Anti-angiogenic therapy for retinal PED
Basal: VA = 34 letters (20/250)
Month 3: VA = 58 letters (20/80)
Month 1: VA = 59 letters (20/63)
While the data in the present study must be viewed as preliminary, they suggest that it may not be necessary to inhibit all VEGF isoforms for treatment of PED, in that selective inhibition of VEGF165 with pegaptanib produced comparable effects to bevacizumab. These findings are relevant to safety in that nonselective VEGF inhibition with ranibizumab was found be associated with a significantly higher incidence of nonocular hemorrhage compared to controls.31 In addition, early data from the SafetyAssessment of Intravitreal Lucentis for AMD (SAILOR) trial examining ranibizumab safety has indicated a significantly increased risk of stroke for the 0.5 mg versus 0.3 mg dose, prompting a physician advisory letter from the manufacturer which can be found at: http://www.fda.gov/medwatch/safety/2007/Lucen- tis_DHCP_01-24-2007.pdf. Whether these risks apply to
Month 6: VA = 68 letters (20/40)
bevacizumab, which is also a nonselective VEGF antagonist, is not known, since its use has not been evaluated in large, properly controlled trials.29
Figure 5 A 61-year-old female patient with a normal right eye having received no prior treatments was administered 4 injections of bevacizumab. A) Fundus photograph at baseline (left panel) and fluorescein angiography (right panel). B) Optical coherence tomography images and visual acuity (VA;EarlyTreatment Diabetic Retinopathy Study [ETDRS] letters) at baseline and months 1, 3, and 6.
The principal finding in this pilot study is that both selective VEGF inhibition with pegaptanib and nonselective VEGF inhibition with bevacizumab provided similar anatomical and functional benefits in the treatment of PED, with no safety signals having emerged. These results are similar to those seen in another recent pilot study with bevacizumab, also directed against PED secondary to AMD.30 In the present report the two agents provided qualitatively similar benefits, while pegaptanib-treated patients showed somewhat greater improvements in terms of mean visual acuity and retinal thickness despite the overall poorer baseline condition. The difference in the number of injections administered between the treatment groups was less than 10%, suggest- ing that undertreatment with bevacizumab was unlikely to be the cause. There also appeared to be a difference in the time courses of the responses to the two drugs, with patients receiving pegaptanib requiring a longer timeframe to achieve visual acuity improvements than bevacizumab, but one that was more sustained over the longer term. It is interesting that for both pegaptanib and bevacizumab the vision seemed to improve despite the fact that the PED size seems to have fluctuated over time.
Another issue of concern is the risk of RPE tears, a recog- nized complication of PED, in patients treated with anti-VEGF therapy. Chang and Sarraf 32 have analyzed reports of RPE tears for all three anti-VEGF agents in the treatment of AMD and found that a pre-existing PED was a common feature. Similar conclusions have been reached in other retrospective studies with bevacizumab.30,33,34 PED is a predisposing factor for RPE tears even in untreated patients, and it remains to be determined whether anti-VEGF therapy accelerates the natural history of these cases, or contributes an additional risk that may require other adjustments in treatment regimens.32
The main limitation of this study is that it enrolled only a small number of patients. Other limitations included a lack of randomization and the relatively short duration of follow-up. Therefore, these findings require confirmation in a larger randomized study, which could also answer questions regarding the optimal dose, long-term efficacy and safety, and criteria for retreatment.
The author reports no conflicts of interest in this work. This paper was supported with a grant from Pfizer Inc.
This study was presented as an oral presentation at the XI Vitreoretinal Spanish Society Congress (“XI Congreso de la Sociedad Española de Retina y Vítreo”), Madrid (16 February 2007).
1. Zayit-Soudry S, Moroz I, Loewenstein A. Retinal pigment epithelial detachment. Surv Ophthalmol. 2007;52:227–243.
Clinical Ophthalmology 2010:4
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