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Biomedical subjects

Michael S Ip

Publications and source records attributed to Michael S Ip.

10 recordsLinked to original sources
PubMed2005

Preferential Hyperacuity Perimeter (PreView PHP) for detecting choroidal neovascularization study.

PURPOSE: To assess the ability of the Preferential Hyperacuity Perimeter (PreView PHP; Carl Zeiss Meditec, Dublin, CA) to detect recent-onset choroidal neovascularization (CNV) resulting from age-related macular degeneration (AMD) and to differentiate it from an intermediate stage of AMD. DESIGN: Prospective, comparative, concurrent, nonrandomized, multicenter study. PARTICIPANTS: Eligible participants' study eyes had a corrected visual acuity of 20/160 or better and either untreated CNV from AMD diagnosed within the last 60 days or an intermediate stage of AMD. METHODS: After obtaining consent, visual acuity with habitual correction, masked PHP testing, stereoscopic color fundus photography, and fluorescein angiography were performed. Photographs and angiograms were evaluated by graders masked to diagnosis and PHP results. The reading center's diagnosis determined if the patient was categorized as having intermediate AMD or neovascular AMD. MAIN OUTCOME MEASURES: A successful study outcome was defined a priori as a sensitivity of at least 80% and a specificity of at least 80%. RESULTS: Of 185 patients who gave consent to be enrolled, 11 (6%) had PHP results judged to be unreliable. An additional 52 were not included because they did not meet all eligibility criteria. Of the remaining 122 patients, 57 had an intermediate stage of AMD and 65 had neovascular AMD. The sensitivity to detect newly diagnosed CNV using PHP testing was 82% (95% confidence interval [CI], 70%-90%). The specificity to differentiate newly diagnosed CNV from the intermediate stage of AMD using PHP testing was 88% (95% CI, 76%-95%). CONCLUSIONS: Preferential Hyperacuity Perimeter testing can detect recent-onset CNV resulting from AMD and can differentiate it from an intermediate stage of AMD with high sensitivity and specificity. These data suggest that monitoring with PHP should detect most cases of CNV of recent onset with few false-positive results at a stage when treatment usually would be beneficial. Thus, this monitoring should be considered in the management of the intermediate stage of AMD.

Aged↗
PubMed2004

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

OBJECTIVE: To investigate the safety and efficacy of intravitreal triamcinolone acetonide as treatment for macular edema associated with central retinal vein occlusion (CRVO). METHODS: We reviewed the medical records of 13 consecutive patients (13 eyes) with macular edema associated with CRVO who were treated with an injection of intravitreal triamcinolone acetonide (4 mg) at the University of Wisconsin and the Bascom Palmer Eye Institute. Each intravitreal injection was delivered through the pars plana using a 27- or 30-gauge needle. MAIN OUTCOME MEASURES: Change in Snellen visual acuity, clinical appearance of macular edema, measurement of foveal thickening with optical coherence tomography (OCT), and frequency of complications. RESULTS: The median age of the 13 patients was 67 years (interquartile range, 57-77 years), and the median duration of symptoms before injection was 8 months (interquartile range, 4-9 months). Mean baseline visual acuity was 20/500 in the affected eye. Mean visual acuity at the 6-month follow-up examination was 20/180 in the affected eye. All 13 patients completed the 6-month examination. Eyes with nonischemic CRVO (n = 5) demonstrated a significant improvement in visual acuity, whereas eyes with ischemic CRVO (n = 8) demonstrated a nonsignificant visual acuity improvement. No patient had a decrease in visual acuity. Mean baseline foveal thickness as measured by OCT was 590 micro m (retinal thickening = 416 micro m). Mean foveal thickness as measured by OCT at the 1-month follow-up examination in 12 patients was 212 micro m (retinal thickening = 38 micro m). At the 3-month follow-up examination, mean foveal thickness as measured by OCT for 13 patients was 193 micro m (retinal thickening = 19 micro m). Between the 3- and 6-month follow-up examinations, 4 patients developed a recurrence of macular edema. Three of the 4 patients were retreated with a second injection of triamcinolone. Two of these 3 patients experienced an improvement in visual acuity following retreatment. At the 6-month follow-up examination, mean foveal thickness as measured by OCT for 13 patients was 281 micro m (retinal thickening = 107 micro m). No adverse effects such as retinal detachment or endophthalmitis occurred. One patient experienced an increase in intraocular pressure that was controlled with 2 aqueous suppressants. CONCLUSIONS: Intravitreal injection of triamcinolone appears to be a possibly effective treatment in some patients with macular edema associated with CRVO. Patients with nonischemic CRVO may respond more favorably than patients with ischemic CRVO, and retreatment may be necessary in some patients. In this case series, severe complications were not noted.

