Background: Multifocal electroretinogram (mfERG) is a device for recording the physiological response of multiple retinal areas in short time. Using this technique enables us to detect the spatial extent and severity of the retinal damage. Objectives: In this study,we aimed to assess the topographic properties of mfERG in normal subjects to use it as a basic data to evaluate eye disease. Methods: We recorded mfERG from 20 eyes of 20 normal subjects. We measured amplitude and latency of recorded waves. We compared between amplitude of these waves between different retinal areas and the same for latency. Results: We found mfERG responses in the form of waves, every wave consists of negative wave (N1) followed by positive wave (P1). The amplitude of N1 wave and amplitude of P1 were largest at the fovea and decreased toward periphery. The latency of N1 and P1 were shorter in upper retina than lower retina. The N1 amplitude and P1 amplitude was larger in upper retina than lower retina, which reflex functional superiority of upper retina. There was no statistical difference between nasal and temporal retina in the amplitude and latency.Conclusion: Multi-focal ERG would be useful for objective examination of the retinal function.

Aim of the work:This study aimed to assess the effect of Panretinal photocoagulation (PRP) on the peripapillary Retinal Nerve Fiber (RNFL) thickness in diabetic patients using Optical Coherence Tomography Angiography. Methods: A prospective study was conducted on 100 eyes of 62 patients who had severe non-proliferative (SNPDR) or proliferative diabetic retinopathy (PDR) and underwent PRP treatment. The study population underwent 4.5×4.5 MM scans centered on the optic nerve head using Optical Coherence Tomography Angiography (OCTA) (RTVue XR Avanti Optovue, Fremont, CA) for measuring the peripapillary RNFL thickness before and after PRP by 2 months and 6 months. Results: Mean age of the study population was 49.85± 8.26 years (25-64 years). There was a significant increase in thickness of the nasal, temporal, superior and inferior peripapillary RNFL from baseline to 2 months post-PRP (all P value <0.05) and then decreased significantly from 2 months to 6 months (all P value <0.05). However, the thickness decreased significantly to amount less than baseline after 6 months for superior and inferior quadrants (P value <0.05) and decreased insignificantly for nasal and temporal quadrants (P value > 0.05). Conclusions: Peripapillary RNFL thickness at 6 months has decreased post-PRP, suggesting that PRP had neuronal insult.