Retinal detachment and pathology following experimental embolization of choroidal and retinal circulation

Summary By means of a micro-surgical technique, the central retinal artery of the owl monkey (Aotus trivirgatus) was embolized with spheric plastic beads (7–25 in diameter). Beads (4–15 ) were also injected into choroidal capillaries through a supero-temporal vortex vein.Choroidal ischemia induced proliferation or degeneration of the pigment epithelium, frequently accompanied by photoreceptor degeneration and circumscribed retinal detachment. Occlusion of retinal vessels resulted in posterior vitreous detachment and micro-cystoid degeneration in inner retinal layers, followed by retinal schisis. In combined retinal and choroidal ischemia long-lasting retinal detachments regularly developed.Supported by U.S. Public Health Service Fogarty International Fellowship IFO5 TWO1799-01 and the Swedish Medical Research Council (Project B72-60R-3655)     

Phacoemulsification and implantation of posterior chamber intraocular lens in eyes with quiescent proliferative diabetic retinopathy

A phacoemulsification procedure, combined with an in-the-bag lens implantation, was performed on ten eyes that once had proliferative diabetic retinopathy (PDR). The ten eyes were in eight patients who had a 20-plus year history of either type I or type II diabetes mellitus. All eyes had reached the quiescent state of diabetic retinopathy 2–13 years before the cataract surgery through either argon laser pan retinal photocoagulation and/or pars plana vitrectomy. Nine of ten eyes remained completely free of retinal neovascularization and rubeosis iridis, with follow-up periods between 1.5 and 5 years. One eye has been lost to recurrent vitreous hemorrhages and an inoperable retinal detachment.Presented in part at the XVth Meeting of the Club Jules Gonin, Copenhagen, 10–15 August 1986     

Integrins in human anterior chamber angle

Background: Integrins, which are composed of an and subunit, are capable of binding to a number of extracellular matrix proteins and, hence, affect cell adhesion and proliferation.Methods: The distribution of the integrin (₁, ₃-₅) and (_1–6 and _v) subunits in human anterior chamber angle was studied in eyes from subjects aged 9 months to 81 years using the indirect immunofluorescence technique.Results: Immunoreaction for the ₁ subunit was found throughout the trabecular meshwork (TM), in the cribriform layer, and in the endothelial lining of Schlemm's canal (SC). Labelling for the ₃ subunit was found in the TM and the cribriform layer only. In infant eyes the ₅ subunit was present in all three areas with the highest concentration in the cribriform layer, whereas no reaction was observed in adult eyes. The ₆ subunit was localized to the endothelium of SC only. Immunoreaction for the _v subunit was present in the TM and the cribriform layer of infants and young adults.Conclusion: The present results suggest the presence of several integrin heterodimers, acting as potential receptors for laminin, collagen, fibronectin, and vitronectin, in the anterior chamber angle.     

Schisis-like rhegmatogenous retinal detachment associated with choroidal colobomas

Background: The breaks that cause retinal detachments in colobomatous eyes are often hidden within the lesion and difficult to find. Method: To elucidate the pathoanatomy and possible pathomechanism of such detachments, histological sections of eight choroidal colobomas were reviewed. Results: Sections of the margin showed central continuation of the inner neuroblastic layer (the intercalary membrane) and eversion and separation of the outer neuroblastic layer. The opposite direction of continuity of the neuroblastic layers created a schisis-like configuration between the intercalary membrane and the everted outer retina. The zone of duplication was a point of retinal adhesion, but also a locus minoris resistentiae due to vitreous attachments and variable glial support at the margin. Conclusion: The subset of coloboma-associated retinal detachments requires both a central break in the inner layer and a break in the outer layer at the margin of the coloboma. The inner layer break may be precipated by retinovascular ischemia or scleral stretching; that in the outer layer may be caused by vitreous traction on the margin of the coloboma or extension of the formerly isolated detachment through the outer marginal zone of decreased glial support.Presented at the Annual Meeting of the Retina Society, San Francisco, California, 20 October 1993     

