Angle-closure glaucoma in East Asian and European people. Different diseases?

Asymmetric Intraocular Pressure Changes in Dominant and Contralateral Eyes: The Dark Room Prone Provocative Test

PURPOSE

To evaluate changes in intraocular pressure (IOP) in dominant and contralateral eyes following the dark room prone provocative test (DRPPT) in the study subjects with shallow anterior chamber.

METHODS

This was a prospective, single-center, non-randomized controlled trial of 43 subjects (86 eyes) with shallow anterior chamber. The dominant eye was identified using the card-hole method. The study subjects underwent the DRPPT for one hour. Pre- and post-DRPPT IOP was measured using an I-Care tonometer, and pupillary parameters, including amplitude of constriction, peak constriction velocity, and peak re-dilation velocity, were also measured using the RAPDx® dynamic pupillometer.

RESULTS

Significant increases in IOP were observed in both the dominant and contralateral eyes after DRPPT, compared to their respective pre-DRPPT IOP levels. (p < .01). Moreover, IOP variation before and after DRPPT was significantly greater in the dominant eye than in the contralateral eye (median 3.60 mmHg vs. 2.70 mmHg, p < .05). The dominant eyes exhibited a smaller amplitude of constriction (1.07 ± 0.35 mm vs 1.14 ± 0.34 mm, P < .05) and slower constriction velocity (3.71 ± 1.12 mm/s vs 3.78 ± 1.11 mm/s, P < .05) as compared to the contralateral eyes.

CONCLUSIONS

This study demonstrated that the dominant eye exhibited greater IOP changes after DRPPT than the contralateral eye. Additionally, it showed smaller pupil constriction and slower contraction, indicating a higher likelihood of pupil blockage in the dominant eye with shallow anterior chambers. This asymmetry partially explains the monocular onset of acute angle-closure attacks.

Anterior Segment Characteristics Changes After Implantable Collamer Lens V4c in Low Anterior Chamber Depth Eyes: An Optical Coherence Tomography Study

PURPOSE

To investigate anterior segment changes after implantable collamer lens V4c (ICL-V4c; STAAR Surgical) implantation in eyes with low anterior chamber depth (ACD) and compare them with eyes with normal ACD.

METHODS

This prospective, interventional case-control study included 96 eyes of 48 patients with a low ACD (< 2.8 mm) and 44 eyes of 22 patients with normal ACD (≥ 2.8 mm) receiving a 12.1-mm ICL. All patients underwent follow-up and comprehensive ophthalmic examinations preoperatively and at 1, 3, and 6 months after surgery. Anterior segment parameters, including ACD, anterior chamber width, crystalline lens rise, anterior chamber angle, trabecular-iris angle (TIA), angle opening distance, trabecular-iris space area, the distance from cornea to ICL, and vault were all conducted by optical coherence tomography. These parameters from the last follow-up (6 months postoperatively) were used for statistical analysis to assess changes in anterior segment structure and their relationship with vault height.

RESULTS

The mean safety and efficacy index in eyes with low ACD were 1.23 ± 0.22 and 1.21 ± 0.08 respectively. In both groups, anterior chamber structure parameters become narrower compared to preoperatively (all P < .05). Preoperative ACD and C-ICL demonstrated significant correlations with ICL vault in eyes with low ACD (P < .001). Compared with eyes with normal ACD preoperatively, eyes with low ACD are more prone to have low vault (P < .01). There is a correlation between normal vault and corneal horizontal white-to-white distance (P = .032), ACD (P = .046), and temporal TIA500 (P = .016).

CONCLUSIONS

ICL-V4c surgery in eyes with low ACD is safe and efficacious. In patients with low ACD, the normal vault could be better anticipated by considering preoperative anterior chamber angle, white-to-white distance, and ACD. [J Refract Surg. 2025;41(4):e342-e355.].

Anterior Chamber Angle and Intraocular Pressure Control After Phacoemulsification in Primary Angle Closure With Different Mechanisms

PRCIS

Different mechanisms of angle closure represented distinct aspects of intraocular pressure (IOP) control after phacoemulsification. Classification of angle closure mechanisms is necessary for postoperative IOP management and glaucoma progression in primary angle closure eyes.

PURPOSE

To investigate the relationship between the anterior chamber angle (ACA) characteristics, measured by swept-source anterior segment optical coherence tomography (SS AS-OCT), and intraocular pressure (IOP) control after phacoemulsification in eyes with primary angle closure disease (PACD) with different angle closure mechanisms.

METHODS

PACD eyes were classified into 3 groups according to angle closure mechanisms using preoperative SS AS-OCT images; pupillary block (PB), plateau iris configuration (PIC), exaggerated lens vault (ELV). This retrospective, clinical cohort study included eighty-five eyes of 85 PACD patients: 34 with PB, 23 with PIC, and 28 with ELV. ACA parameters were measured preoperatively and 1 month postoperatively using SS AS-OCT. IOP measurements were performed preoperatively and during 6 months postoperatively. Postoperative IOP reduction and fluctuation were calculated, and their correlations with SS AS-OCT parameters were analyzed.

RESULTS

PIC group showed the lowest postoperative IOP reduction compared with the other groups ( P =0.023). Preoperative ACA measurements were significantly associated with postoperative IOP reduction in ELV and PB groups, while postoperative measurements were in PIC group. Preoperative and postoperative change of iridotrabecular contact (ITC) index and area were correlated with postoperative IOP reduction in PB and ELV groups but not in PIC group. Postoperative ITC index ( P =0.031) and area ( P =0.003) showed significant correlations with postoperative IOP fluctuation only in PIC group.

CONCLUSIONS

SS AS-OCT parameters including ITC index and area showed different associations with postoperative IOP control, which should be considered in determination of lens extraction and treatment of PACD eyes.

Automated classification of angle-closure mechanisms based on anterior segment optical coherence tomography images via deep learning

Purpose

To develop and validate deep learning algorithms that can identify and classify angle-closure (AC) mechanisms using anterior segment optical coherence tomography (AS-OCT) images.

Methods

This cross-sectional study included participants of the Handan Eye Study aged ≥35 years with AC detected via gonioscopy or on the AS-OCT images. These images were classified by human experts into the following to indicate the predominant AC mechanism (ground truth): pupillary block, plateau iris configuration, or thick peripheral iris roll. A deep learning architecture, known as comprehensive mechanism decision net (CMD-Net), was developed to simulate the identification of image-level AC mechanisms by human experts. Cross-validation was performed to optimize and evaluate the model. Human-machine comparisons were conducted using a held-out and separate test sets to establish generalizability.

Results

In total, 11,035 AS-OCT images of 1455 participants (2833 eyes) were included. Among these, 8828 and 2.207 images were included in the cross-validation and held-out test sets, respectively. A separate test was formed comprising 228 images of 35 consecutive patients with AC detected via gonioscopy at our eye center. In the classification of AC mechanisms, CMD-Net achieved a mean area under the receiver operating characteristic curve (AUC) of 0.980, 0.977, and 0.988 in the cross-validation, held-out, and separate test sets, respectively. The best-performing ophthalmologist achieved an AUC of 0.903 and 0.891 in the held-out and separate test sets, respectively. And CMD-Net outperformed glaucoma specialists, achieving an accuracy of 89.9 % and 93.0 % compared to 87.0 % and 86.8 % for the best-performing ophthalmologist in the held-out and separate test sets, respectively.

Conclusions

Our study suggests that CMD-Net has the potential to classify AC mechanisms using AS-OCT images, though further validation is needed.

Screening Strategies and Methodologies

PRCIS

While glaucoma is a leading cause of irreversible vision loss, it presents technical challenges in the design and implementation of screening. New technologies such as PRS and AI offer potential improvements in our ability to identify people at high risk of sight loss from glaucoma and may improve the viability of screening for this important disease.

PURPOSE

To review the current evidence and concepts around screening for glaucoma.

METHODS/RESULTS

A group of glaucoma-focused clinician scientists drew on knowledge and experience around glaucoma, its etiology, and the options for screening. Glaucoma is a chronic progressive optic neuropathy affecting around 76 million individuals worldwide and is the leading cause of irreversible blindness globally. Early stages of the disease are asymptomatic meaning a substantial proportion of cases remain undiagnosed. Early detection and timely intervention reduce the risk of glaucoma-related visual morbidity. However, imperfect tests and a relatively low prevalence currently limit the viability of population-based screening approaches. The diagnostic yield of opportunistic screening strategies, relying on the identification of disease during unrelated health care encounters, such as cataract clinics and diabetic retinopathy screening programs, focusing on older people and/or those with a family history, are hindered by a large number of false-positive and false-negative results. Polygenic risk scores (PRS) offer personalized risk assessment for adult-onset glaucoma. In addition, artificial intelligence (AI) algorithms have shown impressive performance, comparable to expert humans, in discriminating between potentially glaucomatous and non-glaucomatous eyes. These emerging technologies may offer a meaningful improvement in diagnostic yield in glaucoma screening.

CONCLUSIONS

While glaucoma is a leading cause of irreversible vision loss, it presents technical challenges in the design and implementation of screening. New technologies such as PRS and AI offer potential improvements in our ability to identify people at high risk of sight loss from glaucoma and may improve the viability of screening for this important disease.

Lipid mediators in glaucoma: Unraveling their diverse roles and untapped therapeutic potential

Glaucoma is a complex neurodegenerative disease characterized by optic nerve damage and visual field loss, and remains a leading cause of irreversible blindness. Elevated intraocular pressure (IOP) is a critical risk factor that requires effective management. Emerging research underscores dual roles of bioactive lipid mediators in both IOP regulation, and the modulation of neurodegeneration and neuroinflammation in glaucoma. Bioactive lipids, encompassing eicosanoids, specialized pro-resolving mediators (SPMs), sphingolipids, and endocannabinoids, have emerged as crucial players in these processes, orchestrating inflammation and diverse effects on aqueous humor dynamics and tissue remodeling. Perturbations in these lipid mediators contribute to retinal ganglion cell loss, vascular dysfunction, oxidative stress, and neuroinflammation. Glaucoma management primarily targets IOP reduction via pharmacological agents and surgical interventions, with prostaglandin analogues at the forefront. Intriguingly, additional lipid mediators offer promise in attenuating inflammation and providing neuroprotection. Here we explore these pathways to shed light on their intricate roles, and to unveil novel therapeutic avenues for glaucoma management.

