Traumatic Optic Neuropathy: The Comparison of Visual Outcome by Treatment Modalities / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Traumatic optic neuropathy (TON) is a rare but potentially devastating complication of blunt head trauma. However, the optimal management for the TON is still an open question. In this report, we compared the visual outcome of TON treated with corticosteroids and optic nerve decompression (OND) with those treated with corticosteroids alone. PATIENTS AND METHODS: A total of 32 cases with TON due to blunt head trauma was followed over 6 months at the Chungnam National University Hospital. Twenty-two cases were treated with megadose corticosteroids and eleven cases were treated by surgical decompression of the optic canal combined with corticosteroids. For the purpose of analysis, visual acuity was converted into logMAR (logarithm of the minimum angle of resolution) units. Improvement was measured as the difference in visual acuity between the initial and final visual-acuity units (improvement in logMAR=post-treatment logMAR-initial logMAR). This value was then used to determine the percentage of improvement as the proportion of the visual acuity lost, using 20/13 (logMAR=0.18) as perfect vision (Improvement %=Improvement/{0.18-initial logMAR}). RESULTS: Patients whose initial vision was better than no light perception (NLP) showed better improvement rate (64%) compared with patients whose initial vision was NLP (17%). Vision improved in eight of the steroid-treated groups (38%) and in four of the steroid-OND groups (36%). There were also no significant differences in the improvement or the percentage of improvement in the visual acuity between two groups. CONCLUSION: As might have been expected, patients with initial NLP in both groups attained significantly lower final visual acuities than those who initially had some vision. However, there were no significant differences in the improvement or the percentage of improvement in the visual acuity between two groups. That is, no clear benefit was found for optic canal decompression surgery. But the limitation of this study was that it was difficult to conclude that surgical decompression is not necessary in the treatment of TON. A prospective randomized controlled clinical trial will be needed.