Abstract
Purpose :
To evaluate the ability of the Pattern Electroretinogram (PERG) to detect retinal ganglion cell (RGC) function improvement in glaucoma suspects (GS) after medically reducing intraocular pressure (IOP) using prostaglandin analogue drops
Methods :
Six GS subjects (8 eyes), necessitating IOP lowering treatment based on their clinical examination, were observed at MEETH over an average of 12 months, during which they were tested with Diopsys NOVA PERG (Diopsys©, Inc. Pine Brook, NJ), and other clinical tests, at baseline and 3 months after the treatment was started (on average of 3.1 ± 2.2 months). One-way repeated measures ANOVA [Mag, MagD and MagD/Mag ratio (R)] were conducted as appropriate. This study was IRB approved and informed consent was signed by each subject.
Results :
One-way repeated measures ANOVA was conducted to determine whether there was a statistically significant difference in PERG parameters over the course of 3 months after treatment was started. There were no outliers and the data was normally distributed at each time point, as assessed by boxplot and Shapiro-Wilk test (p >0.05), respectively. The assumption of sphericity was met, as assessed by Mauchly’s test of sphericity. Over time, the treatment intervention did elicit statistically significant changes in magD (F (1, 7) = 10.076, p= 0.016, partial ω2 =0.590) and R (F (1, 7) = 10.455, p= 0.014, partial ω2 =0.599), with MagD and R increasing from pre-intervention (0.944± 0.44 and 0.71± 0.15) to 1.25± 0.36 and 0.82± 0.08, respectively. The intervention did elicit significant changes in IOP decreasing from 21.86± 2.1 to 16.86± 1.9 (22.8 % decrease)
Conclusions :
After reducing IOP by 22.8% for a duration on average of 3 months, PERG detected an improved RGC function, mostly by increased latency. More longitudinal studies are needed to evaluate the beneficial effects of early IOP reductions in slowing progression, and to assess the ability of PERG in monitoring treatment efficacy.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.