Clinical Spectrum of Indirect Traumatic Optic Neuropathy in South Indian Subjects Observational Study

Abstract

Purpose: To report the aetiology, visual outcome, and clinical features of indirect traumatic Optic Neuropathy (TON) patients from the tertiary eye care center in South India. Methods: It is a retrospective and observational study. Details of age, gender, number of days of presentation after injury, Snellen visual acuity at presentation and last follow-up, visual evoked potentials, visual field findings using the Humphrey visual field analyser, associated ocular complications, and mode and time of treatment were obtained from the medical records of all indirect TON patients. Results: Indirect TON patients are mainly young males (94%) and road traffic accident (RTA) (65%) is the main cause of TON, followed by falls (19%) and sport-related activities (11%). Visual acuity loss was severe in more than 50% of the subjects and only 16%% of the patients showed improvement in visual acuity greater than one line. Pattern visual evoked potentials and visual fields are recordable only in 15% of the subjects. Commonly associated ocular complications in indirect TON patients were orbital fracture (43%), lid tear (16%), sub-conjunctival haemorrhage (13.5%), and angle recession (13.5%). Three out of four patients who received methylprednisolone and oral steroids within a week showed an improvement in visual acuity of greater than three lines, while just one patient out of four who received the same medication after a week improved visual acuity of three lines. Conclusion: RTA (road traffic accidents) is the most common cause of indirect TON and mainly young males were the affected individuals. IVMP along with oral steroids within a week, would help TON patients for reasonable visual recovery. Presenting Visual acuity of > 6/600 and recordable pattern VEPs would be the prognostic factors for good visual outcomes in indirect TON patients.