Characterising individuals with retinopathy from retinal image grading data in UK Biobank

Abstract

Purpose : The aims of this study were to identify individuals from the UK Biobank (UKBB) cohort with detectable retinopathy on retinal imaging and to describe their sociodemographic and clinical characteristics.

Methods : Colour fundus photographs and macular optical coherence tomography (OCT) scans were acquired using a Topcon 3D OCT-1000 Mark II system (Topcon, Japan). Grading was performed by trained and certified graders and clinicians of the Network of Ophthalmic Reading Centres UK (NetwORC UK-Belfast, Liverpool, and Moorfields Ophthalmic Image Reading Centres). Retinopathy was defined as the presence of one or more microaneurysms in either eye, with or without other retinal microvascular abnormalities on either imaging modality. Diagnosed diabetes (DM), diabetic retinopathy (DR) and hypertension (HTN) were ascertained from self-reported (verbal interview), linked hospital episode statistics and primary care records at the time of imaging. Self-reported medication history was obtained from touchscreen questionnaire responses. HbA1c >48mmol/mol was considered diagnostic of DM. Systolic or diastolic blood pressure (BP) measurements ≥140mmHg and ≥80mmHg respectively were considered diagnostic of HTN.

Results : Among 68,517 UKBB participants who underwent fundus imaging, 265 (0.4%) individuals were identified to have retinopathy from retinal imaging. The median age at assessment for this group was 59 years (interquartile range 52-64), 70.9% were men and 79.6% were of white ethnic background. When retinopathy grading data were compared against medical records, 69.8% and 49.8% had a diagnosis of DM and DR respectively. The majority (55.5%) had a HbA1c level in the diagnostic range for DM (mean 54.5 mmol/mol) and 47.2% self-reported using insulin. A diagnosis of HTN was recorded for 59.2%, while 55.1% self-reported taking anti-hypertensive medication and 73.6% had BP measurements in the hypertensive range. Overall, 95.1% had either DM or HTN (diagnosed or undiagnosed), while 63.0% had both. Of the 13 (4.9%) individuals without DM or HTN, 7 had only a single microaneurysm in one eye.

Conclusions : This is one of the largest prospective cohort studies containing validated grading data for retinopathy, showing a high prevalence of both DM and or HTN. These results demonstrate the quality of the retinal image grading and highlight the potential for detecting systemic pathology.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.