Abstract
Purpose :
Intravitreal injections acutely and temporarily increase intraocular pressure (IOP), and cumulative long-term effects may include increased risk for glaucoma surgery. We performed a prospective, observational clinical study to study macular and peripapillary changes in perfusion density and macular thickness that occur post-injection using optical coherence tomography (OCT) angiography. We hypothesized that perfusion density and thickness would acutely decrease with IOP changes associated with intravitreal injections.
Methods :
40 eyes of 39 patients receiving intravitreal injections for diabetic retinopathy, retinal vein occlusion, macular degeneration, and radiation retinopathy were included. Consecutive patients over age 18, with vision >20/100, able to fixate, and without media opacities precluding OCT-A were studied. Each received intravitreal bevacizumab or aflibercept and had 3x3 macular and 4.5 x 4.5mm peripapillary OCT-A measurements of perfusion density and macular thickness before and immediately after injection. Tonopen IOP was also measured pre- and post-injection. Regression analysis for potential effects of baseline IOP, IOP change, and age was performed.
Results :
Statistically significant decreases in angiographic perfusion density (p<0.05) were found in most areas of the superficial and deep macula, and the optic nerve head and the RPC, preferentially temporal aspects. Macular OCT thickness was significantly decreased nasally and temporally. Regression analysis showed relationships between age and decreased superficial macular perfusion only. Pre-injection IOP was not related to perfusion density, and was only related to OCT thickness in the fovea. IOP change was related to decreased superficial macular perfusion density only.
Conclusions :
Intravitreal injections produce acute IOP changes and affect macular and peripapillary perfusion density. Therefore, it is possible that patients receiving intravitreal injections are sustaining perfusion-related injury to ocular structures that may produce glaucomatous damage to the optic nerve and macula. Given the peripapillary changes, it may be prudent to follow these patients with serial perfusion scans, RNFL measurements, and visual fields to assess the effects of our intravitreal injections. Temporal peripapillary changes may be most prominent based on acute perfusion changes.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.