Progression rate to primary angle closure following laser peripheral iridotomy in primary angle-closure suspects: a randomised study

Effect of low dose laser cycloplasty on deepening anterior chamber in chronic angle-closure glaucoma

AIM

To describe the outcome of using low-dose laser cycloplasty (LCP) in chronic angle-closure glaucoma (CACG).

METHODS

A retrospective case series. Medical charts of CACG patients who underwent LCP in the Eye Hospital of Wenzhou Medical University were reviewed. The main outcomes included intraocular pressure (IOP), the number of glaucoma medication, anterior segment parameters and surgery-related complications.

RESULTS

A total of 7 eyes of 7 CACG patients (age 38.9±11.0y) underwent LCP with a mean follow-up of 27.1±13.7mo (range 16-48mo). Following LCP, mean IOP and glaucoma medications decreased from 26.1±6.1 mm Hg with 3.1±1.1 glaucoma medications pre-treatment to 14.9±3.1 mm Hg (P=0.027) with 0.4±1.1 glaucoma medications (P=0.001) at final follow-up. The anterior chamber depth (ACD), angle opening distance500 and trabecular-iris angle increased from 1.65±0.33 mm, 0.05 mm (range 0-0.30 mm) and 5.1° (range, 0-31.97°) at baseline to 1.98±0.43 mm (P=0.073), 0.53 mm (range 0.42-0.91 mm, P=0.015), 45.9° (range, 40.2°-59.4°, (P=0.015) in the long-term follow-up, respectively. The deepening of ACD and reopening of anterior chamber angle (ACA) was observed in 6 eyes (85.7%).

CONCLUSION

LCP is a promising treatment option for patients with CACG via reducing IOP and glaucoma medication without serious complications. In addition, LCP can bring a significant deepening in ACD and reopening of ACA.

Biometric Risk Factors for Angle Closure Progression After Laser Peripheral Iridotomy

Importance

Laser peripheral iridotomy (LPI) is the most common primary treatment for primary angle closure disease (PACD). However, there are sparse data guiding the longitudinal care of PAC suspect (PACS) eyes after LPI.

Objective

To elucidate the anatomic effects of LPI that are associated with a protective outcome against progression from PACS to PAC and acute angle closure (AAC) and to identify biometric factors that predict progression after LPI.

Design, Setting, and Participants

This was a retrospective analysis of data from the Zhongshan Angle Closure Prevention (ZAP) trial, a study of mainland Chinese people aged 50 to 70 years with bilateral PACS who received LPI in 1 randomly selected eye. Gonioscopy and anterior-segment optical coherence tomography (AS-OCT) imaging were performed 2 weeks after LPI. Progression was defined as the development of PAC or an acute angle closure (AAC) attack. Cohort A included a random mix of treated and untreated eyes, and cohort B included only eyes treated with LPI. Univariable and multivariable Cox regression models were developed to assess biometric risk factors for progression in cohorts A and B. Data were analyzed from January 4 to December 22, 2022.

Main Outcome and Measure

Six-year progression to PAC or AAC.

Results

Cohort A included 878 eyes from 878 participants (mean [SD] age, 58.9 [5.0] years; 726 female [82.7%]) of whom 44 experienced progressive disease. In a multivariable analysis, treatment (hazard ratio [HR], 0.67; 95% CI, 0.34-1.33; P = .25) was no longer associated with progression after adjusting for age and trabecular iris space area at 500 μm (TISA at 500 μm) at the 2-week visit. Cohort B included 869 treated eyes from 869 participants (mean [SD] age, 58.9 [5.0] years; 717 female [82.5%]) of whom 19 experienced progressive disease. In multivariable analysis, TISA at 500 μm (HR, 1.33 per 0.01 mm2 smaller; 95% CI, 1.12-1.56; P = .001) and cumulative gonioscopy score (HR, 1.25 per grade smaller; 95% CI, 1.03-1.52; P = .02) at the 2-week visit were associated with progression. Persistent angle narrowing on AS-OCT (TISA at 500 μm ≤0.05 mm2; HR, 9.41; 95% CI, 3.39-26.08; P <.001) or gonioscopy (cumulative score ≤6; HR, 2.80; 95% CI, 1.13-6.93; P =.04) conferred higher risk of progression.

