclear. The present study was designed to investigate for the effect of standardized alteration of systemic perfusion parameters on choroidal hemodynamics in healthy volunteers.

Methods Intraocular pressure (IOP; German abreviation: IOD), Ocular Pulse Amplitude (OPA), systemic blood pressure, and pulse rate were measured, and ocular perfusion pressure was calculated in 14 otherwise non-smoking, healthy volunteers prior to and following exercise and smoking.

Results Exercise significantly (sig., p < 0.05) increased pulse rate, systolic blood pressure and ocular perfusion pressure, while it sig. (p < 0.05) reduced IOP and diastolic blood pressure. However OPA was not sig. (p>0.1) affected by changes in these parameters. Smoking sig. (p < 0.05) increased systolic blood pressure, diastolic blood pressure, pulse rate, and ocular perfusion pressure but did not sig. (p>0.09) alter OPA.

Conclusion Despite affecting ocular and systemic perfusion parameters, exercise and smoking did not alter OPA, suggesting functional isolation i.e. autoregulation of the choroidal and/or ophthalmic artery circulation.

Key words Systemic perfusion parameters - Choroid - Ocular Pulse Amplitude - Autoregulation

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S. 245-246 (Art. 404)

Two contact lens holders for vitreoretinal surgery
Matthias Krause, Josef Weindler, Hans-Josef Jakoby, Klaus Wilhelm Ruprecht

Two new lens holders for contact lens use in vitreoretinal surgery were developed: (1) a flexible hand-fixed lens holder and (2) a lid-retractor-fixed lens holder. Advantages are: better stabilization and centering of the lens, reduction of air bubbles and blood in the interface between cornea and contact lens.

Key words Contact lenses - ophthalmologic surgical procedures vitrectomy - surgical instruments - vitreous body surgery

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S. 247-251 (Art. 413)

Progressive corneal ectasia after laser in situ keratomileusis (LASIK)
Lilly Speicher, Wolfgang Göttinger

Background LASIK (Laser in situ keratomileusis) is used in refractive surgery especially for correction of higher degrees of myopia. Preservation of Bowman's layer as well as less postoperative pain and the slight to absent subepithelial haze are regarded as advantages compared to photorefractive keratectomy (PRK). However, numerous serious complications have been described in the literature.

Patients and Methods LASIK treatment was performed elsewhere in two patients to treat myopia or myopic astigmatism between P6 and P9 diopters (D). An astigmatism of P6 D was corrected with the LASIK method in another patient with keratoconus. Progressive corneal ectasia of up to seven diopters occurred in all four eyes within a few months.

Conclusion Corneal ectasia can occur after LASIK even in low degrees of myopia of less than ten diopters. Recently, P12 D has been specified as the upper limit for this technique. It is especially important to rule out an early keratoconus or a forme fruste of keratoconus preoperatively since keratectasia with particularly rapid progression can occur in such cases: we would like to designate this as "malignant keratoconus".

Key words Corneal ectasia - keratoconus - LASIK

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S. 252-253 (Art. 406 DF)

Subretinal neovascular membranes in membranoproliferative glomerulonephritis type II
Carsten Framme, Thomas Herboth, Johann Roider, Horst Laqua

Background So called 'dense deposits' in the retina of a patient suffering from membranoproliferative glomerulonephritis type II (MPGN II) were first demonstrated in 1989. Appearence of subretinal neovascular membranes associated with MPGN II in three patients was described in 1990.

Patient and methods We present a 45-year-old male patient, whose insufficiency of the kidney due to a membranoproliferative glomerulonephritis type II required peritoneal dialysis and later transplantation. In both eyes fundus examination revealed typical disseminated, partly confluencing, drusen-like 'dense deposits' and exsudative degeneration of the macula due to subretinal neovascular membranes. Visual acuity was less than 20/400 and visual fields were reduced to small excentrics islands. There was an atrophy of the optic nerve with nearly extinguished VEP in both eyes.

Conclusion Flecked changes of the retina called 'dense deposits' associated with membranoproliferative glomerulonephritis type II have to be differentiated in particular from drusen, as well as metabolic-toxic and degenerative retinopathy. Development of subretinal neovascular membranes is attributed to altered retinal pigment epithelium, similar to age-related macular degeneration. An atrophy of the optic nerve associated with this disease has not been described so far. It is possible that vascular damage because of hypertensive changes due to renal dysfunction is the reason for the optic nerve atrophy. With another hypothesis this could be caused by intraocular pressure due to a risen flow of water into the vitreous cavity following the altered osmotic gradient after peritoneal dialysis.

Schlüsselwörter Optikusatrophie - dense deposit - Membranoproliferative Glomerulonephritis Typ II - subretinale Neovaskularisationsmembran

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S. 254-255 (Art. 418)

Homologous lamellar central limbokeratoplasty in severe limbal stem cell deficiency
Rainer Sundmacher, Thomas Reinhard

Purpose It is the purpose of this case report to present a new surgical technique for treatment of severe limbal stem cell deficiency.

Case report In a 42-year-old female patient with conjunctivalization of the cornea in congenital aniridia a homologous lamellar central limbokeratoplasty was performed. Postoperatively systemic Ciclosporin A was administered in order to prevent the transplanted limbal stem cells from immunological destruction. During the follow-up period of 16 months no immune reaction against the transplanted limbal stem cells could be observed. Visual acuity was ameliorated considerably.

Conclusions Homologous lamellar central limbokeratoplasty is a promising surgical procedure in selected patients with severe limbal stem cell deficiency having less complications compared with penetrating central limbokeratoplasty.

Key words Limbal stem cell insufficiency - Ciclosporin A - lamellar limbokeratoplasty

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