Fan KRP, et al. - In this randomized double-masked controlled trial, authors researched the neuroprotective effect of Copolymer-1 (Cop-1) in subjects with acute primary angle closure (APAC). They observed a mean of 0.32 progressing points among subjects in the Cop-1 group as compared to 2.74 in the placebo group. They also found that 15.8% of Cop-1 treated cases had 1 or more progressing points vs 36.8% in the placebo group. They recorded no difference in change of retinal nerve fiber layer (RNFL) thickness between groups. An improvement of mean deviation (MD) at week 16 in the Cop-1 group was reported when compared to the worsening of MD in the placebo group. They suggested no difference in visual field (VF) progression following APAC (or RNFL thickness change) between Cop-1 vs placebo groups.