New findings in ocular histoplasmosis.

The ocular histoplasmosis syndrome consists of punched-out, atrophic chorioretinal lesions, and peripapillary scarring in the absence of vitreal inflammation. Choroidal neovascularization is the cause of significant visual loss in involved eyes and is estimated to occur in up to 5% of affected eyes. An experimental primate model has given us a better understanding of the possible etiology and pathogenesis. Laser therapy for extrafoveal and juxtafoveal choroidal neovascularization has been shown to be effective. Recent advances in surgical technique and instrumentation have demonstrated the potential for the successful treatment of subfoveal choroidal neovascularization. The surgical specimens obtained from this approach have allowed for the study of the active process of neovascularization in this disease. This report summarizes our current knowledge regarding the pathogenesis and epidemiology of ocular histoplasmosis and the treatments currently utilized in the management of its associated choroidal neovascularization.

Persistent Torulopsis magnoliae endophthalmitis following cataract extraction.

Postoperative fungal endophthalmitis typically manifests as an indolent uveitis, weeks to months after surgery. In our patient, Torulopsis magnoliae endophthalmitis appeared as an acute, purulent postoperative endophthalmitis on the third day following extracapsular cataract extraction with implantation of a posterior chamber intraocular lens (IOL). The patient required three separate vitrectomy operations with instillation of intravitreal Amphotericin B; the last operation also included complete removal of the posterior capsule and IOL. This case, which is to our knowledge the first reported case of T. magnoliae endophthalmitis, is unusual in that it manifested as an acute, fulminant infection in the early postoperative period and was recalcitrant to standard endophthalmitis therapy.

Pattern-reversal electroretinographic follow-up of laser photocoagulation for subfoveal neovascular lesions in age-related macular degeneration.

Pattern-reversal electroretinograms were used as an objective measure of macular integrity in a subset of 42 patients who were randomly assigned at enrollment in the Macular Photocoagulation Study to receive laser photocoagulation or no treatment for a subfoveal neovascular lesion. Pattern-reversal electroretinograms were obtained before randomization, three months and six months after randomization, and at six-month intervals randomization, and at six-month intervals thereafter. Responses were obtained to phase-alternating checkerboards of varying check size. Extrapolation of the best-fit regression line relating log-check size to amplitude was used to determine retinal acuity. At each follow-up period, including three months after laser photocoagulation, treated eyes showed less loss in pattern-reversal electroretinographic acuity than untreated eyes. The decline in pattern-reversal electroretinographic acuity in untreated eyes corresponded to the rapid growth in the area of the subfoveal neovascular lesion. The more gradual decline in treated eyes was consistent with an increase in the area of the treatment scar caused by spreading atrophy.

Limiting applications of cryotherapy for severe retinopathy of prematurity.

In an effort to minimize surgical and visual morbidity of cryotherapy for retinopathy of prematurity (ROP), 18 eyes of 13 patients with 3 to 7 clock hours of stage 3 ROP with "plus" disease were treated by cryotherapy applications limited to the avascular retina adjacent to the areas of stage 3 disease. In 17 of 18 eyes, this limited use of cryotherapy was sufficient to cause regression of ROP without further treatments. After at least 3 months follow-up, ROP outcome showed a normal macular appearance in 16 eyes; two eyes developed macular dragging; no retinal detachments occurred.

Bilateral inferotemporal dialysis in identical twins.

Retinal detachment associated with inferotemporal dialysis comprises approximately 10% of all retinal detachments. We describe the cases of two patients with bilateral inferotemporal dialyses who were identical twins. This finding suggests that genetic factors play a role in some cases of inferotemporal dialysis. One of the twins was asymptomatic, stressing the importance of examining other family members of patients with nontraumatic retinal dialysis. We believe that the cause of inferotemporal dialysis is multifactorial and there is a definite subpopulation in which a genetic predisposition is present.

Pattern-reversal electroretinographic acuity in untreated eyes with subfoveal neovascular membranes.

