Single-Step Transepithelial Photorefractive Keratectomy in Low to Moderate Myopia: A One-Year Follow-Up Study

Abstract

Aim To evaluate predictability, safety, efficacy, and visual outcome of StreamLight. ™ (SL.), the newly released single-step transepithelial photorefractive keratectomy platform by Alcon WaveLight™ (WL). Methods In this prospective cohort study, photorefractive keratectomy (PRK) was conducted on 500 eyes of 250 patients seeking myopic refractive vision correction. The new single-step transepithelial PRK method was applied, using the SL. platform installed in the WL. Ex 500 excimer laser machine. Patients were followed up to monitor intensity and duration of postoperative pain, as well as speed of epithelial healing in the early post-operative period and visual acuity, postoperative refraction and development of postoperative haze for one year post-operatively. Results Average pain duration was 1.5 days, and the mean pain intensity score on a scale of 0–10 was 3.74 + 1.51. Mean postoperative spherical equivalence was 0.01 ± 0.38 D, and the final postoperative uncorrected distance visual acuity (UCDVA) was 20/20 in 98% of eyes included in this study. None of the eyes lost more than one Snellen chart line or developed visually significant postoperative haze during the follow-up period. Conclusion The new SL. platform for transepithelial PRK is a safe, accurate platform, offering an easier early post-operative recovery, with no compromise in final visual outcome.

Transepithelial Photorefractive Keratectomy—Review

“…The Alcon Streamlight (Alcon, Fort Worth, TX, USA) is another single-step transPRK platform, added to the EX500 Excimer laser platform in 2019. It utilises a set of algorithms (EPI lists) to provide a uniform PTK ablation of the epithelium in 5 µm steps to levels of a normal corneal epithelium (45–65 µm) after epithelial mapping and according to surgeon preference [ 50 ]. This PTK seeks to be refractively neutral.…”

“…Like the Schwind software, there is no interruption between epithelial and stromal ablations, which reduces the treatment time. Using this platform appears to be a safe, effective treatment for low to moderate myopia and hyperopia with and without astigmatism, with the benefit of faster visual recovery and epithelial healing as well as less pain than traditional PRK [ 20 , 50 , 51 ]. Re-epithelialisation in particular was very fast when compared with alcohol-assisted PRK.…”

“…For their study, 0.02% mitomycin C was applied for 20 s when the ablation depth was greater than 60 µm. Only 17% of eyes had grade 0.5 haze at 3–6 months (i.e., not clinically significant or symptomatic), and no patients had haze at the last follow-up visit [ 50 ].…”

Transepithelial Photorefractive Keratectomy for Hyperopia Correction: An Uncharted Territory

“…The size and location of epithelial treatment zone are aligned with the PRK ablation profile, and centration is only required once. 20 , 21 …”

Clinical Outcomes of Transepithelial Photorefractive Keratectomy Performed with Smart Pulse Technology for the Correction of Moderate to High Myopia

“…Schwind AMARIS 1050 Hz excimer laser platform uses a reverse single-step TransPRK procedure, in which ablation to correct the refractive error is performed first, followed by ablation to simulate the epithelium thickness profile of the normal population [ 8 ]. This also maximizes the smoothing effect since it has been recognized that epithelial thickening occurs in areas of stromal irregularity.…”