R-Enantiomer of timolol: a potential selective ocular antihypertensive agent

Various studies were conducted to evaluate the effects of timolol, an S-enantiomer, relative to its R-enantiomer upon intraocular pressure and related ocular systems in the rabbit. The R-enantiomer was about one-third as potent as timolol in displacing³H-dihydroalprenolol binding to iris-ciliary body tissue, reducing aqueous humor formation, and lowering intraocular pressure of -chymotrypsin hypertensive eyes. In contrast, the R-enantiomer was 50 to 90 times less potent than timolol in antagonizing the effects of isoproterenol on pulmonary and atrial -adrenergic receptors. The data indicate that the R-enantiomer may lower intraocular pressure in man at concentrations less likely than timolol to block extraocular -adrenergic receptors. Finally, to account for the differential effect of the R-enantiomer upon ocular as opposed to extraocular -adrenergic receptors, it is tentatively suggested that this agent may also act upon a population of ocular -adrenergic receptors showing relatively poor stereoselectively.     

Effect of Prostaglandin E2 on aqueous humor flow in the rabbit eye

Summary The examinations were carried out in albino rabbits under urethane anaestesia. After intracameral injection of 0.5 g Prostaglandin E₂, dissolved in 10 l 10% ethanol, intraocular pressure increased by 20.5±4.9 mm Hg. Aqueous humor protein concentration in the uninjected control eyes was 0.176±0.03 g%. Thirty minutes after intracameral injection of 10 l 10% ethanol solution the concentration rose to 0.38±0.19 g-%, and after of 0.5 g Prostaglandin E₂ to 1.85 ±0.41 g% These interventions were not followed by significant changes in aqueous humor osmolarity (normal value 313.7±17.9 mOsm, after ethanol 330 5±18. 0, and after prostaglandin E₂ 329.3±6.9).In a special series of experiments the rate of aqueous humor production was determined. In the uninjected control eyes a value of 1.57±0.61 l/min was found, but after intracameral injection of 0.5 g prostaglandin E₂, 5.45±1.99 l/min.The authors draw the conclusion that prostaglandin E₂ increases intraocular tension not by enhancing aqueous humor production but by disrupting the bloodaqueous humor barrier.

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Zusammenfassung Die Untersuchungen wurden an Albinokaninchen in Urethannarkose durchgeführt. Nach Injektion von 0,5 g Prostaglandin E₂ (in 10 l10%iger Äthanollösung) in die Vorderkammer stieg der Augenbinnendruck um 20,5±-4,9 mm Hg an. Der Gesamteiweißgehalt im Kammerwasser der intakten Kontrollaugen betrug 0,176±0,03 g-%. 30 min nach Einspritzung von 10 l 10%iger Äthanollösung in die Vorderkammer erhöhte sich der Gesamteiweißgehalt auf 0,38±0,19 g-%. Diese Einwirkungen hatten keine signifikante Änderung der Kammerwasser-Osmolarität zur Folge (Normalwert 313,7±17,9 mOsm, nach Äthanol 330,5±18,1 und nach Prostaglandin E₂ 329,3±6,9).In einer besonderen Versuchsreihe wurde die Kammerwasserproduktion bestimmt. In den intakten Kontrollaugen ergab sich hierbei ein Wert von 1,57±0,61 (l/m, nach Gabe von 0,5 g Prostaglandin E₂ aber 5,45±1,99 l/min.Die Autoren ziehen den Schluß, daß Prostaglandin E₂ den Augenbinnendruck nicht durch Steigerung der Kammerwasserproduktion, sondern durch Schädigung der Blut-Kammerwasserschranke erhöht.

     

Subthreshold argon-laser irradiation elicits a pronounced vitreal prostaglandin E2 response

Chorioretinal production of prostaglandin type E₂ (PGE₂) as well as changes in vitreal protein and PGE₂ concentrations were studied following retinal irradiation with low-power laser energy that caused ophthalmoscopically invisible (subthreshold) laser burns. This was compared with changes following ophthalmoscopically visible ( suprathreshold ) laser burns. Our results demonstrate that with in eyes exposed to the lower-power levels, the enhancement in vitreal PGE₂ concentration persisted for a longer period and was more pronounced than in eyes exposed to the suprathreshold levels (a 3-fold and a 2-fold increase above baseline values, respectively). Protein leakage into the vitreous was noted only in the suprathreshold group, indicating a blood-retinal barrier (BRB) disruption. The findings of persistent, excessive PGEZ vitreal levels with no protein leakage in the subthreshold group suggest a possible anti-inflammatory role for PGEZ following low-power laser exposure.This work was partially supported by United States Army Medical Research and Development Command contract 17-85-G-5013 Offprint requests to: N. Naveh     

