Plateau iri yndrome: change in angle opening aociated with dark, light, and pilocarpine adminitration Original Reearch Article

PURPOE: To report change in angle configuration aociated with dark, light, and pilocarpine adminitration in plateau iri yndrome. METHOD: In 10 eye of 10 patient with plateau iri yndrome and peritent narrow angle after patent peripheral Nd:YAG laer iridotomy, ultraound biomicrocopy wa ued to image variation in angle opening, iri thickne, and trabecular-ciliary proce ditance. Meaurement were taken in the dark, in full room light, and after adminitration of pilocarpine 2%. REULT: Average angle opening ditance increaed in the light compared with the dark (113 ± 34 μm v 22 ± 34 μm, P = .0001) and increaed further after pilocarpine adminitration (171 ± 52 μm v 113 ± 34 μm, P = .0034). Average iri thickne decreaed in the light compared with the dark (338 ± 34 μm v 436 ± 58 μm, P = .0009) and decreaed further after pilocarpine adminitration (253 ± 48 μm v 338 ± 34 μm, P = .0002). Average trabecular mehwork–ciliary proce ditance meaurement were maller than normal and did not change ignificantly in the light compared with the dark (481 ± 42 μm v 464 ± 44 μm, P = .4001) or after pilocarpine adminitration compared with light (451 ± 67 μm v 481 ± 42 μm, P = .1304). CONCLUION: In plateau iri yndrome, anteriorly located ciliary procee upport the peripheral iri. Change in angle opening in dark and light are olely related to change in iri thickne. Pilocarpine produce iri thinning and i an effective method of opening the angle. Ultraound biomicrocopy can be ued to perform a darkroom provocative tet, which provide information on whether the angle anatomically cloe in the dark.