Week in review: Nanoparticles prevent graft rejection, COVID-19 and retinal vessels, genetics and glaucoma

A weekly roundup of ophthalmic news from around the web.

What if nanoparticles could reduce corneal graft rejections? That’s what Virginia Commonwealth University (VCU) researchers are hoping is the future of postsurgical topical eye drop delivery. A VCU-led team has published results of a study of subconjunctival injections embedded with nanoparticles containing dexamethasone sodium phosphate. In rats given corneal allografts, a single injection was able to prevent graft rejection for up to 6 months. The researchers are optimistic about the study results, writing that this delivery system could have “broad potential clinical impact.” Virginia Commonwealth University; Science Advances

Another COVID-19–related complication: retinal microvasculature loss. A cross-sectional study compared OCTA retinal images from 20 patients who recovered from COVID-19 infection with images from 11 never-infected controls, and found that mean retinal vessel density and average inner retinal volume were significantly lower in those who had severe infection than in the controls or those who had mild infection. These results mirror those from previous studies of retinal microvasculature post–COVID-19 infection. The authors note that while “retinal volume and vessel density loss of this magnitude may not cause significant visual symptoms.…this may be a biomarker for severe COVID or long COVID or COVID damage to the brain and other organs.” Scientific Reports

High genetic risk of glaucoma leads to greater visual field progression, according to data from genotyped participants with early glaucoma or glaucoma suspect enrolled in the PROGRESSA cohort study. Those with the highest polygenic risk scores (top 5%) for the most common single-gene primary open-angle glaucoma variant were 1.5 times more likely to develop visual field worsening than the other participants, and also were more likely to have faster rates of peripheral retinal nerve fiber layer thinning. JAMA Ophthalmology