Predictors of Glaucomatous Progression in Individuals with Small and Large Optic Discs

PURPOSE

To identify factors associated with glaucomatous progression in individuals with small and large optic discs.

DESIGN

Retrospective review.

SUBJECTS

4505 individuals with glaucoma at UCLA; 233 (59.7%) with small discs, 157 (40.3%) with large discs.

METHODS

Small and large disc sizes were defined by OCT or Heidelberg Retinal Tomography as disc area ≤ 5% (≤ 1.3 mm2) and ≥ 95% (≥ 2.9 mm2), respectively. Medical records were reviewed for demographics, systemic comorbidities, glaucoma type, ocular comorbidities, and ocular surgery. Logistic regression was used to identify predictors of visual field (VF) progression in individuals with small and large discs and predictors of large versus small discs.

MAIN OUTCOME MEASURES

The VF deterioration with mean deviation, pointwise linear regression, and glaucoma rate index (GRI); large vs. small disc.

RESULTS

In individuals with small discs, Asian versus non-Hispanic White ethnicity was associated with increased progression (adjusted odds ratio [aOR] = 4.05; 95% confidence interval [CI] = 1.12-14.59 for GRI). Higher intraocular pressure (IOP) range and peak were associated with increased progression in individuals with both small discs (aOR = 1.12; 95% CI = 1.00-1.27 and aOR = 1.05; 95% CI = 1.00-1.10 per 1 mmHg for range and peak with GRI) and large discs (aOR = 1.35; 95% CI = 1.12-1.66 and aOR = 1.11; 95% CI = 1.03-1.20 per 1 mmHg for range and peak with GRI). Multivariable predictors of having large vs. small discs included vasospastic phenotype (aOR = 2.58; 95% CI = 1.35-5.19) and Black (aOR = 20.46; 95% CI = 8.33-61.84), Hispanic/Latino (aOR = 9.65; 95% CI = 4.14-25.39), Asian (aOR = 4.87; 95% CI = 2.96-8.1), and other (aOR = 2.79; 95% CI = 1.69-4.63) versus non-Hispanic White ethnicity.

CONCLUSIONS

Increased odds of glaucomatous progression were associated with Asian vs. non-Hispanic White ethnicity in glaucoma patients with small optic discs, as well as with increased IOP range and peak in those with small and large discs. Individuals with a vasospastic phenotype and those from racial and ethnic minority backgrounds had increased odds of having large vs. small optic discs. Further characterization of discernible phenotypes would improve disease prognostication and help individualize glaucoma treatment.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Longitudinal Rates of Change in Structural Parameters of Optical Coherence Tomography in Primary Angle Closure Glaucoma following Laser Iridotomy along with Peripheral Iridoplasty

Background

This study aimed to investigate longitudinal rates of change (LRCs) of structural parameters from optical coherence tomography (OCT) in patients with primary angle closure glaucoma (PACG) after laser iridotomy (LI) along with laser peripheral iridoplasty (PI).

Methods

Among 146 patients diagnosed with PACG, thirty-two subjects (32 eyes) who underwent LI plus PI and accomplished more than five times of reliable OCT tests were included in the current retrospective study. Retinal nerve fiber layer (RNFL) and Bruch's membrane opening-minimum rim width (BMO-MRW) were measured by spectral-domain OCT with three month interval. LRCs of global and six Garway-Heath sectors were investigated using the linear mixed-effects model which adjusted BMO area, sex, and age. Imaging of dual Scheimpflug analyzer was performed before and at 1 week after LI with PI and yearly thereafter.

Results

The mean follow-up period was 32.28 ± 13.34 months with a mean number of 10.18 ± 3.33 OCT images. Baseline characteristics are as follows: age, 63 ± 7.9 years; female, 62.5%; intraocular pressure(IOP), 15.48 ± 4.79 mmHg; anterior chamber depth, 2.09 ± 0.18 mm; and mean deviation, -7.97 ± 8.48 dB. Global LRC of BMO-MRW was 0.86 ± 1.34 μm/yr and RNFL was -0.64 ± 0.22 μm/yr. IOP decreased significantly to 13.06 ± 2.21 mmHg (p=0.001) while anterior chamber volume (p=0.011) and mean anterior chamber angle (p=0.022) increased significantly after LI along with PI compared to the baseline at the final visit.

Conclusions

LRC of a new parameter, BMO-MRW, and LRC of RNFL were relatively low in patients with PACG, following LI along with PI. After widening of the anterior chamber angle and decrease of IOP due to LI plus PI, PACG might show stable structural prognosis assessed by OCT.

Beyond the optic nerve: Genetics, diagnosis, and promising therapies for glaucoma

Glaucoma stands as a leading global cause of blindness, affecting millions. It entails optic nerve damage and vision loss, categorized into open-angle and closed-angle glaucoma with subtypes like POAG, ACG, XFG, PCG, PDG, and developmental glaucoma. The pathophysiological and genetic factors behind glaucoma remain partially understood, with past studies linking intraocular pressure (IOP) levels to retinal ganglion cell death. Open-angle glaucoma involves elevated resistance to aqueous outflow via the trabecular meshwork, while angle-closure glaucoma typically sees drainage pathways obstructed by the iris. Genes have been identified for POAG, ACG, XFG, PCG, PDG, and developmental glaucoma, allowing for early-onset detection and the emergence of gene therapy as an effective treatment. Nevertheless, diagnostic and treatment options have their constraints, necessitating large-scale, well-designed studies to deepen our grasp of genetics' role in glaucoma's pathogenesis. This review delves into glaucoma's risk factors, pathophysiology, genetics, diagnosis, and available treatment options, including gene therapy. Additionally, it suggests alternative therapies like yoga and meditation as adjunct treatments for glaucoma prevention. Overall, this review advances our comprehension of the pathophysiology and genetic associations of glaucoma while highlighting the potential of gene therapy as a treatment avenue. Further research is imperative to fully elucidate the genetic mechanisms underpinning glaucoma and to devise effective treatments.

Genetic and Environmental Contributions of Primary Angle-Closure Glaucoma and Primary Open-Angle Glaucoma: A Nationwide Study in Taiwan

PURPOSE

To estimate the familial risks of primary angle-closure glaucoma (PACG) and primary open-angle glaucoma (POAG) and assess the relative contributions of environmental and genetic factors to these risks.

DESIGN

Retrospective, population-based cohort study.

METHODS

We used the 2000-2017 Taiwan National Health Insurance Program database to construct 4,144,508 families for the 2017 population (N = 23,373,209). We used the polygenic liability model to estimate glaucoma's heritability and familial transmission. The degree of familial aggregation of glaucoma was obtained from the adjusted relative risk for individuals whose first-degree relatives had glaucoma using Cox's model.

RESULTS

PACG and POAG prevalence rates for individuals whose first-degree relatives had PACG or POAG were 0.95% and 2.40%, higher than those of the general population (0.61% and 0.40%, respectively). The relative risk of PACG in individuals whose first-degree relatives had PACG was 2.44 (95% CI = 2.31-2.58). The relative risk of POAG in individuals whose first-degree relatives had POAG was 6.66 (95% CI = 6.38-6.94). The estimated contributions to PACG and POAG phenotypic variances were 19.4% and 59.6% for additive genetic variance, 19.1% and 23.2% for common environmental factors shared by family members, and 61.5% and 17.2% for nonshared environmental factors, respectively.

CONCLUSIONS

These data highlight the relative importance of genetic contribution to POAG and environmental contribution to PACG. Therefore, future work may need to focus on finding more novel environmental determinants of PACG.

Role of Static and Dynamic Ocular Biometrics Measured in the Dark and Light as Risk Factors for Angle Closure Progression

PURPOSE

To assess the role of static and dynamic ocular biometric parameters measured in the dark and light for predicting progression of primary angle closure suspect (PACS) to primary angle closure (PAC).

DESIGN

Retrospective cohort study using prospective randomized controlled trial data from untreated, control eyes.

METHODS

Zhongshan Angle Closure Prevention Trial subjects underwent anterior segment optical coherence tomography (AS-OCT) imaging in the dark and light. Static biometric parameters were measured, consisting of angle, iris, lens, and anterior chamber parameters. Dynamic change parameters were calculated by subtracting light measurements from dark measurements. Cox proportional hazards regression models were developed to assess risk factors for PACD progression.

RESULTS

A total of 861 eyes of 861 participants were analyzed (36 progressors). On univariable analysis, TISA500 measurements in the light and dark were associated with progression (P < .001), whereas dynamic change parameters were not (P ≥ .08). In the primary multivariable model, older age (hazard ratio [HR] = 1.09 per year), higher intraocular pressure (IOP) (HR = 1.13 per mm Hg), and smaller TISA500 in the light (HR = 1.28 per 0.01 mm2) were significantly associated with greater risk of progression (P ≤ .04). Dark TISA500 had similar significance (HR = 1.28, P = .002) when replacing light TISA500. Risk of progression was more predictive among eyes in the lowest quartile of light TISA500 measurements (HR = 4.56, P < .001) compared to dark measurements (HR = 2.89, P = .003).

CONCLUSION

Static parameters measured in the light are as predictive, and possibly more so, of angle closure progression as those measured in the dark. Ocular biometrics measured under light and dark conditions may provide additional information for risk-stratifying patients for angle closure progression.

PACS plus criteria: a retrospective cohort review of 612 consecutive patients treated with bilateral YAG peripheral iridotomies

INTRODUCTION

With an ageing population and better life expectancy, the prevalence of angle closure disease is expected to increase by 20% per decade. In 2022, the Royal College of Ophthalmologists (RCOphth) issued a guideline on managing angle closure disease. Hospital eye service (HES) referral and prophylactic treatment are recommended only for primary angle closure suspect (PACS) with "Plus" features only. We aimed to examine patients previously treated with YAG peripheral iridotomies (YAG PI) for the presence of "PACS Plus" features.

