Influence of ocular volume and lens status on pharmacokinetics and duration of action of intravitreal vascular endothelial growth factor inhibitors.

Purpose: To assess the effects of ocular axial length, refraction, and lens status on pharmacokinetics and duration of action of the vascular endothelial growth factor (VEGF) inhibitors ranibizumab and bevacizumab after intravitreal injection in humans.

Methods: In 119 eyes of 119 patients, aqueous humor was sampled at different time points after intravitreal injection of ranibizumab or bevacizumab, and either drug or VEGF concentrations were measured by enzyme-linked immunosorbent assays and Luminex multiplex bead technology, respectively. Relative deviation of the measured drug concentrations from the time-corrected mean values was calculated (n = 41).

Semiautomated image processing method for identification and quantification of geographic atrophy in age-related macular degeneration.

Purpose: To determine intraobserver and interobserver longitudinal measurement variability of novel semiautomated software for quantification of age-related macular degeneration-associated geographic atrophy (GA) based on confocal scanning laser ophthalmoscopy fundus autofluorescence (FAF) imaging.

Methods: Three-field FAF (excitation 488 nm, emission 500-700 nm), near-infrared reflectance (820 nm), and blue reflectance (488 nm) images of 30 GA subjects were recorded according to a standardized protocol at baseline after 6 and 12 months. At all visits, the GA area was analyzed on central FAF images by seven independent readers using semiautomated software.

Effects of lipid peroxidation products on lipofuscinogenesis and autophagy in human retinal pigment epithelial cells.

Several lines of evidence suggest that progressive dysfunction of the retinal pigment epithelium (RPE) is central to the pathogenesis of age-related macular degeneration (AMD). We previously demonstrated that protein modifications with lipid peroxidation products, such as 4-hydroxynonenal (HNE) and malondialdehyde (MDA), induce lysosomal dysfunction in RPE cells in vitro. Here, we investigated whether phagocytosis of modified photoreceptor outer segments (POS) affects lipofuscinogenesis and autophagy, two interrelated processes directly connected to lysosomal function.