Intraocular Pressure Lowering Is Associated with an Increase in the Photopic Negative Response (PhNR) Amplitude in Glaucoma and Ocular Hypertensive Eyes

摘要

Purpose.: The aim of our study was to determine whether IOP lowering in glaucomatous and ocular hypertensive (OHT) eyes leads to an improvement in the full-field photopic negative response (PhNR) of the electroretinogram. Methods.: A prospective nonrandomized interventional cohort study was conducted. Patients with OHT or glaucomatous optic neuropathy were recruited, and photopic full-field electroretinograms (ERG) were performed at baseline and then repeated 1 to 2 months later. The change in PhNR amplitude was compared between those eyes that had a significant lowering in IOP (defined as 25% decrease from baseline or to a predetermined target IOP) during follow-up and those that did not. Results.: From a cohort of 30 eyes, 18 eyes had a significant reduction in IOP during follow-up (n = 18) and 12 eyes had no significant change in IOP (25% reduction in IOP, n = 12). A significant increase in PhNR amplitude and the PhNR/b-wave amplitude ratios was observed in the reduced IOP group, but not in the IOP stable group for the two flash intensities used (2.25 and 3.00 cd.s/m2). Conclusions.: The full-field PhNR amplitude provides a potentially reversible measure of inner retinal function that improves after IOP lowering. Further study now is required to assess its use as a measure of optic nerve health in glaucoma patients.