Efficacy of goniosynechialysis for advanced chronic angle-closure glaucoma

Comparison of Long-Term Effects Following Phacoemulsification Combined with Goniosynechialysis and Trabeculectomy in Patients with Primary Angle-Closure Glaucoma and Cataract

INTRODUCTION

Goniosynechialysis (Phaco-GSL) is a logical therapeutic approach for patients with primary angle-closure glaucoma (PACG) and cataract. The aim of this study was to compare the long-term effectiveness and safety of Phaco-GSL and trabeculectomy (TRB) in the management of PACG with coexisting cataract.

METHODS

A review was conducted on 96 Chinese patients (96 eyes) with PACG and cataract from Peking Union Medical College Hospital (PUMCH). Among them, 56 patients underwent Phaco-GSL, while 40 underwent TRB. Intraocular pressure (IOP), best corrected visual acuity (BCVA), use of supplemental antiglaucoma medical therapy, surgery success rates, and complications for both procedures were assessed.

RESULTS

The average follow-up period was 50.3 ± 18.7 months in the Phaco-GSL group and 61.2 ± 15.1 months in the TRB group. At the final follow-up, IOP decreased from 27.0 ± 11.1 mmHg to 13.5 ± 2.1 mmHg in the Phaco-GSL group and in the TRB group IOP decreased from 27.1 ± 7.7 mmHg to 16.5 ± 5.5 mmHg. The long-term postoperative IOP in the Phaco-GSL group was significantly lower than that in the TRB group. There was a statistically significant reduction in medication usage in both groups, with the TRB group having a higher number of postoperative medications at the final follow-up. The incidence of postoperative complications was significantly higher in the TRB group compared to the Phaco-GSL group.

CONCLUSIONS

Phaco-GSL is the recommended surgical approach for Chinese patients with primary angle-closure glaucoma (PACG) and cataract. Compared to traditional TRB, eyes undergoing Phaco-GSL show a reduced requirement for antiglaucomatous medications, improved management of IOP, decreased risk of complications, and higher long-term cumulative probability of treatment success for patients with PACG.

Expression of matrix Metalloproteinases-2 and aquaporin-1 in corneoscleral junction after angle-closure in rabbits

Background

To investigate the expression of Matrix Metalloproteinases 2 and aquaporin-1 in corneoscleral junction and explore the mechanism of trabecular damageafter angle-closure.

Methods

Thirty New Zealand white rabbits were randomly assigned into 2 groups, theexperimental group (Group 1) including twenty five rabbits and the control group (Group 2) including 5 rabbits. The rabbits in the experimental group were used to establish angle-closure models, and the rabbits in the control group were not subjected to any operation. All the rabbits were followed by slit lamp microscopy, Tonopen tonometer, and anterior segment optical coherent tomography (AS-OCT). The expressions of metalloproteinase MMP-2, aquaporin-1, and tissue inhibitors of metalloproteinase-2 in corneoscleral junctionwere evaluatedin both groups byimmunofluorescence, quantitative reverse-transcription polymerase chain reaction (qRT-PCR), and enzyme-linked immunosorbent assay (ELISA).

Results

Slit-lamp examination showed that angle-closure model was successfully established in twenty rabbits. The extent of angle-closure was about 2 to 4 clock hours in all the rabbit models, but the intraocular pressure (IOP) of the rabbits distributed from 8.57 to 15.25 mmHg and no significant high IOP was found in the follow-up period. The AQP-1-positive cells mainly located in Schlemm’s canal, the inner surface of trabecular meshwork (TM), and the surface of iris, which began to decline on 1 month after angle-closure. MMP2 staining was diffuse in trabecular meshwork and iris. Immunofluorescence signal of MMP2 was strong within 1 month after angle-closure, and subsequently became weak. qRT-PCR and ELISA showed that the expression of MMP-2 and TIMP-2 increased within 1 month after angle-closure and then declined gradually. The AQP-1 levels showed slightly declined on 1 month after angle-closure.

Conclusions

Altered levels of MMPs, TIMPs, and AQP-1 were found in the area of angle-closure, which may be involved in the damage of TM and Schlemm’s canal after angle-closure.

Management of Primary Angle-Closure Glaucoma

Primary angle-closure glaucoma (PACG) is a progressive optic nerve degeneration and is defined as a glaucomatous optic neuropathy with associated characteristic enlargement of optic disc cupping and visual field loss that is secondary to ocular hypertension caused by closure of the drainage angle. Angle closure is caused by appositional approximation or adhesion between the iris and the trabecular meshwork. The main treatment strategy for PACG lies in the reduction of intraocular pressure, reopening of the closed angle, and possible prevention of further angle closure. There is no universally agreed best surgical treatment for PACG. Trabeculectomy, goniosynechialysis (GSL), glaucoma implant, and cyclodestructive procedures are effective surgical options. Each of them plays an important role in the management of PACG with its own pros and cons. Accumulating evidence is available to show the effectiveness of visually significant and visually nonsignificant cataract extraction in the treatment of PACG. Trabeculectomy and GSL are often combined with cataract extraction, which may offer additional pressure control benefits to patients with PACG. This review article will discuss laser peripheral iridotomy, argon laser peripheral iridoplasty, and surgeries such as GSL, phacoemulsification, and phaco plus glaucoma surgeries that lower intraocular pressure and also alter the anterior segment and/or drainage angle anatomy. Currently, glaucoma implants and cyclodestruction are mainly reserved for PACG patients who have failed previous filtering operations. Their role as initial surgical treatment for PACG will not be discussed.