Abstract
Purpose::
To compare the safety and efficacy of intravitreal injection of pegaptanib sodium (Macugen) and panretinal photocoagulation (PRP) for treatment of proliferative diabetic retinopathy (PDR). Therapeutic intervention with pegaptanib sodium, a VEGF aptamer, should reduce the progression of PDR and thereby provide a beneficial effect in preventing severe vision loss due to PDR.
Methods::
In this randomized, prospective, open-label, exploratory study, patients with high-risk PDR received either intravitreal pegaptanib 0.3 mg every 6 weeks for 30 weeks or panretinal laser photocoagulation (PRP). If both eyes were eligible, one received pegaptanib and the other was treated with PRP. Ocular health assessments included an ophthalmic and medical history, protocol refraction and best-corrected visual acuity (BCVA; ETDRS), tonometry, ophthalmologic exam, color fundus photography, fluorescein angiography, optical coherence tomography, and visual field testing. Efficacy endpoints included regression of neovascularization, and changes from baseline in BCVA, retinal thickness, and area or volume of macular edema. Safety outcomes included reported and observed adverse events.
Results::
To date, 10 eyes from 10 subjects have received pegaptanib and 10 eyes from 10 others received PRP. After 3 weeks, 9 (90%) pegaptanib-treated eyes showed total regression and 1 (10%) partial regression; 8/9 (89%) remained completely regressed after 6 weeks. In contrast, 9/10 (90%) PRP-treated eyes remained active at weeks 3 and 6; 3 eyes improved from active to partial NV regression at week 6. After 3 weeks, mean change in BCVA was +3.7 letters in pegaptanib-treated eyes and -4.3 in those receiving PRP; mean change in BCVA was +4.9 and +6.5 letters, respectively, after 6 weeks. On average, foveal thickness and macular volume decreased with pegaptanib and increased with PRP at weeks 3 and 6. At 18 weeks, BCVA for the pegaptanib-treated eyes was +4 letters and +0.9 for the PRP group; mean change in BCVA was +2.6 and +0.2 letters, respectively, after 30 weeks. No recurrence of NVD and/or NVE was noted at week 30 for the pegaptanib-treated group. Ocular adverse events in pegaptanib-treated patients were transient and mild to moderate in intensity.
Conclusions::
Pegaptanib appears to effectively induce regression of PDR and decrease the anatomic extent of diabetic macular edema. Use of pegaptanib may reduce the need for and/or extent of PRP in PDR thus optimizing therapeutic results while diminishing iatrogenic effects inherent to retinal ablation. Longer follow-up is needed to confirm this hypothesis.
Clinical Trial::
In process Registration pending
Keywords: diabetes • diabetic retinopathy • retinal neovascularization