Angle closure glaucoma in rural and urban populations in eastern India-The Hooghly River Glaucoma Study

Primary glaucomas in adults: Epidemiology and public health-A review

Glaucoma is a mixed group of optic neuropathies that lead to irreversible visual field loss and blindness if left untreated. It is estimated that 3.5% of the global population aged 40 to 80 years have any glaucoma, being the primary open-angle and the primary angle-closure glaucoma the most prevalent forms. Although the age-standardised prevalence of blindness caused by glaucoma has decreased substantially over the last decades, population growth and ageing impose many challenges in preventing glaucoma-related morbidities on a global level. In addition, difficulties in diagnoses and treatment, along with its chronic and irreversible nature, urge the development and implementation of innovative approaches in confronting the disease. This manuscript reviews recent literature related to the epidemiology of primary glaucomas in adults, the risk factors attributed to the development of the disease, and discuss challenges and potential solutions from a public health perspective.

Air Pollutant Particles, PM2.5, Exposure and Glaucoma in Patients with Diabetes: A National Population-Based Nested Case-Control Study

The global prevalence of diabetes mellitus (DM) has reached 20%. Air pollutants with a particle size of less than 2.5 μm (PM_2.5) are a globally recognized risk factor for diabetes and glaucoma. We examined whether the risk of glaucoma would decrease or increase when patients with DM were exposed to different PM_2.5 concentrations. Data were obtained from the National Health Insurance Research Database (NHIRD) of Taiwan and the Air Quality Monitoring Network between 2008 and 2013. This nested case-control study involved 197 DM patients with glaucoma and 788 DM patients without glaucoma. Cases and controls were matched (1:4) by gender, age (±5 years), and index date (±6 months), and their data were entered in a logistic regression model adjusted for gender, age, urbanization level, income level, and comorbidities. The odds ratio (OR) of glaucoma at PM_2.5 exposure concentration in the fourth quartile (Q4) compared with in the first quartile (Q1) was 1.7 (95% CI: 1.084-2.764). For glaucoma risk, the OR was 1.013 (95% CI: 1.006-1.020) at a PM2.5 exposure concentration in Q1, 1.004 (95% CI: 1.001-1.007) in the third quartile (Q3), and 1.003 (95% CI: 1.001-1.004) in Q4. In the subgroup analysis of patients living in non-emerging towns and non-agricultural towns, the OR for glaucoma in Q4 compared with in Q1 was 2.1 (95% CI: 1.229-3.406) and 1.8 (95% CI: 1.091-2.803), respectively (p trend = 0.001 and 0.011). For patients without migraine, the OR for glaucoma was 1.7 (95% CI: 1.074-2.782; p = 0.006). These results demonstrate that, for patients with DM, PM_2.5 increased the risk of glaucoma and PM_2.5 was an independent risk factor for glaucoma in patients with DM.

Smartphone-Acquired Image Photogrammetry for Detection of Shallow Anterior Chamber

Purpose

This study aimed to explore the role of smartphone imaging of the eye using two perspectives — anterior and temporal — in the detection of a shallow anterior chamber (AC). The AC depth (ACD) of an eye can be used as a surrogate marker for identification of eyes at risk of developing angle-closure disease.

Methods

A prospective observational study was conducted at a university teaching hospital in South India. Each eye was photographed with a smartphone using the two perspectives, followed by quantitative measurement of ACD using optical biometry. The percentage of nasal iris illuminated was measured from the image acquired using the flashlight method (anterior perspective), whereas pupil position relative to the cornea was measured from the image acquired using the temporal perpendicular method (temporal perspective). The receiver-operating characteristic curve and area under the curve (AUC) were studied for both perspectives independently for overall predictive accuracy in detection of shallow AC (ACD <2.7 mm, obtained by IOL Master).

Results

A total of 275 eyes were examined, of which 77 (28%) had an ACD <2.7 mm. The accuracy of detection of shallow AC was found to be 95.2% for both perspectives when used alone or in combination. AUC of the anterior perspective was 0.99 (95% CI 0.982–0.997). The AUC for the temporal perspective was 0.993 (95% CI 0.988–0.999).

Conclusion

Smartphone-acquired image photogrammetry of an eye with anterior and temporal perspectives independently and in combination provided accuracy nearing 95% in the detection of shallow AC (ACD <2.7 mm).

