Esotropia Induced by Optical Correction in Myopic Patients

To describe a specific pattern of esotropia observed in myopic patients occurring exclusively while wearing refractive correction despite a normal accommodative convergence / accommodation (AC/A) ratio and to evaluate the efficacy of its management.

This is a retrospective study which included children and young adults with high myopia who presented with esotropia with spectacles or contact lenses correction only, and orthophoria or near orthophoria without optical correction. AC/A ratio was measured using gradient method. Ductions and versions were evaluated. The angles of deviations were measured with and without optical correction, for both distance and near. Magnetic resonance imaging of the extraocular muscles was performed. The target angle for surgical correction was the preoperative angle of esotropia at distance with spectacle correction, and the changes in the angles of deviation after surgery were evaluated.

Nine patients were identified. The mean age at presentation was 13.6 ± 5.2 years; 6 patients were females (66.7%). The mean angle of esotropia with optical correction was 44 ± 5 PD for distance and 43 ± 4 PD for near. The mean angle of esotropia for near without optical correction was 4 ± 3 PD. Mean spherical equivalent was -10.6 ± 1.8 Diopters. All patients underwent bilateral medial rectus muscle recession. Mean medial muscle recession was 6.9 ± 0.4 mm. Mean follow up was 8 ± 4 months. Successful outcome was achieved in 8 patients, one patient had residual esotropia of 25 PD. None of the patients developed exotropia without glasses after surgery.

Esotropia in myopic patients may appear only with optical correction, including glasses or contact lenses. The exact cause of the absence of esotropia without optical correction cannot be confirmed but cannot be attributed to a high AC/A ratio. These patients benefit from bilateral medial rectus recession similar to those who have esotropia without optical correction, without carrying the risk of overcorrection without spectacles or contact lenses.