To define further the natural history of visual loss in eyes with age-related macular degeneration (ARMD) complicated by a subfoveal neovascular membrane, pattern-reversal electroretinograms (ERGs) were obtained from patients randomized to no treatment at the Dallas center of the Macular Photocoagulation Study (Texas Retina Associates). Study eyes (n = 20) were tested during the initial visit and at 3-, 6-, and 12-month follow-up visits. Responses were obtained to phase-alternating checkerboards of varying check size. Extrapolation of the best-fit regression line relating the logarithm of the check size to amplitude was used to determine "retinal" acuity (log MAR). The pattern-reversal ERG acuity rating (100 - [50 x log MAR]) was derived for each visit. Pattern-reversal ERG acuity ratings for all patients across visits were correlated significantly with visual acuity ratings derived from the Bailey-Lovie chart (r = 0.61, P less than 0.001) and inversely related to neovascular membrane area (r = -0.55, P less than 0.001). During 1 yr of follow-up, pattern-reversal acuity ratings dropped from 53 to 12, corresponding to an average decrease of approximately 0.2 octaves/month. These results suggest that the pattern-reversal ERG, which samples the resolving power of the central 20 degrees, is a sensitive index of visual loss in age-related macular degeneration.

Cataract extraction after brachytherapy for malignant melanoma of the choroid.

Thirteen eyes of 55 consecutive patients treated with brachytherapy for malignant melanoma of the choroid developed postirradiation cataracts. Cataract development was more common in older patients and in patients with larger and more anterior tumors. Eleven eyes had extracapsular cataract extraction and intraocular lens implantation. Initial visual improvement occurred in 91% of eyes, with an average improvement of 5.5 lines. Visual acuity was maintained at 20/60 or better in 55% of the eyes over an average period of follow-up of 24 months (range, 6 to 40 months). These data suggest that, visually, cataract extraction can be helpful in selected patients who develop a cataract after brachytherapy for malignant melanoma of the choroid.

Vitrectomy in eyes at risk for macular hole formation.

Fifteen eyes believed to be at increased risk for macular hole formation underwent vitrectomy in an attempt to prevent macular hole formation. Full-thickness macular holes have not developed in 10 of 11 eyes with stage 1 macular holes. Four eyes were noted to have small full-thickness foveal defects (stage 2 macular holes) at the time of vitrectomy. Two of the four eyes have not progressed to macular hole formation and have 20/25 visual acuity. All patients have been followed for a minimum of 13 months (median, 18 months). The 12 eyes that have not experienced macular hole formation have had a significant (P less than 0.001) improvement in vision with seven (58%) attaining visual acuity of 20/25 or better. The postoperative foveal electroretinogram (ERG) amplitude was higher than the preoperative amplitude in five of the six eyes tested.

The focal electroretinogram in fellow eyes of patients with idiopathic macular holes.

In a prospective study of macular hole formation, focal electroretinograms (ERGs) were obtained from both eyes of 35 patients with a unilateral, idiopathic, full-thickness macular hole. Foveal cone ERG amplitude was significantly correlated with hole diameter at the initial visit. Twenty-six patients had normal foveal cone ERGs in the fellow eye at the baseline visit and for the duration of the study (mean follow-up, 35 months; range, 24 to 56 months). None of these eyes developed a macular hole. Seven eyes had significantly reduced foveal cone ERGs in the fellow eye, despite good visual acuity and a normal-appearing macula on the initial visit. Four of these eyes subsequently developed a full-thickness macular hole during follow-up (mean follow-up, 35 months; range, 25 to 46 months). Foveal ERG amplitude was significantly related to subsequent macular hole formation, suggesting that this test can provide an objective measure of macular function to help identify eyes at risk for macular hole formation.

Oculab Tono-Pen, Goldmann applanation tonometry, and pneumatic tonometry for intraocular pressure assessment in gas-filled eyes.