Registration

This trial was registered with the Clinical Trial Registry of India (CTRI/2018/09/015867, September 28, 2018).

LVPEI Glaucoma Epidemiology and Molecular Genetic Study: teleophthalmology screening for angle-closure disease in an underserved region

OBJECTIVES

To assess the ability of teleophthalmoscopic grading of peripheral anterior chamber depth (PACD) using the van Herick (vH) technique in detecting gonioscopically occludable angle; and to determine whether combining results from vH grading and ocular biometry can improve the accuracy to diagnose gonioscopically occludable angle METHODS: This cross-sectional study was an offshoot of a rural population-based study, Glaucoma Epidemiology and Molecular Genetic Study (GLEAMS). A masked urban ophthalmologist graded digital slit lamp photographs of PACD by vH technique. Sussman four-mirror lens was used to perform dark room indentation gonioscopy. Cutoff values of the tests were, vH technique: grade ≤ 2, central anterior chamber depth (ACD), as well as axial length: ≤ 25th percentile and lens thickness ≥ 75th percentile value of the study population.

RESULTS

We studied 1965 eyes of 1029 adult participants. The vH grade was ≤2 in 188 (9.5%) eyes. The angle was occludable by gonioscopy in 101 (5.1%) eyes. The performance of the vH test to rule out gonioscopically occludable angle was good [negative predictive value (NPV): 97.3%], despite low sensitivity (52.5%), while its efficacy to rule in the condition was low [positive predictive value (PPV): 28.2%] despite high specificity (92.8%). However, test combination strategy increased the PPV nearly twofold (53.8%). The calculated PPV at 10% prevalence of gonioscopically occludable angle was even higher (70.5%).

CONCLUSIONS

Van Herick technique can be incorporated into a teleophthalmology program by means of slit lamp photographs of PACD. Combined vH grading and ocular biometry improved the predictability of a gonioscopically occludable angle.

Factors Associated with Interventions after Laser Peripheral Iridotomy for Primary Angle-Closure Spectrum Diagnoses

PURPOSE

To assess factors associated with receipt of subsequent medical, laser, or surgical interventions after laser peripheral iridotomy (LPI).

DESIGN

Retrospective review.

PARTICIPANTS

A total of 1271 eyes in 692 subjects with narrow angles (NAs) that were treated with LPI.

METHODS

Demographic and clinical factors associated with primary angle-closure (PAC) or PAC glaucoma (PACG) versus PAC suspect (PACS) diagnosis and use of glaucoma medications at the time of LPI, as well as factors predictive of subsequent addition of glaucoma medications, and receipt of selective laser trabeculoplasty (SLT), cataract surgery, and glaucoma surgery were assessed using logistic regression with generalized estimating equations. Kaplan-Meier curves and Cox proportional-hazards regression analysis were used to assess baseline factors affecting the time to SLT, cataract surgery, or glaucoma surgery.

MAIN OUTCOME MEASURES

Diagnosis of PAC/PACG and medical, laser, or surgical interventions after LPI.

RESULTS

African Americans (odds ratio [OR], 2.12; P < 0.001) were significantly more likely than whites to have PAC/PACG than PACS and to already be taking glaucoma medications (OR, 2.25, P < 0.001) at the time of LPI. In multivariable logistic regression analysis, African Americans were significantly more likely to be prescribed additional glaucoma medications after LPI (OR, 1.73; P = 0.025) and receive glaucoma surgery (OR, 2.7; P = 0.007), but were less likely to receive SLT (OR, 0.37; P = 0.009). In multivariate Cox proportional-hazards regression analysis, African Americans had longer time to SLT than whites (hazard ratio [HR], 0.41; P = 0.022), but a shorter time to glaucoma surgery (HR, 2.57; P = 0.004). There was no significant association between race and the likelihood of cataract surgery or time to cataract surgery (P > 0.10).

CONCLUSIONS

African Americans were more likely than whites to carry a diagnosis of PAC or PACG at the time of LPI and were significantly more likely to be prescribed additional glaucoma medications and require glaucoma surgery after LPI. Improved screening methods that target African Americans with NAs are needed so that preventive interventions such as LPI can be performed earlier to decrease the risk of progression.