Predicting the immediate impact of national lockdown on neovascular age-related macular degeneration and associated visual morbidity: an INSIGHT Health Data Research Hub for Eye Health report

Abstract

Objective: Predicting the impact of neovascular age-related macular degeneration (nAMD) service disruption on visual outcomes following national lockdown in the UK to contain SARS-CoV-2.

Methods and analysis: This retrospective cohort study includes deidentified data from 2229 UK patients from the INSIGHT Health Data Research digital hub. We forecasted the number of treatment-naïve nAMD patients requiring anti-vascular endothelial growth factor (anti-VEGF) initiation during UK lockdown (16 March 2020 through 31 July 2020) at Moorfields Eye Hospital (MEH) and University Hospitals Birmingham (UHB). Best-measured visual acuity (VA) changes without anti-VEGF therapy were predicted using post hoc analysis of Minimally Classic/Occult Trial of the Anti-VEGF Antibody Ranibizumab in the Treatment of Neovascular AMD trial sham-control arm data (n=238).

Results: At our centres, 376 patients were predicted to require anti-VEGF initiation during lockdown (MEH: 325; UHB: 51). Without treatment, mean VA was projected to decline after 12 months. The proportion of eyes in the MEH cohort predicted to maintain the key positive visual outcome of ≥70 ETDRS letters (Snellen equivalent 6/12) fell from 25.5% at baseline to 5.8% at 12 months (UHB: 9.8%-7.8%). Similarly, eyes with VA <25 ETDRS letters (6/96) were predicted to increase from 4.3% to 14.2% at MEH (UHB: 5.9%-7.8%) after 12 months without treatment.

Conclusions: Here, we demonstrate how combining data from a recently founded national digital health data repository with historical industry-funded clinical trial data can enhance predictive modelling in nAMD. The demonstrated detrimental effects of prolonged treatment delay should incentivise healthcare providers to support nAMD patients accessing care in safe environments.

Trial registration number: NCT00056836.

Keywords: COVID-19; clinical trial; neovascularisation.

Conflict of interest statement

Competing interests: None declared.

© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.

Figures

Figure 1

Period trends of anti-vascular endothelial growth factor (anti-VEGF) treatment initiation for neovascular age-related macular degeneration (nAMD). Actual (solid line) and predicted (solid line with CIs) number of patients per week needing to initiate anti-VEGF therapy for nAMD at Moorfields Eye Hospital (MEH) (top panel; blue) and University Hospitals Birmingham (UHB) (bottom panel; green); 95% (grey) CI are depicted.

Figure 2

Sampling and matching process to generate cohorts for predicting visual acuity (VA) changes. Flow diagram outlining how patient profiles were generated to model VA changes during a national lockdown. In brief, profiles for the number of neovascular age-related macular degeneration (nAMD) patients forecasted to initiate anti-vascular endothelial growth factor (anti-VEGF) therapy between 16 March 2020 and 31 July 2020 were randomly selected from the pool of patients who initiated therapy in the same period in the two preceding years at Moorfields Eye Hospital (MEH) and University Hospitals Birmingham (UHB). These profiles were matched to patients in the sham-control arm of the Minimally Classic/Occult Trial of the Anti-VEGF Antibody Ranibizumab in the Treatment of Neovascular AMD (MARINA) study on sex, age, VA, VA ≥70 and VA ≤20 at treatment initiation. Some MEH and UHB patients could not be matched to MARINA patient profiles, due to the trial exclusion criteria. Predicted changes in these patients were based on a linear model of VA changes developed from the trial population and extrapolated to the unmatched population. The number of matched and unmatched patients for both NHS Trusts is shown.

Figure 3

Projected visual acuity (VA) thresholds. Bar charts representing the proportion of study eyes for the Moorfields Eye Hospital (MEH) (blue) and University Hospitals Birmingham (UHB) (green) predicted cohorts over time to (A) achieve a VA of ≥70 ETDRS, (B) fall below a VA of 25 ETDRS letters and (C) have a VA of ≤20 ETDRS letters. Matched and unmatched cohorts were combined for this analysis. Last observation was carried over to keep constant denominators.