Faculty Bibliography

A pair-matched, case-control design was used to study exposure to Histoplasma capsulatum and other environmental factors, and to determine various host characteristics including human leukocyte antigen (HLA) typings in 94 young patients with macular choroidal neovascularization (CNV) and in 94 controls with other eye diseases. Patients with two types of retinal patterns were studied: Type I, or those with CNV with one or no chorioretinal atrophic spots in the posterior pole or periphery (n = 51), and Type II, or those with CNV and 2 or more chorioretinal atrophic spots (n = 43). Our purpose was to explore whether these two variants of idiopathic CNV have different and distinguishable epidemiologies which may or may not be related to prior exposure to Histoplasma. We found that histoplasmin skin tests were negative in all but two Type I cases. The combination of the HLA-B7 and HLA-DR2 markers (but not either marker alone) was significantly increased in Type I cases. Among Type II cases, HLA-B7, HLA-DR2, HLA-DQ1, a positive histoplasmin skin test, myopic refractive error, prior residence in a histoplasmosis endemic area, occupations involving exposure to animals, and hypertension were all significantly increased. Histoplasmin skin test responses were positive in 18 Type II cases (45%). In the multivariate analysis, only DR2 and the combined presence of DQ1 and a positive histoplasmin skin test remained predictive of Type II disease. Our findings suggest that histoplasmin sensitivity is associated with some, but not all, cases of Type II disease. However, histoplasmin sensitivity appears to have no relationship to Type I disease. HLA factors may play a role in both disease types, possibly by producing a modified immune response to Histoplasma and/or other unidentified agents

PURPOSE: To investigate the risk factors for cotton-wool spots and for cytomegalovirus retinitis in patients with human immunodeficiency virus infection (HIV). METHODS: A cross-sectional study was performed on 453 consecutive male patients with a positive serodiagnosis for HIV. The possible risk factors of age, race, absolute T-lymphocyte CD4+ count, and mode of HIV acquisition were evaluated. RESULTS: Age and race were not significant predictors of either cotton-wool spots or cytomegalovirus retinitis. Low CD4+ T-lymphocyte counts were the strongest predictor of both types of retinopathy. After adjustment for CD4+ T-lymphocyte counts by logistic regression, patients who had acquired HIV through homosexual or bisexual activity were more likely to have cotton-wool spots (odds ratio, 2.09; P = 0.029) and cytomegalovirus retinitis (odds ratio, 4.14; P = 0.0028) than were patients who had acquired the disease intravenously. CONCLUSIONS: The results of this study showed that the ocular manifestations of HIV infection are associated with low CD4+ counts and HIV acquisition through bisexual or homosexual activity. Patients with these risks factors should be targeted for prophylaxis and prevention strategies for cytomegalovirus retinitis

Administration of timolol to one eye is associated with a decrease in intraocular pressure in both eyes. To further investigate this effect the contralateral decrease in intraocular pressure was measured in a three arm crossover study using a 0.1 mg dose of timolol given topically to an eye, a 0.1 mg dose of timolol given lingually, and a placebo given topically. Two hours after topical timolol administration the mean intraocular pressure reduction in the fellow eye was 3.1 mm Hg compared with baseline (p = 0.0007). Two hours after lingual timolol administration the mean intraocular pressure reduction was 3.9 mm Hg compared with baseline (p = 0.0004). Two hours after topical administration of placebo the mean intraocular pressure reduction in the fellow eye was only 0.33 mm Hg (p = 0.6). These findings suggest the contralateral reduction in intraocular pressure from timolol is caused by systemic absorption. The significant intraocular pressure reduction obtained from lingual timolol raises the possibility that this route of drug administration may be useful in selected patients who cannot use eye drops

The presence of subretinal exudation in a patient with neurosensory detachment of the macula frequently suggests the diagnosis of choroidal neovascularisation. A retrospective chart review of newly diagnosed cases of central serous chorioretinopathy revealed 11 patients, seven men and four non-pregnant women, who had plaques of subretinal exudate, which presumably were fibrin. Each of these patients had a solitary plaque that ranged in size from 300 to 1500 microns in diameter. These patients had no signs or a clinical course suggestive of choroidal neovascularisation. In each case the subretinal plaque was overlying an exuberant leak in the retinal pigment epithelium. The exudate was generally present at the initial examination, and usually showed dissolution before or coincident with the resolution of the neurosensory detachment. After resolution of the central serous chorioretinopathy, patients were left with subtle alterations in the retinal pigment epithelium in the areas of the subretinal plaque. These findings are important for two reasons. Firstly, the presence of subretinal exudation does not necessarily rule out the diagnosis of central serous chorioretinopathy. Secondly, pathophysiological theories of central serous chorioretinopathy must explain how the plaques are deposited behind the retina

Of 141 patients who had clinically significant cystoid macular edema (CME) following cataract surgery, 42 had a visual acuity of 20/200 or worse. Logistic regression demonstrated that of all the systemic and ocular factors studied, the best predictors of visual acuity of 20/200 or worse were the presence of iris in the wounds (odds ratio = 2.86, P = .011) and a fluorescein angiogram grade of 4 (odds ratio = 2.91, P = .0076). Entering into the logistic regression variables such as integrity of the posterior capsule, iritis, vitreous in the wound, or type of intraocular lens did not significantly improve the ability of the model to predict which patients would have poor visual acuity. This study suggests that iris incarceration in the wound may have a more important association with poor vision in patients with chronic postsurgical CME than previously thought