Aneesh Neekhra

Effects of Benzo(e)Pyrene, a Toxic Component of Cigarette Smoke, on Human Retinal Pigment Epithelial Cells In Vitro

PURPOSE To better understand the cellular and molecular basis for the epidemiologic association between cigarette smoke and age-related macular degeneration (AMD), the authors examined the effects of Benzo(e)Pyrene (B(e)P), a toxic element in cigarette smoke, on human retinal pigment epithelial cells (ARPE-19). METHODS ARPE-19 cells were cultured in Dulbecco modified Eagle medium containing 10% fetal bovine serum. Cells were treated for 24 hours with 1000 microM, 400 microM, 200 microM, and 100 microM B(e)P. Cell viability was determined by a trypan blue dye-exclusion assay. Activities of caspase-3/7, caspase-8, caspase-9, and caspase-12 were measured by a fluorescence image scanner, and DNA laddering was evaluated by electrophoresis on 3% agarose gel. RESULTS The mean percentage of cell viabilities of ARPE-19 cells was decreased in a dose-dependent manner after exposure to B(e)P at the higher concentrations of 1000 microM (20.0 +/- 0.4; P < 0.001), 400 microM (35.6 +/- 6.4; P < 0.001), and 200 microM (58.7 +/- 2.3; P < 0.001) but not at 100 microM (95.9 +/- 0.7; P > 0.05) compared with the equivalent dimethyl sulfoxide (DMSO)-treated control cultures. There were significant increases in caspase-3/7, -8, -9, and -12 activities compared with the DMSO-treated controls (P < 0.001). DNA laddering revealed bands at 200-bp intervals. CONCLUSIONS These results show that B(e)P is a toxicant to human retinal pigment epithelial cells in vitro. It causes cell death and induces apoptosis by the involvement of multiple caspase pathways.

Development of choroidal neovascularization in rats with advanced intense cyclic light-induced retinal degeneration.

OBJECTIVES To study the progressive changes of intense cyclic light-induced retinal degeneration and to determine whether it results in choroidal neovascularization (CNV). METHODS Albino rats were exposed to 12 hours of 3000-lux cyclic light for 1, 3, or 6 months. Fundus examination, fundus photography, fluorescein and indocyanine green angiography, and optical coherence tomography were performed prior to euthanization. Light-exposed animals were euthanized after 1, 3, or 6 months for histopathological evaluation. Retinas were examined for the presence of 4-hydroxy-2-nonenal- and nitrotyrosine-modified proteins by immunofluorescence staining. RESULTS Long-term intense cyclic light exposure resulted in retinal degeneration with loss of the outer segments of photoreceptors and approximately two-thirds of the outer nuclear layer as well as development of subretinal pigment epithelium neovascularization after 1 month. Almost the entire outer nuclear layer was absent with the presence of CNV, which penetrated the Bruch membrane and extended into the outer retina after 3 months. Absence of the outer nuclear layer, multiple foci of CNV, retinal pigment epithelial fibrous metaplasia, and connective tissue bands containing blood vessels extending into the retina were observed after 6 months. All intense light-exposed animals showed an increased presence of 4-hydroxy-2-nonenal and nitrotyrosine staining. Optical coherence tomographic and angiographic studies confirmed retinal thinning and leakiness of the newly formed blood vessels. CONCLUSIONS Our results suggest that albino rats develop progressive stages of retinal degeneration and CNV after long-term intense cyclic light exposure, allowing the detailed study of the pathogenesis and treatment of age-related macular degeneration. CLINICAL RELEVANCE The ability to study the progressive pathogenesis of age-related macular degeneration and CNV will provide detailed knowledge about the disease and aid in the development of target-specific therapy.

Suppression of Thrombospondin-1 Expression During Uveal Melanoma Progression and Its Potential Therapeutic Utility

OBJECTIVES To determine whether expression of thrombospondin-1 (TSP1), an endogenous inhibitor of angiogenesis, is downregulated during progression of uveal melanoma and whether administration of TSP1 and/or its antiangiogenic peptides attenuate tumor growth. METHODS Tyrosinase-SV40 T-antigens (Tyr Tag) transgenic mice were used for evaluation of TSP1 expression during tumor progression using immunohistological methods. The therapeutic potential of TSP1 on tumor progression was evaluated either by crossing Tyr Tag mice with a line of transgenic mice overexpressing TSP1 in the eye or by administration of TSP1-mimetic peptide with known antiangiogenic, antitumor activity. Tumor areas were measured in histological sections using Optima software (Media Cybernetics, Inc). RESULTS The Tyr Tag tumors from 3-week-old mice showed significant TSP1 expression, which was dramatically downregulated in tumors from 12-week-old mice. Furthermore, the development and progression of tumor was significantly delayed in Tyr Tag TSP1 transgenic mice or Tyr Tag mice receiving TSP1-mimetic peptide (100 mg/kg/d). CONCLUSIONS Expression of TSP1 was decreased with the angiogenic switch during progression of uveal melanoma, and TSP1 and/or its antiangiogenic peptides were effective in attenuation of tumor growth. CLINICAL RELEVANCE Modulation of TSP1 expression and/or activity may be beneficial in treating uveal melanoma.

