Morphological and functional changes in the rat retina associated with 2 months of intermittent moderate intraocular pressure elevation

TitleMorphological and functional changes in the rat retina associated with 2 months of intermittent moderate intraocular pressure elevation
Publication TypeJournal Article
Year of Publication2018
AuthorsTan, B., A. Gurdita, V. Choh, K. Joos, R. Prasad, and K. Bizheva
JournalScientific Reports
Volume8
Pagination7727
Date PublishedMAY 16
ISBN Number2045-2322
Abstract

Morphological and functional changes in the rat retina and optic nerve head (ONH), associated with 8 weeks of intermittent moderately elevated intraocular pressure (IOP) were measured with a combined ultrahigh resolution optical coherence tomography (UHR-OCT) and electroretinography (ERG) system. The IOP of male Sprague-Dawley rats was raised in one eye to similar to 35 mmHg for 1 hour/day on 6 days each week using vascular loops. Single-flash ERG traces and volumetric UHR-OCT images of the ONH were acquired from both eyes before, during and after IOP elevations at weeks 1, 5 and 9 of the study. The UHR-OCT images showed depression of the posterior eye around the ONH during the IOP elevations, the magnitude of which increased significantly from week 1 to week 9 (p = 0.01). The ERG a-wave and b-wave amplitudes increased temporarily during IOP elevations and returned to normal similar to 30 minutes after loop removal. Recurrent intermittent IOP spikes caused >30% decrease in the ERG a-wave and b-wave amplitudes measured during the IOP elevations over the course of 2 months. This study suggests that recurrent, relatively short-duration IOP spikes for extended period of time are associated with peri-ONH tissue hypercompliance and reduced retinal functional response to visual stimulation during acute IOP elevation.

DOI10.1038/s41598-018-25938-z