The impact of COVID-19 on delivering intravitreal therapy to patients with diabetic macular edema

ABSTRACT

Purpose: To evaluate the effectiveness of our treatment guideline for intravitreal injections (IV), which was implemented in diabetic macular edema (DME) patients. Methods: Retrospective analysis of medical case reports in patients who had an IV appointment at Centro Hospitalar e Universitário do Porto. The first aspect of this analysis was the impact of COVID-19 on treatment appointments by comparing the lockdown period (22 March 2020 - 2 May2020) with the same period in 2019. The second aspect quantified the number of DME patients with delayed treatments based on a COVID-19 treatment guideline (see Figure 1). The impact of delayed appointments was assessed based on best-corrected visual acuity (BCVA) and central foveal thickness (CFT) prior to COVID-19 and then immediately after a missed appointment at the outset of COVID-19 and 6 months after the pandemic began. Results: In 2019, 693 medical retina patients received an IV. During the same period in 2020, 272 maintained their IV appointment, 391 patients experienced a delay and 80 patients missed their IV. 132 DME patients (mean age 70.6 ± 9.7 years;59.1% females) had a delayed IV and were subsequently evaluated following a missed appointment and then 6 months after lockdown began. Prior to COVID-19, mean BCVA was 61.9±19.0 ETDRS letters and CFT was 361±140 μm. Then, immediately after the COVID-19 lockdown and the missed appointment, BCVA and CFT were 59.4±21.1 ETDRS letters and 355±132 μm, respectively. These then improved to 67.7±15.6 ETDRS letters and 314±84 μm, respectively, 6 months after the onset of COVID-19. In the appointment after the delayed IV, a clinical decision was taken to increase the time between IV in 50.8% of patients;to shorten it in 4.5%;in 39.0% it could be kept the same;and, in 5.7%, therapy was switched. Conclusions: These data show that during the enforced COVID-19 lockdown, about half of all our IV appointments were delayed. This had an immediate impact on DME patient's vision as demonstrated by the small reduction in BCVA, which was reversed after reimplementation of DME treatment according to the standard of care, with BCVA and CFT improvement. This highlights the importance of treatment guidelines but also the value of longer duration treatments that can be used to minimize the potential negative impact of interruptions to DME therapy.