METHODS

A retrospective cohort study of consecutive patients treated with YAG PI between 2015 and 2019 at a tertiary referral NHS eye centre was reviewed. Cases were examined to identify and classify patients into Primary Angle Closure (PAC), PACS, and Primary Angle Closure Glaucoma (PACG). Patients with PACS were studied for "Plus" features.

RESULTS

Six hundred twelve patients with gonioscopy-confirmed angle closure (defined as a minimum 180 degrees iridotrabecular contact) treated with YAG PI from years 2015 to 2019 were included in the analysis. The mean age of patients presenting with angle closure disease was 68.5 years (SD 11.3). There were 390 (63.7%) patients with PACS, 102 (16.6%) with PAC and 120 (19.7%) with PACG. Of the PACS patients, 159(40.8%) patients had no "Plus" features. 181 (40.2%) patients had 1 "Plus" feature, 37 (9.5%) had 2 "Plus" features and 13 (3.3%) patients had 3 "Plus" features.

CONCLUSION

In our cohort, a considerable proportion (40.8%) of PACS patients treated with YAG PI did not have Plus features and therefore that would not meet the proposed criteria for HES referral and YAG PI. With the proposed guidance, we expect a considerable reduction in HES referrals. Nonetheless, community optometry services should be supported and trained to provide monitoring for patients with PACS not referred to the HES.

Lens factor as an underlying mechanism in primary angle closure with gonioscopically-visualized ciliary body processes

PURPOSE

To compare the differences in anterior segment parameters between eyes with primary angle closure (PAC) with and without gonioscopically-visualized ciliary body processes (CBP).

STUDY DESIGN

Prospective, observational, comparative clinical study.

METHODS

Detailed ocular examinations and gonioscopy were performed in 89 eyes of 89 patients with PAC to determine the visibility of the CBP. Anterior chamber depth (ACD), anterior chamber width, lens thickness (LT), lens vault (LV) and pupil diameter were determined using ultrasound biomicroscopy. The lens-axial length factor (LAF) and relative lens position (RLP) were calculated. All parameters were compared between eyes with and without gonioscopically visible CBP (PAC+CBP and PAC-CBP groups) after adjusting for age and gender. The association of the parameters with visible CBP was analyzed by univariate logistic regression analysis.

RESULTS

PAC+CBP group included 41 eyes and the PAC-CBP group, 48 eyes. The axial length and ACD were statistically significantly smaller (p = 0.009 and p = 0.005, respectively) and LT, LV and LAF were statistically significantly greater (p = 0.03, p = 0.008 and p = 0.004, respectively) in the PAC+CBP group. In the PAC eyes with glaucoma, the LT, LV and LAF were statistically significantly greater in the PAC+CBP group (p = 0.02, p = 0.001 and p = 0.02, respectively). The LAF had the strongest association with visible CBP in the regression analysis (Odds ratio = 141.70, p = 0.002).

CONCLUSION

Gonioscopical visualization of ciliary processes may suggest that anterior segment crowding, especially lens factor is the underlying mechanism in PAC. It may provide a practical gonioscopic examination method for predicting the predominant pathophysiology of PAC.

Machine learning-couched treatment algorithms tailored to individualized profile of patients with primary anterior chamber angle closure predisposed to the glaucomatous optic neuropathy

Background

Primary angle closure glaucoma (PACG) is still one of the leading causes of irreversible blindness, with a trend towards an increase in the number of patients to 32.04 million by 2040, an increase of 58.4% compared with 2013. Health risk assessment based on multi-level diagnostics and machine learning-couched treatment algorithms tailored to individualized profile of patients with primary anterior chamber angle closure are considered essential tools to reverse the trend and protect vulnerable subpopulations against health-to-disease progression.

Aim

To develop a methodology for personalized choice of an effective method of primary angle closure (PAC) treatment based on comparing the prognosis of intraocular pressure (IOP) changes due to laser peripheral iridotomy (LPI) or lens extraction (LE).

Methods

The multi-parametric data analysis was used to develop models predicting individual outcomes of the primary angle closure (PAC) treatment with LPI and LE. For doing this, we suggested a positive dynamics in the intraocular pressure (IOP) after treatment, as the objective measure of a successful treatment. Thirty-seven anatomical parameters have been considered by applying artificial intelligence to the prospective study on 30 (LE) + 30 (LPI) patients with PAC.

Results and data interpretation in the framework of 3P medicine

Based on the anatomical and topographic features of the patients with PAC, mathematical models have been developed that provide a personalized choice of LE or LPI in the treatment. Multi-level diagnostics is the key tool in the overall advanced approach. To this end, for the future application of AI in the area, it is strongly recommended to consider the following:Clinically relevant phenotyping applicable to advanced population screeningSystemic effects causing suboptimal health conditions considered in order to cost-effectively protect affected individuals against health-to-disease transitionClinically relevant health risk assessment utilizing health/disease-specific molecular patterns detectable in body fluids with high predictive power such as a comprehensive tear fluid analysis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-023-00337-1.

The association between glaucoma and all-cause mortality in middle-aged and elderly Chinese people: results from the China Health and Retirement Longitudinal Study

OBJECTIVES

This population-based, prospective cohort study investigated the association between glaucoma and mortality in older adults.

METHODS

Participants aged 45 years or older at baseline (47.9% male) were enrolled in 2011 for the China Health and Retirement Longitudinal Study (CHARLS). All-cause mortality was observed during 7 years of follow-up. The baseline data were collected in the 2011 CHARLS, and participants were followed up for 7 years (until 2018). The risk of all-cause mortality was investigated using Cox proportional-hazards regression with age as the time scale, adjusting for significant risk factors and comorbid conditions.

RESULTS

Among the 14,803 participants included, the risk of all-cause death was significantly higher among people with glaucoma than among those without glaucoma, after adjustment for other confounders (hazard ratio [HR], 1.46; 95% confidence interval [CI], 1.04 to 2.03). In a subgroup analysis based on the mean age of death, among those who were 75 years and older (n=1,231), the risk of all-cause death was significantly higher in patients with glaucoma than in those without glaucoma (HR, 1.89; 95% CI, 1.24 to 1.89).

CONCLUSIONS

Participants with glaucoma had a higher risk of all-cause mortality, especially those aged 75 years and above. Our findings revealed potential mechanisms underlying an association between glaucoma and all-cause mortality. They also highlighted the importance of glaucoma management to prevent premature death in middle-aged and older adults.

Lens extraction versus laser peripheral iridotomy for acute primary angle closure

BACKGROUND

Acute primary angle closure (APAC) is a potentially blinding condition. It is one of the few ophthalmic emergencies and carries high rates of visual morbidity in the absence of timely intervention. Laser peripheral iridotomy (LPI) has been the standard of care thus far. However, LPI does not eliminate the long-term risk of chronic angle closure glaucoma and other associated sequelae. There has been increasing interest in lens extraction as the primary treatment for the spectrum of primary angle closure disease, and it is as yet unclear whether these results can be extrapolated to APAC, and whether lens extraction provides better long-term outcomes. We therefore sought to evaluate the effectiveness of lens extraction in APAC to help inform the decision-making process.  OBJECTIVES: To assess the effect of lens extraction compared to LPI in the treatment of APAC.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2022, Issue 1), Ovid MEDLINE, Ovid MEDLINE E-pub Ahead of Print, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily (January 1946 to 10 January 2022), Embase (January 1947 to 10 January 2022), PubMed (1946 to 10 January 2022), Latin American and Caribbean Health Sciences Literature Database (LILACS) (1982 to 10 January 2022), ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search. We last searched the electronic databases on 10 January 2022.

SELECTION CRITERIA

We included randomized controlled clinical trials comparing lens extraction against LPI in adult participants ( ≥ 35 years) with APAC in one or both eyes.

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 included two studies conducted in Hong Kong and Singapore, comprising 99 eyes (99 participants) of predominantly Chinese origin. The two studies compared LPI with phacoemulsification performed by experienced surgeons. We assessed that both studies were at high risk of bias. There were no studies evaluating other types of lens extraction procedures.  Phacoemulsification may result in an increased proportion of participants with intraocular pressure (IOP) control compared with LPI at 18 to 24 months (risk ratio (RR) 1.66, 95% confidence interval (CI) 1.28 to 2.15; 2 studies, n = 97; low certainty evidence) and may reduce the need for further IOP-lowering surgery within 24 months (RR 0.07, 96% CI 0.01 to 0.51; 2 studies, n = 99; very low certainty evidence). Phacoemulsification may result in a lower mean IOP at 12 months compared to LPI (mean difference (MD) -3.20, 95% CI -4.79 to -1.61; 1 study, n = 62; low certainty evidence) and a slightly lower mean number of IOP-lowering medications at 18 months (MD -0.87, 95% CI -1.28 to -0.46; 1 study, n = 60; low certainty evidence), but this may not be clinically significant. Phacoemulsification may have little to no effect on the proportion of participants with one or more recurrent APAC episodes in the same eye (RR 0.32, 95% CI 0.01 to 7.30; 1 study, n = 37; very low certainty evidence). Phacoemulsification may result in a wider iridocorneal angle assessed by Shaffer grading at six months (MD 1.15, 95% CI 0.83 to 1.47; 1 study, n = 62; very low certainty evidence). Phacoemulsification may have little to no effect on logMAR best-corrected visual acuity (BCVA) at six months (MD -0.09, 95% CI -0.20 to 0.02; 2 studies, n = 94; very low certainty evidence). There was no evidence of a difference in the extent of peripheral anterior synechiae (PAS) (clock hours) between intervention arms at 6 months (MD -1.86, 95% CI -7.03 to 3.32; 2 studies, n = 94; very low certainty evidence), although the phacoemulsification group may have less PAS (degrees) at 12 months (MD -94.20, 95% CI -140.37 to -48.03; 1 study, n = 62) and 18 months (MD -127.30, 95% CI -168.91 to -85.69; 1 study, n = 60).  In one study, there were 26 adverse events in the phacoemulsification group: intraoperative corneal edema (n = 12), posterior capsular rupture (n = 1), intraoperative bleeding from iris root (n = 1), postoperative fibrinous anterior chamber reaction (n = 7), and visually significant posterior capsular opacification (n = 5), and no cases of suprachoroidal hemorrhage or endophthalmitis. There were four adverse events in the LPI group: closed iridotomy (n = 1) and small iridotomies that required supplementary laser (n = 3). In the other study, there was one adverse event in the phacoemulsification group (IOP > 30 mmHg on day 1 postoperatively (n = 1)), and no intraoperative complications. There were five adverse events in the LPI group: transient hemorrhage (n = 1), corneal burn (n = 1), and repeated LPI because of non-patency (n = 3).  Neither study reported health- or vision-related quality of life measures.

