Reduction in admissions of patients with acute primary angle closure occurring in conjunction with a rise in cataract surgery in Taiwan

Trends in admission rates of primary angle closure diseases for the urban population in China, 2011-2021

Background

Cataract surgery and laser peripheral iridotomy (LPI) are effective approaches for preventing primary angle closure diseases (PACDs), as well as acute primary angle closure (APAC). Due to the development of population screening and increases in cataract surgery rates, this study aimed to examine trends in the admission rates of PACD among the urban population in China.

Methods

This cross-sectional study examined patients who were admitted to a hospital for PACD, and who underwent cataract surgery or LPI operations. The data were obtained from the Yinzhou Regional Health Information Platform (YRHIP) from 2011 to 2021. The annual rates of PACD and APAC admissions, cataract surgery and LPI were analyzed, with the number of cases used as numerators and the annual resident population in Yinzhou district used as denominators.

Results

A total of 2,979 patients with PACD admissions, 1,023 patients with APAC admissions, 53,635 patients who underwent cataract surgery and 16,450 patients who underwent LPI were included. The number of annual admissions for PACD gradually increased from 22 cases (1.6/100000) in 2011 to 387 cases (30.8/100000) in 2016, after which it decreased to 232 cases (16.2/100000) in 2019 and then increased to 505 cases (30.6/100000) in 2021. The number of cataract surgeries gradually increased from 1728 (127.7/100000) in 2011 to 7002 (424.9/100000) in 2021. Similarly, the number of LPI gradually increased from 109 (8.0/100000) in 2011 to 3704 (224.8/100000) in 2021.

Conclusion

The admission rates of PACD for the urban population in China have declined in recent years after a long increasing trend in the rates of cataract surgery and LPI. However, it increased rapidly during the COVID-19 epidemic. The national health database should be further utilized to investigate temporal trends in the prevalence of PACD.

How Cultural Behaviors and Superstitions Associate the Willingness to Undergo Cataract Surgery in Taiwan: A Nationwide Survey

Background and Objectives: Cultural beliefs influence the conceptualization, adaptation, and coping strategies for diseases. This study aimed to investigate the impact of cultural beliefs and customs on the willingness to undergo cataract surgery in Taiwan. Materials and Methods: The data were retrospectively retrieved from the national Longitudinal Health Insurance Database 2000 (LHID2000). From the national database, we enrolled patients that were diagnosed with cataracts and underwent cataract surgery from 2001 to 2010. All the patients were stratified according to their gender and living area. Gender was categorized as male or female, and the living area was classified as urban or rural. We compared the difference in the number of surgeries between stratified patient groups in each Chinese lunar month. Results: The number of cataract surgeries decreased significantly in the seventh and twelfth lunar months for both genders. There was a significant reduction in cataract surgeries in both the urban and rural groups during the seventh lunar month. Interestingly, only the seventh lunar month had an association with sex in different living areas, which meant that in the seventh month, there was a gender-specific difference in the surgical numbers. Conclusions: The Taiwanese population holds a belief that surgical procedures, including cataract surgery, during the lunar ghost month is inauspicious. Citizens tend to avoid elective surgery due to cultural practice, resulting in a decrease in surgical numbers during the period of the Chinese New Year. The authorities should consider these cultural behaviors when developing medical policies and allocating resources. Healthcare providers should be aware of these superstitions and take them into account when providing medical care and advice to patients.

The Global Extent of Undetected Glaucoma in Adults: A Systematic Review and Meta-analysis

TOPIC

Glaucoma is the leading cause of irreversible blindness, despite having good prognosis with early treatment. We evaluated the global extent of undetected glaucoma and the factors associated with it in this systematic review and meta-analysis.

CLINICAL RELEVANCE

Undetected glaucoma increases the risk of vision impairment, which leads to detrimental effects on the quality-of-life and socioeconomic well-being of those affected. Detailed information on the extent and factors associated with undetected glaucoma aid in the development of public health interventions.

