Isolated Visual Loss and Neurological Causes: A Hospital-Based Study

Abstract

Visual loss is a common presenting symptom in the Outpatient Departments of Neurology, Ophthalmology and General Medicine disciplines. The present prospective study aims at evaluating 48 patients with partial or total visual loss as the predominant or only presenting symptom and with no associated ocular problems like cataract, glaucoma or diabetic retinopathy. The neurological causes were identified, analysed and tabulated; 39% of patients were below 20 years of age and there was 3:2 ratio of female versus male prevalence. Nearly 66% had acute visual loss and 35% had chronic visual loss. Majority of patients (48%) had profound visual loss limited to finger counting; 6% had normal visual acuity associated with field defects. The visual evoked potentials were abnormal in all cases with acute and sub-acute presentation and in some patients with sudden or chronic presentation also. The VEP abnormalities consisted of prolonged P100 latencies, loss of amplitudes or poor wave morphology. Cranial CT scan was done in 36 patients and was abnormal in 83% patients. It showed intracranial tumours in 8% patients and infarcts in another 8% patients. Cranial MRI scan was done in 12 patients and was normal in 83% patients. The aetiological considerations and treatment protocols followed are discussed. The limitations of such study in the present setup are also highlighted.