Clinical Study Of Transepithelial Photorefractive Keratectomy For Correction Of Refractive Regression And Undercorrection After Femtosecond Laser Corneal Small Incision Lenticule Extraction

Objective:To evaluate the effectiveness,safety,predictability,stability of Transepithelial photorefractive kerataectomy(TransPRK)for correction of refractive regression and undercorrection in fellow eyes after femtosecond laser corneal small incision lenticule extraction(SMILE).Methods:A serial cases-observational study was carried out under the approval of our hospital and informed consent of patients.Forty-seven eyes of twenty-seven patients with refractive regression and undercorrection after SMILE were included in our hospital from May 2014 to June 2015.All the patients received TransPRK and followed-up for twelve months duration.The uncorrected visual acuity(UCVA),best corrected visual acuity(BCVA),refractive data,intraocular pressure,corneal epithelial thickness,higher-order aberrations,contrast sensitivity were examined before surgery and 1 week,1 month,3 months,6 months,12 months after surgery.The classification of haze when it appeared.The long-term efficacy of TransPRK for correction of refractive regression and undercorrection after SMILE included effective index,safety index,predictability and refractive stability.Results:The preoperative BCVA was ? 5.0 in 43 eyes.with the percentage of 91.4%,UCVA>5.0 were found in 41 eyes and 39 eyes in postoperative 3 months and 12 months respectively(87.23%and 82.98%).The effective index was(1.027± 0.162)and(1.019± 0.201)in postoperative 3 months and 12 months respectively,showing on insignificant difference between them(t=0.405,p>0.05).The safety indexes were(1.128±0.174)and(1.210±0.139)at 3 months and 12 months,with no significant difference between them(t=0.438,p>0.05).The SE was(+0.37±0,81)(-0.23±0.79)(-0.30±0.75)(-0.27±0.77)and(-0.32±0.84).1 week,1 month,3 months,6 months,12 months after surgery respectively,and there were no significant difference among different time points(F=1.165,p>0.05).Compared with the preoperative BCVA,3 eyes and 1 eye lost 1 line at 3 months and 12 months after surgery respectively.Haze appeared in 5 eyes at 3 months and in 3 eyes at 12 months.Conclusions:TransPRK appears to be good in effectiveness,safety,predictability,and refractive stability for correction of refractive regression and undercorrection after SMILE.