Acute Vision Loss Remains a Threat in Neovascular AMD, Despite Anti-VEGF Injections

Acute vision loss of at least 3 lines affects 39.5% of patients with neovascular age-related macular degeneration (nAMD), despite treatment with continuous anti-vascular endothelial growth factor (VEGF) injections, according to a study published in Retina. Most patients’ vision loss was recovered temporarily, however, they experienced a poor visual outcome after 4 years of follow-up, the researchers explain.

A total of 76 eyes of 76 patients were diagnosed with nAMD at the Nagasaki University Hospital between January 2013 and December 2016 and were found eligible to participate in the study. 

All patients received an initial loading dose of 3 monthly injections and were then treated according to a treat-and-extend regimen. 

The main outcome measure was the incidence of acute vision loss, defined as 3 lines of vision loss compared with the previous examination. Best-corrected visual acuity (BCVA) was measured using Landolt C and converted to logMAR for statistical analysis.

The researchers found acute vision loss in 30 eyes (39.5%) at a median follow-up time of 11.5 months after the initial treatment and a median period of 52 days from the last injection. No difference was found between patients treated with aflibercept and ranibizumab. 

The team presumed a number of findings could be responsible for the vision loss. These include an increase/development of subretinal fluid (4 eyes, 13.3%), increase/development of subretinal hemorrhage (4 eyes, 13.3%), increase in macular edema (3 eyes, 10.0%), development of macular atrophy (3 eyes, 10%), formation of fibrotic scar (3 eyes, 10%), formation of retinal pigmented epithelium tear (3 eyes, 10%, occurred only during the first year), increase/development of subretinal hyperreflective material (2 eyes, 6.7%), progression of cataract (4 eyes, 13%), severe retinal schisis due to progressive traction (1 eye, 3.3%). The remaining 3 eyes had no findings that explained their vision loss.

When compared with patients without vision loss, patients with vision loss had lower baseline BCVA, larger central retinal thickness, and more frequent disruption of the external limiting membrane, and the ellipsoid zone. The same parameters were also found to have lower survival on the Kaplan-Meier survival curve. Both baseline BCVA and ellipsoid zone disruption remained important predictors of acute vision loss in logistic regression analysis.

The team also found that half of the patients with vision loss experienced it during the first year. That indicates the importance of the initial treatment, they explain. 

While 4 patients experienced permanent vision loss, the rest improved to their prevision loss level with continued injections and other treatments such as cataract surgery. The frequency of patient dropouts and cessation was found to be increased by acute vision loss, according to previous studies. “Our data, suggest that visual acuity is likely to improve with continued long-term treatment in most cases. Therefore, encouraging patients to continue treatment would help their recovery”, the researchers explain. “Even when vision loss is temporary, these patients are at higher risk of gradual loss of vision in the long term.” 

The limitation of the study includes its retrospective nature and dropouts of patients from follow-up.