Throughout the COVID-19 outbreak, various health and safety protocols have been prioritized to help protect our communities, impacting ophthalmology practices by reducing the number of patients seen in person. As a result, many patients have had to endure treatment delays, potentially impairing the effectiveness and outcomes of therapy. Patients who have been unable to maintain routine treatment during the pandemic include those being treated with anti-vascular endothelial growth factor (VEGF) therapy. Even if treatment was reinitiated within six months, a recent study found that patients undergoing anti-VEGF for retinal disease had worse visual and anatomical outcomes than those treated regularly throughout the pandemic, suggesting that the damage from delayed treatment may be irreversible.

A total of 234 adult patients were included in the study and split between two groups: the study group (129 patients who experienced a treatment delay during the pandemic) and the control group (105 patients who received regular care throughout the pandemic). The study group resumed treatment (receiving at least two anti-VEGF injections) between six weeks and six months following the delay (mean delay time was 11.8 weeks). All patients had either neovascular age-related macular degeneration, diabetic macular edema or retinal vein occlusion. Measured outcomes included changes in visual acuity and central macular thickness (CMT) on optical coherence tomography (OCT).

Overall, visual outcomes for the study group were quite poor compared with the control group. Upon resumption of treatment, visual acuity in the study group worsened from 0.38 logMAR at baseline to 0.65 logMAR, and CMT on OCT worsened from 279.9µm at baseline to 381.9µm following anti-VEGF treatment delay. After six months of resumed anti-VEGF injections, visual acuity in the study group improved non-significantly from 0.65 logMAR to 0.58 logMAR, still worse than baseline, and CMT on OCT worsened from 279.9µm to 308.1µm. These results show that delayed treatment had a notable impact on visual acuity in anti-VEGF patients. 

On the other hand, the control group had much better luck receiving continuous treatment. Visual acuity improved from 0.44 logMAR at baseline to 0.33 logMAR at six months, and CMT on OCT improved from 298.9µm at baseline to 271.2µm after follow-up. 

“Three times as many patients in the study group lost three or more lines of visual acuity compared with patients who received continuous care in the control group during the study period, and about twice as many patients in the study group had visual acuity worse than the baseline value compared with the control group at the end of the study period,” the researchers wrote in their study. “The final logMAR visual acuity was almost twice as high in the study group compared with the control group at the end of the study period, highlighting the devastation that delay in anti-VEGF treatment can have on patients.”

Due to the possibility of permanent vision damage and worsened visual outcomes, delays in anti-VEGF treatment for patients with retinal disease should be avoided at all costs, the researchers concluded.

Rush PR, Rush SW. Outcomes in patients resuming intravitreal anti-VEGF therapy following treatment delay during the COVID-19 pandemic. Retina. August 2, 2021. [Epub ahead of print].