ABSTRACT
Background The alteration of dominance eye is associated with visual quality in patients with age-related cataract or after cataract-surgery.However,the study on the relationship of dominance eye shift with vision following cataract-surgery is lack.Objective This study was to observe the influence of age-related cataract and cataract surgery on ocular dominance in the elderly.Methods A serial cases-observational study was designed.Eighty-seven patients with age-related cataract were collected from December 2011 to April 2012 in Affiliated Eye Hospital of Wenzhou Medical University,and phacoemulsification combined with intraocular lens (IOL) implantation was performed in all the patients.The patients were grouped into binocular vision difference (best corrected distance vision) ≥2 lines group (42 patients) and ≤ 1 line group (45 patients) on the standard logarithmic visual acuity chart.The frequency and shift of dominant eye were determined by card-hole method or thumb method before operation and 1 day,1 week,1 month and 3 months after operation.The difference in the frequencies of dominant eye between before and after operation was analyzed with MecNmar test.Results The median of best corrected distance vision (LogMAR) was 0.40 (0.00-1.40) in preoperation and 0.00 (-0.08-0.30) in postoperation,with significant difference between them (Z=-9.481,P =0.000).In the binocular vision difference ≥ 2 lines group,the dominant eyes were 24 in the right eyes and 18 in the left eyes.The milder cataractous eyes were identified as dominant eyes in 33 (78.57％) patients and heavier cataractous eyes were determined as dominant eyes in 9 (21.43％) patients before operation.However,the right eye was evidenced as dominant eye in 31 patients and the left eye was in 11 patients after operation.In the 42 patients,dominant eye shifted from the left eyes to the right eyes in 10 patients and from the right eyes to the left eyes in 3 patients,and 4 patients presented an unstable change binocularly.In 45 patients of the binocular vision difference ≤ 1 line group,the dominant eyes were the right eyes in 27 patients and the left eyes in 18 eyes in preoperation ; while after operation,dominant eye altered form the left eyes to the right eyes in 3 patients and form the right eyes to the left eyes in 1 patient,and unstable change occurred in 5 patients.There were no significant differences in the frequency of dominant eyes between before and after operation both the two groups (group A:P =0.092 ; group B:P =0.727).Conclusions Age-related cataract impact on eye dominance.Dominance eye may occur alteration binocularly following cataract surgery,which is one of causes of visual discomfort.