AUTHORS' CONCLUSIONS

Low certainty evidence suggests that early lens extraction may produce more favorable outcomes compared to initial LPI in terms of IOP control. Evidence for other outcomes is less clear. Future high-quality and longer-term studies evaluating the effects of either intervention on the development of glaucomatous damage and visual field changes as well as health-related quality of life measures would be helpful.

Rates and Patterns of Diagnostic Conversion from Anatomical Narrow Angle to Primary Angle-Closure Glaucoma in the United States

PURPOSE

To assess rates of diagnostic conversion from anatomical narrow angle (ANA) to primary angle-closure glaucoma (PACG) in the United States and identify factors associated with diagnostic conversion.

DESIGN

Retrospective case-control study.

PARTICIPANTS

Patients diagnosed with ANA between the years 2007 and 2019 were identified based on International Classification of Diseases (ICD) codes in the Optum Clinformatics Data Mart Database. Inclusion was limited to newly diagnosed ANA, defined as the following: (1) continuous enrollment during a 2-year look back period and 6-year study period from index (first) date of ANA diagnosis; (2) diagnosis by an ophthalmologist or optometrist and record of gonioscopy; and (3) no history of intraocular pressure (IOP)-lowering drops, laser peripheral iridotomy (LPI), or intraocular surgery.

METHODS

Cox proportional hazards models were developed to assess factors associated with diagnostic conversion, defined as a change in ICD code from ANA to PACG.

MAIN OUTCOME MEASURES

New diagnosis of PACG within the 6-year study period recorded after an index diagnosis of ANA.

RESULTS

Among 3985 patients meeting inclusion criteria, 459 (11.52%) had detected diagnostic conversion to PACG within the study period. The conversion rate was stable at 3.54% per year after the first 6 months of ANA diagnosis. In the Cox proportional hazards model, age > 70 years and early (within 6 months of ANA diagnosis) need for LPI or IOP-lowering drops were positively associated with diagnostic conversion (hazard ratio [HR] > 1.59; P < 0.02). Cataract surgery at any time and late (after 6 months of ANA diagnosis) need for IOP-lowering drops appeared protective against diagnostic conversion (HR < 0.46; P < 0.004).

CONCLUSIONS

Annual risk of diagnostic conversion from ANA to PACG is relatively low overall; elderly patients are at higher risk whereas patients receiving cataract surgery are at lower risk. The utility of long-term monitoring seems low for most patients with ANA, highlighting the need for improved clinical methods to identify patients at higher risk for PACG.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Assessment of Iridotrabecular Contact and Its Association With Intraocular Pressure After Phacoemulsification in Primary Angle Closure

PURPOSE

To investigate the association between the quantitative assessment of iridotrabecular contact (ITC), measured by swept-source anterior segment optical coherence tomography (SS AS-OCT), and intraocular pressure (IOP) control after phacoemulsification in patients with primary angle closure disease (PACD).

DESIGN

Retrospective, clinical cohort study.

METHODS

Preoperative and postoperative anterior chamber angle parameters were measured using SS AS-OCT. IOP was measured preoperatively and until 6 months postoperatively. Percent IOP reduction and fluctuation after surgery were calculated, and their relationships with SS AS-OCT parameters were assessed by correlation analyses and locally weighted scatterplot smoothing (LOWESS) regression with change-point analysis.

RESULTS

A total of 51 eyes of 51 PACD patients were included. Preoperative ITC index and area (r = 0.626, r = 0.551), as well as changes in ITC index and area (r = 0.632, r = 0.543) after surgery, were significantly correlated with postoperative IOP reduction, after adjusting for age and gender (all P <.001). Higher postoperative ITC index (r = 0.405, P = .005) and ITC area (r = 0.460, P = 0.001) were associated with greater postoperative IOP fluctuations. Change points on LOWESS curves were observed for preoperative ITC index (33.0%) and change in ITC index (27.0%) and percent IOP reductions were significantly correlated with them above (β = 0.386, β = 0.664, all P < .001) but not below the change points.

CONCLUSIONS

Quantitative assessment of circumferential ITC can predict postoperative IOP control after phacoemulsification, and thus it may be used as a reference for determining lens extraction in PACD eyes.

Increase in anterior chamber angle depth after topical pilocarpine measured by spectral domain optical coherence tomography: A possible additional indicator for laser peripheral iridotomy in primary angle-closure suspects in an opportunistic set-up

Purpose

Indication of laser peripheral iridotomy (LPI) is often conjectural due to dependency on gonioscopy and strict dichotomous classification of occludability. Indentation gonioscopy is the gold standard but is under-utilized for various reasons. The prevalence of primary angle closure disease (PACD) in eastern India is 1.5-1.9%, with a 22% five-year progression rate. Many angle closure patients may go blind without timely diagnosis and iridotomy. General ophthalmologists need alternate, validated methods for diagnoses. Pilocarpine eye drop causes miosis, and flattens the iris, producing angle changes detectable by spectral domain optical coherence tomography (SD-OCT). We hypothesized that the amount of angle change may be a suitable indicator for iridotomy.

Methods

Our prospective cross-sectional single-masked observational study evaluated pilocarpine-induced changes in angle parameters detected by SD-OCT. Out of 372 patients enrolled, 273 patients (539 eyes) remained, with a mean age of 48.6 years (SD = 10.36). All eyes were graded by the Van Herick (VH) method, gonioscopy, and anterior segment (AS) SD-OCT and reassessed after pilocarpine drops.

Results

The sensitivity and specificity of tomography measurements against gonioscopy grades were 61% and 85%, respectively. The receiver operating characteristic (ROC) curve was 0.85. Pilocarpine-induced angle widening was significant in gonioscopically narrower angles. Low Van Herick grades (217 eyes), narrow gonioscopy grades (238 eyes), and a narrow OCT angle value (165 eyes) were candidates for iridotomy.

Conclusion

Our study results showed that pilocarpine-induced angle widening detected by SD-OCT could be a strong objective indicator for LPI.

Changes in intraocular pressure after pharmacological pupil dilatation in an elderly Chinese population in Taiwan: The Shihpai eye study

BACKGROUND

Mydriatic drugs are often used in ophthalmic clinics for pupil dilatation to assess the optic nerve and retina. Clinical studies have indicated that an increase in intraocular pressure (IOP) after pupil dilation is noted in open-angle glaucoma patients, those with narrow angles and in normal subjects. Asians are more likely to have narrow angles. Moreover, age-related cataract may increase the crowdedness of the angle. This study aimed to assess the effects of mydriatic pupil dilatation on IOP in an elderly Chinese population.

METHODS

The Shihpai Eye Study was a community-based, cross-sectional survey of vision and eye diseases among noninstitutionalized subjects aged 65 years and older in Shihpai, Taipei, Taiwan. IOP was taken using noncontact tonometry. The pupil was dilated with 1% tropicamide. IOP was measured again after maximal pupil dilatation 1 hour after mydriasis.

RESULTS

Of the 2045 participants, 1361 (66.6%) participated in both the questionnaire and eye examinations. The mean IOP before pupil dilatation was 12.9 ± 3.1 mmHg and was 12.8 ± 3.4 mmHg (range: 5-36 mmHg) after pupil dilatation. IOP higher than 21 mmHg after pupil dilation was noted in 17 (1.34%) participants, of whom IOP exceeded 30 mmHg in two (0.16%). Overall, the changes in IOP before and after pupil dilatation were insignificant ( p = 0.04). In the final regression analyses, refractive status toward hyperopia ( p < 0.01) was the only significant factor associated with an increase in IOP of at least 4 mmHg after pupil dilatation.

CONCLUSION

Our results revealed that the increase in IOP after pharmacological pupil dilatation was minimal, and the incidence of acute angle-closure attack was insignificant. Hyperopic status was the only factor related to an increase in IOP of > 4 mmHg. Caution should be exercised if one is hyperopic or has a history of glaucoma and rechecking IOP in these subjects is suggested after pharmacological mydriasis.

Asian Race and Primary Open-Angle Glaucoma: Where Do We Stand?

Primary open-angle glaucoma (POAG) is an optic neuropathy characterized by irreversible retinal ganglion cell damage and visual field loss. The global POAG prevalence is estimated to be 3.05%, and near term is expected to significantly rise, especially within aging Asian populations. Primary angle-closure glaucoma disproportionately affects Asians, with up to four times greater prevalence of normal-tension glaucoma reported compared with high-tension glaucoma. Estimates for overall POAG prevalence in Asian populations vary, with Chinese and Indian populations representing the majority of future cases. Structural characteristics associated with glaucoma progression including the optic nerve head, retina, and cornea are distinct in Asians, serving as intermediates between African and European descent populations. Patterns in IOP suggest some similarities between races, with a significant inverse relationship between age and IOP only in Asian populations. Genetic differences have been suggested to play a role in these differences, however, a clear genetic pattern is yet to be established. POAG pathogenesis differs between Asians and other ethnicities, and it may differ within the broad classification of the Asian race. Greater awareness and further research are needed to improve treatment plans and outcomes for the increasingly high prevalence of normal tension glaucoma within aging Asian populations.

Glaucoma Progression After Lens Extraction in Primary Angle-closure Glaucoma According to Angle-closure Mechanism

PRCIS

Long-term prognosis of primary angle-closure was assessed after lens extraction (LE) according to different mechanisms of angle closure (AC). Patients with pupillary block (PB) had a higher probability of glaucomatous progression than patients with plateau iris configuration (PIC).

PURPOSE

The aim was to investigate and compare the clinical characteristics and long-term prognosis of primary angle-closure disease (PACD) after LE according to different mechanisms of AC.

