Researchers at the Johns
Hopkins Wilmer Eye Institute and 14 clinical centers
United States have shown that the drug ranibizumab can
reduce retinal thickness and improve the
visual acuity of patients with diabetic macular edema, or
DME, better than the current standard
treatment, laser photocoagulation.
"The READ-2 study results are promising and show that
ranibizumab injection into the eyes
improves vision by resolving retinal thickening much better
than laser photocoagulation," said Quan
Dong Nguyen, an assistant professor of ophthalmology at
Johns Hopkins' Wilmer Eye Institute.
Macular edema, one of the most common causes of
blindness among working-age people, occurs
when fluid and protein deposits collect on or under the
macula of the eye, a yellow central area of the
retina, causing it to thicken and swell.
The READ-2 (Ranibizumab for Edema of the mAcula in
Diabetes phase 2) Study examined 126
diabetic patients with an average age of 62 years. The
majority of participants had chronic DME with
20/80 vision. Patients were randomly assigned to one of
three groups: ranibizumab injection alone,
focal laser photocoagulation alone or a combination of
ranibizumab injection plus focal laser
photocoagulation. At each visit over the course of six
months, patients were evaluated for vision,
retinal thickening and general eye health. Although the
study ended at six months, patients will be
followed for two years.
Eyes treated with ranibizumab had a mean visual acuity
of 20/63+3 at month six compared to a
mean visual acuity of 20/80+2 in the laser group and
20/80+3 in the combination treatment group. In
addition, eyes treated with ranibizumab had a 56 percent
reduction in excess retinal thickness
compared to only an 11 percent reduction in laser treated
"Although the results of this study are promising, a
several-year-long phase 3 randomized trial
is needed to determine the ultimate value of ranibizumab
for patients with DME," Nguyen said. Two
phase 3 trials currently are under way.
The research project is funded in part by Genentech;
Nguyen is not a paid consultant.
The results of the study were presented at the 2008
Annual Meeting of the Association for
Research in Vision and Ophthalmology, held April 27 to May
1 in Fort Lauderdale, Fla.