A study on the risk factors for the reoperation rate in strabismus surgeries in Eskisehir

Reoperation may be necessary after strabismus surgery. Although different variables have been studied as predispoding to a reoperation, there is no consensus in this issue. In this study, in addition to previously studied parameters, it was aimed to investigate the effects of accommodative convergence/accommodation (AC/A) ratio, near convergence point (NPC), forced duction positivity and optical biometry on reoperation rates in strabismus surgery.

Data of patients between 2010 and 2021 with minimum follow-up of 12 months were retrospectively reviewed. The study group (Group 1) included 77 patients who underwent surgery for strabismus for a second time, and the control group (Group 2) included 75 patients. Patients' surgical outcomes with a deviation of less than 10 prism diopters (PD) were defined as successful. Sex, family history of strabismus, presence of neurological comorbidities, follow-up time, spherical equivalent values, visual acuity, amblyopia, ocular rotations, preoperative and postoperative distance angles of deviation, asymmetric/symmetric surgery, diplopia, fixation preference, AC/A, NPC, stereopsis, forced duction test positivity and ocular biometry values were evaluated.

Asymmetric surgery, fixation preference, younger age at first surgery, shorter follow-up time, greater preoperative angle of deviation, a more distant NPC and greater lens thickness were found to be statistically significant predictors of reoperation (p < .05). There was no statistically significant difference in AC/A values (p = .92) and forced duction test positivity (p = 1) between the reoperation and control groups. Although amblyopia was more common in the reoperation group than in the control group, the difference was not statistically significant (p = .08).

Asymmetric surgery, fixation preference, younger age at first surgery, shorter follow-up time, greater preoperative angle of deviation, a more distant NPC and greater lens thickness were found to be statistically significant for reoperation. In this study, convergence insufficiency was more frequent in the reoperation group. There may have been an increase in lens thickness to increase convergence in this group. Also, as optical biometric data changes with age, this may have affected the data results. Accordingly, it would be appropriate to investigate the parameters we studied with larger case series.