Abstract

Study design:Case report. Purpose:To present a unique case of ATT induced Toxic Optic Neuropathy (TON) .Methods:Thorough ocular examination done which included evaluation of both anterior and posterior segments.Required investigations like Fundus photo, Ishihara test, HVF 30-2,OCT RNFL, GCL,IPL , MRI Brain and Orbit were done for further evaluation. Results: Fundus photo confirmed mild temporal optic disc pallor in both eyes(OU) .Ishihara colour vision test showed normal response in OU. HVF 30-2 detected peripheral constriction of the field in OU. (pRNFL) in circular scan of optical coherence tomography showed focal thinning in OU with ganglion cell layer(GCL) and inner plexiform layer(IPL) thinning. MRI Brain and Orbit revealed microangiopathic changes in both cerebral hemispheres with diffuse cerebral atrophy and slight reduction in optic nerve calibre of OU.Conclusion:GCL-IPL thinning on OCT is now found to be more reliable imaging biomarker in comparison to pRNFL changes for TON.