APR 25, 2011
This retrospective chart review compared 12-month outcomes of ranibizumab (Lucentis) treatment using the loading dose (LD) or pro re nata (PRN) dosing protocols in treatment-naïve wet AMD patients. The results indicate that a loading dose followed by monthly injections was superior to OCT-guided re-treatment on a PRN basis among these patients.
Subjects in the study were 78 consecutive patients (78 eyes) who received initial treatment for wet AMD with intravitreal ranibizumab (0.5 mg/0.05 ml) at one hospital in London and were followed for at least 12 months. Thirty-one eyes were treated from baseline under the PRN regimen based on OCT-guided re-treatment criteria immediately after the drug was licensed but before the National Institute of Health and Clinical Excellence had approved use of the drug on an LD basis. The LD protocol, under which the other 47 eyes were subsequently treated, consists of three initial injections at monthly intervals followed by OCT-guided re-treatment.
The study's authors found no significant differences in mean changes in visual acuity or central macular thickness between the treatment groups. Visual acuity was similar in the two groups at six months. However, 29.8 percent of patients in the LD group gained 15 or more letters compared with 12.9 percent in the PRN group (P = 0.01).
The authors conclude that despite the significant increase in the number of hospital visits for patients, increased work load for retinal specialists and consequent increase in economic burden to healthcare providers, this study and review of published studies show that improvement in visual acuity in treatment-naïve wet AMD patients given ranibizumab is best achieved with a loading dose of three injections and higher rate of injections.