Pattern electroretinogram optimized for glaucoma screening (PERGLA) and retinal nerve fiber thickness in suspected glaucoma and ocular hypertension

Abstract

The purpose of this study is to evaluate pattern electroretinogram optimized for glaucoma screening (PERGLA) and retinal nerve fiber layer (RNFL) at spectral optical coherence tomography (OCT) in eyes with suspected glaucoma (GS) and in eyes with ocular hypertension (OHT). This is a cross-sectional, observational study. Twenty-four patients with GS (BCVA 20/20, normal visual field, intraocular pressure, IOP, less than 21 mmHg, and glaucomatous optic neuropathy, GON) and 14 patients with OHT (BCVA 20/20, intraocular pressure 25 mmHg, absence of glaucomatous optic neuropathy and normal visual field) were considered in this study. GON was intended as vertical cup-disk ratio of 0.5 or more; asymmetry of greater than 0.2, disk notching, disk splinter hemorrhages. PERGLA amplitude and phase were measured, while thickness of the RNFL was obtained with spectral OCT. A control group of 50 age-matched healthy patients was added. In the GS group, 16 eyes (66.7%) showed normal average RNFL analysis and normal PERGLA, 3 eyes (12.5%) showed abnormal average RNFL analysis and abnormal PERGLA, 5 eyes (20.8%) presented with normal average RNFL analysis and abnormal PERGLA. In the OHT group, 11 eyes (78.6%) showed an average normal RNFL and normal PERGLA, while 3 eyes (21.4%) presented with an average normal RNFL and abnormal PERGLA. PERGLA is a non-invasive, fast, and fully automatic version of the pattern ERG. In eyes with OHT and in eyes with GS, PERGLA abnormalities in presence of a normal RNFL could suggest an early functional damage of viable retinal ganglion cells.