There are several studies which have shown that the drainage angle opens significantly after PEI in subjects with PAC/G.17;18 Only one paper described the effects of PEI on extent of peripheral anterior synaechiae. This showed that in subjects with PACG and PAS, there was a significant reduction in the extent of PAS after PEI, by approximately 25%.8 Most studies of PEI-GSL also describe opening of the drainage angle in subjects with PAC/G. Several studies also describe reduction in extent of PAS, including complete elimination of PAS.