Refractive outcomes using Barrett formulas and patient characteristics of cataract surgery patients with and without prior LASIK/PRK

Purpose The goal of this study is to describe characteristics of cataract surgery patients who previously underwent laser in situ keratomileusis/photorefractive keratectomy (LASIK/PRK) in comparison to non-LASIK/PRK cataract surgery patients including psychiatric comorbidities, as well as describe refractive prediction error after cataract surgery while accounting for axial length (AL) using the Barrett True-K and Barrett Universal II formulas. Methods This was a retrospective study of patients from the University of Colorado Cataract Outcomes Registry. The primary outcomes were refraction prediction error (RPE), mean absolute RPE, and median absolute RPE. Outcomes were stratified by five axial length groups. Univariate and multivariate models for RPE were stratified by the AL group. Results Two hundred eighty-one eyes with prior LASIK/PRK and 3101 eyes without are included in the study. Patients with prior LASIK/PRK were significantly younger: 67.0 vs 69.9 years, p < 0.0001. The LASIK/PRK group had significantly better mean pre-operative BCVA in comparison to the non-LASIK group, logMAR 0.204 vs logMAR 0.288, p = 0.003. The LASIK/PRK group had significantly lower rates of cardiovascular disease (18.5% vs 29.3%, p < 0.001), hypertension (49.1% vs 59.3%, p < 0.012), and type 2 diabetes (10.7% vs 26.0%, p < 0.001), and no significant difference in psychiatric disease. The absolute RPE was higher for the LASIK group for all ALs, but only significantly higher for eyes with AL less than 25 mm. Conclusion Patient eyes with prior LASIK/PRK surgery undergoing cataract surgery were significantly younger, had significantly less comorbidities, and a significantly better pre-operative BCVA. Using the Barrett formulas, absolute prediction error for eyes with longer ALs was not significantly worse for LASIK/PRK eyes than those without and the difference was smaller for eyes with longer AL.