METHODS

In this retrospective observational cohort study, 118 eyes with PACD that underwent LE (mean follow-up; 6.0±3.5 y after surgery) were included. PACD eyes were categorized into three subgroups according to their dominant AC mechanisms, determined by anterior segment optic coherent tomography obtained before LE; PB, PIC, and exaggerated lens vault (ELV). Postoperative glaucomatous progression was determined according to functional (visual field) or structural (optic disc photographs or optic coherent tomography measured retinal nerve fiber layer thickness) criteria. Univariate and multivariate logistic regression analysis was performed to determine the risk factors associated with glaucomatous progression.

RESULTS

Fifty-two, 51, and 15 eyes with PB, PIC, and ELV, respectively, were included. All eyes showed significant intraocular pressure reduction, with a greater reduction in the ELV group than in the PB group after LE (27.0% vs. 12.5%, P=0.018). Lower baseline retinal nerve fiber layer thickness [odds ratio (OR): 0.966, P=0.004] and thinner central corneal thickness (OR: 0.985, P=0.021), and the PB group (OR: 2.891, P=0.022, reference to PIC group) were significantly associated with glaucomatous progression after LE.

CONCLUSIONS

In eyes with PACD, glaucoma progression was observed following LE despite reduced intraocular pressure. The probability of progression was highest in eyes with pupil block as a mechanism of AC. Close monitoring of glaucoma in these patients is suggested.

Long-Term Outcome of Corneal and Anterior Chamber Angle Parameters after Combined Laser Iridotomy and Iridoplasty Using Dual Scheimpflug Analyzer: 1 Year Results

Background: To investigate the outcomes of corneal and anterior chamber angle (ACA) parameters after laser iridotomy (LI) combined with peripheral iridoplasty (PI) using dual Scheimpflug analyzer in the long term. Methods: Fifty-eight eyes (58 subjects) with shallow AC were included in this prospective cohort study. Images of the Dual Scheimpflug analyzer were obtained before, 1 week, and 1 year after LI and PI. Pachymetry from three zones (central, middle, and peripheral), corneal aberration, and spherical equivalent (SE) were acquired. AC depth (ACD), AC volume (ACV), ACA from four quadrants, and intraocular pressure (IOP) were also obtained. For comparison of the results, the linear mixed-effects model was employed. Results: ACD significantly increased from 2.09 ± 0.25 mm to 2.10 ± 0.23 mm at 1 year after laser (all p < 0.05). ACV and ACA increased significantly after laser at 1 year (all p < 0.05). IOP significantly decreased from 15.97 ± 4.20 mmHg to 13.73 ± 2.63 mmHg at 1 year (all p < 0.0001). No significant changes were found in the coma, trefoil, total corneal aberration, pachymetry from three zones, corneal volume, central corneal thickness, and SE after LI and PI until 1 year (all p > 0.05). Conclusions: LI plus PI ameliorated parameters of ACA efficiently and significantly reduced IOP in eyes with shallow AC until 1 year of long-term follow-up. However, parameters of the cornea and SE were not influenced by LI with PI until after 1 year.

Prevalence of Plateau Iris in Primary Angle Closure Glaucoma: An Egyptian Hospital Based Ultrasound Biomicroscopy Study

Purpose

To determine the distribution and the anatomical characteristics of plateau iris (PI) in primary angle closure glaucoma (PACG) using ultrasound biomicroscopy (UBM).

Methods

Fifty UBM images of PACG cases were studied over one year by retrospective analysis. The data from UBM images including angle opening distance at 500 and 750 μm (AOD500 and AOD750), trabecular-iris angle (TIA), angle recess area at 750 μm (ARA750), maximum ciliary body thickness (CBTmax), anterior placement of ciliary processes (APCP), central anterior chamber depth (CACD), axial lens thickness (ALT), and ciliary sulcus status were analyzed and compared between the PI and non-PI cases.

Results

Eighteen cases had PI (36%). The mean AOD500, AOD750, and TIA were significantly smaller in PI than in non-PI eyes (P = 0.01; P = 0.046; and P = 0.026). Values of the ARA750 and CBTmax were not significantly different between the two groups (P = 0.208 and P = 0.368). CACD was deeper in the PI group (P = 0.011). ALT was higher in the non-PI group (P = 0.001). The mean APCP of the PI group was more than those of the non-PI group (P < 0.001). The number of cases with obliterated ciliary sulcus in more than two quadrants was significantly more in the PI group (P < 0.001).

Conclusion

Around one-third of PACG eyes were found to have PI on UBM imaging. The number of obliterated ciliary sulcus and APCP were important UBM parameters that help in PI diagnosis.

[Primary anterior chamber angle closure: progression from suspect to glaucoma. Part 2. Predictors of primary angle closure]

To review the literature devoted to the search of predictors of primary angle closure (PAC) progression as an important link in the pathogenesis of primary angle-closure glaucoma. This part presents a cluster analysis, describes the mechanisms of PAC development, and considers the studies aimed at discovering the risk factors for the progression of primary angle closure suspect into true angle closure. The results of the analyzed literature are ambiguous, indicating the need for further research that would involve strict inclusion criteria, and a standard approach to defining the primary angle closure disease and expanding the diagnostic parameters, in which a key role belongs to anterior segment optical coherence tomography (AS-OCT).

[Primary anterior chamber angle closure: progression from suspect to glaucoma. Part 1. Frequency and rate of transition from suspected primary angle closure to true angle closure and primary angle closure glaucoma]

To review the literature devoted to the problem of primary anterior chamber angle closure (PAC) and the development of this pathology from glaucoma suspect to primary angle closure glaucoma. The paper includes a trend analysis of the studies concerning primary angle closure suspects (PACS). The concept of this review is conditioned by the conflicting strategies for treating patients with initial PAC without glaucomatous optic neuropathy. Solving the problem of angle closure plays a key role in preventing the development of PAC glaucoma, which is the world's leading cause of irreversible blindness. This part of the review provides information on the frequency and rate of disease progression in PACS. The analyzed literature data is contradictory and indicates the need for further search that would consider a standardized approach to defining the concept of PAC disease, demographic factors and unified examination methods for generalizing and systematizing data in order to draw out unified treatment recommendations.

Correlation between choroidal thickness and intraocular pressure control in primary angle-closure glaucoma

Purpose:

To study the correlation between choroidal thickness (CT) and IOP control in primary angle-closure glaucoma (PACG).

Methods:

In total, 61 patients (102 eyes) with PACG underwent subfoveal CT (SFCT) scanning using enhanced depth imaging–optical coherence tomography. The subjects with PACG were further grouped as controlled IOP (≤21 mm Hg on maximal medical therapy) and uncontrolled IOP (>21 mm Hg on maximal medical therapy). The average CT of the PACG eyes was calculated and compared between both groups. A correlation analysis was done between CT and intereye difference in CT with the disease parameters.

Results:

The mean CT was 274.38 ± 42.10 μm in 102 PACG eyes. SFCT was significantly increased in the uncontrolled IOP group as compared with the controlled IOP group. The mean SFCT was 245.57 ± 62.10 μm in the controlled group and 294.46 ± 51.05 μm in the uncontrolled group (P < 0.01). Factors associated with a thicker choroid were younger age, high IOP, and higher optic nerve head cupping (P < 0.001). Neither the visual field-mean deviation (VF-MD) nor pattern standard deviation (PSD) was found to be associated with overall CT. The intereye asymmetry between CT was significantly associated with poor VF-MD and PSD.

Conclusion:

PACG eyes with thicker choroid may be a risk factor for poor IOP control on medical anti-glaucoma therapy. Thicker choroid as compared to the fellow eye is a poor prognostic sign and these eyes should be monitored closely.

Genetic Markers PLEKHA7, ABCC5, and KALRN Are Not Associated With the Progression of Primary Angle Closure Glaucoma (PACG) in Malays

Introduction PLEKHA7, ABCC5, and KALRN have been identified as susceptible genetic markers related to glaucoma. We aimed to investigate the association between the identified susceptible genetic markers PLEKHA7 rs11024102, ABCC5 rs17217796, and KALRN rs1392912 in the progression of primary angle-closure glaucoma (PACG) in Malay patients. Methods For this study, 163 Malay patients with PACG were recruited from April 2015 to April 2017 at Hospital Universiti Sains Malaysia and Hospital Raja Perempuan Zainab II, Kota Bharu. Venesection was performed. DNA was extracted using a commercial DNA extraction kit. The primer was optimized for rs11024102, rs17217796, and rs1392912 of the PLEKHA7, ABCC5, and KALRN genes, respectively. Polymerase chain reaction (PCR) was performed, and PCR products were purified. A DNA sequencer was used to identify polymorphisms. Progression was based on the agreement between the Advanced Glaucoma Intervention Study scoring system and the Hodapp-Parrish and Anderson staging system. The scoring was conducted on two reliable consecutive Humphrey visual fields (HVFs) during the recruitment period and two baseline HVFs obtained when the diagnosis was made. Based on the scoring, patients were grouped into progressed and non-progressed. A chi-square test was used to analyze the association between the genetic markers and the progression of PACG. Results One hundred and sixty-three Malay patients with PACG (58 men and 105 women) were recruited. Twenty-nine patients (18%) had visual field progression of PACG after a mean (SD) follow-up of 6.0 (1.0) years. The minor allele frequencies for PLEKHA7 rs11024102 (G/A), ABCC5 rs17217796 (C/G), and KALRN rs1392912 (A/G) were 0.44, 0.08, and 0.48, respectively. We found that rs11024102 (p=0.828), rs17217796 (p=0.865), and rs1392912 (p=0.684) were not associated with PACG progression in the Malay patients. Conclusion Although PLEKHA7 and ABCC5 were found to be genetic markers associated with the risk of PACG, they played no roles in PACG progression in the Malay population. Moreover, KALRN was not significantly associated with PACG progression. Other susceptible genetic markers may be responsible for PACG progression.

Implications of the Relationship Between Refractive Error and Biometry in the Pathogenesis of Primary Angle Closure

Purpose

The purpose of this study was to investigate the relationship between refractive error and ocular biometry and its implication in the pathogenesis of primary angle closure (PAC).

