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Purpose: To present a new epidemiological method relying on randomized controlled clinical trial (RCT) data to assess whether a treatment was effective, aiding in the decision to continue or stop the treatment in clinical patients., Methods: A cutoff point is calculated in the change of a continuous outcome for which a proportion of treated patients clearly achieved a change better than this cutoff point as a result of the treatment. This cutoff point can then be applied to individual patients during routine therapy. The method was applied to reports of the Minimally Classic/Occult Trial of the Anti-VEGF Antibody Ranibizumab in the Treatment of Neovascular AMD (MARINA) trial, which included patients with AMD treated with monthly intravitreal injections of ranibizumab, and to reports of trials involving patients with high IOP, macular edema, and convergence insufficiency., Results: The cutoff point in the change in visual acuity (number of letters), above which a proportion of patients clearly benefited due to ranibizumab treatment, was -5.0 at 24 months follow-up. The proportion of treated patients who ended above this cutoff point due to the treatment was 60%. The cutoff point varies with time of follow-up and by subgroup., Conclusions: Contrary to common interpretation, no change, or a limited decline, in the outcome (visual acuity) can still imply that the patients are better off with the treatment than with no treatment. Stopping the treatment above the cutoff point may not be appropriate since it was effective in at least a proportion of patients. This method applies to a broad range of scales and conditions. (ClinicalTrials.gov number, NCT00056836.).

Purpose: Transforming growth factor (TGF)-beta2 and hepatocyte growth factor (HGF) have been implicated in the pathogenesis of proliferative vitreoretinopathy (PVR) after retinal detachment surgery. The exact role of these factors in the early events, immediately after primary retinal detachment, is not yet known, and determining their roles was therefore the purpose of this study., Methods: Subretinal fluids were collected prospectively from 144 patients during surgery for scleral buckling. TGF-beta2 and HGF were measured with commercially available ELISA kits. Thirty patients in whom a redetachment caused by postoperative PVR developed, were compared with 114 patients with an uncomplicated retinal detachment. The controls included 18 vitreous samples from patients with macular hole or pucker. Multivariate regression analysis was used to compare the relative roles of growth factors and clinical factors in the development of PVR., Results: The median amount of subretinal TGF-beta2 was approximately two times lower in patients with postoperative PVR (1.9 ng/mL) than in the uncomplicated detachment group (3.3 ng/mL; P=0.002). TGF-beta2 levels in the PVR-positive group were similar to control vitreous levels (1.8 ng/mL). Subretinal HGF concentrations were not significantly different between the two groups of patients (PVR positive: 8.8 ng/mL; PVR negative: 8.9 ng/mL), but were higher than control vitreous levels (4.6 ng/mL; P=0.01). Stepwise multivariate logistic regression analysis revealed that of all factors under study, decreased TGF-beta2 content was the exclusive predictor of postoperative PVR (P=0.01)., Conclusions: High TGF-beta2 levels in subretinal fluid at the time of primary retinal detachment may protect a patient against subsequent development of PVR.