Effect of Laser Peripheral Iridotomy on Anterior Chamber Angle Anatomy in Primary Angle Closure Spectrum Eyes

Purpose. To evaluate the effect of phacoemulsification and intraocular lens (IOLs) implantation in eyes with medically uncontrolled primary angle-closure glaucoma (PACG) previously treated with trabeculectomy and to quantify the anatomical changes in the anterior chamber angle by ultrasound biomicroscopy (UBM). Methods. Forty-four eyes of 37 consecutive patients with medically uncontrolled PACG coexisting cataracts with a surgical history of trabeculectomy were included in this study. Each patient underwent phacoemulsification and IOL implantation. Indentation gonioscopy and UBM were performed preoperatively and then again 3 months after surgery. The main outcome measures were best-corrected visual acuity (BCVA), intraocular pressure (IOP), number of antiglaucoma medications and anatomical changes in the anterior chamber angle. Results. The mean logarithm of the minimum angle of resolution BCVA significantly improved from 0.52 ± 0.30 preoperatively to 0.26 ± 0.23 postoperatively (p<0.001). The mean IOP significantly decreased from 24.33 ± 9.65 mmHg preoperatively to 18.04 ± 7.86 mmHg postoperatively (p<0.05). 001). The median number of antiglaucoma medications decreased from 2 preoperatively to 1 postoperatively (p<0.001). There was no significant difference in the extent of peripheral anterior synechia after the surgery (p>0.05). Some parameters, including anterior central chamber depth, angle opening distance at 500 μm, trabecular-iris angle, and scleral ciliary process angle, were significantly higher after than before surgery (p<0.001). However, the crystalline lens rise was significantly smaller following the surgery (p<0.001). Conclusions. Phacoemulsification and IOL implantation reduced the IOP and improved vision in eyes with medically uncontrolled filtered PACG. The mechanism underlying the outcomes observed following surgery might be related to the anterior chamber deepening, widened drainage angle, and improved aqueous fluid flow to the trabecular meshwork.

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Does an iridotomy provide protection against narrowing of the anterior chamber angle during Valsalva maneuvre in eyes with primary angle closure

Eye ◽

10.1038/sj.eye.6702646 ◽

2007 ◽

Vol 22 (3) ◽

pp. 389-393 ◽

Cited By ~ 13

Author(s):

R Sihota ◽

T Dada ◽

A Aggarwal ◽

G Srinivasan ◽

V Gupta ◽

...

Keyword(s):

Anterior Chamber ◽

Angle Closure ◽

Anterior Chamber Angle ◽

Primary Angle Closure ◽

Chamber Angle

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Biometric Indicators of Anterior Segment Parameters Before and After Laser Peripheral Iridotomy by Swept-Source Optical Coherent Tomography

10.21203/rs.3.rs-1113315/v1 ◽

2021 ◽

Author(s):

Bo Yu ◽

Kang Wang ◽

Xiaoli Xing

Keyword(s):

Anterior Chamber ◽

Anterior Segment ◽

Angle Closure ◽

Laser Peripheral Iridotomy ◽

Swept Source ◽

Optical Coherent Tomography ◽

Primary Angle Closure ◽

Before And After ◽

Anterior Segment Parameters ◽

Peripheral Iridotomy

Abstract Background Primary angle closure glaucoma (PACG) is the most common type of glaucoma in China. Laser peripheral iridotomy (LPI) is the primary choice to treat PAC. We aim to evaluate the changes and to find the biometric indicators of anterior segment parameters before and after laser peripheral iridotomy (LPI) in primary angle closure (PAC) eyes using swept-source optical coherent tomography (OCT). Methods LPI was performed in 52 PAC eyes of 28 participants. The change of intraocular pressure and anterior segment parameters, including angle opening distance (AOD500), AOD500 area, trabecular iris space area (TISA500), TISA500 volume, trabecular iris angle (TIA500), iridotrabecular contact (ITC) index, ITC area, anterior chamber volume (ACV), anterior chamber depth (ACD), lens vault (LV) and lens thickness (LT) before and 1 week after LPI were measured by Tomey CASIA2 anterior segment OCT. We also estimate and analyze potential contributing factors possibly affecting the change of anterior chamber angle parameters. Results No post-laser complications were found. The LV and LT did not change significantly 1 week after LPI. AOD500, AOD500 area, TISA500, TISA500 volume, TIA500, ACV and ACD increased significantly after LPI. There was significant decrease in ITC index and ITC area. LT was positively correlated to the change of ITC index (r=0.411, p=0.002) and ITC area (r=0.384, p=0.005). ACD was negatively correlated to the change of ITC index (r=0.292, p=0.036). Conclusions The anterior segment architecture significantly changed after LPI in PAC spectrum eyes. Crystalline lens measurements remained unchanged before and after LPI. AS-OCT can be used to follow anterior chamber parameter changes in PAC spectrum eyes. Pre-treatment LT and ACD affect the therapeutic effect of LPI.

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