Слабость конвергенции как причина астенопии после лазерных рефракционных операций

Abstract

Purpose. To evaluate the frequency of astenopia and effect of refractive surgery on muscle balance and accommodation in patients with convergence insufficiency (CI). Methods. This study prospectively evaluated 240 eyes (120 patients) with myopia. CI was found in 15 patients (12.5 %), 91 patients with normal binocular vision were included in control group. Accommodative amplitude and facility, positive and negative relative accommodation, binocular vision, near point of convergence (NPC), phoria measurement for near and distance, positive and negative fusion vergence, AC/A ratio were assessed, symptoms were measured by Convergence Symptom Survey (CISS) before, 1 month and 1 year after LASIK. Results. Asthenopia was found in 7.5 % of patients in 1 month after surgery. It was related with CI in 5 %. There was a statistically significant improvement of near exodeviation from 13.2±3.9 to 8.4±3.7 pd and of NPC from 12.2±2.7 to 8.3±2.3 сm which remained unchanged within 1 year. CISS score improved from 24.3±4.8 to 13.5±2.5 in 1 month after surgery and to 9.6±2.8 within 1 year. 1 patient had deterioration of exodeviation in 1 month. 6 patients needed in-office vergence/accommodative therapy after surgery. None of the patients in control group presented postoperative asthenopia, worsening in muscle balance and binocular vision. Conclusions. Laser refractive surgery does not cause asthenopia in patients with normal accommodation and vergence. CI is not a contraindication for refractive surgery, leading to a decrease in exodeviation. In cases of accurate fusion vergence lack, patients will experience asthenopia. In patients with CI it is necessary that positive fusion vergence exceed the exophoria by two times before surgery and overlap presbyopia addition which will be required in future. Key words: refractive surgery; asthenopia; convergence insufficiency.