We performed 84 intraocular pressure measurements with the Oculab Tono-Pen, Goldmann applanation tonometer, and pneumatic tonometer in 47 eyes that had undergone pars plana vitrectomy and gas-fluid exchange. Measurements made by using the Tono-Pen were accurate when compared to those made by Goldmann tonometry (mean difference, 0.74 mm Hg). In a subset of eyes with increased intraocular pressure (greater than or equal to 25 mm Hg), the Tono-Pen provided measurements similar to those made by Goldmann applanation tonometry (P greater than .60), with only three of 39 readings (8%) underestimating the Goldmann pressure by more than 3 mm Hg. Pneumatic tonometry significantly underestimated the intraocular pressure in eyes with increased pressure (P less than .001), with 20 of 39 readings (51%) underestimating the Goldmann pressure by 5 mm Hg or more.

Laser treatment for choroidal neovascularization outside randomized clinical trials.

This study was undertaken to determine whether the treatment benefit reported in randomized trials for patients with extrafoveal choroidal neovascular membranes (NVMs) secondary to age-related macular degeneration (AMD) or the ocular histoplasmosis syndrome (OHS) can be duplicated in other clinical settings. The visual results and recurrence rates in treated extrafoveal NVMs of 70 patients with AMD and 21 patients with OHS were similar to those reported by the Macular Photocoagulation Study Group, in which all treated patients received argon blue-green laser photocoagulation after the administration of retrobulbar anesthesia. In this study, 78% (71/90) of the patients were treated with krypton laser and only 35% (32/90) had retrobulbar anesthesia. These results suggest, but do not prove, that the wavelength of the laser used or the administration of retrobulbar anesthesia may not be critical variables in determining the success of treatment in patients with extra-foveal NVMs.

Anterior segment ischaemia following laser photocoagulation in a patient with systemic lupus erythematosus.

The authors report the occurrence of occlusive retinal arterial disease and retinal neovascularisation in a 44-year-old woman with systemic lupus erythematosus (SLE). Two days after uncomplicated panretinal photocoagulation the patient developed an acute anterior segment ischaemic syndrome. To our knowledge this complication has not been reported in any other patient following laser photocoagulation or in association with SLE.

Factors related to spontaneous visual recovery in the ocular histoplasmosis syndrome.

In an effort to better describe the phenomenon of spontaneous visual recovery in the ocular histoplasmosis syndrome (OHS), 700 patient records were reviewed. Spontaneous visual recovery was defined as a two or more line improvement in Snellen acuity after a minimum of 12 months of stable visual reduction to 20/70 or less, secondary to central disciform scarring. Ten cases of spontaneous visual recovery were found. Eight patients had recovery of vision only when visual acuity was reduced to 20/80 or less in the fellow eye. One patient experienced spontaneous recovery without visual loss in the fellow eye. Another patient experienced spontaneous visual recovery 57 months after xenon photocoagulation in the study eye. This group of patients was compared to 14 similar patients who did not experience spontaneous recovery when visual acuity was reduced to less than 20/80 in the fellow eye. Compared to the nonrecovery group, patients experiencing spontaneous visual recovery in OHS were younger at the time of visual loss in the fellow eye (30 years vs. 48 years, p less than 0.01); had a shorter interval of visual loss prior to visual loss in the fellow eye (44 months vs. 150 months, p less than 0.10); had smaller diameter scars (1,711 microns vs. 3,078 microns, p less than 0.05); and had shorter distances from the foveal center to adjacent normal retina (267 microns vs. 846 microns, p less than 0.01).

Atypical retinitis proliferans, retinal telangiectasis, and vitreous hemorrhage in a patient with tuberous sclerosis.

This report describes an unusual case of recurrent vitreous hemorrhage and atypical retinal neovascularization in a patient with tuberous sclerosis. During three years of observation, the patient also developed retinal telangiectasis with macular edema and lipid exudation. Although the patient did not have an obvious astrocytic hamartoma, a diffuse, flat retinal hamartoma within the nerve fiber layer was suspected.