Title of article :
Safety, Efficacy, Predictability and Stability Indices of Photorefractive Keratectomy for Correction of Myopic Astigmatism with Plano-Scan and Tissue-Saving Algorithms
Author/Authors :
Mohammadpour, Mehrdad Assistant Professor of Ophthalmology - Eye Research Center - Farabi Eye Hospital - Tehran University of Medical Sciences, Tehran , Hashemi, Hassan Professor of Ophthalmology - Eye Research Center - Farabi Eye Hospital - Tehran University of Medical Sciences, Tehran , Jabbarvand, Mahmoud Professor of Ophthalmology - Eye Research Center - Farabi Eye Hospital - Tehran University of Medical Sciences, Tehran , Rahimi, Firoozeh Professor of Ophthalmology - Eye Research Center - Farabi Eye Hospital - Tehran University of Medical Sciences, Tehran , Hashemian, Mohammad Naser Professor of Ophthalmology - Eye Research Center - Farabi Eye Hospital - Tehran University of Medical Sciences, Tehran , Houshang Beheshtnejad, Amir Associate Professor of Ophthalmology - Eye Research Center - Farabi Eye Hospital - Tehran University of Medical Sciences, Tehran , Zare, Mohammad Ali Associate Professor of Ophthalmology - Eye Research Center - Farabi Eye Hospital - Tehran University of Medical Sciences, Tehran , Fallah Tafti, Mohammadreza Associate Professor of Ophthalmology - Eye Research Center - Farabi Eye Hospital - Tehran University of Medical Sciences, Tehran , Aslani, Asieh Eye Research Center - Farabi Eye Hospital - Tehran University of Medical Sciences, Tehran , Zandian, Mehdi Eye Research Center - Farabi Eye Hospital - Tehran University of Medical Sciences, Tehran , Safi, Sare Eye Research Center - Farabi Eye Hospital - Tehran University of Medical Sciences, Tehran
Abstract :
Purpose: To assess the safety, efficacy and predictability of photorefractive keratectomy (PRK) [Tissuesaving
(TS) versus Plano-scan (PS) ablation algorithms] of Technolas 217z excimer laser for correction of
myopic astigmatism
Methods: In this retrospective study one hundred and seventy eyes of 85 patients (107 eyes (62.9%) with PS
and 63 eyes (37.1%) with TS algorithm) were included. TS algorithm was applied for those with central
corneal thickness less than 500 μm or estimated residual stromal thickness less than 420 μm. Mitomycin C
(MMC) was applied for 120 eyes (70.6%); in case of an ablation depth more than 60 μm and/or astigmatic
correction more than one diopter (D). Mean sphere, cylinder, spherical equivalent (SE) refraction,
uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA) were measured preoperatively, and 4
weeks,12 weeks and 24 weeks postoperatively.
Results: One, three and six months postoperatively, 60%, 92.9%, 97.5% of eyes had UCVA of 20/20 or better,
respectively. Mean preoperative and 1, 3, 6 months postoperative SE were -3.48±1.28 D (-1.00 to -8.75),
-0.08±0.62D, -0.02±0.57 and -0.004± 0.29, respectively. and also, 87.6%, 94.1% and 100% were within ±1.0
D of emmetropia and 68.2, 75.3, 95% were within ±0.5 of emmetropia. The safety and efficacy indices were
0.99 and 0.99 at 12 weeks and 1.009 and 0.99 at 24 weeks, respectively. There was no clinically or
statistically significant difference between the outcomes of PS or TS algorithms or between those with or
without MMC in either group in terms of safety, efficacy, predictability or stability. Dividing the eyes with
subjective SE≤4 D and SE≥4 D postoperatively, there was no significant difference between the predictability
of the two groups. There was no intra- or postoperative complication.
Conclusion: Outcomes of PRK for correction of myopic astigmatism showed great promise with both PS and
TS algorithms.
Keywords :
Astigmatism , Photorefractive Keratectomy , Myopia
Journal title :
Astroparticle Physics
