Predictive value of the initial quantified relative afferent pupillary defect in 19 consecutive patients with traumatic optic neuropathy

Purpose: To study the predictive value of the initial quantified relative a fferent pupillary defect (RAPD) in patients with indirect traumatic neuropa thy as it relates to final visual outcome. Methods. The RAPD was measured and quantified by neutral density filters in patients with unilateral indirect traumatic neuropathy. All patients were treated with megadose methylprednisolone by of the protocol established by the Second National Acute Spinal Cord Injury Study. Patients were followed twice daily during treatment and then at 3-month intervals. Results. Nineteen patients were enrolled over a 23-month period. Patients r anged in age from 12 to 78 years old; 18 of the 19 patients were male, No p atient with an RAPD of 2.1 log units or greater had visual recovery to bett er than hand motion vision. The 7 patients with an initial RAPD of less tha n 2.1 log units showed improvement in their RAPD and were found to have vis ion of 20/30 or better during the follow-up period. Conclusions: In patients treated with megadose methylprednisolone with an i nitial RAPD of less than 2.1 log units, visual acuity improved to 20/30 or better; however, patients with an initial RAPD of 2.1 or greater showed lit tle visual improvement. The initial quantified RAPD appears to have a predi ctive value related to final visual outcome.