Comparison of patients with high and low preoperative corrected distance visual acuity undergoing trans-epithelial photorefractive keratectomy in terms of surgical outcomes

Session Details

Session Title: Refractive
Session Date/Time: Sunday 22/02/2015 | 08:30-11:00
Paper Time: 09:51
Venue: Sadirvan A
First Author: : S.Adib Moghaddam IRAN
Co Author(s): :    S. Soleyman-Jahi   F. Adili Aghdam           

Abstract Details


To compare optical objective indices in patients with preoperative corrected distance visual acuity above 10/10 and below 10/10


Bina Eye Hospital, Tehran, Iran


79 eyes (51 patients) with different refractive errors were recruited in a prospective study from July 2013 to September 2014. All of the cases underwent refined Trans-PRK by same expert refractive surgeon (S.A.M.) using SCHWIND AMARIS 500 laser (SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany). Visual acuity, refraction, CS and high order aberrations (HOA) were registered in pre-op and post-op visits . Patients were divided into two groups: preoperative CDVA ≤10/10 as low CDVA group and >10/10 as high CDVA group. Two sample t-test and Mann–Whitney U test, when appropriate, were used to compare different optical indices in two groups.


Mean age of LCG (48 eyes) was significantly higher(29.26±5.00vs26.45±3.74,P=0.006). F/M ratio was comparable in two groups and 2.7 in total. Post-op CDVA was comparable in two groups(1.22±0.23vs1.25±0.44,P = 0.7). Post-op UDVA was higher in HCG(1.31±0.37vs1.15±0.23,P =0.001). Pre-op mean manifest SE was more myopic in LCG(-4.41±2.02vs-3.28±1.41,P = 0.001) while post-op SE were comparable. Mean post-op photopic and mesopic contrast sensitivities were better in HCG; however mean improvement of contrast sensitivities were higher in LCG. Pre-op mean defocus and pentafoil aberrations were higher in LCG. After the operation they became comparable.


In patients with low pre-op CDVA, one-step refined TransPRK could improve CDVA and refraction so that these indices were comparable with high CDVA group after the operation. Additionally, this operation could notably improve photopic and mesopic contrast sensitivities as well as higher order aberrations in this group.

Financial Disclosure:


Back to previous