Methods

We have retrospectively recruited 119 PAC eyes and 388 non-PAC eyes with an axial length (AL) of ≤25.0 mm and a spherical equivalent (SE) of ≥−6.0 diopters (D). Stepwise multiple regression was performed for keratometry value (K), AL, anterior chamber depth (ACD), and SE.

Results

PAC eyes were more likely to be in women and have a higher IOP and shorter AL than non-PAC eyes. In a multiple regression analysis, SE was not associated with PAC. The associations between AL and SE or AL and ACD were not different in PAC eyes compared with non-PAC eyes. However, the cornea was flatter in PAC eyes (β = −0.448, P < 0.001), and a flatter cornea was associated with more hyperopic refraction (β = −0.454, P < 0.001) and shallower ACD (β = 0.073, P < 0.001) in PAC eyes. ACD was not associated with SE in non-PAC eyes, but shallower ACD was associated with greater myopic refraction in PAC eyes (β = 1.117, P = 0.006).

Conclusions

PAC eyes seem to have flatter cornea compared with non-PAC eyes. A shallower ACD seems to be associated with greater myopic refraction in PAC eyes, but not in non-PAC eyes.

Anterior chamber morphology changes in eyes with narrow angles by Scheimpflug imaging: Pilocarpine versus laser peripheral iridotomy

PURPOSE

To evaluate morphometric variables, like anterior chamber angle (ACA), anterior chamber volume (ACV) and central anterior chamber depth (CACD) after pilocarpine administration and after prophylactic laser peripheral iridotomy (LPI) in eyes with primary angle-closure disease (PACD).

DESIGN

Prospective cohort study METHODS: Ninety-one eyes of 91 patients with narrow angles were consecutively enrolled in this prospective interventional study. All patients were classified into primary angle-closure suspect (PACS), primary angle-closure (PAC) and primary angle-closure glaucoma (PACG). If both eyes were eligible, one eye was randomly selected for study inclusion. ACV, ACD and ACA were evaluated using Scheimpflug imaging technology at three time points: at baseline (T0), 45 min after application of pilocarpine before LPI (T1) and at one-month post-LPI (T2).

RESULTS

PACS, PAC and PACG groups included 25 (27.4%), 24 (26.3%) and 42 (46.1%) eyes, respectively. At both time points T1 and T2, mean pupil diameter, ACV and ACA changed significantly (P = 0.00). In all subgroups, ACD decreased significantly at T1 and then increased significantly at T2. ACA was widened by 6 degrees in angles < 26 degrees as compared to 3 degrees in > 26 degrees eyes. In PACG group, mean ACV increased significantly between T0 and T2 (P = 0.0). Other parameters like mean cornea volume (P = 0.27), central corneal thickness (P = 0.29) showed no significant change between time points (T0, T1 and T2). Pilocarpine instillation caused a significant increase in ACA, ACV and ACD CONCLUSION: Scheimpflug imaging detected significant changes in ACD post-LPI and post-pilocarpine in all groups. However, ACV changed significantly only in PACS and PACG.

CLINICAL TRIALS REGISTRATION

Gels and blots/image manipulation: Author declares that the final image submitted represent the original data. All unprocessed images are with corresponding author and will make available if required.

Epidemiology and clinical presentation of glaucoma in a referral facility in Ghana: Any lessons for public health intervention?

The purpose of this study was to evaluate the epidemiological and clinical profile of patients living with glaucoma and receiving care in a tertiary eye center in Ghana. This was a hospital-based retrospective study of clinical records of glaucoma patients from January 2010 to December 2019. The study involved collating demographic information of patients, clinical presentation, and the management of glaucoma. A total of nineteen thousand (19,000) charts were retrieved from the eye center's archives. Out of these, 660 (3.5%) records of patients qualified for the study and were analyzed. There were 398 (60.3%) males and 262 (39.7%) females. Their ages ranged from 9 to 86 years (mean age = 47.30; SD ± 16.86 years). The averages of ocular parameters of 1,320 eyes (660 patients) were visual acuity = 0.26 ± 0.55 logMAR; intraocular pressure: 17.31 ± 6.11 mmHg; cup-to-disc ratios: 0.67 ± 0.17 D; and the average retinal nerve fibers thickness was 95.03 ± 21.74 μm. The mainstay of treatment was the sole use of medication. Males were the major group receiving glaucoma care at the tertiary level. Glaucoma cases included juveniles but the mean age suggests most were of adult-onset. Socio-demographic characteristics affected the diagnosis and management of glaucoma among patients receiving care at a referral center. Public health, stakeholders, and policymakers' interventions can help identify individuals with glaucoma.

Plateau Iris and Severity of Primary Angle Closure Glaucoma

PURPOSE

To compare the distribution of plateau iris in eyes across varying severity of primary angle closure glaucoma (PACG) using standardized ultrasound biomicroscopy (UBM) criteria.

DESIGN

Cross-sectional study.

METHODS

UBM was performed on 210 patients with PACG who had previously undergone laser peripheral iridotomy. Plateau iris was defined as the presence of all the following UBM criteria in ≥2 quadrants of the angle: anteriorly directed ciliary body, absent ciliary sulcus, iris angulation, flat iris plane, and iridotrabecular contact. Disease severity was based on the visual field mean deviation (MD) and classified as early-to-moderate (MD ≥ -12 dB), advanced (-12.01 dB to -20 dB), and severe (MD < -20 dB).

RESULTS

Of 210 subjects recruited, 23 were excluded because of poor quality UBM images. The remaining 187 patients were categorized as having early-to-moderate (n = 103), advanced (n = 38), and severe PACG (n = 46). Of these subjects, 48.1% were male, and 90.9% were of Chinese ethnicity. The overall proportion of plateau iris was 36.9%, with 32.0% (33/103) in early-to-moderate, 34.2% (13/38) in advanced, and 50% (23/46) in severe PACG (P = .03, comparing severe PACG with early-to-moderate groups). Among the severe PACG group, those with plateau iris configuration had significantly smaller anterior chamber area (P = .03) and volume (P = .01) compared with those without plateau iris.

CONCLUSION

The higher proportion of plateau iris configuration in eyes with severe PACG compared with early-to-moderate PACG suggest that this may be a contributory factor for disease severity.

The 100 Most Cited Articles in Ophthalmology in Asia

PURPOSE

The aim of this study was to review the top 100 most-cited articles in ophthalmology in Asia since 1970.

METHODS

The Scopus database was used to identify the top 100 most-cited ophthalmology articles published in ophthalmology (T100-Eye) and nonophthalmology (T100-General) journals.

RESULTS

The T100-Eye articles were published between 1982 and 2015, and T100-General from 1982 to 2017. T100-Eye had higher citations [median (range) = 317 (249-1326)] than T100-General [158 (105-2628)], but T100-General were published in journals with higher impact factor (IF) than T100-Eye (median IF= 5.5 vs 4.4) and produced more landmark papers (3 vs 1 articles that were cited >1000 times). Fifty-five % of T100-Eye were published in 3 journals: Ophthalmology (n = 22), Investigative Ophthalmology and Visual Science (n = 17), and American Journal of Ophthalmology (n = 16). T100-Eye had 88 original research articles and 12 reviews, whereas T100-General had 84 original research and 16 reviews. The most-frequent studied disease categories were myopia (n = 16) and age-related macular degeneration (n = 15) in T100-Eye and diabetic retinopathy (n = 24) and glaucoma (n = 16) in T100-General. Japan and Singapore contributed most to T100-Eye (n = 42, n = 17) and T100-General (n = 36, n = 26) articles. More than 80% and 95% of first and last authors were male in both lists. Emerging research topics were optical coherence tomography in T100-Eye and artificial intelligence in T100-General.

CONCLUSIONS

Our citation analysis reveals differences in the focus of research topics of top-cited ophthalmology articles published in ophthalmology and nonophthalmology journals in Asia. It highlights that certain eye diseases are studied more in Asia and shows the contribution of specific countries to highly cited publications in ophthalmology research in Asia.

Smartphone-aided Quantification of Iridocorneal Angle

As the upgrading of smartphone technology revolutionizes the field of ophthalmic imaging, we put forward one more of its novel applications. This article presents the possibility of iridocorneal angle (ICA) estimation through smartphone-captured images. Such measured inferior ICA (at 6'o clock position) was comparable to the anterior segment optical coherence tomography measured trabecular iris angle at 500 μ at 270 degrees (P=0.06). They both had an excellent positive correlation (ρ=0.81, P<0.001). Therefore, smartphone image-aided angle estimation may be a simple, effective, and economical method for quantification of ICAs, paving a more evident way for identification of angle-closure disease.

Cluster analysis reveals patterns of age-related change in anterior chamber depth for gender and ethnicity: clinical implications

Purpose

To identify patterns of age‐, gender‐ and refractive‐ related changes in Scheimpflug‐based anterior chamber depth across the central 8 mm of chamber width, to derive normative models, potentially useful for angle closure disease diagnosis.

Methods

This was a retrospective, cross‐sectional study. Scheimpflug photography was used to obtain anterior chamber depth measurements at 57 points across the central 8 mm of the chamber width from one eye of each healthy subject (male Caucasians (n = 189), female Caucasians (n = 186), male Asians (n = 165) and female Asians (n = 181)). Sliding window and nonlinear regression analysis was used to identify the age‐related changes in chamber depth. Hierarchical cluster analysis was used to identify test locations with statistically identical age‐related shifts, which were used to perform age‐correction for all subjects, resulting in normative distributions of chamber depth across the chamber width. The model was examined with and without the contribution of spherical equivalent refractive error.

Results

Distinct clusters, demonstrating statistically indistinguishable age‐related changes of chamber depth over time, were identified. These age‐related changes followed a nonlinear regression (fifth or sixth order polynomial). Females tended to have a greater rate of chamber depth shallowing. Incorporating refractive error into the model produced minimal changes to the fit relative to the ground truth. Comparisons with cut‐offs for angle closure from the literature showed that ageing alone was insufficient for identifying angle closure disease.

Conclusions

Age‐, ethnicity‐ and gender‐related differences need to be acknowledged in order to utilise anterior chamber depth data for angle closure disease diagnosis correctly. Ageing alone does not adequately account for the angle closure disease process.