METHODS

We conducted a systematic review and meta-analysis of population-based studies published between January 1, 1990, and June 1, 2020. Article search was conducted in online databases (PubMED, Web-of-Science), grey literatures (OpenGrey), and nongovernment organization reports. Our outcome measure was the proportion of glaucoma cases that were undetected previously. Manifest glaucoma included any form of glaucoma reported in the original studies and may include primary open-angle glaucoma (POAG), primary angle-closure-glaucoma, secondary glaucoma, or a combination thereof. Undetected glaucoma was defined as glaucoma cases that were undetected prior to diagnosis in the respective study. Random-effect meta-analysis was used to estimate the pooled proportion of undetected glaucoma. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the Meta-analysis of Observational Studies in Epidemiology guidelines in our study.

RESULTS

We identified 61 articles from 55 population-based studies (n = 189 359 participants; n = 6949 manifest glaucoma). Globally, more than half of all glaucoma cases were undetected previously on average in each geographical region. Africa (odds ratio [OR], 12.70; 95% confidence interval [CI], 4.91-32.86) and Asia (OR, 3.41; 95% CI, 1.63-7.16) showed higher odds of undetected glaucoma as compared with Europe. Countries with low Human Development Index (HDI; <0.55) showed a higher proportion of undetected manifest glaucoma as compared with countries of medium to very high HDI (≥0.55; all P < 0.001). In 2020, 43.78 million POAG cases were projected to be undetected, of which 76.7% were in Africa and Asia.

DISCUSSION

Undetected glaucoma is highly prevalent across diverse communities worldwide and more common in Africa and Asia. Strategies to improve detection are needed to prevent excess visual disability and blindness resulting from glaucoma.

How Does Cataract Surgery Rate Affect Angle-closure Prevalence

PRCIS

A data simulation study suggests that prevalence of occludable angle will decrease when the cataract surgical rate increases in particularly when the surgery focuses on 70+ years old.

PURPOSE

The purpose of this study was to estimate the effects of cataract surgical rates (CSR) on the prevalence of primary angle-closure glaucoma in the Chinese population.

METHODS

Participants aged 50 years and older from the Liwan Eye Study were included as the study sample. Occludable angle (OA) as a surrogate of primary angle-closure glaucoma was evaluated using static gonioscopy and anterior chamber depth was measured before dilation using A-mode ultrasound. Random sampling was used to generate 50 cohorts with a sample size of 200 for each predefined CSR at 2000, 4000, 6000, 8000, 10,000, 12,000, according to the multinomial distribution. The mean anterior chamber depth and OA rates of each cohort were calculated. Logistic function models of nonlinear least-squares estimation were used to predict the prevalence of OA.

RESULTS

Data of the right eye from 1280 participants were included. The prevalence of cataract surgery and OA was 2.27% and 11.3%, respectively. The projected prevalence of OA in the cohorts with CSR of 2000, 4000, 6000, 8000, 10,000 and 12,000 was 11.4% [95% confidence interval (CI), 10.8%-12.0%], 11.2% (95% CI, 10.6%-11.9%), 10.9% (95% CI, 10.3%-11.6%), 11.4% (95% CI, 10.8%-12.1%), 10.8% (95% CI, 10.2-11.4%), and 10.1% (95% CI, 9.46-10.7%), respectively. The OA rates decreased remarkably as CSR increased for those aged 70 years and older.

CONCLUSIONS

Our study indicated that with CSR increased, the OA prevalence could decrease remarkably especially in the older population. It is advisable to perform cataract surgery at an appropriate time for patients in their late 60s to 70s with significant cataracts.

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.

The Prevalence and the Incidence of Diagnosed Open-Angle Glaucoma and Diagnosed Angle-Closure Glaucoma: Changes From 2001 to 2010

PURPOSE

To explore the trends in diagnosed open-angle glaucoma (OAG) and diagnosed angle-closure glaucoma (ACG) in Taiwan during the period of 2001 to 2010.

MATERIALS AND METHODS

Data were sourced from the National Longitudinal Health Insurance Database 2000 (LHID2000). The study population comprised all patients with a diagnosis of OAG or ACG (International Classification of Diseases, 9th Revision, Clinical Modification codes 365). Patients were stratified by their sex and age; differences in standardized incidence rates were compared between the stratified groups.