Aged↗
PubMed2002

Anatomical outcomes of surgery for idiopathic macular hole as determined by optical coherence tomography.

OBJECTIVES: To determine the rate of anatomical closure of idiopathic macular holes undergoing vitreous surgery with respect to preoperative horizontal diameter as determined by optical coherence tomography (OCT) and to correlate postoperative visual acuity, duration of symptoms, and late reopening with initial idiopathic macular hole diameter by OCT. MATERIALS AND METHODS: Forty eyes of 40 patients with an idiopathic macular hole were examined with OCT before and after vitreous surgery. All eyes were treated with pars plana vitrectomy, peeling of posterior cortical vitreous, and dilute perfluoropropane or sulfur hexafluoride gas. Face-down positioning was maintained for 7 to 14 days. RESULTS: Twenty-two (92%) of 24 eyes with a preoperative idiopathic macular hole diameter smaller than 400 microm measured by OCT attained anatomical closure following surgery. Anatomical closure was observed in 9 (56%) of 16 eyes with a macular hole diameter of 400 microm or larger measured by OCT (P =.02). The median postoperative visual acuity improvement was 4 Snellen lines in the 31 eyes achieving anatomical closure and no change in the 9 eyes not achieving anatomical closure (P< .001). Late macular hole reopening at longer than 6 months occurred in 3 (10%) of 31 eyes with an initially closed macular hole. This event was observed only in macular holes 400 microm or larger measured by OCT. The preoperative macular hole diameter (P =.02) and duration of symptoms (P =.02) were factors predictive of anatomical closure of the macular hole postoperatively. CONCLUSIONS: The postoperative closure of idiopathic macular holes following vitreous surgery was related to the preoperative macular hole diameter determined by OCT, with lesions smaller than 400 microm demonstrating higher success rates. A trend toward greater visual acuity improvement was demonstrated for idiopathic macular holes smaller than 400 microm. Late reopening was only seen in macular holes that were 400 microm or larger measured by OCT. Preoperative analysis and measurement of idiopathic macular holes with OCT may help delineate postoperative expectations for successful anatomical closure of the macular hole, visual acuity, and long-term closure.

Adult↗
PubMedDate not supplied

Two discrete uveal melanomas in a child with ocular melanocytosis.

OBJECTIVE: To describe a case of two uveal melanomas in a child with mild ocular melanocytosis. METHODS: A 6-year-old girl was followed for 5 years with an ill-defined, slowly enlarging presumed choroidal nevus in the postequatorial fundus. Ocular oncology evaluation revealed mild sectorial scleral and uveal melanocytosis and an episcleral sentinel vessel superotemporally. Two discrete uveal melanomas were present. In the circumpapillary and macular region, tumor 1 was diffuse at 9.0 mm in base and 4.1 mm in thickness and with overlying subretinal fluid. In the ciliary body, tumor 2 was discovered by transillumination and was 6.0 mm in base and 2.2 mm in thickness. Enucleation was performed. RESULTS: Histopathologic analysis disclosed two discrete uveal melanomas in a bed of diffuse mild uveal melanocytosis. Tumor 1 was a mixed, predominantly epithelioid cell melanoma with active mitotic figures, and tumor 2 was a mixed, predominantly spindle cell melanoma. The choroid between the melanomas showed only benign, dendritic melanocytes consistent with melanocytosis. There was no extrascleral extension. CONCLUSIONS: Ocular melanocytosis can predispose to one or multiple uveal melanomas. Lifetime ophthalmic monitoring of affected patients is warranted.

Child↗
PubMedDate not supplied

Optical coherence tomography findings in central retinal artery occlusion.

This article describes optical coherence tomography (OCT) findings in patients with central retinal artery occlusion by conducting a retrospective review of two cases. Central retinal artery occlusion shows a distinct pattern on OCT images. In the acute phase, OCT images demonstrate the increased reflectivity and thickness of the inner retina and a corresponding decrease of reflectivity in the outer layer of the retina and retinal pigment epithelium/choriocapillaris layer. Follow-up OCT images demonstrate a decrease in the reflectivity and thickness of the inner retinal layers and a corresponding increase of reflectivity in the outer retina and retinal pigment epithelium/choriocapillaris layer compared with the baseline OCT image, suggesting a generalized atrophy of the neurosensory retina as a late finding. Therefore, the use of OCT may help facilitate prompt recognition of acute and chronic central retinal artery occlusion.

Disease Progression↗