Non-contact tests for identifying people at risk of primary angle closure glaucoma

BACKGROUND

Primary angle closure glaucoma (PACG) accounts for 50% of glaucoma blindness worldwide. More than three-quarters of individuals with PACG reside in Asia. In these populations, PACG often develops insidiously leading to chronically raised intraocular pressure and optic nerve damage, which is often asymptomatic. Non-contact tests to identify people at risk of angle closure are relatively quick and can be carried out by appropriately trained healthcare professionals or technicians as a triage test. If the test is positive, the person will be referred for further specialist assessment.

OBJECTIVES

To determine the diagnostic accuracy of non-contact tests (limbal anterior chamber depth (LACD) (van Herick test); oblique flashlight test; scanning peripheral anterior chamber depth analyser (SPAC), Scheimpflug photography; anterior segment optical coherence tomography (AS-OCT), for identifying people with an occludable angle.

SEARCH METHODS

We searched the following bibliographic databases 3 October 2019: CENTRAL; MEDLINE; Embase; BIOSIS; OpenGrey; ARIF and clinical trials registries. The searches were limited to remove case reports. There were no date or language restrictions in the searches.

SELECTION CRITERIA

We included prospective and retrospective cross-sectional, cohort and case-control studies conducted in any setting that evaluated the accuracy of one or more index tests for identifying people with an occludable angle compared to a gonioscopic reference standard.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed data extraction and quality assessment using QUADAS2 for each study. For each test, 2 x 2 tables were constructed and sensitivity and specificity were calculated. When four or more studies provided data at fixed thresholds for each test, we fitted a bivariate model using the METADAS macro in SAS to calculate pooled point estimates for sensitivity and specificity. For comparisons between index tests and subgroups, we performed a likelihood ratio test comparing the model with and without the covariate.

MAIN RESULTS

We included 47 studies involving 26,151 participants and analysing data from 23,440. Most studies were conducted in Asia (36, 76.6%). Twenty-seven studies assessed AS-OCT (analysing 15,580 participants), 17 studies LACD (7385 participants), nine studies Scheimpflug photography (1616 participants), six studies SPAC (5239 participants) and five studies evaluated the oblique flashlight test (998 participants). Regarding study quality, 36 of the included studies (76.6%) were judged to have a high risk of bias in at least one domain.The use of a case-control design (13 studies) or inappropriate exclusions (6 studies) raised patient selection concerns in 40.4% of studies and concerns in the index test domain in 59.6% of studies were due to lack of masking or post-hoc determination of optimal thresholds. Among studies that did not use a case-control design, 16 studies (20,599 participants) were conducted in a primary care/community setting and 18 studies (2590 participants) in secondary care settings, of which 15 investigated LACD. Summary estimates were calculated for commonly reported parameters and thresholds for each test; LACD ≤ 25% (16 studies, 7540 eyes): sensitivity 0.83 (95% confidence interval (CI) 0.74, 0.90), specificity 0.88 (95% CI 0.84, 0.92) (moderate-certainty); flashlight (grade1) (5 studies, 1188 eyes): sensitivity 0.51 (95% CI 0.25, 0.76), specificity 0.92 (95% CI 0.70, 0.98) (low-certainty); SPAC (≤ 5 and/or S or P) (4 studies, 4677 eyes): sensitivity 0.83 (95% CI 0.70, 0.91), specificity 0.78 (95% CI 0.70, 0.83) (moderate-certainty); Scheimpflug photography (central ACD) (9 studies, 1698 eyes): sensitivity 0.92 (95% CI 0.84, 0.96), specificity 0.86 (95% CI 0.76, 0.93) (moderate-certainty); AS-OCT (subjective opinion of occludability) (13 studies, 9242 eyes): sensitivity 0.85 (95% CI 0.76, 0.91); specificity 0.71 (95% CI 0.62, 0.78) (moderate-certainty). For comparisons of sensitivity and specificity between index tests we used LACD (≤ 25%) as the reference category. The flashlight test (grade 1 threshold) showed a statistically significant lower sensitivity than LACD (≤ 25%), whereas AS-OCT (subjective judgement) had a statistically significant lower specificity. There were no statistically significant differences for the other index test comparisons. A subgroup analysis was conducted for LACD (≤ 25%), comparing community (7 studies, 14.4% prevalence) vs secondary care (7 studies, 42% prevalence) settings. We found no evidence of a statistically significant difference in test performance according to setting. Performing LACD on 1000 people at risk of angle closure with a prevalence of occludable angles of 10%, LACD would miss about 17 cases out of the 100 with occludable angles and incorrectly classify 108 out of 900 without angle closure.

AUTHORS' CONCLUSIONS

The finding that LACD performed as well as index tests that use sophisticated imaging technologies, confirms the potential for this test for case-detection of occludable angles in high-risk populations. However, methodological issues across studies may have led to our estimates of test accuracy being higher than would be expected in standard clinical practice. There is still a need for high-quality studies to evaluate the performance of non-invasive tests for angle assessment in both community-based and secondary care settings.

Nationwide Incidence of Acute Angle Closure Glaucoma in Korea from 2011 to 2015

BACKGROUND

Despite the significant disease burden, there is a paucity of data addressing the population-based incidence of acute angle closure glaucoma (AACG). Therefore, we estimated the nationwide, population-based standardized incidence rate of AACG in Korea.

METHODS

We conducted a nationwide, population-based, retrospective study using the database of National Health Insurance (NHI) system, which includes the entire Korean population (approximately 50 million people) from 2009 to 2015. We identified patients with incident AACG during the 5-year study period from 2011 to 2015 based on their diagnosis and AACG-related treatments (laser iridotomy and cataract surgery), and estimated age- and gender-standardized incidence rate of AACG during the study period.

RESULTS

We identified 11,049 patients (8,022 women, 72.6%) with incident AACG during the 5-year study period. Of these, after excluding 6 patients under 20 years old, 11,043 patients (8,020 women, 72.6%) aged ≥ 20 years were included in the analysis. The average standardized incidence rate during the 5-year study period was 59.95 (95% confidence interval [CI], 58.87-61.03) per 1,000,000 person-years. The incidence rates increased sharply with age and peaked at individuals aged 75-79 years; in men, those peaked at the same age group, however, in women, those peaked at individuals aged 70-74 years. Women has a 2.56 folds higher incidence rate (85.84 [95% CI, 84.03-87.66] per 1,000,000 person-years) than men (33.48 [95% CI, 32.33-34.62] per 1,000,000 person-years).

CONCLUSION

The present study provides detailed estimates for AACG incidence according to all age groups and gender through the 5-year study period.

Corneal topography and angle parameters after laser iridotomy combined with iridoplasty assessed by dual Scheimpflug analyzer

PURPOSE

To investigate the changes in corneal topography including parameters such as corneal curvature and corneal aberrations, along with anterior chamber angle (ACA) after laser iridotomy (LI) combined with peripheral iridoplasty (PI) using dual Scheimpflug analyzer.

METHODS

In this prospective observational study, dual Scheimpflug analyzer images were acquired before and 1 week after LI plus PI. Corneal curvature of both axial and instantaneous maps from anterior and posterior surface, respectively, and total corneal power (TCP) were acquired. These corneal parameters from three zones (central, middle, and peripheral) and total corneal wavefront aberration, trefoil, and coma were obtained. The ACA from four quadrants, anterior chamber depth (ACD), anterior chamber volume (ACV), and intraocular pressure (IOP) were also inspected.

RESULTS

ACD increased significantly from 2.15 ± 0.25 to 2.18 ± 0.24 mm (P = 0.002). ACV and ACA from all four quadrants increased significantly after the laser treatment (all P < 0.05). IOP decreased significantly from 16.9 ± 3.1 to 14.7 ± 2.9 mmHg following LI plus PI (P = 0.000). No significant changes were detected in corneal axial and instantaneous curvature from three zones on the anterior and posterior corneal surface after LI plus PI (all P > 0.05). The TCP, total corneal wavefront aberration, trefoil, and coma also revealed no significant changes after the laser procedure (all P > 0.05).

CONCLUSIONS

Treatment with LI combined with PI did not affect the corneal topographic parameters from both anterior and posterior surfaces. However, LI plus PI improved ACA parameters significantly and effectively.

Has the EAGLE landed for the use of clear lens extraction in angle-closure glaucoma? And how should primary angle-closure suspects be treated?

Angle-closure glaucoma is an aggressive condition that causes millions to become blind worldwide. This review explores the use of prophylactic laser peripheral iridotomy (PI) in patients classified as primary angle-closure suspects (PACS), and additionally, the use of clear lens exchange as a primary treatment option in established angle-closure disease with or without glaucoma. As PI has a strong prophylactic effect in fellow eyes of patients who have had an acute attack, its use has been widely adopted in those patients classified as PACS, but with limited evidence to support this. A large randomised trial conducted in China has demonstrated that although PI reduces the risk of incident angle-closure disease, the incidence of disease that would threaten vision was much lower than anticipated. This suggests that the benefit of prophylactic PI is very limited. Health services data shows an association between rising cataract surgical rates and of decreasing rates of acute angle-closure. Age-related growth of the lens is a major component of angle-closure disease. Several studies have shown that clear lens extraction (CLE) effectively lowers IOP in angle-closure. The use of CLE as a primary treatment option has been tested against LPI in the EAGLE study, a large RCT that enroled people with angle-closure and an IOP > 30 mmHg, and those with angle-closure glaucoma. The trial showed CLE to be superior to PI both for IOP control and patient reported quality of life. On these grounds, CLE should be considered for first-line treatment of more advanced angle-closure disease.

Vitreous Zonule and its Relation to Anterior Chamber Angle Characteristics in Primary Angle Closure

PRECIS

Primary angle-closure (PAC) eyes with no vitreous zonule (VZ) appear to have a narrower angle despite similar lens vault and iris configuration than eyes with visible VZ.

PURPOSE

To assess the clinical significance of the VZ in PAC.

METHODS

Medical records of 91 eyes of 91 participants with PAC or PAC glaucoma were retrospectively reviewed. Anterior segment parameters were measured using anterior segment optical coherence tomography; presence of the VZ was assessed with ultrasound biomicroscopy. Parameters were compared between eyes with vitreous zonule group (VZG) and no vitreous zonule group (NVZG). Factors associated with VZ presence were determined using logistic regression analysis.

