Glaucoma in Singapore

Efficacy of goniosynechialysis for advanced chronic angle-closure glaucoma

Purpose:

To evaluate the intraocular pressure (IOP)-lowering efficacy of goniosynechialysis (GSL) for advanced chronic angle-closure glaucoma (CACG) using a simplified slit-lamp technique.

Patients and methods:

Patients with CACG with one severely affected eye with best-corrected visual acuity below 20/200 and a mildly or functionally unaffected fellow eye were enrolled in this study. All patients underwent ophthalmologic examinations including measurement of visual acuity, best-corrected visual acuity, and IOP; biomicroscopy; specular microscopy; fundus examination; and gonioscopy followed by anterior chamber paracentesis and GSL for nasal peripheral anterior synechiae in the eye with severe CACG.

Results:

Thirty patients (18 men, 12 women) were identified as having CACG with an initial mean IOP of 47.1 ± 6.7 mmHg (range 39–61 mmHg) in the severely affected eye. One week after GSL, the mean IOP of the treated eyes decreased to 19.3 ± 2.8 mmHg (range 14–26 mmHg) without antiglaucoma medication (average decrease 27.7 ± 6.5 mmHg; range 16–41 mmHg), which was significant (P < 0.00001) compared with baseline. After an average follow-up period of 36.6 ± 1.0 months (range 35–38 months), the mean IOP stabilized at 17.4 ± 2.2 mmHg (range 12–21 mmHg). The nasal angle recess did not close again in any one of the patients during the follow-up period. The average significant (P < 0.00001) decrease in corneal endothelial cell density in the treated eyes was 260 ± 183 cells/mm² (range 191–328 cells/mm²).

Conclusions:

Anterior chamber paracentesis and GSL lowers IOP in advanced CACG, though it may lead to mild corneal endothelial cell loss.

Lens extraction for chronic angle-closure glaucoma

BACKGROUND

Angle-closure glaucoma is characterized by obstruction to the outflow of aqueous humor and consequent rise in intraocular pressure. The obstruction may result from an anatomical predisposition of the eye or may be due to pathophysiologic processes in any part of the eye. The former is considered the primary form and the latter a secondary form of angle closure. Relative pupillary block obstructing free flow of aqueous from the posterior chamber of the eye to the anterior chamber is considered to be the most common mechanism of angle closure. Crowding of the angle is another mechanism, which often coexists with pupillary block. This can result from an anterior placement of the lens due to an increase in the thickness of the lens (as occurs with aging), anterior displacement by a posterior force (for example choroidal effusion), or laxity of the zonules.

OBJECTIVES

The objective of this review was to assess the effectiveness of lens extraction for chronic primary angle-closure glaucoma compared with other interventions for the condition in people without past history of acute-angle closure attacks.

SEARCH STRATEGY

We searched CENTRAL (2005, Issue 3), MEDLINE (1950 to April 2006), EMBASE (1980 to April 2006), and LILACS (to August 2005). We searched the reference lists of included studies and used the Science Citation Index database.

SELECTION CRITERIA

In the absence of any randomized trials we included non-randomized studies comparing lens extraction with other treatment modalities for chronic primary angle-closure glaucoma including, but not limited to, laser iridotomy, medications, and laser iridoplasty. We excluded studies with a case-series design.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data on methodological quality of the included studies, outcomes for the review, and study characteristics including participant characteristics, interventions, and sources of funding. Differences were resolved through discussion.

MAIN RESULTS

We found no randomized trials evaluating the effects of lens extraction as a treatment for chronic primary angle-closure glaucoma. Two non-randomized comparative studies included in the review have several methodological flaws including selection bias. While these studies and other non-comparative studies provide information on biological plausibility and treatment effect they do not provide proof of effectiveness. Also, they do not address the question of how primary lens extraction compares with other treatments for chronic primary angle-closure glaucoma.

AUTHORS' CONCLUSIONS

There is no evidence from good quality randomized trials or non-randomized studies of the effectiveness of lens extraction for chronic primary angle-closure glaucoma.