Three new studies highlight advancements in anti-VEGF research for age-related macular generation and, in a first, diabetic retinopathy.
• Intravitreal injections of Avastin (bevacizumab, Genentech/Roche) improved visual acuity and reduced macular thickness in patients with neovascular age-related macular degeneration, according to a study in the October issue of the British Journal of Ophthalmology.1 The authors examined 44 eyes with neovascular AMD that received an average of 2.6 intravitreal injections of bevacizumab during a mean of 3.9 months. At final examination, nine eyes demonstrated reduced visual acuity, 10 eyes had stable visual acuity and 25 eyes exhibited improved visual acuity from baseline measurements. Furthermore, the authors documented a reduction in mean macular thickness from 332µm to 248µm.
“Any patient with active choroidal neovascularization secondary to AMD should be treated [with anti-vascular endothelial growth factor compounds] as long as the lesion is active, there are no severe side effects, and the eye has a potential for useful vision,” says senior author Itay Chowers, M.D., of the Hadassah-Hebrew University School of Medicine in Jerusalem.
• Patients with AMD may develop elevated intraocular pressure following injections of bevacizumab or ranibizumab (Lucentis, Genentech/Roche), according to data presented at the Scientific Program of the 2009 Joint Meeting of the American Academy of Ophthalmology.2 In a recent study at the Yale University of Medicine, researchers examined 116 subjects with wet AMD who received intravitreal injections of either bevacizumab or ranibizumab from 2006 to 2008. Four of the patients developed a significant and persistent rise in IOP.
“To our knowledge, ours is the first study to document persistent ocular hypertension following intravitreal bevacizumab injections in patients with no personal or family history of glaucoma or ocular hypertension,” says study leader Ron A. Adelman, M.D., M.P.H. “Patients’ ocular hypertension may continue over several AMD treatments and may require IOP-lowering therapy.”
• Intravitreal injections of Macugen (pegaptanib sodium, EyeTech/Pfizer) showed significantly greater success at reducing diabetic retinal neovascularization than pan-retinal laser photocoagulation (PRP), according to a study in the November issue of the British Journal of Ophthalmology.3 The researchers randomly assigned 20 subjects with active proliferative diabetic retinopathy (PDR) into either a pegaptanib sodium treatment group or a PRP laser group. The subjects in the pegaptanib sodium group received five 0.3mg injections during a 36-week period.
At 36-week follow-up, all subjects in the pegaptanib sodium group exhibited complete regression of PDR compared to just two subjects in the PRP laser group. Additionally, subjects in the pegaptanib sodium group demonstrated a mean improvement in best-corrected visual acuity of 5.8 Snellen letters, where as subjects in the PRP laser group experienced a loss of 6.0 Snellen letters.
“This limited study suggests that Macugen may have the potential to produce marked and rapid short-term regression of diabetic neovascularization,” says lead author Victor H. Gonzalez, M.D., medical director of the Valley Retina Institute in McAllen, Texas. “The fact that the regression was maintained throughout the study is particularly encouraging.”
“Further research is needed to determine if Macugen is a safe and effective treatment for PDR,” adds Dr. Gonzalez. “There are currently no approved pharmacologic treatments for patients with diabetic retinopathy.”
1. Galbinur T, Averbukh E, Banin E, et al. Intravitreal bevacizumab therapy for neovascular age-related macular degeneration associated with poor initial visual acuity. Br J Ophthalmol. 2009 Oct;93(10):1351-2.
2. Adelman RA. Wet macular degeneration treatment may increase intraocular pressure. Lecture presented at the 2009 Joint Meeting of the American Academy of Ophthalmology. San Francisco, October 24-27, 2009.
3. Gonzalez VH, Giuliari GP, Banda RM, Guel DA. Intravitreal injection of pegaptanib sodium for proliferative diabetic retinopathy. Br J Ophthalmol. 2009 Nov;93(11):1474-8.