Functional activity of the retina before and after IOP normalization in glaucoma

Abstract

Abstract Purpose To study dynamics of bioelectrical activity of the retina before and after normalization of intraocular pressure (IOP) in primary open angle glaucoma (POAG). Methods 20 normal subjects and 68 patients with different stages of glaucoma (early–I, advanced – II, late – III) and high level of IOP were included in our study. IOP ranged from 27 to 36 mmHg. All patients underwent complete eye examination, HRT II imaging, ERG including full‐field, flicker, pattern ERG (PERG), oscillatory potentials (OP), long‐duration flash ERG, chromatic macular ERG to red, green and blue stimuli (MBN, Russia). Results Different decrease of ERG amplitudes were detected depending on the stage of POAG. Subnormal flicker, as well as subnormal macular ERG to red and green stimuli, diminished or unrecordable off‐response were observed in all stages of POAG with increased IOP. A pathological configuration and decreased amplitudes of OPs, prolonged N95‐component of PERG and subnormal full‐field ERG was revealed in advanced and late stages of glaucoma. After reduction of IOP significant increase of amplitude values and shortening of implicit time (IT) were observed in early and advanced stages of POAG (p≤0,05), whereas those in late stage of POAG showed slight positive dynamics. Conclusion ERG symptoms in POAG have high value for assessment the functional state of the retina and optic nerve, determination of degree of IOP normalization and must be used in treatment control.