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Biomedical subjects

Sam S Yang

Publications and source records attributed to Sam S Yang.

6 recordsLinked to original sources

Retinal damage caused by air-fluid exchange during pars plana vitrectomy.

PURPOSE: To report two cases of retinal damage associated with air infusion during pars plana vitrectomy. DESIGN: Observational case report. METHODS: The authors reviewed the course of two patients who had retinal damage during par plana vitrectomy and air-fluid exchange for the treatment of macular hole and optic pit-related macular detachment, respectively. The intraoperative observations, postoperative course, and outcomes were reported. RESULTS: As a result of high air infusion flow during air-fluid exchange, retinal damage was created in the area contralateral to the infusion port. In Case 1, an oval area of whitening was noted on the first postoperative day. This area subsequently developed into a large retinal break associated with retinal detachment. In the second case, retinal whitening was noted intraoperatively. This region of pallor resolved quickly during the early postoperative period but resulted in a corresponding inferotemporal visual field defect. CONCLUSIONS: High infusion flow during air-fluid exchange in eyes undergoing vitrectomy surgery may result in significant retinal damage. This pressure-induced trauma initially causes retinal whitening that may be seen intraoperatively or during the early postoperative period. The region of damaged retina may develop a retinal break and detachment or a corresponding visual field defect.

Adult↗

Intravitreal triamcinolone acetonide treatment of macular edema associated with central retinal vein occlusion.

PURPOSE: To evaluate treatment of macular edema associated with central retinal vein occlusion (CRVO) using intravitreal triamcinolone acetonide. METHODS: Retrospective review of data for 29 eyes of 29 patients with CRVO and macular edema treated with intravitreal triamcinolone acetonide. Initial visual acuity, intraocular pressure, and history of glaucoma were recorded. Final visual acuity, intraocular pressure, and adverse events were recorded during the treatment period. RESULTS: Twenty-nine eyes were treated with intravitreal injection. The mean follow-up was 348 days. The median initial Early Treatment Diabetic Retinopathy Study visual acuity was 20/250 (median logMAR, 1.1). The median visual acuity 3 months after injection was 20/125 (median logMAR, 0.8). This difference was statistically significant. The median final visual acuity was 20/250 (median logMAR, 1.1). This difference in visual acuity was not statistically significant. Elevated intraocular pressure, excluding that related to neovascularization, occurred in 5 of 22 patients. Subgroup analysis revealed that patients who received multiple injections had better outcomes. CONCLUSION: Intravitreal triamcinolone acetonide may improve vision transiently but does not appear to result in a sustained visual acuity benefit for patients with macular edema associated with CRVO. Repeated injections may be necessary. The risk of glaucoma is significant, and additional study is required to further characterize this and other risks.

Adult↗

Massive spontaneous choroidal hemorrhage.

PURPOSE: To describe the course, management, and prognosis of massive spontaneous choroidal hemorrhage. METHODS: The presenting visual acuity, ocular findings, duration to surgical intervention, and outcomes of five patients were retrospectively reviewed. RESULTS: Five eyes from four patients (median age, 80 years; range, 66-85 years) were studied. The patients were observed from 4 to 72 months (median, 33 months). Three patients were on anticoagulation therapy with warfarin; one patient had bilateral involvement with no history of anticoagulation therapy. Three patients were hypertensive, and three of the four had been diagnosed with age-related macular degeneration. Four eyes underwent choroidal drainage procedures, and one was observed. In all patients whose choroids were drained, the final vision was no light perception. CONCLUSIONS: Massive spontaneous choroidal hemorrhage may be associated with hypertension, systemic anticoagulation, advanced age, and age-related macular degeneration. Final visual acuities are generally poor.

Age Factors↗