Evaluation of a new nomogram for Ferrara ring segment implantation in keratoconus

AIM: To evaluate the short-term clinical outcomes of Ferrara rings in keratoconus using an optimized nomogram developed after several years research and retrospective analysis data. METHODS: This prospective longitudinal non-comparative trial evaluated 88 eyes patients (age 18-62y) with diagnosis from two Spanish centers. ring segment (AJL Ophthalmic) implantation was performed all cases, mechanical procedure 25 (28.4%) a femtosecond laser-assisted 63 (71.6%). The segments implanted each case were selected new that considered variables such as anterior corneal asphericity astigmatism or discrepancy among coma orientations. Visual, refractive, topographic, aberrometric, pachymetric changes surgery during 3-month follow-up. RESULTS: implants induced significant refractive change well improvement uncorrected (UDVA) corrected distance visual acuity (CDVA; P<0.001). Postoperative CDVA 0.10 logMAR better achieved 28.4% 46.5% eyes, respectively. Two (2.3%) lost more lines whereas total 53.5% gained CDVA. A central posterior flattening (P≤0.003), reduction (P<0.001) astigmatisms (P=0.048), (P<0.001). Total primary (6 mm pupil) also statistically (preoperative 3.66±3.04 µm vs postoperative 2.33±2.26 µm, No differences found effect between cases techniques (P≥0.101). CONCLUSION: based on is safe effective for promoting rehabilitation keratoconus, relevant control aberration.