RESULTS

Throughout the study period, the prevalence of diagnosed OAG (slope=0.18, P<0.0001) and ACG (slope=0.09, P<0.0001) increased. Before 2005, the prevalence of ACG was higher than that of OAG; however, from 2005 to 2010, the prevalence of OAG was higher than that of ACG. The standardized incidence of diagnosed OAG increased insignificantly (slope=1.06, P=0.18), and that of diagnosed ACG decreased significantly (slope=-1.17, P=0.009). The prevalence and the incidence of OAG and ACG were the highest among people of advanced age. Women had higher standardized incidence rates of ACG during the study period. Men had higher standardized incidence rates of OAG in every year of the study with the exception of 2007.

CONCLUSIONS

In Taiwan, ACG was more prevalent in women and OAG might be more prevalent in men. The prevalence of ACG was higher than that of OAG before 2005, but the prevalence of OAG has been higher than that of ACG since 2005.

Trends in Glaucoma Medication Expenditures under Universal Health Coverage: A National Population-Based Longitudinal Survey in Taiwan

Medical care in Taiwan is well known for its low cost, high efficiency, high quality, excellent medical accessibility, and high equity. We investigate the trends in medication expenditures for glaucoma from 1997 to 2010. The results show that higher medical expenditures were incurred by patients who were aged ≥40 years, male patients, and patients in the highest salary population whereas lower medical expenditures were incurred by blue-collar workers. The medications with the most significant increases in expenditure were prostaglandin analogs (PGAs), α-agonists, and fixed combinations, whereas the medications with the most significant decreases in expenditure were β-blockers and cholinergic agonists. The number of trabeculectomies shows two downward break points in 1999 and 2000 when PGAs were listed and were reimbursed. These results suggest socioeconomic disparities in glaucoma care, as well as understanding of the changes in the expenditure of glaucoma medications under such universal health insurance coverage system.

Increased risk of acute angle closure in retinitis pigmentosa: a population-based case-control study

Purpose

To investigate the association between retinitis pigmentosa (RP) and acute angle closure during a 15-year follow-up period.

Methods

Using the Taiwan Longitudinal Health Insurance Database 2000, we identified 382 RP patients based on the diagnostic code of RP (International Classification of Diseases, 9^th Revision, Clinical Modification (ICD-9-CM) 362.74) made during 1996–2010, excluding subjects under age of 20 years at diagnosis or subjects undergoing lens extraction before the index date. The control group included 3820 randomly selected non-RP subjects matched with the RP patients in age, gender and the index date of diagnosis. The incidence of acute angle closure during the study period was observed based on an ICD-9-CM code of 365.22. Cochran-Mantel-Haenszel test was used to determine the odds ratio (OR) of having acute angle closure in RP patients.

Results

The mean age at the diagnosis of RP was 51.1years (standard deviation [SD] 16.7). Acute angle closure occurred in 5 RP patients (1.3%) and in 15 controls (0.4%). The mean age with the acute angle closure was 53.3 years (SD 8.0) in RP patients and 64.6 years (SD 8.4) in controls (P = 0.015). After adjusting for age, gender and comorbid disorders, RP patients had 3.64-fold (95% confidence interval [CI], 1.29–10.25, P<0.001) greater odds of having acute angle closure. After stratification for gender and age, the risk of acute angle closure in RP was higher in patients under age of 60 years (adjusted OR 11.84; 95% CI, 2.84–49.48) and male patients (adjusted OR 19.36; 95% CI, 3.43–109.40)(both P = 0.001).

Conclusions

RP patients had increased risk of acute angle closure than controls. Contrary to the fact that angle closure disease is more prevalent in elderly females in general population, acute angle closure attack occurred earlier in life and the risk was higher in males among RP patients.

Six-year incidence of angle-closure disease in a South Indian population: the Chennai Eye Disease Incidence Study

PURPOSE

To estimate the 6-year incidence of primary angle-closure (PAC) disease among adult population aged 40 years and older from rural and urban south India.

DESIGN

Population-based longitudinal study.

