A clinical, electrophysiological and radiological study of optic neuropathies in Northeast India: hospital-based study

Background and aims: Optic neuropathy refers to disease of the optic nerve which can present in isolation and/or in association with other neurological or systemic diseases. The present study has been undertaken to study the clinical, electrophysiological and radiological features of various optic neuropathies. Materials and methods: This is a prospective observational study and conducted from August 2015 to July 2017 at Gauhati Medical College, Guwahati. Detailed neurological evaluations along with investigation were done in all patients. Results: A Total of 112 patients were included among which 57(50.9%) were male and 55(49.1%) were female. Mean age and duration of symptoms was 35.44 years& 2.06±0.97 weeks respectively. Out of 112 patients, bilateral involvement was noted in 57(50.9%) and unilateral in 55(49.1%), so, total 169 abnormal eyes and 55 normal eyes were examined. Associated ocular symptoms were ocular pain, colour vision defect, subjective contrast sensitivity and relative afferent pupillary defect. On fundoscopy; patients were grouped into involvement of optic disc (IOOD/Papillitis), retrobulbar and neuroretinitis on the basis of affected part of optic nerve. Relevant positive findings were aquaporin-4 IgG antibody, Angiotensin converting enzyme, Antinuclear Antibody with reactive VDRL, Toxoplasma serology, anti hepatitis C virus, leptospira serology and low serum vitamin B12 level. VEP, OCT, CSF and neuro imaging study were done in all patients. Patients were further classified etiologywise among which demyelinating patients’ group (MS, NMOSD and AIDON), i.e., 65(58.03%) was major group. Other etiologies included ischemic, Neurosarcoidosis, toxic and others. Conclusion: The differential diagnosis of optic neuropathy is extensive and apart from demyelination, other causes like ischemic, nutritional, toxic, infective and autoimmune should be considered. All patients need long term follow up.