Twelve-month outcomes of single-step transepithelial photorefractive keratectomy for moderate hyperopia and hyperopic astigmatism

Abstract

Background Conventional mechanical or alcohol-assisted photorefractive keratectomy (PRK) techniques for correction of hyperopia and hyperopic astigmatism were associated with inconsistent results. The aim of this study is to evaluate the 12-month visual and refractive outcomes of the relatively new single-step transepithelial photorefractive keratectomy (TE-PRK) for moderate hyperopia and hyperopic astigmatism. Methods This is a prospective interventional study. Forty-eight eyes of 30 patients with moderate hyperopia or hyperopic astigmatism with a cycloplegic spherical equivalent refraction (SEQ) between 2.0 and 4.5 diopters (D) underwent single-step StreamLight® TE-PRK using EX500 excimer laser (Alcon Laboratories, USA). The main outcome measures were recorded at 6 and 12 months postoperatively including assessment of logarithm of the minimum angle resolution (logMAR) uncorrected and corrected distance visual acuity (UDVA, CDVA), cycloplegic refraction, corneal topographic changes as well as post-PRK peripheral haze grading. Results The mean preoperative cycloplegic SEQ was significantly reduced from 3.21 ± 0.61 D to 0.35 ± 0.04 D and 0.41 ± 0.04 D at 6 and 12 months, respectively (P < 0.001). The mean preoperative UDVA significantly improved from 0.53 ± 0.02 logMAR to 0.07 ± 0.01 logMAR and 0.08 ± 0.01 logMAR at 6 and 12 months, respectively (P < 0.001) while the mean preoperative logMAR CDVA showed non-significant change over time throughout the study (P = 0.135). At the end of the study, 41 eyes (85.4%) achieved UDVA of 20/25 or better and no eye lost any lines of CDVA. Thirty-eight eyes (79.1%) had a postoperative cycloplegic cylinder of 0.5 D or less at 12 months. The mean preoperative mean keratometry showed significant increase at 6 and 12 months postoperatively (P < 0.001) while there was no significant change between the two postoperative visits denoting topographic stability (P = 0.058). The mean postoperative Q value at 6 and 12 months showed a significant prolate shift (P < 0.001). No haze was observed in 62.5% and 85.4% of the enrolled eyes at 6 and 12 months, respectively. Conclusions Single-step StreamLight® TE-PRK for moderate hyperopia and hyperopic astigmatism achieved acceptable visual and refractive outcomes. Trial registration: (Clinicaltrials.gov): NCT05261685, 2 March 2022, retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT05261685

Transepithelial Photorefractive Keratectomy for Hyperopia Correction: An Uncharted Territory

“…They also included parameters of pachymetry >500 microns and steep keratometry <46 diopters in their selection criteria. 24 …”

“…In the study by Abdel-Radi et al, patients with large angle kappa (chord mu >0.3 mm) and with unilateral or bilateral hyperopic amblyopia (corrected distance visual acuity <0.2 logMAR) were also excluded. 24 …”

“… 23 Abdel-Radi et al included Pentacam (Oculus GmbH, Germany) for keratorefractive assessment and anterior segment ocular coherence tomography (AS-OCT, Heidelberg, GmbH, Germany) for epithelial mapping in their study subjects. 24 …”

“…Moghaddam et al and Abdel-Radi et al used Mitomycin C 0.02% solution placed with a soaked sponge over the ablated area for maximum 30 to 60 seconds after ablation, followed by irrigation with 100 mL chilled BSS. 23 , 24 Ortueta et al did not use Mitomycin C in their surgeries. 17 A bandage contact lens was placed at the end of the treatment.…”

“…There was no loss of Snellen lines of BCVA, and two eyes gained one line (4.2%) at the last follow-up. 24 …”