Terminology for Retinal Findings in Sickle Cell Disease Research: A Scoping Review

Abstract

To review the current sickle cell disease (SCD) literature to assess how "retinopathy" has been defined and to identify ocular outcomes that have been measured and described. A systematic scoping review of SCD literature was completed regarding ocular manifestations of SCD and vision outcomes across all medical specialties. Participants with SCD and control patients were included in our data extraction. We reviewed English-language literature from 2000 to 2021 for eligible studies by searching PubMed, Google Scholar, Embase, and the Cochrane library using terms to encompass SCD and ocular findings. Data collection included study information, patient characteristics, vision-related findings (inclusion criteria and/or study outcomes), and retinopathy characteristics (definition, when, how and by whom diagnosed). We identified 4006 unique citations and 111 were included in the analysis. Ophthalmologists were senior authors of about half (59/111; 53.2%) of the articles; most articles were published between 2016 and 2021 (71/111; 70.0%). The studies had been conducted primarily in North America (54/111; 48.6%) or Europe (23/111; 20.7%); designs were cross-sectional (51/111; 45.9%), prospective cohort (28/111; 25.2%), retrospective cohort (27/111; 24.3%), and case-control (4/111; 3.6%). Among studies reporting any retinopathy, it was commonly defined as a combination of nonproliferative sickle cell retinopathy and proliferative sickle cell retinopathy (PSR;52/87; 59.8%), infrequently as PSR only (6/87; 6.9%), or not defined at all (23/87; 26.4%). The Goldberg classification was used to grade retinopathy in almost half of the studies (41/87; 47.1%). Investigators reporting diagnostic methods used clinical fundus examination (56/111; 50.4%), OCT (24/111; 21.6%), fluorescein angiography (20/111; 18.0%), ultrawidefield fundus photographs (15/111; 13.5%), and OCT angiography (10/111; 9.0%), or did not report methods (28/111; 25.2%). There are inconsistencies in documentation of methods and outcomes in studies of SCD ophthalmic findings. Particularly concerning is the lack of documentation of ophthalmic examination methods, qualifications of examiners, and clarity and specificity of sickle cell retinopathy definitions. With the increase in SCD treatment research and novel systemic therapies available, it is important to adopt clear and consistent descriptions and rigorous data collection and reporting of ophthalmic outcomes in SCD studies. The authors have no proprietary or commercial interest in any materials discussed in this article.