Evaluation of a calculation model to estimate the impact of the COVID-19 pandemic lockdown on visual acuity in neovascular AMD

Author: Martin Stattin (Austria)

Co-authors: Anna-Maria Haas, Daniel Ahmed, Alexandra Graf, Katharina Krepler, Siamak Ansari-Shahrezaei

Purpose

To evaluate a calculation model performed during the Austrian coronavirus disease 2019 (COVID-19) pandemic lockdown to estimate the effect of short-term treatment interruption due to health care restrictions on visual acuity (VA) in exudative neovascular age-related macular degeneration (nAMD).

Setting/Venue

Retrospective data collection of 142 eyes in 142 patients receiving repeated intravitreal injections with anti-vascular endothelial growth factor at the Medical Retina Unit service (Rudolf Foundation Hospital, Vienna) in a personalized pro re nata regimen prior to the COVID-19 associated lockdown, when treatment was deferred between March 16 and May 4, 2020.

Methods

During the lockdown, the preliminary data was integrated into pre-existing formulae based on the natural course of the disease in the long term. Patients were re-scheduled and treated after gradually opening operating rooms. The calculation model was compared to the effective VA change.

Results

The model calculated an overall VA loss of 3.5±0.8 letters early treatment diabetes retinopathy study (ETDRS) (p<0.001 [95% CI:3.3;3.6]) on average compared to 2.5±6 letters ETDRS (p<0.001 [95% CI:1.5;3.5]) as measured after re-opening the doors with a mean treatment delay of 61±14 days. The total difference between the model exercise and the real-life outcomes accounted for 1±5.9 letters ETDRS (p=0.051 [95% CI:0;2]).

Conlusions

The herein presented calculation model might not be suitable to estimate the effective VA loss correctly. Untreated eyes and eyes under previous therapy behave differently after short-term treatment interruption. However, this study demonstrated the potentially negative impact of the COVID-19 pandemic lockdown on patients compromised by nAMD.

Financial Disclosure

No financial disclosure