Delayed optic nerve decompression for indirect optic nerve injury.

OBJECTIVE

To test the efficacy of delayed optic nerve decompression in traumatic optic nerve injury.

STUDY

DESIGN

Critical analysis of Proforma-based, prospectively accrued data of all cases with injury to surgery interval of greater than 2 weeks.

METHODS

Thirty-five cases with a median injury to surgery interval of 56 days (range, 16-374 d). Surgical decompression was undertaken only in cases that continued to have poor vision after treatment with steroids in conventional doses (1 mg/kg prednisolone). Pre- and postoperative visual acuity measurements were converted to the logMAR scale of visual acuity and the percentage of visual improvement was calculated.

RESULTS

Surgery was universally unrewarding in all 9 cases with persistent and complete blindness of greater than 2 weeks and no response to steroid therapy. Of the cases with some residual vision, 20 of 26 cases improved (mean percentage improvement, 41.0 +/- 5.7%). Cases were categorized on the basis of the injury to surgery interval into groups of 2 weeks to 2 months, 2 months to 4 months, and greater than 4 months. No significant difference was demonstrated in the probability or quantum of improvement in these groups (P =.97).

CONCLUSIONS

Optic nerve decompression remains useful as a salvage procedure for conventional dose steroid failed cases of traumatic optic neuropathy. In cases that are not completely blind, vision can be improved even when surgery is undertaken a few months after the injury.