Ethiology, Clinical Features and Therapeutic Outcomes of Sensory Strabismus

To evaluate demographic and ocular features, etiologies and outcomes of surgery in patients with sensory strabismus as well as to detect factors influencing the type of deviation and outcomes. One hundred and seventy-seven patients with strabismus related to low vision included in this interventional case series. Data related to demographic features, visual acuity, refraction, etiologies of low vision, age at the time of visual loss and age of deviation onset, type and amount of deviation, type of surgery and its outcomes after 2 months and at the last follow up visit was collected from the patients’ records. The association between ocular parameters and the direction of deviation and results of surgery was investigated. The mean patient age was 24.4±11.4 years and 110 (62%) patients were male. The mean follow up period was 30 months. One hundred and seventeen (66.1%) patients were exotropic and 60 (33.9%) patients were esotropic (P=0.035). The mean age at the time of visual loss in the esotropic group was lower than that in the exotropic group (5.8±7.2 vs. 11.1±9.7 years, P=0.001). The main causes of visual loss in the esotropic and exotropic patients were congenital and acquired, respectively (P<0.001). The most common congenital etiologies were anisometropia and cataract whereas, the most common acquired cause was trauma. The most common refractive error was hyperopia in the esotropic patients and myopia myopia in the exotropic patients (P=0.01). The mean axial length of the normal fellow eye was significantly shorter in the esotropic patients (22.18±1.24 vs. 23.15±1.77 mm, P=0.001). At the last examination, 69% of patients were orthophoric. Overcorrection and undercorrection more than 20 PD were observed in 4.6% of patients. The success of the surgery correlated significantly with the preoperative amount of deviation (P=0.003) and visual acuity (P=0.026) The most common type of deviation in sensory strabismus is exotropia and its most common cause is ocular trauma. Exotropic patients are predominantly myopic with higher axial lengths in comparison with esotropic patients. Outcomes of surgery in sensory strabismus are acceptable. Preoperative amount of deviation and visual acuity of the deviated eyes were two important factors influencing final outcomes.