Comparative study on plateau iris between different subtypes of primary angle closure glaucoma after laser peripheral iridotomy

Abstract

Objective To compare the prevalence of plateau iris in acute primary angle closure glaucoma (APACG) and chronic angle closure glaucoma (CACG) after laser peripheral iridotomy.Methods 37 cases (37 eyes) with APACG and 29 cases (29 eyes) with CACG were enrolled in the study.In APACG group,the fellow eyes of the eyes with acute attack were studied.In CACG group,eyes with less than 90° PAS were studied.UBM was used for all cases at one month after laser peripheral iridotomy and stopping pilocarpine eyedrops more than one week.Platau iris in a quadrant was defined by anteriorly directed ciliary body,absent ciliary sulcus,steep iris root from its point of insertion followed by a downward angulation,flat iris plane,and irido-angle contact.At least two quadrants had to fulfill these UBM criteria for an eye to be classified as having platau iris.Results 12 of 29 (41.4％) cases in CACG group fulfilled all the criteria for platau iris,while in APACG group,7 of 37 (18.9％) cases were diagnosed as platau iris.The difference was statistically significant (P =0.045) after laser peripheral iridotomy.Conclusion Platau iris has a higher prevalence in CACG than in APACG after laser peripheral iridotomy. Key words: Glacoma, angle closure, primary; Platau iris