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20 | EYEWORLD | JUNE 2022 EYEWORLD JOURNAL CLUB ASCRS NEWS by Neal Patel, MD, and Nandini Venkateswaran, MD reaching the endothelium. 12 In this study, the authors retrospectively compared outcomes of TECXL and CACXL techniques along with stan- dard epi-off CXL in patients with progressive keratoconus. Design and methods This retrospective, single-center study included 58 eyes that underwent CXL for progressive keratoconus at the Cornea Services of Advanced Eye Center in Chandigarh, India, between January 2013 and June 2018. Patients were included if they had keratoconus with evidence of progression, as defined by consistent changes in keratometry, refraction, and/or pachymetry on two consecutive visits and had post-proce- dure follow-up of at least 2 years. Keratometry and corneal thickness measurements were per- formed with Scheimpflug imaging on Pentacam (Oculus). The standard epi-off technique was used only in eyes with minimal corneal thick- ness (MCT) of at least 450 microns as measured with an intact epithelium. TECXL and CACXL were used for patients with MCT between 350 microns and 450 microns. There were no predetermined criteria or systematic approach to select among epi-off, TECXL, and CACXL techniques in patients, except that TECXL was initially avoided in patients under the age of 18 years due to concern of possible reduced effica- cy in the pediatric population. 13 All patients were examined on the first and fifth postoperative day, 1 month, 3 months, and 6 months, followed by every 6 months. Efficacy of each CXL technique was judged based on the ability of the procedure to halt or stabilize ecta- sia. Progression, stabilization, or regression of Review of "Comparison of contact lens-assisted and transepithelial corneal crosslinking with standard epithelium-off crosslinking for progressive keratoconus: 24-month clinic results" continued on page 22 Neal Patel, MD Resident Massachusetts Eye and Ear Boston, Massachusetts Alice Lorch, MD Residency Program Director Massachusetts Eye and Ear Boston, Massachusetts Nandini Venkateswaran, MD Cornea, Cataract, and Refractive Surgeon Massachusetts Eye and Ear, Waltham Waltham, Massachusetts O ver the last decade, corneal cross- linking (CXL) has rapidly grown in popularity among ophthalmologists for its ability to halt the progression of keratoconus and other corneal ectasias. The Dresden protocol is widely re- garded as the standard for CXL, against which other protocols for CXL are compared. 1 In this standard epithelium-off (epi-off) technique, the central 8 mm of corneal epithelium is removed before saturation of the corneal stroma with riboflavin and subsequent treatment with UV-A. 2 Removing the epithelium has been shown to al- low improved absorption of riboflavin and UV-A penetration into the corneal stroma. 3–5 However, this technique is relatively contraindicated in corneas with pachymetry less then 400 microns after epithelium removal due to risk of endo- thelial damage by UV-A. 6 Additionally, epithelial debridement is associated with complications including increased postoperative pain, corneal haze, and risk of infective keratitis. 7 Several alternative techniques have been described to overcome these limitations of epi- off techniques and improve the safety of CXL in thinner corneas. Among these techniques are transepithelial CXL (TECXL) and contact lens-assisted CXL (CACXL). TECXL avoids ep- ithelial removal and uses a riboflavin solution containing substances that enhance epithelial penetration. 8 This technique has been demon- strated to have improved postoperative comfort and reduced corneal haze, however, the efficacy of this technique as compared to standard epi- off CXL has been questioned. 9–11 CACXL involves the use of a riboflavin-soaked UV barrier-free contact lens placed on a deepithelialized cornea to compensate for reduced corneal thickness and prevent damaging levels of UV-A from

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