Abstract:AIM: To investigate the 3D morphology changes of anterior segment in the fellow eye of acute primary angle closure glaucoma(PACG)before and after neodymium: yttrium aluminum garnet(Nd: YAG)laser periphery iridotomy(LPI)by using Pentacam system and evaluate the safety and efficiency of LPI.
METHODS: Fifty patients(50 eyes)with PACG were enrolled in the study. Before and 1 day, 6 months after LPI, comparison of intraocular pressure(IOP)was measured, comparison of anterior segment parameters such as central corneal thickness(CCT), central anterior chamber depth(CACD), peripheral anterior chamber depth(PACD), anterior chamber volume(ACV), anterior chamber angle(ACA), lens thickness(LT)and pupil diameter(PD)were analyzed by the Pentacam system. The axial length(AL)of eye was measured by IOL-Master, and then comparison of relative position of the lens(RPL)was estimated.
RESULTS: There were no differences among the IOP before and 1 day, 6 months after LPI. The Pentacam system clearly showed the convex configuration of the iris was flattened and the peripheral AC depth was deepened after LPI. Before and 1 day, 6 months after LPI, no statistic changes of CCT were found(548.02 ±20.22mm, 549.32±21.78mm, 551.34±26.37mm, respectively); no statistic changes of CACD were found(1.65±0.28mm, 1.72±0.31mm, 1.71±0.23mm, respectively); no statistic changes of PD were found(2.32±0.55mm, 2.20±0.39mm, 2.38±0.40mm, respectively); no statistic changes of LT were found(1.90±0.55mm, 1.82±0.39mm, 1.98±0.40mm, respectively); no statistic changes of AL were found(23.08±1.05mm, 22.91±1.12mm, 22.94±0.96mm, respectively); no statistic changes of RPL were found(0.118±0.035, 0.126±0.041, 0.121±0.028, respectively). PACD was deepened, temporal from 0.88±0.31mm to 1.19±0.25mm(1 day), 1.17±0.30mm(6 months), superior(0.83±0.32mm, 1.01±0.42mm, 1.02±0.36mm), nasal(0.80±0.42mm, 0.95±0.21mm, 0.94±0.24mm), inferior(0.83±0.34mm, 1.13±0.14mm, 1.12±0.25mm); ACV was increased from 57.06±18.43mm3 to 80.65±20.02mm3(1 day), 81.43±17.21mm 3(6 months); ACA was widened from 27.02°±6.65° to 30.41°±5.87°(1 day), 31.52°±6.98°(6 months), which were increased significantly between before and after LPI, and no difference between 1 day and 6 months after LPI.
CONCLUSION:LPI can induce dramatic changes of 3-D anterior segment morphology in the fellow eye of acute primary angle closure glaucoma(PACG). The changes of AC after LPI can be demonstrated by Pentacam qualitatively and quantitatively.
