Risk factors affecting the visual outcome in patients with indirect traumatic optic neuropathy

To evaluate the etiology and possible prognostic factors affecting the visual outcome in patients with indirect traumatic optic neuropathy (TON). The records of patients with indirect TON were reviewed and compared the results of treatment with high doses of corticosteroids (Group 1) and simple observation without treatment (Group 2). The mean age at the time of injury was 34.7 +/- 11.4 (18-58) years in Group 1 and 37.5 +/- 17.7 (8-73) years in Group 2 (p = 0.513). The mean value for the first referral of the patient to the ophthalmology clinic following trauma was 2.4 +/- 2.4 (1-10) days in Group 1 and 16.7 +/- 13.9 (1-30) days in Group 2 (p = 0.004). The most common causes of trauma were road traffic collision (57.1 and 68%) in the Group 1 and 2, respectively (p = 0.606). The mean initial visual acuity was 0.03 +/- 0.07 (0.00-0.30) in Group 1 and 0.17 +/- 0.21 (0.00-0.80) decimal in Group 2 patients (p = 0.001). The mean visual acuity at the final follow-up was 0.21 +/- 0.35 (0.00-1.00) and 0.46 +/- 0.42 (0.00-1.00) in Group 1 and Group 2, respectively, indicating better initial and final visual acuity values in Group 2 (p = 0.022), and also a statistically significant recovery of visual acuity between initial and final values in both groups (p < 0.05). The most important determinant of the final visual acuity was initial visual acuity (p < 0.001; 95.0% CI: 0.792-2.096). Our study demonstrated that road traffic collision is the leading cause of indirect traumatic optic neuropathy, and the best predictor of final visual acuity outcome is the initial visual acuity.