Laser Procedure Safe and Effective For Extreme Myopia After 12 Months

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Patients maintained visual results following trans-epithelial photorefractive keratectomy with nontouch debridement.

This article is part of Ophthalmology Advisor’s conference coverage from the 2021 meeting of American Society of Cataract and Refractive Surgery (ASCRS), held in Las Vegas from July 23 to 27, 2021. The team at Ophthalmology Advisor will be reporting on a variety of research presented by the cataract and refractive surgery experts at ASCRS. Check back for more from the ASCRS 2021 Meeting.


After a year for follow-up, patients who underwent a laser procedure for extreme cases myopia (worse than -10 D) maintained good visual quality, according to research presented at the annual meeting of the American Society of Cataract and Refractive Surgery (ASCRS), held in Las Vegas on July 23 to 27, 2021. The study authors reviewed patients who underwent trans-epithelial photorefractive keratectomy (TE-PRK).1 The investigation used the SCHWIND AMARIS® 1050 system with SmartSurface laser beam profile (SCHWIND eye-tech-solutions GmbH), allowing nontouch debridement rather than a manual or alcohol-aided method.2 

The retrospective case series demonstrated refractive results and safety for 150 highly myopic eyes; participants’ mean baseline spherical equivalent refraction was -11.69 D.1 This study took place at a laser eye center in Canada, and each participant underwent a single TE-PRK treatment, with no later retreatments. Immediately after ablation, mitomycin C 0.02% was applied.

The achieved treatment effect ranged from -10.1 D to -16.9 D (mean -12.1 D).1 Of 150 participants, 132 (88%) reached uncorrected distance visual acuity of 20/40 or better, and 143 (95%) displayed improved or no change in corrected distance visual acuity. Fifty three (35%) experienced corrected distance visual acuity by 1 line or more, and 9 (6%) had a gain of 2 lines or more.1 Two eyes lost 2 or more lines, and 4 eyes displayed haze that was visually significant.1

The faster repetition rate of high-speed excimer laser systems have the potential for reduced procedure time — thus corneal drying. Also, with advanced laser beam profile, normal corneas may experience faster healing than with manual surface treatment, according to SCHWIND.2

A previous study published in 2019 found that despite a smaller postoperative epithelial defect and faster healing time in 80 eyes (40 patients) who underwent TE-PRK, pain and “vision fluctuation” were significantly greater during the first days post-op than for those who had mechanical debridement — although the differences between the groups resolved by 1 week after the procedure, and both techniques were safe and effective, according to the research.3

Overall results of the current study show acceptable safety, defined as change of corrected distance visual acuity from preoperative numbers.1 Effectiveness was also demonstrated, with 88% exhibiting 20/40 or better final uncorrected distance acuity. “TE-PRK with a high-speed excimer laser procedure may be a good option to consider for correction of extreme myopia,” according to the study.1

Disclosure: Multiple study authors have declared affiliations with biotech and pharmaceutical companies. Please see the original reference for a full list of authors’ disclosures.

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1. Hamroush A, Lin DTC, Holland SP, Mosquera SA, Verma S. Outcome of trans-epithelial photorefractive keratectomy (PRK) for extreme myopia with high speed excimer laser and advanced laser beamprofile. Presented at the American Society of Cataract and Refractive Surgery (ASCRS) annual meeting; July 23–27, 2021, Las Vegas, Nevada. Paper 76407.

2. SCHWIND eye-tech-solutions GmbH. Focus on performance: The SCHWIND AMARIS® product family. Brochure dated September, 2020. Accessed July 21, 2021.

3. Zarei-Ghanavati S, Shandiz JH, Abrishami M, et al. Comparison of mechanical debridement and trans-epithelial myopic photorefractive keratectomy: A contralateral eye study. J Curr Ophthalmol. 2019;31(2):135-141. doi:10.1016/j.joco.2019.01.003