Prognostic preoperative factors for successful outcome of surgery in horizontal strabismus.

CONTEXT

Surgery for horizontal strabismus reportedly has a success rate of 60%-80%. However, which preoperative factors are predictive of this success is not clear.

AIMS

To identify prognostic factors those are predictive of successful outcome in horizontal strabismus surgery.

SETTINGS AND DESIGN

Observational analytical study using multiple logistic regression (MLR).

SUBJECTS AND METHODS

We assessed the medical records of patients who had undergone first-time horizontal muscle strabismus surgery between 2002 and 2013, where complete follow-up data were available for ≥6 weeks, and also, we collected data prospectively on patients operated between January 2014 and September 2015. Successful outcome was defined as a postoperative angle of deviation within 10 prism diopter of orthophoria at ≥6 weeks postoperatively. Independent variables considered were age at onset, age at surgery, duration, gender, deviation - type and amount, logMAR visual acuity (VA) - mean and of the poorer eye, mean refractive error, amount of anisometropia, and presence of dense amblyopia. Only those with < 0.2 on univariate analyses (UAs) were included in the MLR, with significance set at ≤ 0.05.

STATISTICAL ANALYSES

UA (Chi-square for categorical variables and -tests for continuous variables), followed by logistic regression analysis.

RESULTS

Of 113 patients, on UA, type of deviation ( = 0.01), age at surgery ( = 0.16), absence of dense amblyopia ( = 0.002), and logMAR VA of the poorer eye ( = 0.005) qualified for the inclusion in MLR. On MLR, esotropia (ET) (odds ratio [OR]: 4.46) and absence of dense amblyopia (OR: 5.90) were associated with success.

CONCLUSIONS

With an overall success rate of 83%, ET and absence of dense amblyopia were significantly predictive of surgical success.