Activated protein C resistance, factor V Leiden, and central retinal vein occlusion in young adults.

OBJECTIVE: To confirm the relationship between resistance to activated protein C (APC), factor V Leiden, and central retinal vein occlusion in young adults as reported in a recent study of patients younger than 50 years. PATIENTS AND METHODS: Patients younger than 50 years with central retinal vein occlusion were identified from the medical records of the Wills Eye Hospital Retina and Retina Vascular Services. Blood samples were taken from each patient and analyzed for resistance to APC and identification of factor V Leiden. RESULTS: Only 1 (4.7%) of 21 patients evidenced resistance to APC and the presence of factor V Leiden. This patient was also the only one to report a family history of thrombotic disease. CONCLUSIONS: We were unable to confirm the high percentage of resistance to ACP among young adult patients with central retinal vein occlusion. The finding of resistance to APC in only 1 (4.7%) of 21 patients is similar to that found in the general population.

Peripapillary staphyloma.

PURPOSE: To report a rare case of peripapillary staphyloma. METHOD: Case report. A 5-month-old infant was examined for esotropia associated with a retinal and optic nerve abnormality of the left eye. RESULTS: Detailed clinical examination along with diagnostic ultrasonography and electroretinography established a diagnosis of a peripapillary staphyloma of the left eye measuring 9.77 mm in depth. The patient's right eye was entirely normal, and she showed no systemic abnormalities. CONCLUSION: Although extremely rare, the peripapillary staphyloma may cause severe visual impairment of the affected eye in an otherwise healthy individual unassociated with systemic abnormalities.

Central serous chorioretinopathy in women.

BACKGROUND: Central serous chorioretinopathy is a disorder that typically affects young and middle-aged men. Although extensive information is available pertaining to the clinical features of central serous chorioretinopathy in men, little is known about this condition in women. MATERIALS AND METHODS: The authors reviewed the medical records and photographic files of women who received a diagnosis of central serous chorioretinopathy. The women were divided into three groups for data analysis: idiopathic, exogenous corticosteroid use, and pregnancy. RESULTS: Fifty-one women with active central serous chorioretinopathy were evaluated. These findings in women with idiopathic serous chorioretinopathy were similar to those described in men, with the exception that women tend to be older at the time of onset. Central serous chorioretinopathy in women taking exogenous corticosteroids more likely was characterized by bilateral involvement and subretinal fibrin. Central serous chorioretinopathy in pregnant women typically developed in the third trimester and resolved spontaneously within 1-2 months after delivery. CONCLUSION: Idiopathic central serous chorioretinopathy is similar in women and men, with the exception that women tend to be more older at the time of onset. The finding of exogenous corticosteroid use in a significant number of women in our study provides further support that cortisol may play a role in the development of central serous chorioretinopathy. The mechanism by which cortisol influences the development of central serous chorioretinopathy is unclear.

Choroidal blastomycosis. A report of two cases.

PURPOSE: To review the presentation and course of choroidal blastomycosis, a rare chorioretinal mycotic infection, which results from disseminated blastomycosis. METHODS: Two cases of disseminated blastomycosis with ocular infection limited to the choroid are presented. Each patient was diagnosed through biopsy of skin lesions demonstrating the characteristic histologic features and the budding yeast. RESULTS: Systemic evaluation revealed extensive disseminated disease with involvement of the eye, lung, skin, bone and joint, central nervous system, and genitourinary system. Both patients were successfully treated with intravenous amphotericin B with elimination of ocular and systemic disease. CONCLUSION: Although rare, blastomycosis can result in choroidal mycotic infection in immune competent individuals. Tissue biopsy to confirm the diagnosis and extensive systemic evaluation are required.

The effects of intravitreal triamcinolone acetonide on experimental pre-retinal neovascularization.

Corticosteroids, alone or in combination with other drugs, have been shown to inhibit angiogenesis. The purpose of this study was to evaluate the efficacy of triamcinolone acetonide in a new model of preretinal neovascularization. Rabbit eyes were treated with intravitreal triamcinolone acetonide 24 h before partial liquefaction of the posterior vitreous with hyaluronidase and injection of 250,000 homologous tissue-cultured dermal fibroblasts. Triamcinolone acetonide effectively inhibited new vessel growth in treated eyes. Only 14% of the treated eyes developed new blood vessels compared to 100% of sham-injected control eyes (P < 0.001). These results suggest that intravitreal triamcinolone acetonide might be effective in inhibiting new vessel growth in patients with inflammatory retinal neovascularization, such as that associated with sarcoidosis or other uveitic syndromes.

An experimental model of preretinal neovascularization in the rabbit.

Although progressive retinal neovascularization is a potentially blinding complication of several diseases, there are no good animal models. The authors developed a consistent model of preretinal neovascularization in the rabbit by partially digesting the posterior vitreous with repeated injection and aspiration of 1 IU of hyaluronidase before injection of 250,000 homologous dermal fibroblasts. The evolution of the new preretinal vessels was monitored by indirect ophthalmoscopy, fundus photography, and fluorescein angiography. A grading system was devised using fundus photographs and fluorescein angiograms to describe the progression of new vessel growth and the extent of fluorescein leakage. Ninety-five percent of the eyes had vascular enlargement and hyperemia but no fluorescein leakage by day 1. Fifteen percent of the eyes had clinically evident new preretinal vessels, and 32% had severe fluorescein leakage by day 7. Ninety-five percent of the eyes had definite neovascularization by day 14. Severe fluorescein leakage peaked at day 14 (55% of the eyes) and decreased thereafter. Involution or atrophy of the vessels occurred in all eyes by day 42. This model will be useful for studying the pathogenesis of preretinal neovascularization and evaluating potential treatments for its prevention.

The safety of intravitreal hyaluronidase. A clinical and histologic study.

The authors previously developed a new model of preretinal neovascularization in the rabbit eye using hyaluronidase for enzymatic vitreolysis. The purpose of this study was to evaluate the safety of intravitreal injections of hyaluronidase. Concentrations of 1, 15, 30, 50, and 150 IU of hyaluronidase in 0.1 ml of 0.9% saline were injected intravitreally and aspirated repetitively until the vitreous was partially liquified. The animals were examined with indirect ophthalmoscopy, fundus photography, and fluorescein angiography before injection and on days 1 and 7 after injection. Light and electron microscopic retinal sections were prepared from enucleated eyes at days 1 and 7. All concentrations of hyaluronidase were effective in producing partial vitreolysis. Eyes treated with 1 IU showed no abnormalities on days 1 or 7. Eyes treated with 15 IU showed no retinal abnormalities on day 1, but on day 7 histologic abnormalities were present in two of four eyes. At higher concentrations, clinical and histologic changes were seen in proportion to the concentration and included focal whitening, edema, vitreous haze, vascular abnormalities, and retinal necrosis at the highest doses. Histologic evaluation of the retina revealed marked destruction in all layers at the higher concentrations. The authors conclude that 1 IU of intravitreal hyaluronidase is sufficient for partial vitreolysis and nontoxic to the rabbit retina.