To evaluate efficacy and safety of minus lens therapy as a first-line treatment in children with intermittent exotropia.

In this retrospective case-series, children with intermittent exotropia who had received minus lens therapy for at least 6 months and had a minimum of 12-month follow-up were included. Visual acuity, refractive error, deviation angle, and the level of control in exotropia were recorded.

In total, 163 subjects met the inclusion criteria. The mean age was three years (range 1-6 years). Ninety-nine of the children were male (60.7%). The power of the lenses used ranged from -1.00 to -4.00 diopters. The mean treatment duration was 32.3 months and the mean follow-up time was 46.3 months. Mean angle of deviation at initial visit was 24.7 prism diopters (PD) that improved to 10.6 PD with the overminus lens treatment. In 69.3% of patients the final angle of deviation was less or equal of 10 PD. Sixty-eight (%42) patients with minus lens therapy had a good control score and did not require surgical intervention. Of the 92 (%56) patients who underwent surgery, failure in minus therapy termination in 44 individuals lead to surgery after an average time of 37.9 months despite a good control score. The rest of forty-eight patients with a poor control score had surgery after an average time of 25.3 months. Three remaining patients developed esotropia that disappeared after cessation of therapy. No significant association was found between the annual change in refractive error and lens power or treatment duration.

Minus lens therapy is a safe and viable option for initial management of intermittent exotropia in children with intermittent exotrpia.