Dr.Pradeep Balam

Dr.Ajita Sasidharan, Dr.Mithun Thulasidas

Abstract

Case Report:A 33 year old,male patient has come for regular eye checkup.He had strong family history of glaucoma.BCVA 6/6,N6.IOP 12mm Hg RE,10 mm of Hg LE.Gonioscopy shows open angles in both eyes.Fundus shows optic disc ratio of 0.8 with superior notching and inferior NRR thinning in both eyes.Visual fields BE WNL.RNFL OCT AND GCC IPL COMPLEX BE WNL.PhNR ERG shows reduced PhNR amplitude wave and reduced P72/b wave ratio in RE.Discussion:PhNR is relatively slow negative wave that occurs after positive b-wave and is produced by ganglion cells. In early stages of glaucoma retinal ganglion cells axons are damaged locally which can be detected by PhNR ERG.When focal PhNR amplitude was abnormally reduced,the eyes were defined as glaucomatous.Conclusion:PhNR serves as added tool for identifying retinal ganglion cell activity in patients who are at risk of glaucoma.PhNR is useful imaging modality in pre-perimetric glaucomatous eyes when both RNFLOCT and visual fields fail to show any changes.