Effect of refractive surgery on binocular vision and ocular alignment in patients with manifest or intermittent strabismus.

OBJECTIVE: To evaluate the effect of refractive surgery on binocular vision and ocular alignment in patients with manifest or intermittent strabismus, with or without vertical component.

SETTING: University Hospital Antwerp, Edegem, Belgium.

PATIENTS AND METHODS: 13 patients (22 eyes) with strabismus underwent refractive surgery. Five of these patients presented with an esotropia and four of them with a small vertical deviation. Five patients had a manifest exotropia, of whom two presented with a small vertical deviation. Two patients had an intermittent exotropia with binocular vision, of whom one patient had a vertical deviation. One patient had a hypertropia with a dissociated vertical deviation.

RESULTS: Ocular alignment and binocular function remained unchanged postoperatively in all except two patients with high anisometropia who experienced an improvement in binocular function. In these patients, the preoperative manifest deviation became intermittent or latent after surgery, allowing fusion and stereopsis. Vertical deviation was found preoperatively in 8 of the 13 patients. This vertical deviation remained unchanged postoperatively, but improved in one patient with anisometropia.

CONCLUSION: Preoperative intermittent or manifest strabismus is not a contraindication for refractive surgery provided some specific recommendations are taken into account, such as an adequate preoperative orthoptic examination and aiming at emmetropia for both eyes.