Optimizing OCT acquisition parameters for assessments of vitreous haze for application in uveitis

Detection and evaluation of inflammatory activity in uveitis is essential to the management of the condition, and yet continues to be largely dependent on subjective clinical measures. Optical coherence tomography (OCT) measurement of vitreous activity is an alternative to clinical vitreous haze scoring and has passed a number of early validation studies. In this study we aimed to evaluate the impact of ‘operator factors’ on the variability of the technique as part of the validation process, and to help evaluate its suitability for ‘real world’ use. Vitreous haze index was calculated as a ratio between the reflectivity of the vitreous and of the outer retina in each scan. Different scanning conditions were tested and their effect on the measurement is reported. Our results show that the ‘quantitative imaging’ technique of OCT-measured vitreous activity had good reliability in normal subjects under a range of ‘real world’ conditions, such as when the operator changes the averaging value. The technique was however vulnerable to highly inaccurate focussing or abnormal downward displacement of the image. OCT-based quantification of vitreous activity is a promising alternative to current subjective clinical estimates, with sufficient ‘tolerance’ to be used in routine clinical practice as well as clinical trials

Aflibercept Nanoformulation Inhibits VEGF Expression in Ocular In Vitro Model: A Preliminary Report

Age-related macular degeneration (AMD) is one of the leading causes of blindness in the United States, affecting approximately 11 million patients. AMD is caused primarily by an upregulation of vascular endothelial growth factor (VEGF). In recent years, aflibercept injections have been used to combat VEGF. However, this treatment requires frequent intravitreal injections, leading to low patient compliance and several adverse side effects including scarring, increased intraocular pressure, and retinal detachment. Polymeric nanoparticles have demonstrated the ability to deliver a sustained release of drug, thereby reducing the necessary injection frequency. Aflibercept (AFL) was encapsulated in poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs) via double emulsion diffusion. Scanning electron microscopy showed the NPs were spherical and dynamic light scattering demonstrated that they were uniformly distributed (PDI \u3c 1). The encapsulation efficiency and drug loading were 75.76% and 7.76% respectively. In vitro release studies showed a sustained release of drug; 75% of drug was released by the NPs in seven days compared to the full payload released in 24 h by the AFL solution. Future ocular in vivo studies are needed to confirm the biological effects of the NPs. Preliminary studies of the proposed aflibercept NPs demonstrated high encapsulation efficiency, a sustained drug release profile, and ideal physical characteristics for AMD treatment. This drug delivery system is an excellent candidate for further characterization using an ocular neovascularization in vivo model