Photorefractive keratectomy after DMEK for corneal decompensation by phakic IOL

Purpose To provide the first description of photorefractive keratectomy (PRK) for the correction of mild residual refractive error after Descemet membrane endothelial keratoplasty (DMEK). Methods Case report. Results A 45 year-old woman presenting with phakic intraocular lens (PIOL)-related corneal decompensation underwent staged DMEK surgery following PIOL explantation and cataract surgery. Eighteen months after DMEK, uncorrected distance visual acuity (UDVA) was 20/60 and best-corrected visual acuity (BCVA) was 20/22, with a stable refraction. The patient requested refractive surgery to decrease spectacle dependance, and wavefront-optimized PRK was performed. At last follow-up observation thirty-three months after PRK (54 months after DMEK surgery), UDVA was 20/20, the cornea remained clear without signs of rejection or endothelial failure, and the endothelial cell loss rate was not accelerated after PRK. Conclusion Since long-term visual and refractive stability can be expected after DMEK, PRK may be a particular safe and effective approach for the correction of mild residual refractive errors after DMEK. However, we consider that surgeons must exercise caution when considering keratorefractive surgery in these eyes due to postoperative changes in corneal curvature and thickness, and further studies are encouraged.

Laser Assisted In Situ Keratomileusis (Lasik) Versus Trans Epithelial Photorefractive Keratectomy (T-Prk) In Astigmatic Patients

Purpose: To compare the results of LASIK versus Trans Epithelial Photorefractive Keratectomy (T-PRK) in correcting astigmatic refractive error. Study Design: Quasi experimental study. Place and Duration of Study: Lahore Medicare Hospital from January to October 2018. Methods: One hundred and twenty six eyes of 63 patients, age 18 to 35 years, either gender, presenting with astigmatism were enrolled in this study. Myopes with spherical equivalent (SE) ? -13.0 diopter sphere (DS), hyperopes with SE ? +5.0 DS and astigmatism ? 1.5 D with visual acuity better or equal to 0.3 LogMAR were included. Astigmatic eyes with < 1.5D and with any other ocular pathology were excluded. Refractive status was assessed by Canon Autorefractor and Heine Retinoscope. Average reading of both methods was taken. Patients were divided into two groups (31: LASIK; 32: trans-PRK) by spin of a coin method. Refractive surgery was done in both groups. Data was analyzed by SPSS 20. Normality of quantitative data was checked by Shapiro Wilk test. Mann Whitney-U test was used for non-parametric data. P-value ? 0.05 was taken as significant. Results: Mean age of the patients was 25.83 ± 3.09 years. The difference in residual sphere, amount of cylinder, axis of cylinder and CCT (central corneal thickness) after surgery in two groups was insignificant. P values were as follows; for sphere p = 0.85, amount of cylinder p = 0.22, axis of cylinder P = 0.46 and CCT p = 0.07. Conclusion: Both techniques are equally good in correcting astigmatism (p = 0.22). LASIK or T?PRK can be done alternatively in patients with astigmatism. Key Words: LASIK, Trans epithelial PRK, Astigmatism.

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.

Clinical Outcomes of Single-Step Transepithelial Photorefractive Keratectomy and Off-Flap Epipolis-Laser in Situ Keratomileusis in Moderate to High Myopia: 12-Month Follow-Up

Background To compare the quantitative and qualitative optical outcomes of single-step transepithelial photorefractive keratectomy (TPRK) and off-flap epipolis-laser in situ keratomileusis (Epi-LASIK) in moderate to high myopia. Methods In this prospective self-control study, we included patients with moderate to high myopia who were randomized to undergo TPRK in one eye and Epi-LASIK in the other eye. Twelve-month follow-up results for visual acuity, refraction, ocular high-order aberrations, contrast sensitivity, postoperative pain, epithelial healing, and haze grade were assessed. Results A total of 64 eyes (32 patients) were enrolled in the study. More eyes completed re-epithelialization in the TPRK group than in the Off-flap Epi-LASIK group 3–4 days postoperatively, while all eyes completed re-epithelialization by seven days. More eyes achieved a visual acuity (both UDVA and CDVA) of better than 20/20 in the TPRK group than in the Off-flap Epi-LASIK group. The ± 0.50 D predictability for correction of the spherical equivalent (SE) was higher in the eyes of the TPRK group (91%) than in those of the off-flap Epi-LASIK group (80%) 12 months after surgery. No significant differences in ocular aberrations, including coma, spherical, and trefoil, were found between the two groups at 12 months. There were also no significant differences in visual acuity, contrast sensitivity, pain, and haze grading between the two groups. Conclusions Both TPRK and off-flap Epi-LASIK are safe, effective, and predictable treatments for moderate to high myopia with comparable surgical outcomes. Trial registration: This study was retrospectively registered on ClinicalTrial.gov (NCT05060094, 17/09/2021).