Pre-perimetric Optic Neuropathy

Abstract

We present a case of a 32-year-old male who came with the history of blurring of vision in both eyes. Diagnosed as a glaucoma suspect at another centre, he had a best corrected visual acuity (BCVA) of 20/20 in both eyes and there was no relative afferent pupillary defect (RAPD) in either eye. Intraocular pressure (IOP) was also normal in both eyes. Fundus examination revealed very subtle temporal pallor accompanied by reduced retinal nerve fibre layer (RNFL) striations in the papillomacular bundle (PMB) in both eyes. RNFL optical coherence tomography (OCT) demonstrated thinning of the RNFL in the temporal sector along with thinning of the ganglion cell complex (GCC) on the ganglion cell analysis, whilst his visual fields (24-2) were normal in both eyes. After all necessary laboratory investigations a diagnosis of vitamin B12 and folate deficiency with nutritional optic neuropathy was made and appropriate management was initiated. Hence, diligent clinical evaluation along with a high level of suspicion goes a long way in diagnosing these almost sub clinical cases with pre-perimetric optic neuropathy. Timely diagnosis and appropriate management can help to preserve vision and reverse changes in an otherwise preventable irreversible optic neuropathy.