METformin for the MINimization of Geographic Atrophy Progression (METforMIN): A Randomized Trial.

Purpose: Metformin use has been associated with a decreased risk of age-related macular degeneration (AMD) progression in observational studies. We aimed to evaluate the efficacy of oral metformin for slowing geographic atrophy (GA) progression. Design: Parallel-group, multicenter, randomized phase II clinical trial. Participants: Participants aged ≥ 55 years without diabetes who had GA from atrophic AMD in ≥ 1 eye. Methods: We enrolled participants across 12 clinical centers and randomized participants in a 1:1 ratio to receive oral metformin (2000 mg daily) or observation for 18 months. Fundus autofluorescence imaging was obtained at baseline and every 6 months. Main Outcome Measures: The primary efficacy endpoint was the annualized enlargement rate of the square root-transformed GA area. Secondary endpoints included best-corrected visual acuity (BCVA) and low luminance visual acuity (LLVA) at each visit. Results: Of 66 enrolled participants, 34 (57 eyes) were randomized to the observation group and 32 (53 eyes) were randomized to the treatment group. The median follow-up duration was 13.9 and 12.6 months in the observation and metformin groups, respectively. The mean ± standard error annualized enlargement rate of square root transformed GA area was 0.35 ± 0.04 mm/year in the observation group and 0.42 ± 0.04 mm/year in the treatment group (risk difference = 0.07 mm/year, 95% confidence interval = -0.05 to 0.18 mm/year; P = 0.26). The mean ± standard error decline in BCVA was 4.8 ± 1.7 letters/year in the observation group and 3.4 ± 1.1 letters/year in the treatment group (P = 0.56). The mean ± standard error decline in LLVA was 7.3 ± 2.5 letters/year in the observation group and 0.8 ± 2.2 letters/year in the treatment group (P = 0.06). Fourteen participants in the metformin group experienced nonserious adverse events related to metformin, with gastrointestinal side effects as the most common. No serious adverse events were attributed to metformin. Conclusions: The results of this trial as conducted do not support oral metformin having effects on reducing the progression of GA. Additional placebo-controlled trials are needed to explore the role of metformin for AMD, especially for earlier stages of the disease. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Intravitreal bevacizumab (Avastin) treatment of neovascular age-related macular degeneration.

PURPOSE: To report the change in visual acuity and central retinal thickness by optical coherence tomography (OCT) after intravitreal injections of bevacizumab for the treatment of neovascular age-related macular degeneration (AMD). METHODS: A retrospective case series in a university-based practice evaluated patients with subfoveal choroidal neovascularization (CNV) due to AMD. Patients received intravitreal injections (1.25 mg) of bevacizumab and were monitored monthly with determination of best-corrected ETDRS visual acuity and OCT for persistence of retinal thickening. Eyes were retreated on an "as needed" basis, defined by presence of intraretinal or subretinal fluid. Patients were monitored every 2 months to 3 months for persistence of angiographic leakage. RESULTS: Seventy-nine eyes of 74 consecutive patients received the initial injection of bevacizumab between August 1, 2005, and January 30, 2006. Sixty-eight eyes (86%) of 64 patients had at least 3 months of follow-up. Mean central retinal thickness +/- SD decreased from 304 +/- 83 microm at baseline to 237 +/- 105 microm at 3 months (P = 0.00002). Mean ETDRS visual acuity gained 4 letters from 20/100 at baseline to 20/80-1 at 3 months (P = 0.040). Twenty eyes (25%) appeared to have a sustained response to a single injection and did not require further injections through 3 months. Two patients had a potentially drug-related adverse event (ischemic stroke and myocardial infarction). No serious injection-related adverse events occurred. CONCLUSIONS: Intravitreal bevacizumab injection affects a rapid decrease in retinal thickness to normal or near-normal levels and improvement in visual acuity in eyes with CNV due to AMD. The sustainability of changes in retinal thickness and visual acuity in response to bevacizumab treatment warrant further investigation and long-term follow-up.

Apoptosis stimulated by the 91-kDa caspase cleavage MEKK1 fragment requires translocation to soluble cellular compartments.

MEKK1, a 196-kDa mitogen-activated protein kinase (MAPK) kinase kinase, generates anti-apoptotic signaling as a full-length protein but induces apoptosis when cleaved by caspases. Here, we show that caspase-dependent cleavage of MEKK1 relocalizes the protease-generated 91-kDa kinase fragment from a particulate fraction to a soluble cytoplasmic fraction. Relocalization of MEKK1 catalytic activity is necessary for the pro-apoptotic function of MEKK1. The addition of a membrane-targeting signal to the 91-kDa fragment inhibits caspase activation and the induction of apoptosis but does not change the activation of JNK, ERK, NFkappaB, or p300. These results identify the caspase cleavage of MEKK1 as a dynamic regulatory mechanism that alters the subcellular distribution of MEKK1, changing its function to pro-apoptotic signaling, which does not depend on the currently described MEKK1 effectors.