The importance of early diagnosis and regular treatment to prevent progression of eye diseases like glaucoma and diabetic retinopathy is often discussed. How about treatment as prophylaxis to prevent vision loss for individuals who are at risk of developing but don’t yet have an active disease?

Two studies published in JAMA Ophthalmology suggest that early treatment may delay the start of disease or slow progression but does not significantly improve vision loss which is one of the key outcomes you look for in a treatment.

In the first study, Dr. Michael Kass (Washington University), examined long term data from a landmark 2002 clinical trial. This study established that eye drops were effective at lowering eye pressure and reducing progression to primary open-angle glaucoma in patients who had elevated eye pressure but did not yet have glaucoma.

However, 20 years later researchers discovered that only 25% of individuals had vision loss from glaucoma, lower than expected. In addition, patients who had received early eye drops only had a slightly lower risk of vision loss than the control group who didn’t
receive drops until seven years into the study. Based on this data, Dr. Kass suggests that doctors should discuss personal risk factors with their patients. Patients with elevated eye pressure but at lower risk of developing glaucoma may be able to delay starting drops as long as they are receiving regular and frequent monitoring so that
treatment can start if glaucoma damage appears.

The second study presents two-year data from a trial looking at early anti-VEGF treatment for diabetic retinopathy (DR). In the early stages of DR, blood vessel growth in the retina can be seen, but there usually isn’t any impact on vision. If the vessels continue to grow this can lead to proliferative DR or diabetic macular edema (DME).

This study divided patients with non-proliferative DR into two groups. The early treatment group received anti-VEGF injections. The second group, the control group, did not receive anti-VEGF injections unless their disease progressed, at which point they started treatment.

Patients receiving early anti-VEGF developed less proliferative DR or DME compared to patients in the control group (14% vs 33%). Interestingly, despite this, after two years the amount of vision loss was essentially the same between the early treatment and control group.

Researchers say it’s important to see if this trend continues after longer follow up. The data suggests that if patients are closely monitored, treatment could be delayed until DR has progressed since early treatment does not appear to significantly improve vision.

In both of these studies, the researchers aren’t advocating for no treatment, but instead suggesting that individuals who are ableto receive regular monitoring and are at lower risk of disease progression could delay the start of treatment until active disease begins.