Eyeworld

JUNE 2022 | EYEWORLD | 23 Contact Lorch: Alice_Lorch@meei.harvard.edu Patel: neal_patel@meei.harvard.edu Venkateswaran: nandini_venkateswaran@ meei.harvard.edu two factors that have both been associated with greater corneal flattening after CXL in previous publications. 13,14 Detailed evaluation of depth of treatment demarcation lines as well as endothelial cell structure and function would have been useful to have but were unfortunately not performed in this retrospective study. Complications were minimal and interestingly, only occurred in the TECXL group that did not undergo true epi- thelial debridement; however, exposure of the corneas to significant amounts of benzalkonium chloride in the riboflavin solution may have rendered the epithelium more irregular and susceptible to keratitis in these patients. The retrospective nature, limited sample size par- ticularly in the TECXL and CACXL groups, and lack of randomization or systematic selection of CXL techniques are notable limitations that may have prevented some observed trends from reaching statistical significance. Conclusions The results of this study suggest that both TECXL and CACXL are comparable to standard epi-off CXL in regressing and/or stabilizing progressive keratoconus over a 2-year follow-up period. Each of these three techniques must be chosen judiciously and can play a useful role in the treatment of patients with progressive keratoconus, with TECXL and CACXL being particularly useful in patients with the thinnest pachymetric readings below 400 microns. More research with larger sample sizes and standard- ized treatment protocols are needed to investi- gate these techniques further and help clinicians determine when and in which patients each of these techniques should be implemented to treat corneal ectasias. Comparison of contact lens-assisted and transepithelial corneal crosslinking with standard epithelium-off crosslinking for progressive keratoconus: 24-month clinic results Malhotra C, et al. J Cataract Refract Surg. 2022;48(2):199–207 n Purpose: To compare outcomes of contact lens-assisted corneal crosslinking (CACXL) and transepithelial corneal crosslinking (TECXL) with standard "epithelium-off" ("epi-off") crosslinking (CXL) for progressive keratoconus n Setting: Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India n Design: Retrospective, comparative study n Methods: Patients with progressive keratoconus undergoing CXL with a minimum follow-up of 24 months were included. CACXL and TECXL was performed in patients with "epithelium-on" minimal pachymetry between 350 µm and 450 µm. Main outcome measures included change in maximum keratometry (Kmax), corrected distance visual acuity (CDVA), and efficacy in halting progression (increase in Kmax ≥ 1 diopter [D]). n Results: Standard "epi-off" CXL, CACXL, and TECXL was performed in 34, 14, and 10 eyes, respectively. Baseline Kmax and CDVA were comparable for all groups. Kmax was reduced significantly by –2.83±3.35 D, –3.18±2.74 D, and –2.02±1.66 D in the standard "epi-off" CXL (p<0.01), CACXL (p=0.001), and TECXL (p=0.004) groups, respectively; the reduction was comparable for all groups (p=0.63). CDVA improved by –0.14±0.24, –0.04±0.19, and –0.12± 0.17 logMAR units in the standard "epi-off" CXL (p=0.006), CACXL (p=0.42), and TECXL (p=0.05) groups, respectively; the reduction was comparable for all groups (p=0.46). Progression was documented in 2 eyes (6%) of the standard "epi-off" CXL group and 0% eyes of the CACXL and TECXL groups (p=0.61). n Conclusion: CACXL and TECXL were comparable to standard "epi-off" CXL for progressive keratoconus. 10. Magli A, et al. Epithelium-off corneal collagen cross-linking versus transepithelial cross-link- ing for pediatric keratoconus. Cornea. 2013;32:597–601. 11. Soeters N, et al. Transepithelial versus epithelium-off corneal cross-linking for the treatment of progressive keratoconus: a randomized controlled trial. Am J Ophthalmol. 2015;159:821–828.e3 12. Jacob S, et al. Contact lens-as- sisted collagen cross-linking (CACXL): A new technique for cross-linking thin corneas. J Refract Surg. 2014;30:366–372. 13. Greenstein SA, Hersh PS. Characteristics influencing outcomes of corneal collagen crosslinking for keratoconus and ectasia: implications for patient selection. J Cataract Refract Surg. 2013;39:1133–1140. 14. Spadea L, Mencucci R. Transepithelial corneal collagen cross-linking in ultrathin kerato- conic corneas. Clin Ophthalmol. 2012;6:1785–1792.

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