Methods of visual acuity determination with the spatial frequency sweep visual evoked potential

Purpose The spatial frequency sweep visual evoked potential (sVEP) is used to rapidly determine visual acuity in children or non-responsive patients. Two techniques have been used to separate signal from noise: (1) the 95% confidence interval for the signal amplitude (95% CI) or (2) the amplitude of a Fourier frequency adjacent to 2×the signal frequency (DFT). The purpose of this study is to determine if there is a significant difference in acuity estimates with these techniques.Methods Ten normal subjects (approximately 0.00logMAR acuity) and 11 patients with decreased visual acuity took part in this project. Stimulus production and data analysis were done with an Enfant 4010 (Neuroscientific Corp). Standard VEP recording techniques were employed. The stimulus was a horizontal-oriented, sine wave grating that swept up the spatial frequency spectrum (contrast 80%, temporal reversal rate 7.5Hz). Sweeps were repeated until the confidence intervals for the data were no longer decreasing. The Bailey LovielogMAR chart was used to determine visual acuity. A line was fit to the high spatial frequency data using either the 95% CI or the DFT as the noise estimate. By using these linear equations, acuity estimates were obtained at 0, 1, and 2V signal amplitudes.Results The average logMAR acuity for the subjects with normal acuity was –0.06±0.070 (SD). The sVEP acuity estimates were 0.08±0.098, 0.18±0.092, and 0.33±0.195 (0, 1, and 2V extrapolations) with the 95% CI used as noise and 0.07±0.100, 0.18±0.103, and 0.33±0.202 (0, 1, and 2V extrapolations) with the DFT used as noise. By using the average noise from the Fourier frequency as the extrapolation level, the acuity was 0.10±0.098logMAR. The averagelogMAR acuity for the subjects with decreased visual acuity was 0.67±0.306 (SD). The sVEP acuity estimates were 0.53±0.175, 0.66±0.171, and 0.88±0.295 (0, 1, and 2V extrapolations) with the 95% CI used as noise and 0.53±0.179, 0.65±0.176, and 0.86±0.268 (0, 1, and 2V extrapolations) with the DFT used as noise. By using the average noise from the Fourier frequency as the extrapolation level, the acuity was 0.57±0.186logMAR. No significant difference was found between the two acuity estimate techniques for all of the subjects (repeated measures ANOVA, p=0.16, F₂₀=2.131). The sVEP estimates of acuity to the 0V and noise levels were not significantly different from the logMAR acuity (paired t-test, all p values >0.05).Conclusions The results indicate that the sVEP acuity does not depend on the noise estimation technique. In agreement with prior studies, the sVEP acuity underestimates the logMAR acuity in normally sighted individuals by about an octave.     

The effect of chemical stability and purification of perfluorocarbon liquids in experimental extended-term vitreous substitution

Background: To determine the importance of chemical stability and purification of perfluorocarbon liquids (PFCLs) in experimental retinal tolerance, we tested four different substances as long-term vitreous tamponade: purified and nonpurified perfluorodecalin (PFD) and perfluoro-octylbromide (PFOB) Method: After mechanical vitrectomy we replaced the vitreous of 65 rabbit eyes. Five groups were formed; four of them received the four PFCLs, while one served as control and received Ringer solution. The eyes were observed clinically every week and examined histologically after 1, 2, 4 and 8 weeks Results: After 1 week we observed foam cells and intraretinal macrophages in all eyes with PFCLs. Purified PFD caused retinal lesions in the photoreceptor, ganglion cell and outer nuclear layers after only 2 weeks in the lower part of the eyes. In eyes filled with purified PFOB we observed more pronounced damage of the same nature. Unpurified substances caused severe inflammation and retinal detachment Conclusion: Our study demonstrates that purification and chemical stability are important factors in retinal tolerance of PFCLs for vitreous replacement. Although purified PFD was tolerated by the rabbit eyes for 1 week, we cannot recommend this substance for short-term clinical use as a vitreous substitute.     

