Changes in Accommodation and Binocular Vision Change after Excimer Laser Photorefractive Keratectomy

ABSTRACT

Many patients complain of near vision difficulty after PRK surgery. In the prospective study, we report the effect of PRK surgery for myopia on accommodation and binocular vision. 45 myopic eyes (39 patients, 9 males, 30 females) underwent PRK for myopia. Mean preoperative amplitude of accommodation in moderate degree myopia (group 1 -6.00D in spherical equivalent range -6.10 ~ -10.75D) was 6.85+/-1.41D. Mean postoperative amplitude of accommodation of group 1 was 8.13+/-1.38D, mean postoperative amplitude of accommodation of group 2 was 7.80+/-1.33D, the difference of both groups were statistically significant(p>0.05). Mean preoperative amplitude of accommodation of all patients was 6.91+/-1.35D, mean postoperative amplitude of accommodation was 7.93+/-1.36D, the difference are statistically significant (p>0.01). 12 of 39 patients complained of near vision difficulty while reading after PRK surgery on their one eye, but 3 of them who underwent PRK surgery on their the other eye noticed the disappearance of near vision difficulty. Stereopsis was tested and 15 of 36 patient lost more than 50 sec/arc of streoacuity. Near vision difficulty was not related to the amount of myopia corrected, not related to the stereoacuity change but seemed to related to their adaptability or their reaction time of accommodation with their operated eyes.