The As-Needed Treatment Strategy for Choroidal Neovascularization: A Feedback-Based Treatment System

摘要: HOROIDAL NEOVASCULARIZATION (CNV) SECONDary to age-related macular degeneration (AMD) causes decreased visual acuity (VA) through a variety of mechanisms including intraretinal edema, subretinal fluid (SRF), hemorrhage, fibrosis and scarring, disruption the photoreceptors. Treatment CNV secondary AMD with monthly injections ranibizumab (Genentech Inc, South San Francisco, California, USA), an antibody fragment that avidly binds vascular endothelial growth factor (VEGF), exudation cessation CNV, concomitant stabilization or improvement in VA. 1,2 Although dosing frequency once month proved effective, optimal schedule is not known. Optimal, meaning most desirable, inevitably defined relation specific viewpoint. Given personal societal burden lifelong treatment, testing alternate strategies decrease treatment was logical first step. In highly influential Prospective Optical coherence tomography (OCT) imaging patients Neovascular Treated intraOcular (PrONTO) Study, 3,4 Rosenfeld associates gave for 3 consecutive doses. Patients were then evaluated at intervals using OCT signs accumulation offluid (SRF cystoid edema) within macula. VEGF one powerful agents causing increased permeability; accumulating macula potentially serves as intraocular indicator local levels. given reinjection if they demonstrated accumulation. Leakage seen during fluorescein angiography (FA), which done quarterly intervals, served another criterion administer intravitreal injection ranibizumab. Mimicry may be highest form flattery, but mimicry aids comparison scientific studies (Table). Bashshur 5,6 modeled study bevacizumab Inc) after PrONTO Study exquisite detail. After up doses 2.5 mg showed by examination had leakage FA intervals. Similar majority on basis findings. However, there significant difference OCT-based criteria. Whereas mandated any persistent fluid, occurred patient met 1 different fluid-related criteria: recurrence SRF cystic maculopathy previously dry lesion, increase central retinal thickness more than 100 m from lowest recorded value, 5 letters best-corrected VA associated OCT. Note no provision reinject only fluid. Thus it possible could have even subtly increasing get unless 5-letter acuity. are unavoidable differences limit direct results, tempting do so. The results both broadly comparable. striking similarity 3-line responder rate (that is, proportion experiencing acuity) 43% groups. mean change appeared somewhat different, reported completing study. This did include who developed submacular lost 31 acuity, dropped out