Oxidative reactions in the tear fluid of patients suffering from dry eyes

Purpose: To evaluate whether products of oxidative and inflammatory reactions are detectable in the tear fluid of patients suffering from dry eyes. Methods: The tear fluid of 217 patients (397 eyes) was sampled. Criteria for grouping of the patients were (1) basic secretion test (sicca l: BST = 0–5 mm, n = 78 eyes; sicca 2: BST = 6–10 mm, n = 109 eyes) and (2) subjective symptoms (normal BST, burning, foreign body sensations, tearing, dryness of the eyes: n = 78 eyes). One group of healthy patients (normal BST, n = 132 eyes) served as controls. Lipid peroxide levels and myeloperoxidase activity, as parameters for oxidative tissue damage and inflammatory activity, were determined in the tear fluid. Those patients whose consent could be obtained were subjected to the rose bengal test (sicca 1: 56 eyes; sicca 2: 97 eyes; subjective symptoms: 44 eyes; controls: 49 eyes). The correlation between BST and rose bengal test results was calculated. Results: Lipid peroxides were significantly (P < 0.05) higher in the groups sicca 1 and subjective symptoms than in healthy controls, as was the inflammatory activity in groups sicca 1, sicca 2 and subjective symptoms. Additionally, the inflammatory activity in the group sicca 1 was significantly (P < 0.05) higher than in the groups sicca 2 and subjective symptoms. No evidence of a significant correlation between BST and rose bengal test results was observed. Conclusions: Both oxidative tissue damage and polymorphonuclear leukocytes indicating an oxidative potential occur in the tear film of patients suffering from dry eyes. These reactions lead to severe damage of the involved tissue. Free radicals and inflammation may be involved in the pathogenesis or in the self-propagation of the disease.     

Vergleich der Bromcyanbruchstücke von Glaskörperkollagen und Typ II Kollagen

Zusammenfassung Aus Rinderglaskörper wurde pepsin-lösliches Kollagen isoliert, das bei der Untersuchung mit der Disk-Elektrophorese eine -Komponente zeigte, die im 1-Bereich wanderte. Auffallend sind mehrere Farblinien zwischen der - und der -Komponente. Bei der Disk-Elektrophorese der Bromcyan-Peptide von pepsin-löslichem Glaskörperkollagen kann festgestellt werden, daß das Peptidmuster nicht mit dem identisch ist, das aus pepsin-löslichem Typ II Kollagen erhalten werden kann.

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Comparison of the cyanogen bromide peptides of vitreous body collagen and type II collagen

Summary Pepsin-soluble collagen was isolated from bovine vitreous humor. This collagen showed only one -chain in disc electrophoresis, migrating in the 1-chain position and between the - and -components some colored bands were visible. The disc electrophoretic patterns of the cyanogen bromide peptides of pepsinsoluble vitreous body collagen and pepsin-soluble type II collagen revealed no identity.

     

Scintillatio nivea corporis vitrei und Melanosarkom der Uvea

Zusammenfassung Es wird gezeigt, daß die Körperchen bei einer bestehenden Scintillatio nivea corporis vitrei von in den Glaskörper ausgewanderten Pigmentepithelien gebildet wurden. Die doppelbrechenden Körperchen sind zunächst noch von Pigmentepithelien umgeben, die hier im Bereiche eines Melanoblastoms (-Sarkoms) durch die Netzhaut in den Glaskörper auswanderten. In pathogenetischer und morphologischer Hinsicht stimmen die Körperchen bei der Scintillatio nivea corporis vitrei mit den Drusen der Lamina vitrea weitgehend überein.Mit 7 Textabbildungen     

Cytotoxic effects of antiproliferative agents on human retinal glial cells in vitro

