A prospective randomized self-controlled study of LASIK combined with accelerated cross-linking for high myopia in Chinese: 24-month follow-up

Abstract

Background To assess the visual and refractive outcomes of femtosecond laser-assisted in situ keratomileusis (FS-LASIK) concurrent with accelerated cross-linking (LASIK Xtra) compared with conventional FS-LASIK (convLASIK) for high myopia in Chinese individuals. Methods In this prospective, randomized, fellow-eye comparison study, 25 patients with high myopia were treated randomly with LASIK Xtra in one eye and convLASIK in the other. A 24-month follow-up was conducted, and the main outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent (MRSE) and corneal tomography. Results The UDVA was 0.09 ± 0.15 logMAR in the LASIK Xtra group, which was significantly worse than that in the convLASIK group 1 day postoperatively (P = .001), but the difference became nonsignificant from 1 week after surgery. The efficacy index was 0.88 ± 0.18 in the LASIK Xtra eyes and 0.99 ± 0.13 in the convLASIK eyes at 24 months (P = .028). Throughout the follow-up period, a slight myopic shift in the MRSE and keratometry values were observed in both groups without significant intergroup differences. The coefficient of determination was 0.9982 in the LASIK Xtra eyes and 0.9987 in the convLASIK eyes. The corneal density was significantly higher, and demarcation lines were visible in the first 6 months in LASIK Xtra eyes, but both signs of cross-linking gradually disappeared during follow-up. No severe complications were detected in either group. Conclusions LASIK Xtra showed comparable safety and predictability with convLASIK for high myopia in Chinese, but lower efficacy and no greater stability was observed up to 24-month follow-up.

Comparison of refractive surgeries (SMILE, LASIK, and PRK) with and without corneal crosslinking: systematic review and meta-analysis

“…29,30,32 Dong et al noted mild haze in 76% of LASIK Xtra patients, of which 12 cases persisted at the 3month mark. 23 Low et al described mild haze in five patients, all of which resolved by the 3-month follow-up. 27 Seiler et al was the sole study reporting cases of diffuse lamellar keratitis, diagnosing 29 eyes (38.2%) with stage 1 or stage 2 diffuse lamellar keratitis in the LASIK Xtra group compared with three eyes (4.0%) in the LASIK-alone group-a statistically significant difference (P < .001).…”

“…29,30,32 Dong et al noted mild haze in 76% of LASIK Xtra patients, of which 12 cases persisted at the 3-month mark. 23 Low et al described mild haze in five patients, all of which resolved by the 3-month follow-up. 27…”

“…Randomized controlled trials were of high quality, except for the study by Dong et al, which had missing patient data because of COVID-19. 23 The risk of bias arose in the observational studies because of the confounding factors, whereas they had a minimum risk of bias in other domains as assessed by ROBINS-I. 13…”

“…Subgroup analysis revealed a significant difference in the efficacy index only within the SMILE and SMILE Xtra subgroups, consistent with the findings previously documented by Ng et al 22 In addition, Dong et al observed a lower efficacy index in LASIK Xtra previously. 23 On performing sensitivity analysis for the LASIK subgroup, eliminating the study by Low et al (2018) made the efficacy index significantly lower in the CXL group (Supplementary Figure 12, available at http://links.lww.com/JRS/B89). 27 Other postoperative outcomes including UDVA of 20/20 or better at ≥12 months; safety: postoperative CDVA same or The postoperative safety index was significant between both groups (MD, À0.02; 95% CI, À0.04 to À0.01; P = .001; I 2 = 15%).…”

“…Randomized controlled trials were of high quality, except for the study by Dong et al, which had missing patient data because of COVID-19. 23 The risk of bias arose in the observational studies because of the confounding factors, whereas they had a minimum risk of bias in other domains as assessed by ROBINS-I. 13 The funnel plot analysis for the outcome of UDVA demonstrated that the studies had a symmetrical distribution, except for one study by Kohnen et al, which is an RCT, depicting a need for more randomized trials on this topic (Supplementary Figure 9, available at http://links.lww.com/JRS/B86).…”