Indirect traumatic optic neuropathy--visual outcome of operative and nonoperative cases.

From 1968 through 1984, 110 cases (113 eyes) with indirect traumatic optic neuropathy were seen at the Department of Ophthalmology and Otorhinolaryngology of the Kobe University Hospital; 43 eyes were treated nonsurgically with steroid and 70 eyes were operated on by the endonasal-transethmoidal method of optic canal decompression. By comparison of the visual improvements in the two groups, the effectiveness of the surgical treatment was evaluated. In the nonsurgical group, 19 eyes showed a visual improvement, giving an overall improvement rate of 44.2%. In 9 eyes with complete visual loss at the initial visit no visual improvement could be seen. In 34 eyes with the vision better than light perception at the initial visit, vision improved in 19 eyes, ie, the improvement rate was 55.9%: the recovery occurred relatively rapidly within 3-4 weeks, and thereafter the condition remained unchanged. In 30 eyes treated within 3 weeks after trauma, 17 eyes (57%) showed visual improvement, but in 13 eyes where treatment started after 3 weeks, improvement was seen only in 15%. In the surgical group, 34 eyes showed a visual improvement; the overall rate of improvement was 47.7%. In 28 eyes where complete visual loss was seen at the first visit, 7 eyes showed visual improvement. In 38 eyes treated within 3 weeks after trauma, 18 eyes (45%) showed visual improvement, and in 32 eyes where the surgery was performed after 3 weeks, 16 eyes (50%) showed improvement. The latter improvement rate was significantly higher (P less than 0.05) than the improvement rate of 15% found in eyes of the nonsurgical group, where the treatment started 3 weeks after trauma. In cases with indirect traumatic optic neuropathy, surgical decompression of the optic canal can give a visual improvement even when complete visual loss is found in the early period. The surgery is effective in cases where visual recovery by conservative treatment is not satisfactory after 3 weeks. On this basis the criteria for surgical treatment were determined: when the vision is better than light perception in the early period, conservative treatment must first be given, but surgery is indicated when the vision does not improve to 0.5 or better within 3 weeks. In cases where complete visual loss is found soon after injury, earliest possible surgical intervention is recommended.