Divya Srikumaran

Clinical registries have been developed for decades in the field of ophthalmology, and they are especially well-suited to the study of keratoplasty practices. A comprehensive donor/recipient registry system can provide insight into donor, recipient, and surgical factors associated with immediate and long-term outcomes and adverse reactions. Furthermore, linkage with demographic databases can elucidate relationships with social determinants of health and potentially shape public policy. The vast sample size and multicenter nature of registries enable researchers to conduct sophisticated multivariate or multilayered analyses. In this review, we aim to emphasize the importance of registry data for keratoplasty practice and 1) summarize the structure of current keratoplasty registries; 2) examine the features and scientific contributions of the registries from Australia, the United Kingdom, Singapore, the Netherlands, Sweden, Eye Bank Association of America, and European Cornea and Cell Transplant registries; 3) compare registry-based studies with large single-site clinical studies; 4) compare registry-based studies with randomized control studies; and 5) make recommendations for future development of keratoplasty registries. Keratoplasty registries have increased our knowledge of corneal transplant practices and their outcomes. Future keratoplasty registry-based studies may be further strengthened by record linkage, data sharing, and international collaboration.

Purpose. To evaluate whether unilateral crosslinking (CXL) and conservative follow-up of the fellow eye is an acceptable management strategy in patients with keratoconus (KC). Methods. Seventy-nine fellow eyes of KC subjects that initially underwent unilateral CXL were included. Thirty fellow eyes ultimately received CXL (group 1) whereas 49 fellow eyes were followed (group 2). Best spectacle corrected visual acuity (BSCVA) and corneal tomographic parameters were collected in all eyes preoperatively and at the last follow-up. Results. Subjects who received CXL in the fellow eye (group 1) were younger than subjects who did not (group 2, p = 0.026 ). Group 1 eyes had higher baseline K1 ( p = 0.026 ), K2 ( p = 0.006 ), Km ( p = 0.01 ), and Kmax ( p = 0.002 ) compared to group 2 eyes. Amongst the 49 naïve fellow eyes (group 2), 19 eyes showed evidence of progression. Progressing naïve eyes had higher baseline K1, K2, Km, and Kmax ( p < 0.01 ); progressors also had thinner pachymetry at the pupil, apex, and thinnest point ( p < 0.01 ). Baseline values of K1 ≥ 43.5 Diopter (D), K2 > 45.1D, Km > 44.3D, Kmax > 47.9D, astigmatism > 1.4D, pachymetry at the pupil <475 μm, and thinnest pachymetry <478 μm were tentative predictors of progression in the naïve fellow eye. Conclusions. Unilateral CXL with vigilant follow up of the fellow eye may be an acceptable management strategy in a subset of KC eyes.