Purchase this article with an account.
L. Meeks, S. Martin, T. H. Tezel; A Normogram to Predict the Functional and Anatomical Outcome of Intravitreal Pharmacotheraphy for Diabetic Macular Edema. Invest. Ophthalmol. Vis. Sci. 2007;48(13):5036.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Intravitreal injections of steroids ( triamcinolone acetonide) and/or anti-VEGF agents (bevacizumab or ranibizumab) are currently used in the treatment of diabetic macular edema. However, presence of several confounding factors, i.e systemic hypertension and macular ischemia, makes it hard to predict the outcome. Herein, we used structural (= retinal thickness and hydration) and functional (= visual acuity) variables to develop a normogram for predicting the outcome of intravitreal injections.
Visual acuity, foveal thickness and hydration of 122 diabetic patients were plotted on a three-dimensional Lorentzian plot. This normogram was then used to analyze the functional and anatomical response to intravitreal pharmocotherapy in 14 patients that received bevacizumab (2.5 mg), 21 patients treated with triamcinolone acetonide (4 mg) and 5 patiens that were injected with a combination of bevacizumab (1.25 mg) and triamcinolone acetonide (2 mg). Each patient’s shift towards the ‘Ideal Point’ on the normogram was calculated for comparison.
Initial foveal hydration and thickness were similar between different treatment groups. Overall, patients receiving triamcinolone made greater progress towards the ‘Ideal Point’ (-36.6 ± 22.8 arbitary units vs. -13.7 ± 21.4 arbitary units for bevacizumab alone and -24.9 ± 48.0 arbitary units for triamcinolone/becvacizumab combination, p = 0.002). Triamcinolone injections also yielded much greater reductions of foveal thickness (25.2 ± 3.9% vs. 9.6 ± 4.1% for bevacizumab and 18.0 ± 11.8% for combined trimacinolone/bevacizumab injections). However, those receiving bevacizumab alone experienced greater gain in visual acuity (0.16 ± 0.03 vs. 0.01 ± 0.02 for triamcinolone acetonide injections and 0.03 ± 0.05 for combined injections, p < 0.001). Combining bevacizumab with triamcinolone resulted in a synergistic effect on foveal dehydration (36.2 ± 9.7% vs. 15.0 ± 14.3% for triamcinolone and 9.1 ± 9.6% for bevacizumab alone).
Reduction of foveal thickness and hydration in patients with diabetic macular edema does not necessarily translate into restoration of visual acuity. The outcome of intravitreal therapeutic agents can be predicted using structural and anatomical features which can avoid any unnecessary risks associated with intravitreal injections, such as hemorrhage, infection, retinal detachment and cataract formation. The visual gain in patients receiving bevacizumab suggests a possible neuroprotective effect of blocking VEGF receptors.
This PDF is available to Subscribers Only