Conclusions and Relevance

Study results suggest that persistent angle narrowing detected by AS-OCT or cumulative gonioscopy score was predictive of disease progression in PACS eyes after LPI. These findings suggest that AS-OCT and gonioscopy may be performed to identify patients at high risk of developing angle closure who may benefit from closer monitoring despite patent LPI.

Iridotomy to slow progression of visual field loss in angle-closure glaucoma

BACKGROUND

Primary angle-closure glaucoma is a type of glaucoma associated with a physically obstructed anterior chamber angle. For example, contact between the iris and lens at the pupillary margin creates a pupillary block that increases resistance to aqueous outflow. Obstruction of the anterior chamber angle blocks drainage of fluids (aqueous humor) within the eye and may raise intraocular pressure (IOP). Elevated IOP is associated with glaucomatous optic nerve damage and visual field loss. Laser peripheral iridotomy ('iridotomy') is a procedure to eliminate pupillary block by allowing aqueous humor to pass directly from the posterior to anterior chamber, which is achieved by creating a hole in the iris using laser. Iridotomy is used to treat patients with primary angle-closure glaucoma, patients with primary angle-closure (narrow angles and no signs of glaucomatous optic neuropathy), and patients who are primary angle-closure suspects (patients with reversible obstruction). However, the effectiveness of iridotomy on slowing progression of visual field loss is uncertain.

OBJECTIVES

To assess the effects of iridotomy compared with no iridotomy for primary angle-closure glaucoma, primary angle-closure, and primary angle-closure suspect.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2021, Issue 10), which contains the Cochrane Eyes and Vision Trials Register; MEDLINE Ovid; Embase Ovid; PubMed; LILACS; ClinicalTrials.gov; and the WHO ICTRP. The date of the most recent search was 10 October 2021.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials that compared iridotomy with no iridotomy in primary angle-closure suspects, people with primary angle-closure, or people with primary angle-closure glaucoma in one or both eyes were eligible.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology and assessed the certainty of the body of evidence for prespecified outcomes using the GRADE approach.

MAIN RESULTS

We identified four studies (3086 eyes of 1543 participants) that compared iridotomy with no iridotomy in participants (range of mean age 59.6 to 62.9 years) who were primary angle-closure suspects from China, Singapore, or the UK. Study investigators randomized one eye of each participant to iridotomy and the other to no iridotomy. Two studies provided long-term (five or more years) results. We judged the certainty of the evidence as moderate to low across the prespecified outcomes, downgrading for high risk of bias (e.g. performance and detection biases) and imprecision of results. Meta-analyses of data from two studies suggest that iridotomy probably results in little to no difference in IOP compared with no iridotomy at one year (mean difference (MD) 0.04 mm Hg, 95% confidence interval (CI) -0.17 to 0.24; I2 = 65%; 2598 eyes of 1299 participants; moderate certainty evidence) and five years (MD 0.12 mm Hg, 95% CI -0.11 to 0.35; I2 = 0%; 2016 eyes of 1008 participants), and in best-corrected visual acuity measured as logMAR at one year (MD 0.00, 95% CI -0.01 to 0.01; I2 = 69%; 2596 eyes of 1298 participants; moderate certainty evidence) and five years (MD 0.01, 95% CI -0.01 to 0.03; I2 = 0%; 2002 eyes of 1001 participants). In terms of gonioscopic findings, eyes treated with iridotomy likely had wider angles in Shaffer grading scale (MD 4.93 units, 95% CI 4.73 to 5.12; I2 = 59%; 2598 eyes of 1299 participants at one year; MD 5.07, 95% CI 4.78 to 5.36; I2 = 97%; 2016 eyes of 1008 participants at five years; moderate certainty evidence) and experienced fewer peripheral anterior synechiae (PAS) than eyes that received no iridotomy at five years (risk ratio (RR) 0.41, 95% CI 0.24 to 0.67; I2 = 28%; 2 studies, 2738 eyes of 1369 participants), but the evidence was less conclusive at one year (RR 0.62, 95% CI 0.25 to 1.54; I2 = 57%; 3 studies, 2896 eyes of 1448 participants; low certainty evidence). No studies reported data on the proportion of participants with progressive visual field loss during follow-up (the primary outcome of this review), mean number of medications to control IOP, or quality of life outcomes. Low certainty evidence suggests that iridotomy may result in little to no difference in the incidence of acute angle-closure (RR 0.29, 95% CI 0.07 to 1.20; I2 = 0%; 3 studies, 3006 eyes of 1503 participants). Other ocular adverse events (e.g. eye pain, dry eye, redness of eyes, and ocular discomfort), although rare, were more common in eyes treated with iridotomy than in eyes in the control group.  AUTHORS' CONCLUSIONS: We did not find sufficient evidence to draw any meaningful conclusions on the use of iridotomy for the purpose of slowing progression of visual field loss. No study reported on progressive visual field loss, the primary outcome of this review. Although there is moderate certainty evidence that iridotomy results in improved gonioscopic findings, in is unclear if these findings translate to clinically meaningful benefits.

