Abstract
Abstract: :
Purpose: To investigate the relationship between pattern electroretinogram (PERG) amplitudes, optic disc topography, and retinal nerve fiber layer thickness in early glaucoma and normal eyes. Methods: Early glaucoma group included 45 eyes (defined by standard automated perimetry, SAP–SITA, and/or appearance of the optic nerve head) from 32 African–American (AA) and 12 Caucasian (C). Control group included 45 eyes from age–matched normal controls (23 AA, 23 C). Visual function was assessed with SAP–SITA. Optic nerve head appearance was assessed with simultaneous stereophotographs by two independent masked graders. Optic disc topography was measured with confocal scanning laser ophthalmoscope (HRT II). Retinal thickness (RT) was measured with OCT–3 (Fast Macular). Retinal nerve fiber layer thickness (RNFLt) was measured with (OCT–3 fast RNFL) and with GDX VCC. Transient response (P50 and N95) and steady–state (SS) response of the PERG was recorded following ISCEV standards. One eye selected randomly from each participant was included in the analysis. Results: Significant differences were found between normal and glaucoma eyes in the Mean Deviation and Pattern Standard Deviation (SAP–SITA), all the HRT parameters, retinal and RNFL thickness parameters (OCT–3 and GDX), and PERG amplitudes of P50, N95, and SS (p<0.005). Regression analysis showed a significant relationship between the PERG amplitudes and the following parameters:
*Adjusted for age, +adjusted for disc area, significant parameters (p<0.005) are in bold. Conclusions: In the present study of early glaucoma our initial results show a weak, but significant relationship between the PERG amplitudes and the optic disc topography. A stronger relationship was observed between PERG amplitudes and the RNFL measurements by both instruments. No significant relationship was found between RT and PERG amplitudes.
Keywords: electrophysiology: clinical • optic disc • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)