In 1987, we presented a study of 141 eyes treated prophylactically following retinal detachment in the fellow eye. A hundred and nine of these patients are reviewed with a minimum follow-up of five years. Only the evolution was studied, whether a peripheral retinal lesion was present or not at the time of prophylactic treatment. The examiner noted if new lesions had occurred, or if lesions present at the time of the first examination had developed: lattice degeneration or snail track developing into a retinal tear, hole or tear causing a retinal detachment, contained or not by laser treatment. Our study contained sixty two myopes. Fifty eyes had visible, dangerous lesions, and fifty nine a normal retina. Forty five circular barrages with four anterior radial rows returning to the ora serrata were performed, and sixty four barrages with tight anterior grids and a localised barrage of visible lesions. The results were judged on one criterion only: retinal detachment requiring emergency surgery. Only one retinal detachment occurred behind the barrage, caused by proliferative vitreoretinopathy due to multiple tears, and surgical results were good. Eight tears appeared in front of the barrage, five of these in healthy retina. Two very posterior tears behind the barrage were blocked with no problem by laser treatment. Four localised detachments occurred in front of the barrage, three of these without anterior grid treatment. The advantage of this is undeniable since out of sixty three cases treated in this way, only three tears were seen to be blocked by the laser shots, and one anterior localised detachment where the anterior grid was insufficient.(ABSTRACT TRUNCATED AT 250 WORDS)