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Purpose: To propose an algorithm to facilitate lens-based surgery in keratoconus., Methods: A literature review was performed to prepare a software algorithm based on cone location, stability, best spectacle-corrected distance visual acuity (BSCVA) level and whether there is a clear or cataractous lens. The software usability was assessed through a 10-question questionnaire and two hypothetical keratoconus case histories (moderately simple and moderately complex) given to 15 trainees. The usability questionnaires were graded on a Likert scale (1 = strongly disagree to 5 = strongly agree) and two case histories (1 = very difficult to 7 = very easy)., Results: The algorithm can be found at https://www.sussexeyelaserclinic.co.uk/keratoconus/. Thirteen trainees completed the questionnaire. 91.9% would frequently use it; for 100%, it was easy to use independently without technical support; for 63.7%, it was strongly integrated; for 100%, it was consistent; 100% thought that most people would learn to use it quickly, 91.9% found the system not cumbersome to use, felt very confident to use it and need not learn a lot to use it. The first case was found easy by 63.7% and the second by 45%., Conclusion: We present an algorithm as a guide for lens-based surgery in stable and progressing keratoconus, which is classified based on cone location. This algorithm will help trainee and "non-specialist" ophthalmic surgeons understand the pre-operative planning for the surgery and referral to the "specialist" corneal surgeon, considering factors such as progression, BSCVA, keratometry, topography and apex location of the cone in keratoconus patients.

Purpose: To assess the flattening of central, paracentral, and peripheral cones following non-accelerated (non-A-CXL) and accelerated (A-CXL) epithelium-off corneal cross-linking with 10 times higher intensity., Methods: In this multicenter study of 200 eyes (100 in each group), following 10 minutes of soak time with riboflavin 0.1%, continuous CXL was performed for 30 minutes (intensity: 3 mW/cm 2 , fluence: 5.4 J/cm 2 ) in the non-A-CXL group and 3 minutes (intensity: 30 mW/cm 2 , fluence: 5.4 J/cm 2 ) in the A-CXL group. Anterior and posterior cone flattening were compared at 12 months. Multiple regression analysis was performed to establish correlation of age, sex, cone location, and preoperative maximum keratometry (Kmax) values with postoperative flattening at 12 months., Results: In the non-A-CXL and A-CXL groups, central cones were the steepest, followed by paracentral and peripheral cones. Both groups showed significant flattening in central (1.54 ± 1.94 and 1.09 ± 1.79 diopters [D]) and paracentral (0.62 ± 1.59 and 0.55 ± 0.98 D) cones only. In the non-A-CXL group, there was a positive correlation between postoperative flattening and preoperative Kmax values, whereas paracentral and peripheral cone locations were negatively related. In the A-CXL group, only paracentral location was negatively correlated to postoperative flattening and showed posterior cone steepening at 12 months., Conclusions: Although central cones were the steepest in both groups, there was no difference in postoperative flattening between the groups for all cone locations. In the non-A-CXL group, postoperative flattening was proportional to preoperative Kmax values in central cones and was less with paracentral and peripheral locations. With A-CXL, postoperative flattening was less only with paracentral location. In the A-CXL group, significant posterior cone steepening was noticed only in paracentral cones. [ J Refract Surg . 2022;38(5):310-316.] .