Browsing by Subject "Intravitreal Injections"
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Item Open Access Calcineurin activation causes retinal ganglion cell degeneration.(Mol Vis, 2012) Qu, Juan; Matsouaka, Roland; Betensky, Rebecca A; Hyman, Bradley T; Grosskreutz, Cynthia LPURPOSE: We previously reported that calcineurin, a Ca(2+)/calmodulin-dependent serine/threonine phosphatase, is activated and proposed that it participates in retinal ganglion cell (RGC) apoptosis in two rodent ocular hypertension models. In this study, we tested whether calcineurin activation by itself, even in the absence of ocular hypertension, is sufficient to cause RGC degeneration. METHODS: We compared RGC and optic nerve morphology after adeno-associated virus serotype 2 (AAV2)-mediated transduction of RGCs with constitutively active calcineurin (CaNCA) or unactivated, wild-type calcineurin (CaNwt). Retinas and optic nerves were harvested 7-16 weeks after injection of the AAV into mouse vitreous. In flatmounted retinas, the transduced RGCs were identified with immunohistochemistry. The morphology of the RGCs was revealed by immunostaining for neurofilament SMI32 or by using GFP-M transgenic mice. A modified Sholl analysis was applied to analyze the RGC dendritic morphology. Optic nerve damage was assessed with optic nerve grading according to the Morrison standard. RESULTS: CaNwt and CaNCA were highly expressed in the injected eyes. Compared to the CaNwt-expressing RGCs, the CaNCA-expressing RGCs had smaller somas, smaller dendritic field areas, shorter total dendrite lengths, and simpler dendritic branching patterns. At 16 weeks, the CaNCA-expressing eyes had greater optic nerve damage than the CaNwt-expressing eyes. CONCLUSIONS: Calcineurin activation is sufficient to cause RGC dendritic degeneration and optic nerve damage. These data support the hypothesis that calcineurin activation is an important mediator of RGC degeneration, and are consistent with the hypothesis that calcineurin activation may contribute to RGC neurodegeneration in glaucoma.Item Open Access Effect of Prior Anti-VEGF Injections on the Risk of Retained Lens Fragments and Endophthalmitis after Cataract Surgery in the Elderly.(Ophthalmology, 2016-02) Hahn, Paul; Yashkin, Arseniy P; Sloan, Frank APURPOSE: To investigate the effect of prior intravitreal anti-vascular endothelial growth factor (VEGF) injections on surgical and postoperative complication rates associated with cataract surgery in a nationally representative longitudinal sample of elderly persons. DESIGN: Retrospective, longitudinal cohort analysis. PARTICIPANTS: A total of 203 643 Medicare beneficiaries who underwent cataract surgery from January 1, 2009, to December 31, 2013. METHODS: By using the 5% sample of Medicare claims data, the study assessed risks of 3 adverse outcomes after receipt of cataract surgery for beneficiaries with a history of intravitreal injections. Risks of these outcomes in beneficiaries with a history of intravitreal injections relative to those without were calculated using the Cox proportional hazard model. MAIN OUTCOME MEASURES: The primary outcome was the risk of subsequent removal of retained lens fragments (RLFs) within 28 days after cataract surgery. Secondary outcomes were a new diagnosis of acute (<40 days) or delayed-onset (40+ days) endophthalmitis and risk of a new primary open-angle glaucoma (POAG) diagnosis within 365 days after cataract surgery. RESULTS: Prior intravitreal anti-VEGF injections were associated with a significantly increased risk of subsequent RLF removal within 28 days after cataract surgery (hazard ratio [HR], 2.26; 95% confidence interval [CI], 1.19-4.30). Prior injections were also associated with increased risk of both acute (HR, 2.29; 95% CI, 1.001-5.22) and delayed-onset endophthalmitis (HR, 3.65; 95% CI, 1.65-8.05). Prior injections were not a significant indicator of increased risk of a new POAG diagnosis. CONCLUSIONS: A history of intravitreal injections may be a risk factor for cataract surgery-related intraoperative complications and endophthalmitis. Given the frequency of intravitreal injections and cataract surgery, increased preoperative assessment, additional intraoperative caution, and postoperative vigilance are recommended in patients with a history of intravitreal injections undergoing cataract extraction.