Purpose: Proliferative vitreoretinopathy (PVR) is characterizedby the formation of cellular membranes on the detached retina and also in the vitreous. Glial cellscan be found in epiretinal and subretinal membranes from eyes with PVR, proliferative diabeticretinopathy (PDR), idiopathic macular pucker, uveitis and other diseases affecting theretina. Proliferation and contraction of glial cells appears to play a role in the pathogenesisof PVR. This study is designed to inspect the effectiveness of harringtonine, as well as colchicine,daunomycin and fluorouracil, against cellular proliferation of cultured human retinal glial cellsthat might be involved in the retinal and/or vitreous proliferation. Methods: Cultures of human retinal glial cells were preparedusing the enzyme digesting method. Cells that had been in culture for 2–5 passages were usedin this study. Harringtonine (0.063 g/ml 2.0 g/ml), colchicines(0.5 g/ml 16.0 g/ml), daunomycin (0.1 g/ml 3.2 g/ml) and 5-fluorouracil(0.5 g/ml 16.0 g/ml) were added to cultures of human retinal glial cellsand the proliferation rates of the cells were measured by the MTT method. Results: Harringtonine at the dosage of 0.063 g/mlinduced suppression of cellular growth, but the changes were not statistically significant (p > 0.05).At a dosage ranging from 0.125 g/ml to 2.0 g/ml, harringtonine significantly suppressedcellular growth according to the test (p < 0.01). Likewise, other antiproliferativeagents inhibited cellular growth significantly at a dosage from 1.0 g/ml to 16.0 g/ml(colchicine), 0.2 g/ml to 3.2 g/ml (daunomycin) and 1.0 g/ml to 16.0 g/ml(5-fluorouracil), but not at 0.5 g/ml (colchicine), 0.1 g/ml (daunomycin) and0.5 g/ml (5-fluorouracil). The ID₅₀ were 0.33 g/ml (harringtonine), 3.11 g/ml (colchicine), 0.79 g/ml (daunomycin) and 5.23 g/ml (5-fluorouracil), respectively.Conclusions: Harringtonine was extremely effective ininhibiting human retinal glial cell proliferation, like other antiproliferative drugs such as colchicine,daunomycin and 5-fluorouracil. Harringtonine, therefore, may be a candidate for further studies regardingthe treatment of experimental PVR.     

Surgical risk factors for severe postoperative proliferative vitreoretinopathy (PVR) in retinal detachment with grade B PVR

Background: Previous studies have shown that grade B proliferative vitreoretinopathy (PVR) is a considerable risk factor for the development of severe postoperative PVR. We conducted a prospective study to elucidate which surgical procedures used in retinal detachment management may stimulate the PVR process in such eyes. Materials and methods: The study included 156 eyes of 152 consecutive patients with rhegmatogenous retinal detachment complicated by grade B PVR referred before any failed surgery and operated on between 1983 and 1993. The parameters evaluated by multivariate statistical analysis included the cumulative circumferential extent of the retinal tears, the extent of the scleral buckle, gas injection, vitrectomy, the method used for retinopexy, and the time of surgical management during the period of the study. Results: The incidence of severe postoperative PVR was 25.8% in eyes managed with cryotreatment versus 2.2% in eyes managed with argon laser photocoagulation (P=0.001). The rate of severe postoperative PVR was not influenced by the other surgical variables. Conclusion: We conclude that cryotherapy may be a risk factor for the development of severe postoperative PVR in retinal detachments associated with grade B PVR.     

The effect of argon laser trabeculoplasty on the blood-aqueous barrier and intraocular pressure in human glaucomatous eyes treated with diclofenac 0.1%

