Careful observation a must for central retinal vein occlusion

Fort Lauderdale, FL-Monthly intravitreal injections of ranibizumab (Lucentis, Genentech) for central retinal vein occlusion (CRVO) is effective, but careful, long-term observation is often necessary to maintain a positive treatment benefit when shifting to an as-needed treatment regimen.

Ranibizumab injections to treat CRVO result in increases in visual acuity but based on previous studies it is unclear how long the intravitreal injections must continue to be administered to achieve stabilized vision.

In the first study, the patients received three injections of ranibizumab in the first few months and then quarterly injections on an as-needed basis for 1 year. The results were not favorable. In the second study, patients received monthly as-needed injections for 1 year. Both groups were switched to monthly as-needed ranibizumab injections at the physician's discretion for recurrent or persistent macular edema at the start of the second year. Both cohorts had a substantial decrease (average, 300 μm) in the macular thickness after the first intravitreal injection; that decrease in retinal thickness disappeared and the visual acuity deteriorated below the baseline level in the first group with the start of quarterly injections. This increase in retinal thickness did not occur in the second group who received as-needed injections of ranibizumab for 1 year; however, some patients had CRVO that was refractory to treatment, Dr. Avery said.

Some patients in each cohort gained best-corrected visual acuity: 40% in each cohort gained three or more lines of vision by the 3-year examination. In the second group, 30% lost three lines of vision at the last visit. In some patients in the first group, investigators observed a rebound in central retinal edema, in which the edema resolved and returned during periods of no treatment.