Delaying Intravitreal Injections May Lead to Short-Term Visual Acuity Loss

Patients being treated with intravitreal injections for DME, RVO, or nAMD who delay treatment may experience visual acuity loss in the short term, but not in the long term.

Interruption in care for patients treated with intravitreal injection affects vision outcomes in the short term, but not in the long term, according to research published in the Journal of VitreoRetinal Diseases. Patients with neovascular age-related macular degeneration (nAMD), diabetic macular edema (DME), or retinal vein occlusion (RVO) who experience a delay in care of 5.7 weeks or longer demonstrate these short-term effects, the researchers explain.

This retrospective study reviews all patients scheduled to see a retina provider at Cleveland Cole Eye Institute during a month-and-a-half period when clinic downsizing was implemented due to the COVID-19 pandemic.

Included patients had a diagnosis DME, nAMD, or RVO. They had an injection during the previous 12 weeks (baseline visit) and a follow-up visit at least 12 months after the baseline visit.

Patients were grouped into a completed-care or delayed-care group, depending on whether they completed or missed their first scheduled visit. At each visit, the VA was measured using a Snellen chart and the values were converted to Early Treatment Diabetic Retinopathy Study (ETDRS) letters for analysis. Primary endpoints included changes in visual acuity (VA) from the baseline visit to the next completed visit and last visit. Additional endpoints included the mean central subfield thickness (CST) as measured by optical coherence tomography (OCT) at each visit, change in VA stratified by diagnosis, and causes of significant VA loss (≥15 ETDRS letters).

In this current study, we further found that in the short term, patients lost 15 or more ETDRS letters, mostly as a result of worsening retinal fluid.

A total of 1172 patients were included in the study. Of those, 725 (62%) were allocated to the completed-care group and 447 (38%) to the delayed-care group. 

The investigators report a short-term VA loss in the delayed-care group and a short-term gain of vision in the completed-care group. No statistically significant long-term change in vision was found in either group. 

The team found a statistically significant short-term VA loss between the baseline and first completed visit in patients with nAMD (-1.34±0.50 ETDRS; P =.0203) and RVO (-5.23±1.28 ETDRS; P =.0012) that had a delay in care, as well as a statistically insignificant VA loss in patients with DME (-1.42±1.61; P =.5568). Patients with DME and timely care had significantly significant short-term VA gains (4.18±1.33 ETDRS; P =.0021). Participants with nAMD lost vision in the long-term visit in both the completed and delayed groups. Patients with RVO and DME, and delayed care did not show a significant long-term change in vision, while patients with DME in the completed-care group maintained their gain in vision.

A statistically significant short-term increase in mean CST was observed in the delayed-care group, while no significant short-term change was found in the completed-care group. CST at one year decreased significantly in both groups when compared with the baseline CST.

“In this current study, we further found that in the short term, patients lost 15 or more ETDRS letters, mostly as a result of worsening retinal fluid. This was most pronounced in patients who had delayed care,” the researchers report. “After 1 year, patients with DME and without delayed care maintained vision gains that were not observed in patients with delayed care, while patients with RVO and delayed care regained vision that was lost and nAMD patients in both the on-time care and delayed-care groups experienced VA loss that possibly reflected chronic disease progression.”

The limitations of the study include its retrospective nature and lack of information on disease and treatment duration.

References:

Song W, Kanyo E, Bastian R, Singh RP, Rachitskaya A V. Visual acuity in patients requiring intravitreal injections : short-term and long-term effects of delay in care. Published online December 16, 2022. doi:10.1177/24741264221136637