Fixed-Interval Treatment Showing Promise for Macular Degeneration

Laird Harrison

August 11, 2014

SAN DIEGO — Fixed-interval dosing with vascular endothelial growth-factor (VEGF) inhibitors might be more effective than as-needed dosing, a new study shows.

"It's a safe, effective means of treating wet macular degeneration," Marc Peden, MD, from the University of Florida in Gainesville, said here at the 32nd Annual Meeting of the American Society of Retina Specialists.

Concerns about geographic atrophy with VEGF inhibitors has led some clinicians to reduce dosing by using an as-needed or treat-and-extend approach.

Although previous research has shown good results with fixed-interval dosing for up to 2 years, longer-term data are lacking, said Dr. Peden. To help fill that gap, he and his team retrospectively analyzed data on macular degeneration patients treated at fixed intervals with ranibizumab, bevacizumab, or aflibercept at the University of Florida.

They identified 109 eyes with 5 years of follow-up data, 74 eyes with 6 years, and 44 eyes with 7 years. The patients received an average of 10.5 injections per year. To measure visual acuity, they converted Snellen vision data recorded at each injection to logMAR and then letter values.

The team documented a peak gain of 16.1 letters at 2 years, and then a mean decline of approximately 0.54 letters per year over the next 5 years. Still, driving vision was maintained by 46.8% of patients at 5 years and by 43.2% at 7 years.

Table. Change in Visual Acuity Measured by Letters

Baseline Vision 5 Years 7 Years
≤20/200 +24.5 +25.5
20/50 to 20/100 +6.7 +6.9
20/20 to 20/40 +3.7 +3.4


"Geographic atrophy did not appear to have an impact on visual acuity outcomes," Dr. Peden said, although he acknowledged that the researchers did not measure this directly. He also noted that selection bias could have affected the results if patients with worse results dropped out.

In previous studies, such as HORIZON and SEVEN-UP, patients lost visual acuity sharply after their dosing was given on an as-needed or treat-and-extend basis, Dr. Peden reported.

This is the longest-term evaluation of fixed-interval dosing, said session moderator Suber Huang, MD, from Case Western Reserve University in Cleveland, who was not involved in the study.

"It suggests that this is effective long-term," said Dr. Huang told Medscape Medical News

Dr. Peden reports a financial relationship with Genentech. Dr. Huang reports financial relationships with Bausch + Lomb, Lumoptik Eye, and Second Sight.

32nd Annual Meeting of the American Society of Retina Specialists (ASRS). Presented August 9, 2014.


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