Comparison of visual quality after Femto-LASIK and TransPRK in patients with low and moderate myopia

Advances in Transepithelial Photorefractive Keratectomy versus Laser-Assisted In Situ Keratomileusis

(1) Background: Laser-assisted refractive surgery is a safe and effective surgical correction of refractive error. For most patients, both the newer Trans-PRK and the established LASIK technique can produce the required surgical correction, sparking the question of which technique should be opted for. (2) Methods: The study prospectively evaluated 121 patients (230 eyes) for at least one month postoperatively; 66 patients (126 eyes) and 45 patients (85 eyes) returned for 6 months and 1 year follow-up. (3) Results: No statistical difference was recorded at 1 week or 1 month post-operation. At 6 months, a difference was found for spherical diopters (Trans-PRK -0.0476 ± 0.7012 versus FS-LASIK +0.425 ± 0.874, p = 0.004) and spherical equivalent (Trans-PRK -0.1994 ± 0.0294 versus FS-LASIK +0.225 ± 0.646, p = 0.025) but not for CYL D (Trans-PRK -0.3036 ± 0.5251 versus FS-LASIK -0.4 ± 0.820, p = 0.499). Uncorrected visual acuity was better for Trans-PRK 6 months post-operation (UCVA logMAR 0.02523 versus 0.0768 logMAR; p = 0.015 logMAR). At 1-year, Trans-PRK was favored for spherical diopters (Trans-PRK -0.0294 ± 0.6493 versus FS-LASIK +0.646 ± 0.909, p < 0.001) and spherical equivalent (Trans-PRK -0.218 ± 0.784 versus FS-LASIK 0.372 ± 1.08, p = 0.007). Overall speed in visual recovery, variance of results and surgically induced astigmatism were in favor of Trans-PRK. (4) Conclusions: The study reported improvements for Trans-PRK patients, with both techniques found to be safe and effective.

Comparison of clinical outcomes of LASIK, Trans-PRK, and SMILE for correction of myopia

Transepithelial photorefractive keratectomy (Trans-PRK), laser-assisted in situ keratomileusis (LASIK), and small incision lenticule extraction (SMILE) are three mainstay refractive surgeries worldwide. The applicability, efficacy, safety, and predictability of these different techniques are quite similar. Trans-PRK has the strongest biostability, earliest return to normal corneal sensitivity but the longest recovery time, most uncomfortable postoperative experience, and possibility of corneal haze. LASIK possesses the fastest visual rehabilitation but the slowest corneal nerve reinnervation, and flap displacement is possibly lifelong. SMILE incurs no flap-related complications and has intermediate vision recovery time and biomechanics compared with Trans-PRK and LASIK. However, it lacks the cyclotorsion-compensation system, eye-tracking system, and customized treatment profile for high astigmatism or irregular corneal surface. This review aims to introduce the mechanisms, pros, and cons of these three types of refractive surgery. With full understanding, practitioners could advise patients on the most suitable treatment of choice.

Efficacy and safety of single-step transepithelial photorefractive keratectomy with the all-surface laser ablation SCHWIND platform without mitomycin-C for high myopia: A retrospective study of 69 eyes

BACKGROUND

Studies suggest that transepithelial photorefractive keratectomy (TransPRK) with the all-surface laser ablation (ASLA)-SCHWIND platform is effective and safe for both low-moderate myopia and high myopia. In most studies, mitomycin-C is administered immediately after surgery to prevent corneal opacification (haze), which is a significant complication of photorefractive keratectomy in general. However, there is evidence that adjuvant mitomycin-C induces endothelial cytotoxicity. Moreover, a recent study showed that omitting adjuvant mitomycin-C did not increase haze in low-moderate myopia. The present case-series study examined the efficacy, safety, and haze rates of eyes with high myopia that underwent ASLA-SCHWIND TransPRK without adjuvant mitomycin-C.

METHODS

All consecutive eyes with high myopia (≤-6 D) that were treated in 2018-2020 with the SCHWIND Amaris 500E® TransPRK excimer laser without adjuvant mitomycin-C in a tertiary-care hospital (France) and were followed up for 6 months were identified. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and spherical equivalent (SE) were recorded before and after surgery. Postoperative haze was graded using the 4-grade Fantes scale. Efficacy rate (frequency of eyes with 6-month UCVA ≤0.1 logMAR), safety rate (frequency of eyes that lost <2 BSCVA lines), predictability (frequency of eyes with 6-month SE equal to target SE±0.5 D), efficacy index (mean UCVA at 6 months/preoperative BSCVA), and safety index (BSCVA at 6 months/preoperative BSCVA) were computed.

