Comparison of binocular vision parameters pre-and post-epilasik laser vision correction surgery for myopia in a pilot study – can vision therapy augment refractive results?

Abstract

Purpose: To analyze the changes in the binocular vision parameters after bilateral Epilasik laser vision correction surgery (LVCS). Setting: Medical Research Foundation, Tamil Nadu, India. Study design: Prospective cohort study. Methods: Subjects with a best corrected visual acuity of ≤ 0.0 Log MAR scale and refractive error: < 6.00DS of myopia, < 0.75D of astigmatism, and < 1D of anisometropia were included in the study. All subjects underwent a comprehensive eye examination, LVCS workup which included corneal topography, tomography, aberrometry, and dry eye assessment prior to binocular vision assessment. Complete Binocular vision assessment which included stereopsis, fusion for distance and near, near point of convergence, phoria measurement, vergence amplitudes and facility, accommodative amplitudes, response, and facility was performed with the best corrected vision prior to LVCS, one month and six months after the surgery. Results: Twenty-five subjects of age 23.8 ± 2.9 years were included. Age ranged from 20 to 32 years. Ten were female and 15 were male. The median spherical power was –2.00DS with an inter quartile range (IQR) of –1.50DS to –3.00DS for both eyes. The median cylindrical power was plano with IQR –0.50DC to –1.00DC for both eyes. There was a statistically significant decrease in monocular and binocular accommodative amplitudes (accounting for age-related changes) as well as positive fusional vergence recovery for near between baseline and one month after surgery (p < 0.05). Conclusion: Though subjects were asymptomatic post LVCS, still there is an indication that myopic LVCS could precipitate or aggravate an existing non-strabismic binocular vision anomaly. Comprehensive binocular vision assessment and appropriate management is recommended before and after LVCS.