A systemic review and network meta-analysis of accuracy of intraocular lens power calculation formulas in primary angle-closure conditions

BACKGROUND

For primary angle-closure and angle-closure glaucoma, the fact that refractive error sometimes deviates from predictions after intraocular lens (IOL) implantation is familiar to cataract surgeons. Since controversy remains in the accuracy of IOL power calculation formulas, both traditional and network meta-analysis on formula accuracy were conducted in patients with primary angle-closure conditions.

METHODS

A comprehensive literature search was conducted through Aug 2022, focusing on studies on intraocular lens power calculation in primary angle-closure (PAC) and primary angle-closure glaucoma (PACG). A systemic review and network meta-analysis was performed. Quality of studies were assessed. Primary outcomes were the mean absolute errors (MAE) and the percentages of eyes with a prediction error within ±0.50 diopiters (D) or ±1.00 D (% ±0.50/1.00 D) by different formulas.

RESULTS

Six retrospective studies involving 419 eyes and 8 formulas (Barrett Universal II, Kane, SRK/T, Hoffer Q, Haigis, Holladay I, RBF 3.0 and LSF) were included. SRK/T was used as a reference as it had been investigated in all the studies included. Direct comparison showed that none of the involved formula outperformed or was defeated by SRK/T significantly in terms of either MAE or % ±0.50/1.00 D (all P>0.05). Network comparison and ranking possibilities disclosed BUII, Kane, RBF 3.0 with statistically insignificant advantage. No significant publication bias was detected by network funnel plot.

CONCLUSIONS

No absolute advantage was disclosed among the formulas involved in this study for PAC/PACG eyes. Further carefully designed studies are warranted to evaluate IOL calculation formulae in this target population.

TRAIL REGISTRATION

Registration: PROSEPRO ID: CRD42022326541.

EFFICACY OF PHACOEMULSIFICATION AND PHACOEMULSIFICATION COMBINED WITH GONIOSYNECHIALYSIS IN SURGICAL TREATMENT OF CHRONIC ANGLE-CLOSURE GLAUCOMA: 2-YEARS STUDY

Aim. To study the degree of angle opening and the decrease of intraocular pressure in primary angle-closure glaucoma (PACG) after cataract phacoemulsification and cataract phacoemulsification with goniosynechialysis (phaco + GLS). Materials and Methods. The study involved 28 patients (28 eyes) with primary chronic angle-closure glaucoma. The patients were divided into two groups, group 1 of 15 patients undergoing phaco with posterior chamber IOL implantation, and group 2 of 13 patients undergoing phaco with IOL implantation and GLS. The patients were followed for 24 months. Phaco was indicated in cases with IOP above 22 mmHg, appositional anterior chamber angle closure, and optic neuropathy; Phaco with GSL was indicated in cases of synechial angle closure and IOP above 22 mmHg Results. In group 1 after Phaco, postoperative anterior chamber angle opening was >20° in all quadrants. Postoperative IOP after 24 month follow-up it decreased by 32,6 % from the preoperative levels. In group 2 after Phaco+GSL, anterior chamber angle opened at least to 20° in three or more quadrants in all cases. Postoperative IOP after 24 month follow-up it decreased by 33.0% from the preoperative levels. Conclusions. Thus, phacoemulsification is an efficient procedure for PACG and appositional angle closure, leading to reopening of the anterior chamber angle with significant IOP reduction. Phacoemulsification alone does not lead to reopening of anterior chamber angle in cases with synechial angle closure, necessitating a combined surgery of phacoemulsification with GSL.