Comparing outcomes of Tel-Aviv Protocol vs Athens Protocol in the treatment of progressive keratoconus

Purpose: To compare outcomes of accelerated crosslinking combined with either epithelial photorefractive keratectomy (Tel-Aviv Protocol) or topography-guided photorefractive keratectomy (Athens Protocol) for keratoconus. Setting: Bochner Eye Institute, Toronto, Canada, and Care Vision Laser Center, Tel Aviv, Israel. Design: Multicenter retrospective comparative study. Methods: Consecutive progressive keratoconus eyes treated with either Tel-Aviv or Athens Protocol were included. Preoperative and 1-year posttreatment uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalence (SEQ), astigmatism, maximal keratometry (Kmax), and minimal corneal thickness (MCT) were assessed. Propensity score matching (PSM) was used to adjust for differences in baseline characteristics. Results: 35 eyes of 35 patients were treated with Tel-Aviv Protocol and 60 eyes of 60 patients with Athens Protocol. At baseline, the Tel-Aviv Protocol group was younger ( P = .03) and had worse UDVA ( P < .001), better CDVA ( P = .005), and lower MCT ( P < .001). At 1 year, both groups improved in UDVA, CDVA, astigmatism, and Kmax ( P < .05 for all). The Tel-Aviv Protocol group demonstrated significant improvement in SEQ ( P < .001). PSM revealed that Athens Protocol had a 1.84 D greater reduction in Kmax ( P = .02) and 19.44 μm greater MCT reduction ( P = .02) compared with Tel-Aviv Protocol ( P = .02). The Tel-Aviv Protocol group had 3.4-line greater improvement in UDVA ( P = .03) compared with Athens Protocol. Conclusions: Both protocols improve visual and topographic outcomes. Tel-Aviv Protocol provides better visual gains, and Athens Protocol offers greater corneal flattening. Tel-Aviv Protocol may be preferred in patients with thinner corneas due to its reduced stromal tissue ablation.