Background: We studied the effect of argon laser trabeculoplasty (ALT) on the bloodaqueous barrier (BAB) in 41 eyes of 41 patients with primary open-angle glaucoma, pseudoexfoliation glaucoma, or pigment dispersion glaucoma using the Fluorotron Master II. Methods: Fluorophotometry was performed the day before ALT and on the 3rd day after surgery at 30 and 60 min after intravenous injection of 7 mg/kg body weight sodium fluorescein 10%. Intraocular pressure (IOP) was measured using Goldmann applanation tonometry on the day before surgery and at 3rd days and 1 year (mean) after ALT. Patients were treated with argon laser by one surgeon (180°, 0.1 s, 50 m 0.6–1.0 W 56 laser burns). Eyes were randomly assigned to either diclofenac-sodium 0.1 % eye drops or vehicle. Eye drops were applied six times 1 h before ALT into the operated eyes and five times daily for 3 days postoperatively. Results: On the 3rd day after ALT there was significant disruption of the BAB in the placebo-treated eyes compared to the diclofenac 0.1%-treated eyes. In the placebo-treated eyes as well as in diclofenac-sodium 0.1 %-treated eyes there was a significant decrease of IOP postoperatively for up to 1 year. There was no significant difference concerning the IOP reduction after 1 year. Diclofenac-sodium 0.1 % eye drops significantly stabilized the BAB on the 3rd day after ALT, compared to placebo, in this model. Conclusion: Diclofenac-sodium 0.1 % significantly stabilized the disruption of the blood-aqueous barrier on the 3rd day after ALT. Concerning the IOP-lowering effect of ALT, the postoperative application of steroids should be avoided.     

Anterior segment findings in AIDS patients with cytomegalovirus retinitis

Background: Anterior segment findings in AIDS patients presenting with cytomegalovirus (CMV) retinitis have not been specifically addressed in the American literature. Methods: Our study evaluated 21 AIDS patients with CMV retinitis. Results: Nineteen (90%) of these patients exhibited corneal endothelial deposits concurrent with CMV retinitis. The endothelial deposits were microscopic, opaque, linear flecks arranged in a reticular-like fashion. Of 42 eyes evaluated, 32 (76%) demonstrated active CMV retinitis. Corneal endothelial deposits were noted in 26 (81%) of the 32 eyes with retinitis. These corneal endothelial deposits were absent in the eyes which did not have CMV retinitis. Conclusion: Meticulous examination of the retina of an HIV-positive or AIDS patient who presents with reticularly arranged, linear, flecked corneal endothelial deposits should be performed to ensure that the diagnosis of CMV retinitis can be ruled out.     

Pulsatile Ocular Blood Flow: Changes Associated with Scleral Buckling Procedures

Purpose To determine the changes in the pulse amplitude (PA) and the pulsatile ocular blood flow (POBF) after scleral buckling (SB).Methods Retrospectively, we studied 24 patients (average age, 52 years) who had undergone SB to repair a retinal detachment in one eye. The patients were divided into two groups: those in whom SB had been performed less than 6 months earlier (n = 10), and those in whom the procedure had been performed more than 6 months previously (n = 14). In each group, the PA and the POBF were determined with a computerized tonometry system, and the values in the SB eyes were compared with those in the control fellow eyes.Results Within 6 months postoperatively, the mean PA in the SB eyes (0.66 ± 0.30mmHg) was significantly lower than that in the control eyes (1.43 ± 0.34mmHg; P < 0.05). The mean POBF in the SB eyes (349.5 ± 154.1µl/min) was also significantly lower than that in the control eyes (631.0 ± 226.6µl/min; P < 0.05). After more than 6 months postoperatively, there were no significant differences in the PA or the POBF between the SB eyes (1.08 ± 0.49mmHg and 612.4 ± 341.2µl/min, respectively) and the control eyes (1.50 ± 0.51mmHg and 589.5 ± 278.4µl/min, respectively).Conclusions These results indicate that the choroidal blood flow decreases after SB but returns to normal levels after 6 months. Jpn J Ophthalmol 2005;49:162–165 © Japanese Ophthalmological Society 2005     

