Investigative ophthalmology & visual science
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Invest. Ophthalmol. Vis. Sci. · Dec 2015
Bevacizumab and Aflibercept Activate Platelets via FcγRIIa.
To confirm the formation of a drug-growth factor complex and investigate the effects of three VEGF inhibitors in the activation of platelets. ⋯ A complex composed of bevacizumab or aflibercept, but not ranibizumab, and growth factors activates platelets via FcγRIIa.
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Invest. Ophthalmol. Vis. Sci. · Dec 2015
Light Induces Ultrastructural Changes in Rod Outer and Inner Segments, Including Autophagy, in a Transgenic Xenopus laevis P23H Rhodopsin Model of Retinitis Pigmentosa.
We previously reported a transgenic Xenopus laevis model of retinitis pigmentosa in which tadpoles express the bovine form of P23H rhodopsin (bP23H) in rod photoreceptors. In this model, retinal degeneration was dependent on light exposure. Here, we investigated ultrastructural changes that occurred in the rod photoreceptors of these retinas when exposed to light. ⋯ Our results indicate that ultrastructural defects in outer and inner segment membranes of bP23H expressing rods differ from those observed in drug-induced apoptosis. We suggest that light-induced retinal degeneration caused by P23H rhodopsin occurs via cell death with autophagy, which may represent an attempt to eliminate the mutant rhodopsin and/or damaged cellular compartments from the secretory pathway.
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Invest. Ophthalmol. Vis. Sci. · Dec 2015
Hyperosmolar Tears Induce Functional and Structural Alterations of Corneal Nerves: Electrophysiological and Anatomical Evidence Toward Neurotoxicity.
In an effort to elucidate possible neural mechanisms underlying diminished tearing in dry eye disease, this study sought to determine if hyperosmolar tears, a ubiquitous sign of dry eye disease, produce functional changes in corneal nerve responses to drying of the cornea and if these changes correlate with alterations in corneal nerve morphology. ⋯ These results demonstrate that tear hyperosmolarity, considered to be a "core" mechanism of dry eye disease, significantly decreases physiological sensitivity and morphologic integrity of the corneal nerves important in tear production. These alterations might contribute to the diminished tearing seen clinically in dry eye patients.
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Invest. Ophthalmol. Vis. Sci. · Oct 2015
Rare Variants in the Functional Domains of Complement Factor H Are Associated With Age-Related Macular Degeneration.
Age-related macular degeneration (AMD) has a substantial genetic risk component, as evidenced by the risk from common genetic variants uncovered in the first genome-wide association studies. More recently, it has become apparent that rare genetic variants also play an independent role in AMD risk. We sought to determine if rare variants in complement factor H (CFH) played a role in AMD risk. ⋯ In this large A-AMD cohort, rare variants in the CFH gene were enriched and tended to be located in functional sites or led to low serum levels. These data, combined with those indicating a similar, but even more striking, increase in rare variants found in CFI, strongly implicate complement activation in A-AMD etiopathogenesis as CFH and CFI interact to inhibit the alternative pathway.
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Invest. Ophthalmol. Vis. Sci. · Sep 2015
In Vivo Imaging of Retinal Oxidative Stress Using a Reactive Oxygen Species-Activated Fluorescent Probe.
In vivo methods for detecting oxidative stress in the eye would improve screening and monitoring of the leading causes of blindness: diabetic retinopathy, glaucoma, and age-related macular degeneration. ⋯ Hydrocyanine-800CW detects retinal ROS in vivo and shows potential as a novel biomarker for ROS levels in ophthalmic diseases.