RESULTS

The NVZG was more likely to have PAC glaucoma than PAC (51.4% vs. 25.0%; P=0.010) and use more glaucoma medications (0.77 vs. 0.36; P=0.004) than the VZG. The NVZG had a smaller anterior chamber area than the VZG (13.6 mm vs. 15.1 mm; P=0.020) but there were no significant between-group differences in anterior chamber depth (1.97 vs. 2.08 mm; P=0.119) and lens vault (1.21 vs. 1.13 mm; P=0.337). NVZG had a smaller scleral spur angle (11.5 vs. 17.4 degrees; P<0.001), angle opening distance at 500 μm (AOD500, 105 vs. 168 μm; P<0.001), and trabecular-ciliary process angle (75.7 vs. 81.9 degrees; P=0.029) than VZG. Older age [odds ratio (confidence interval), 1.087 (1.014-1.164); P=0.018], less AOD500 (0.984 (0.975-0.993); P<0.001), and less trabecular-ciliary process angle (0.938 (0.901-0.977); P=0.002) were independently associated with an absence of VZ.

CONCLUSIONS

PAC eyes with no VZ had a narrower angle and required more glaucoma medications than eyes with a VZ.

Glaucoma detection using image processing techniques: A literature review

The term glaucoma refers to a group of heterogeneous diseases that cause the degeneration of retinal ganglion cells (RGCs). The degeneration of RGCs leads to two main issues: (i) structural changes to the optic nerve head as well as the nerve fiber layer, and (ii) simultaneous functional failure of the visual field. These two effects of glaucoma may lead to peripheral vision loss and, if the condition is left to progress it may eventually lead to blindness. No cure for glaucoma exists apart from early detection and treatment by optometrists and ophthalmologists. The degeneration of RGCs is normally detected from retinal images which are assessed by an expert. These retinal images also provide other vital information about the health of an eye. Thus, it is essential to develop automated techniques for extracting this information. The rapid development of digital images and computer vision techniques have increased the potential for analysis of eye health from images. This paper surveys current approaches to detect glaucoma from 2D and 3D images; both the limitations and possible future directions are highlighted. This study also describes the datasets used for retinal analysis along with existing evaluation algorithms. The main topics covered by this study may be enumerated as follows.

Upside-down position leads to choroidal expansion and anterior chamber shallowing: OCT study

Background

To determine whether dynamic changes in choroidal thickness (CT) cause shallowing of the anterior chamber.

Methods

34 healthy volunteers were enrolled. The participants in our study adopted the upside-down position for 1.5 min, which was the model we used to study the dynamic changes in CT. Intraocular pressure (IOP) elevation, optical coherence tomography images of the choroid and anterior chamber were obtained at baseline, after being in an upside-down position in an inversion machine and after 15 min of rest. The changes in IOP, anterior chamber and choroidal blood flow between the baseline and the upside-down position were compared.

Results

Sixty-eight eyes from 34 subjects were analysed. After being in upside-down position for 1.5 min, there was a significant increase in CT from 226.39±52.44 µm to 238.34±54.84 µm (p<0.001). Choroidal flow index decreased from 0.3357±0.0251 to 0.3004±0.0190 in upside-down position, and there was a decrease in anterior chamber depth (3.21±0.22 mm to 3.13±0.21 mm, p<0.001) and angle opening distance at 500 µm from the scleral spur (0.65±0.24 mm to 0.58±0.20 mm, p=0.007). Pearson correlation analysis showed that the increase in CT was positively related with CT at baseline CT (p=0.001).

Conclusion

When the body position changed from sitting to upside-down position, there was choroidal thickening, anterior chamber shallowing and IOP elevation with reduced choroidal blood flow. The data provide evidence about the relationship between choroid expansion and shallowing of the anterior chamber, which may be of relevance for the pathogenesis of angle closure.

Comparative Evaluation of Phacoemulsification Alone versus Phacoemulsification with Goniosynechialysis in Primary Angle-Closure Glaucoma: A Randomized Controlled Trial

PURPOSE

Comparative evaluation of phacoemulsification (phaco) alone versus phacoemulsification combined with goniosynechialysis (phacoGSL) in primary angle-closure glaucoma (PACG).

DESIGN

Prospective, randomized, parallel group, active controlled trial.

PARTICIPANTS

Patients with PACG.

METHODS

A total of 120 consecutive patients with PACG were screened, of whom 80 met inclusion criteria, with PACG uncontrolled on maximal hypotensive therapy and were recruited. Patients were randomized into 2 groups and underwent phaco alone in group 1 or phacoGSL in group 2. The patients were examined at baseline and at 1 week and 1, 3, and 6 months. The anterior chamber angle parameters on swept-source anterior segment OCT (SS-ASOCT) were noted at 1 and 6 months.

MAIN OUTCOME MEASURES

The primary outcome measure was intraocular pressure (IOP) reduction. A reduction in IOP of ≥ 20% from baseline IOP with or without medications was considered a success. Secondary outcome measures included change in the anterior chamber angle temporal parameters, angle-opening distance, trabecular-iris space area and scleral spur angle, surgical safety, visual acuity, and reduction in the number of glaucoma medications postoperatively.

RESULTS

The average age of patients was 58.77±8.14 years and 56.50±9.17 years in groups 1 and 2, respectively (P = 0.31). The mean baseline IOP was 29.48±6.76 mmHg and 30.72±3.88 mmHg in groups 1 and 2, respectively (P = 0.13). Success was obtained in 93.33% of patients in group 1 and 91.18% of patients in group 2 at 6 months (P = 0.39). Mean IOP was 13.17±1.66 mmHg and 13.21±1.97 mmHg at 6 months in groups 1 and 2, respectively (P = 0.001). The reduction in IOP was 55.32% and 56.99% at 6 months in groups 1 and 2 (P = 0.48). Significant widening of the angle parameters was noted at 6 months with an increase compared with baseline values in both groups. In multivariate analysis, the significant predictor of decrease in IOP was the higher baseline IOP.

CONCLUSIONS

Both phaco and phacoGSL are associated with a significant reduction in IOP along with a noteworthy widening of the anterior chamber angle parameters. Both procedures succeeded in reducing the necessity of glaucoma medications postoperatively in PACG eyes. There is no additional benefit of phacoGSL over phaco in PACG.

Cost-effectiveness and cost-utility of population-based glaucoma screening in China: a decision-analytic Markov model

BACKGROUND

Glaucoma, particularly primary angle closure glaucoma (PACG), is a leading cause of global blindness. Nearly half of all people with PACG are of Chinese descent. Population-level glaucoma screening has generally not been found to be cost-effective in high-income countries; however, this assessment has rarely been done in low-income or middle-income countries. We aimed to assess the cost-effectiveness and cost-utility of population-level glaucoma screening in China.

METHODS

We developed decision-analytic Markov models for separate and combined screening for PACG and primary open angle glaucoma (POAG) to evaluate costs and benefits of community-level screening versus opportunistic case finding from a societal perspective. A cohort of individuals was followed in the model from age 50 years through a total of 30 1-year Markov cycles. Analyses were done separately for rural and urban settings. We did a meta-analysis of glaucoma prevalence studies in China to obtain prevalence estimates for PACG and POAG. Screening costs were taken from a Chinese screening programme and treatment costs from a tertiary Chinese eye hospital. Main outcomes were incremental cost-utility ratios (ICURs) using quality-adjusted life-years and incremental cost-effectiveness ratios (ICERs) using years of blindness avoided. We did one-way deterministic and simulated probabilistic sensitivity analyses to reflect uncertainty around ICURs and ICERs.

FINDINGS

Compared with no screening, combined screening of POAG and PACG in rural China is predicted to result in an ICUR of US$569 (95% CI 17 to 4180) and an ICER of $1280 (-58 to 7940), both of which are below the WHO cost-effectiveness threshold of one to three times rural gross domestic product. For the urban China setting, combined screening is predicted to result in fewer net costs and greater gain in health benefits than no screening. Findings were robust in all sensitivity analyses. Over 30 years, a total of 246 (95% CI 63 to 628) and 1325 (510 to 2828) years of blindness are predicted to be avoided for every 100 000 rural and urban residents screened, respectively.

INTERPRETATION

Population screening for glaucoma (POAG and PACG combined) is likely to be cost-effective in both urban and rural China. Future studies should investigate the effectiveness of interventions to improve acceptance of definitive care among people screened.

FUNDING

Ulverscroft Foundation, Wenzhou Medical University Research Fund, Zhejiang Province Health Innovation Talents Project, and Wenzhou's Ten Major Livelihood Issues 2015.

A collaborative care pathway for patients with suspected angle closure glaucoma spectrum disease

BACKGROUND

Currently, no specific collaborative care pathway exists that distinguishes open angle glaucoma from narrow angle or angle closure disease. This study evaluates a newly developed referral and collaborative care pathway specifically for patients with angle closure spectrum disease.

METHODS

The medical records of consecutive patients referred to the Centre for Eye Health for glaucoma assessment were examined, six months before (Pre Suite) and after (Post Suite) the introduction of a novel referral pathway for anterior chamber angle assessment (Angle Suite). Patient demographic and clinical data, the referral letter and practitioner characteristics were extracted.

RESULTS

Angle Suite (n = 77) patients had an appointment much sooner compared to Pre (n = 383) and Post Suite (n = 425) patients (p < 0.0001). Following the introduction of Angle Suites, there was a reduction of incidental angle closure disease found in routine, non-angle closure glaucoma assessment. Onward referral was required by 36.4 per cent of patients referred for suspected angle closure disease, while the rest could be discharged back into the community (13.0 per cent) or reviewed at the Centre for Eye Health (50.6 per cent). Multinomial logistic regression found that the presence of an angle description in the referral letter improved the true positive rate for angle closure disease (p < 0.0001).

CONCLUSIONS

The clinical pathway may reduce the number of incidental angle closure patients and improved the timeliness of appropriate clinical care delivered to a subset of patients who may benefit from prompt medical attention. This pathway provides an opportunity for appropriately staffed and equipped collaborative care clinics to reduce the burden on tertiary level ophthalmic facilities.