Result Analysis According to Surgical Amout after Unilateral Lateral Rectus Recession in Patients with Exodeviation under 25PD

Purpose: Study by result analysis the proper recession amount according to the deviation angle after unilateral lateral rectus recession in exodeviation. Methods: A retrospective analysis data from 139 patients who underwent unilateral lateral rectus recession with 15～24PD exodeviation and monitored for 12 months or longer was performed. The analyzed patients were divided into 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm groups according to the surgical amount of recession and 15～18PD, 19～20PD, 21～24PD groups according to the deviation angle. The strabismus surgery and results analyses were based on distance deviation. Alignment within 4PD of esodeviation and 10PD of exodeviation was considered a surgical success. Results: The success rates were 53.8% for the 15～18PD group and 40% for the 19～20PD group in the 7.5 mm recession group, 77.7% for the 15～18PD group and 66.7% for the 19～20PD group and 63.6% for the 21～24PD group in the 8 mm recession group, 100% for the 15～18PD group and 81.2% for the 19～20PD group and 72.7% for the 21～24PD group in the 8.5 mm recession group, 83.3% for the 15～18PD group and 85.7% for the 19～20PD group and 83.3% for the 21～24PD group in the 9 mm recession group, 100% for the 19～20PD group and 76.9% for the 21～24PD group in the 9.5 mm recession group at 1 year postoperative. The rates of -1 abduction limitation were respectively 3.1%, 12% and 21.4% in the 8.5 mm, 9 mm and 9.5 mm recession groups and the rate of -2 abduction limitation was 14.3% in the 9.5 mm recession group at 1 year postoperative. Conclusions: Considering the success state and abduction limitaions, the proper surgical amount of recession is 8.5 mm in the 15～18PD group and 9 mm in the 19～20PD and 21～24PD groups.