ABSTRACT
Background: With ultrasound biomicroscopy (UBM), radial scans are taken by using a typical ciliary process, to show the details of the iridocorneal angle, the anterior surface of the ciliary body, and its relation to the posterior iris. Appositional closure represents potentially reversible contact between the peripheral iris and trabecular meshwork. The appositional closure can further be classified according to the configuration of iridotrabecular contact (ITC). UBM can be performed in dark and light conditions, which has been shown to be useful for detecting changes in iridocorneal angle configuration associated with dark and light. Purpose: To image ITC configuration in appositional angle closure and also image iridocorneal angle in dark and bright light room illumination. Synopsis: UBM demonstrates two types of ITC configuration in appositional closure which are, B?type and S?type. It can also demonstrate the presence of sinus of Mapstone in S?type of ITC. Highlights: UBM allows imaging of dynamic changes in the iris and shows that the degree of appositional angle closure is a dynamic process that can change rapidly depending on the lighting conditions.
ABSTRACT
BackgroundLaser peripheral iridotomy(LPI) can break the pupillary block,and is an effective method of treating acute primary angle closure (APAC).However,a part of APAC eyes may gradually develop a formation and extension of peripheral anterior synechia(PAS) and increased intraocular pressure(IOP) after LPI.ObjectiveTo investigate the relationship between appositional angle closure and darkroom provocative test(DRPT) in the fellow eyes with APAC after LPI.Methods Fellow eyes of APAC without PAS after LPI were studied.Ultrasounic biomicroscopy(UBM) were performed in darkness to observe whether appositional angle closure occurred and compare the relationship between the quadrants with appositional angle closure and the results of DRPT.Results Fifty-four patients were included in the study.Appositional angle closure was observed in at least one quadrant in 20(37.0％ ) of the 54 fellow eyes with APAC after LPI.Fifty-one patients were given DRPT and positive result in 9 patients( 17.6％ ).According to the quadrants with appositional angle closure,there were 5 patients with DRPT positive results in 46 patients with appositional angle closure 0 to 2 quadrants,and 4 patients with DRPT positive results in 5 patients with appositional angle closure 3 to 4 quadrants ( P =0.003 ).Bivariate correlation analysis indicated a positive correlation between the value of the increased IOP in DRPT and the number of quadrants with appositional angle closure in darkness( r =0.397,P =0.004).ConclusionsA certain proportional fellow eyes of APAC appeared appositional angle closure in darkness and DRPT positive result after LPI.The more the quadrants of appositional angle closure after LPI,the greater the likelihood of a positive DRPT.It suggests that the APAC fellow eyes and attack eyes with the same anatomical configuration still have the possibility of angle closure after LPI,and need follow-up and treatment for a long time.
ABSTRACT
Background Laser peripheral iridotomy(LPI) is used as the primary therapy for the eyes at risk of angle closure.But there are still 28% eyes with primary angle closure suspect occur angle closure within 2 years after LPI.It is necessary to explore the associated factors of the efficacy of LPI.Objective The aim of this study was to explore the changes of intraocular pressure(IOP) and anterior chamber angle in the fellow eyes of patients with unilateral acute attack of primary angle closure glaucoma (PACG) and analyze the relevant factors influencing the successful rate of LPI.Methods Eighty-seven fellow eyes received LPI from 87 patients with unilateral acute attack of PACG were included in this study and retrospectively analyzed.The IOP and gonioscopy were performed before and 1 week,3,6,9,12 months after LPI.Successful signs of LPI were defined as an IOP 6-21mmHg without any anti-glaucoma medication,none of glaucomatous neuropathy and the coincident visual field loss,and no need of additional glaucomatous medication or surgery.This study was approved by Ethic Committee of the First Hospital of Xinxiang Medical College,and written informed consent was obtained from each patient.Results Seventy-nine eyes of 79 cases finished the medical visit throughout the follow-up duration with the age 61.4±0.4 years and 33(41.8%) males and 46(58.2%) females.The mean IOP was lowed in various time points after LPI in comparison with before operation with the general difference among different time visiting groups(F=4.056,P＜0.01).Shaffer grade was increased in superior,temporal and nasal quadrants and significant differences were found between 1 week group,3 months group or 6 months group and before operation group (P＜0.05).LPI lessened the range of appositional angle closure (AAC) in postoperative 1 week group and 3 months group compared with pre-operative group (P＜0.05),but no statistically significant reduce was seen in range of AAC from 6 months through 12 months after LPI in comparison with pre-operation (P＞0.05).LPI was determined as successful in 61 cases (77.2%) during one-year fellow-up period.Several variables,such as preoperative IOP,Shaffer grade of each quadrant,mean Shaffer grade and the extent of AAC,were significantly different between LPI success and failure group(P＜0.01).Cox stepwise regression analysis found that the success rate was significantly associated with the extent of AAC (Wald=48.150,RR=1.963,P＜0.01) rather than pre-IOP,Shaffer grade of each quadrant,mean Shaffer grade,age and gender (P＞0.05).Conclusion LPI can widen the anterior chamber angle and low IOP in the fellow eyes of PACG attack eyes.The success rate of LPI is associated with the extent of pre-AAC,suggesting that it is necessary for LPI in consideration of the extent of pre-AAC.