Purpose. To determine the changes of amplitude of accommodation (AA) and facility of accommodation (FA) in myopic patients after photorefractive keratectomy (PRK).
Methods. Using Technolas 217Z excimer laser, 160 myopic eyes of 80 patients underwent PRK. The patients were categorized into two age groups: <30 and ≥30 years. Changes in AA and FA were observed before PRK and at 2 weeks, 1 month, and 3 months after PRK. The role of preoperative AA, FA, refractive spherical equivalent, age, and sex on postoperative AA and FA was evaluated.
Results. In younger patients, the preoperative AA and FA values 7.77 ± 1.75 D and 7.75 ± 3.97 cpm changed to 8.36 ± 1.26 D and 11.57 ± 4.20 cpm (p < 0.001), respectively, at 3 months after PRK. In older patients, the preoperative AA and FA values 6.66 ± 1.41 D and 5.05 ± 3.26 cpm changed to 6.72 ± 1.26 D (p = 1.000) and 9.58 ± 4.29 cpm (p < 0.001), respectively. Two weeks after surgery, preoperative AA and spherical equivalent had a significant effect on postoperative AA, whereas preoperative AA and age had a significant effect on postoperative AA after 3 months (p < 0.001). Postoperative FA was positively related to preoperative FA and female sex (p < 0.05).
Conclusions. This study suggests that some of the near-vision problems in younger myopes in early postoperative days after PRK might be due to decrease in AA and FA, which will eventually increase. However, in older patients, despite increase in FA, AA did not change.
Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran (FK, AB-R, AB, HB, SA), School of Medicine, Tehran University of Medical Sciences, Tehran, Iran (ME), Department of Public Health, Tehran University of Medical Sciences, Tehran, Iran (MY), and Department of Optometry, Shahid Beheshti University of Medical Sciences, Tehran, Iran (AA-S).
Received May 20, 2010; accepted July 23, 2010.
Farid Karimian; Ophthalmic Research Center; #23 Paidar Fard Street; Boostan 9 Street, Pasdaran Avenue; Tehran 16666, Iran; e-mail: firstname.lastname@example.org