Postoperative visual acuity in patients with fuchs dystrophy undergoing descemet membrane-stripping automated endothelial keratoplasty: correlation with the severity of histologic changes.

OBJECTIVE To investigate a correlation between the severity of histologic changes of the Descemet membrane in patients with Fuchs endothelial dystrophy and the best-corrected visual acuity (VA) after Descemet membrane-stripping automated endothelial keratoplasty (DSAEK). METHODS In a retrospective study design, we created a histologic grading system based on common characteristics observed histologically among 92 DSAEK specimens sent to the University of Wisconsin Eye Pathology Laboratory with a clinical diagnosis of Fuchs dystrophy from 3 separate corneal surgeons. Cases were graded as mild, moderate, or severe on the basis of guttae dispersion, presence of a laminated Descemet membrane, presence of embedded guttae, and density of guttae. Regression models were built to study the relationship among preoperative VA, histologic findings, and best-corrected VA 6 months and 1 and 2 years after DSAEK. RESULTS No correlation was found between the severity of histologic changes of Descemet membrane and preoperative VA. However, a correlation was noted between the preoperative and final VA. Cases with a laminated Descemet membrane but no embedded guttae (n = 8) appeared to be less responsive to DSAEK. Otherwise, the severity of histologic changes of Descemet membrane observed in patients with Fuchs corneal dystrophy after DSAEK did not show a statistically significant correlation with final VA. CONCLUSIONS Our analysis fails to show an inverse relationship between the severity of histologic changes of the Descemet membrane and the best-corrected VA of at least 20/40 after DSAEK for Fuchs endothelial dystrophy. However, in a subset of patients with Fuchs dystrophy who develop a laminated Descemet membrane without embedded guttae, the visual recovery after DSAEK is less than expected. The laminated architecture of Descemet membrane without embedded guttae may facilitate separation between the membrane layers and, thus, incomplete removal of the recipients Descemet membrane during DSAEK, which may then limit the postoperative visual outcome.

Sebaceous cell carcinoma of the eyelid: A rapidly enlarging lesion with massive xanthogranulomatous inflammation

A 76-year-old man presented atypically with a 4-week history of a rapidly enlarging ulcerated nodular lesion of the left upper eyelid that was found to be sebaceous cell carcinoma. Further investigation showed no metastatic disease, and Mohs surgery was performed to resect the tumor. Histopathologic analysis showed features diagnostic of sebaceous cell carcinoma. However, most of the mass consisted of xanthomatous granulomatous inflammatory reaction vastly out of proportion with the tumor burden. The patient was spared from orbital exenteration, and no evidence of recurrence was present 6 months after resection.

Choroidal Melanoma Occurring in a Nonhuman Primate

Comment. Ocular involvement with tuberculosis is rare. In this case, diagnosis was based on positive PCR results following negative results on multiple cultures and stains for AFB on tissue sections and body fluids. Histopathologic analysis may not always offer adequate sensitivity, especially when bacteria are few. This report exemplifies the importance of quantitative PCR in such cases. A confounding factor in this case was tissue immunoreactivity to herpes simplex virus type 1 antibody. Although the antibodies used have a high sensitivity, variable specificity and false-positive reactions may occur. This case also highlights the difficulty in treating multidrug-resistant tuberculous scleritis, which is more likely to have a dismal prognosis as has scleritis secondary to drug-resistant atypical mycobacteria. Correspondence: Dr Goldstein, Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W Taylor St, M/C 648, Chicago, IL 60612 (debrgold@yahoo.com). Financial Disclosure: None reported.

Uveal Melanoma Masquerading as Pigment Dispersion Glaucoma

To the Editor: A 64 year old caucasian female presented from an outside ophthalmologist with a history of pigment dispersion glaucoma unresponsive to medical therapy in the right eye. She was subsequently found to have a ciliary body melanoma and was sent to the ocular oncology clinic for further evaluation. The clinical course and outcome are presented.