A comparative study of strabismus surgery with retained or removed scleral explant after retinal detachment surgery

Purpose To compare, in a larger study population, the outcomes of strabismus surgery in patients who either had the scleral explant (EX) retained or removed after surgery for retinal detachment. Methods A comparative retrospective study includes data from 2 centres. Surgical outcome, motor success, sensory success, the number of secondary operations for strabismus and complications were compared between the two groups. Motor success was defined as horizontal deviation of ≤6 prism diopters (PD) and vertical deviation of ≤6PD. Sensory success was defined as no diplopia without use of prism. Results Forty-seven patients were included in the study; 70% had retained the EX and 74% had vertical strabismus. Horizontally, the final alignment was equal between the 2 groups, 4 PD vs.5 PD in the EX removed group. The patients with retained EX were referred with a significant lower mean vertical deviation and had a significant lower post-operative mean vertical deviation of 2 PD vs. 3 PD in the EX-removed group. The rates of motor success (76% vs. 71%) and sensory success (79% vs. 93%) did not differ significantly between the EX-retained and EX-removed groups. No patients underwent more than 2 operations. Two complications occurred in the EX-retained group: a subconjunctival cyst and an exposed EX. In the EX-removed group, 2 patients with retinal re-detachment were found in the follow-up period. Conclusion Good surgical outcomes including high motor and sensory success were obtained regardless of the presence of the EX. Retinal re-detachment was observed in two patients with previously removed EX.