RESULTS

Sixty-nine eyes (38 patients) were included. Mean preoperative and 6-month SE were -7.44 and -0.05 D, respectively. Mean 6-month UCVA and BSCVA were 0.00 and -0.02 logMAR, respectively. Efficacy rate and index were 95.7% and 1.08, respectively. Safety rate and index were 95.7% and 1.13, respectively. Predictability was 85.5%. Grade 3-4 haze never arose. At 6 months, the haze rate was zero.

CONCLUSIONS

ASLA-SCHWIND TransPRK without mitomycin-C appears to be safe as well as effective and accurate for high myopia.

Femtosecond laser assisted in situ keratomileusis (FS-LASIK) yields better results than transepithelial photorefractive keratectomy (Trans-PRK) for correction of low to moderate grade myopia

INTRODUCTION

The purpose of this study was to compare the outcomes of transepithelial photorefractive keratectomy (Trans-PRK) with femtosecond laser assisted in situ keratomileusis (FS-LASIK) for the correction of low to moderate myopia.

METHODS

A retrospective cohort study design was used. The study group included patients with myopia less than -6.0 D, with or without concomitant astigmatism under 2.0 D, who were treated with FS-LASIK or Trans-PRK in 2013 through 2014. Background, clinical and outcome data were collected from the patient files. A comparison between eyes treated with FS-LASIK or Trans-PRK was performed.

RESULTS

The Trans-PRK group was comprised of 1793 eyes and the FS-LASIK group of 666 eyes. Mean ± SD spherical equivalent (SE) refraction prior to surgery was -3.43 ± 1.27 D in the Trans-PRK group and -3.18 ± 1.34 D in the FS-LASIK group (p < 0.001). Efficacy index values were 0.95 ± 0.14 in the Trans-PRK group and 0.98 ± 0.12 in the FS-LASIK group (p < 0.001), and corresponding safety index values were 0.96 ± 0.13 and 0.99 ± 0.12 (p < 0.001). Distance from target refraction was 0.45 ± 0.42 D in Trans-PRK group and 0.43 ± 0.38 D in the FS-LASIK group (p = 0.537); 71.6% and 74.2% of eyes were within ±0.5 D of attempted correction, respectively (p = 0.193).

CONCLUSIONS

Both Trans-PRK and FS-LASIK demonstrated excellent results, mostly comparable with the current literature. FS-LASIK achieved better results than Trans-PRK surgery in the efficacy and safety parameters.

Anterior uveitis after transepithelial photorefractive keratectomy: Demographics and clinical characteristics - a one-year analysis

PURPOSE

To report a case series of anterior uveitis after Transepithelial Photorefractive Keratectomy (TransPRK) and determine its incidence, demographics and associated clinical features over a study period of 1 year.

METHODS

This retrospective case series comprised of 200 eyes (100 patients) which underwent elective TransPRK surgery for ametropia correction at a tertiary eye care center by two refractive surgeons over 1 year. TransPRK was performed on Streamlight software (EX500, Alcon Wavelight, Inc.). Postoperatively, all patients received topical antibiotic and steroid eye drops and tapered over 4 weeks.

RESULTS

The mean age of study patients was 25.76 ± 4.29 years with a pre-operative mean refractive spherical equivalent (MRSE) of -3.49 ± 2.12 diopter (D); 11.76% eyes had simple myopia and 88.23% had compound myopic astigmatism, mean ablation depth of 61.99 ± 24.27 um. Four patients (seven eyes) developed anterior uveitis with mean age of 25 ± 3.53 years, mean MRSE -2.91 ± 0.32 D, ablation depth 44.75 ± 5.29 um with a mean onset at 33.28 days postoperatively after surgery and 5.28 days after the routine postoperative topical steroid withdrawal. Laboratory and immunological tests were negative in all four patients. The incidence of TransPRK-related anterior uveitis was 3.5% over 1 year.

CONCLUSION

Anterior uveitis after TransPRK is infrequent. It could be due to intraocular transmittance of high frequency excimer laser beams used for longer durations to provide continuous, single step ablation in this novel type of PRK surgery. Further studies are needed to investigate the mechanisms of this association.