Comparison of mechanical debridement and trans-epithelial myopic photorefractive keratectomy: A contralateral eye study

Abstract

Purpose To compare clinical outcomes between mechanical debridement photorefractive keratectomy (m-PRK) and trans-epithelial photorefractive keratectomy (t-PRK) in myopic patients. Methods Eighty eyes of 40 myopic patients with age between 18 and 55 years were included in this study. In each patient, one eye was randomly assigned for t-PRK, using the Amaris laser's ORK-CAM software and the other eye for m-PRK, using a spatula. Stromal ablation was done by Schwind Amaris 750S. Uncorrected and best corrected visual acuity (BCVA), refractive outcomes, epithelial healing, pain, and discomfort were compared between the groups on day 1, 3, 7 and month 1, 3, and 6. Results Preoperative spherical equivalent (SE) were −3.97 ± 2.08 diopter (D) and −3.98 ± 2.06 D in m-PRK and t-PRK eyes, respectively ( P = 0.981). Operation time was significantly shorter in the t-PRK group than m-PRK ( P < 0.001). Postoperative pain was experienced significantly higher in the t-PRK group measured by 11-point numeric scale of pain questionnaire on the first postoperative day ( P < 0.001). Photophobia, tearing, and vision fluctuation were also significantly higher in the t-PRK group postoperatively. However epithelial defect size and re-epithelialization time were lower in the t-PRK group ( P = 0.012 and P < 0.001, respectively). Postoperative parameters including SE, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and contrast acuity did not show any significant difference between the two groups during all intervals. Conclusions Although epithelial defect size and epithelial healing time were lower in t-PRK, postoperative pain, photophobia, and vision fluctuation were significantly less in the m-PRK group in the first postoperative days. There was no statistically significant difference between the groups after one week, and both mechanical and trans-epithelial techniques were shown to be safe and effective.

Fellow eye comparison between alcohol-assisted and single-step transepithelial photorefractive keratectomy: late mid-term outcomes

“…No statistically significant differences either in visual acuity or in refractive results (represented by sphere, cylinder, spherical equivalent and defocus equivalent) between PRK and TransPRK, were found, as already reported by other previously published studies [ 3 , 4 , 11 - 13 , 17 , 19 , 23 , 25 ]. However, other researchers have reported some better results using TransPRK (especially with the new refinements of the software) including better UDVA and CDVA results [ 14 , 18 , 20 , 21 , 24 ].…”

“…The present study used the comparison approach between the two eyes of the same individual, and like, in the four published contralateral studies, which had a maximum postoperative follow-up of one year, there were no significant differences in refraction and visual results between PRK and one-step TransPRK treated eyes [ 12 - 14 , 23 ].…”

“…However, the importance of this work is based on the comparison of two different techniques in contralateral eyes, which allowed the homogenization features of studied samples, since many biological variables remained constant in both eyes, expecting to allow more reliable comparison in outcomes that represent the postoperative behavior of refractive surgery (v.gr. in contrast sensitivity performance), and in addition, to have the longest postoperative follow-up time that has been published in this type of comparative study (35.2 months) [ 12 - 14 , 23 ].…”

Transepithelial Laser versus Alcohol Assisted Photorefractive Keratectomy Safety and Efficacy: 1-Year Follow-up of a Contralateral Eye Study

“…To our knowledge, there is only one published contralateral eye study comparing these two techniques [ 13 ]. Another contralateral eye study published by Zarei-Ghanavati et al [ 14 ] was comparing TPRK and mechanical PRK.…”

Effect of Transepithelial Photorefractive Keratectomy without Mitomycin C in the Treatment of Femtosecond Laser In Situ Keratomileusis Corneal Flap Complications

“…The causes of haze include postoperative roughening of the corneal stroma, delayed epithelial healing, the depth of ablation, correction of high astigmatism, ultraviolet exposure, and genetic effects. On the other hand, TPRK results in a smooth corneal stroma, a shorter epithelial healing time, a lower degree of pain, and less incidence of postoperative haze than traditional surface surgery [ 20 – 22 ]. Most of our patients had low to moderate myopia or hyperopia requiring less cutting depth, so good therapeutic effects were still achieved without the combination with MMC.…”