Effects of norfloxacin on the retina in rabbits

Background: Fluoroquinolones have a strong affinity with melanin, and their ocular effects have been reevaluated. Norfloxacin, one of the fluoroquinolones, has broad-spectrum activity against aerobic gram-positive and gram-negative bacteria. We examined the retinal toxicity and intraocular pharmacokinetics of intravitreal norfloxacin in rabbits. Methods: Twenty-three albino and 23 pigmented rabbits were divided into three groups to evaluate retinal toxicity and two groups to investigate the intraocular pharmacokinetics. Each of these five groups was further divided into two subgroups (albino rabbits and pigmented rabbits). Results: With 500 Etg norfloxacin, the oscillatory potential of the electroretinogram was transiently and selectively deteriorated in albino and pigmented rabbits, whereas the electroretinogram remained unchanged with 50 g in pigmented rabbits. No changes were observed in the visual evoked potential or on histology of the retina 7 days after an intravitreal injection of 50 or 500 ltg norfloxacin. The electroretinogram and the retinal histology became abnormal 7 days after four intravitreal injections of 500 g norfloxacin at 7-day intervals. As regards the intraocular pharmacokinetics after an intravitreal injection, the norfloxacin concentration in the chorioretina was as high as that in the vitreous 3 h after injection and was much higher than that in the vitreous 7 days after injection. Similar results were obtained after multiple injections. Conclusion: These results indicate a high concentration of norfloxacin in the melanin-containing ocular tissues.     

Familial exudative vitreoretinopathy: surgical intervention and visual acuity outcomes

Background: Familial exudative vitreoretinopathy (FEVR) is a hereditary condition that may lead to vitreous hemorrhage and traction retinal detachment necessitating surgical intervention. In this paper we review the results of surgery on seven such patients (eight eyes). Methods: Seven patients (eight eyes) were followed up after surgery that had been performed because of vitreous hemorrhage and/or traction retinal detachment due to FEVR, in an effort to evaluate outcomes. Parameters that were noted were the current age, gender, age at the time of first surgery, length of follow-up and postoperative retinal status and visual acuity. Results: Seven patients (eight eyes) ranging in age from 6 months to 44 years with a mean of 24.7 and a median of 26 years were followed. There were three females and four males. The lowest age at which surgery was first performed was 6 months and the highest was 28 years, with a mean of 14.7 and a median of 17 years. Six of the 8 eyes were reattached following surgery, although some required multiple procedures. Conclusion: Vitreoretinal surgery may be of benefit in helping to preserve some degree of vision in eyes of patients with FEVR who develop vitreous hemorrhage and/or retinal detachment.Presented at the combined meeting of the Club Jules Gonin and the Retina Society, 3 September 1996     

Therapeutic use of the 193-nm excimer laser in corneal pathologies

Purpose: To analyze the results of phototherapeutic keratectomy. Patients and methods: We performed 193-nm excimer laser phototherapeutic keratectomy (PTK) in 252 eyes of 216 patients suffering from pain and/or decrease in visual acuity. One hundred and three eyes had recurrent erosions of the cornea, 86 eyes underwent excimer laser smoothing of the cornea after pterygium surgery, 29 eyes had a bandlike keratopathy (25 rough, 4 smooth) and 34 eyes had other pathologic conditions such as amyloidosis of the cornea, anterior corneal dystrophies, scars after injuries, alkali burns, superficial stromal dystrophies and infections. Recurrent erosions and epithelial dystrophies were treated with 15–20 pulses (160–200 mJ/cm², 8 mm ablation zone) after mechanical abrasion of the epithelium. Removal of corneal opacities and scars required the use of a masking fluid (methylcellulose) in different concentrations and slit-lamp control (integrated in the delivery system of the excimer laser). Results: Some 91% of the eyes with recurrent erosions were recurrence-free. Fifty-two per cent of the eyes with pterygium had recurrences if the baresclera technique was used and 33% of the eyes if a free conjunctival graft was used. The difference was not significant. All of the patients with bandlike keratopathy were pain-free. In 88% of the eyes with special indications the treatment goal was achieved. No positive effect was seen after alkali burn, in a patient with anterior membrane dystrophy (Grayson-Wilbrandt corneal dystrophy) or in a patient with a corneal protuberance. In one patient with scleroperikeratitis a late recurrence of the opacity was observed 3 years after surgery. A loss of best corrected visual acuity was found only in one patient with bullous keratopathy in whom the treatment goal was the reduction of pain. All patients with smooth bandlike keratopathy had an improvement in best corrected visual acuity of at least one line. About 70% of patients with special indications improved by at least one line, up to nine lines. A possible hyperopic shift in all groups could be minimized using a large ablation zone. Conclusion: PTK with the 193-nm excimer laser is a safe and effective treatment for many superficial diseases of the cornea.Werner Förster is the Primary Investigator for Schwind Keratom