METHODS

A complete ophthalmologic examination, including applanation tonometry, gonioscopy, biometry, stereoscopic fundus examination, and automated perimetry was performed at both baseline and at the 6-year follow up at base hospital. Incident PAC disease was defined as the development of PAC disease during the 6-year follow-up in phakic subjects without PAC disease at baseline. Diagnosis was made using the International Society Geographical and Epidemiological Ophthalmology classification.

RESULTS

The data were analyzed for 3350 subjects (mean age, 56.4 ± 8.9 years; 1547 males, 1803 females) for a diagnosis of PAC disease at baseline and at follow-up examinations. The incidence of PAC disease was identified in 134 subjects (6-year incidence rate, 4.0%; 95% confidence interval (CI), 3.3-4.7). Among the 134 subjects, 88 subjects (2.6%, 95% CI, 2.1-3.2) were primary angle-closure suspects; 37 subjects (1.1%, 95% CI, 0.7-1.5) had primary angle closure, and 9 subjects (0.3%, 95% CI, 0.1-0.4) had primary angle-closure glaucoma. There was an inverse relationship between the incidence of PAC disease and the cataract surgery rates. Significant risk factors for PAC disease on logistic regressions were higher intraocular pressure, increased lens thickness, shorter axial length, shallow anterior chamber depth, anteriorly positioned lens, and hyperopia.

CONCLUSIONS

The average incidence of PAC disease per year was 0.7%. All biometric parameters were found to be strong predictors for the incidence of PAC disease.

Comparison of 2007-2012 Korean trends in laser peripheral iridotomy and cataract surgery rates

PURPOSE

To investigate the association between the trends in the rates of laser peripheral iridotomy (LPI) for primary angle closure (PAC) or primary angle-closure glaucoma (PACG) and cataract surgery in Korea.

METHODS

Acute or subacute PAC(G) patients (251,769) along with patients who had undergone LPI (20,632) or cataract surgery (1,163,729) between 2007 and 2012 were included. The LPI rate was defined as the number of LPI cases per 100 PAC(G) patients by quarter; the cataract surgery rate was defined as the number of cataract surgeries per 100,000 population by quarter.

RESULTS

The number of acute or subacute PAC(G) patients per 100,000 population showed a gradual increase, specifically from 45.63 in the first quarter of 2007 to 49.56 in the second quarter of 2012. The LPI rate manifested a slow decline, from 9.59 to 7.94, and the cataract surgery rate showed a sharp rise, from 260.75 to 387.53, over the same period. In other words, a negative correlation tendency between the two rate trends (r = -0.244, P = 0.273) was revealed. With respect to age, significant negative correlations were observed in the 40-49 (r = -0.488, P = 0.021) and ≥ 70 (r = -0.450, P = 0.036) groups.

CONCLUSIONS

The respective trends in the LPI and cataract surgery rates showed a negative correlation. Although other possible explanations might exist, this result supports the hypothesis that cataract surgery contributes to a reduction in the incidence of LPI in PAC(G) patients.

Primary phacoemulsification and intraocular lens implantation for acute primary angle-closure

BACKGROUND

To investigate the effect of primary phacoemulsification on intraocular pressure (IOP) in patients with acute primary angle-closure (PAC) and coexisting cataract.

METHODOLOGY

Sixteen eyes of 14 patients with acute PAC received phacoemulsification and intraocular lens implantation as initial management for medically uncontrolled IOP in a retrospective chart review. The effects on IOP, vision, anterior chamber depth (ACD), and number of antiglaucoma medications were evaluated.

PRINCIPAL FINDINGS

The postoperative IOP was reduced in 16 eyes (100%). The mean ± standard deviation preoperative IOP was 48.81 ± 16.83 mm Hg, which decreased postoperatively to 16.46 ± 10.67 mm Hg at 1 day, 9.43 ± 3.03 mm Hg at 1 week, 9.49 ± 2.14 mm Hg at 2 weeks, 10.78 ± 3.56 mm Hg at 1 month, and 10.70 ± 2.80 mm Hg at 3 months (p < 0.001). The mean number of antiglaucoma medications decreased from 3.56 ± 1.14 to 0.13 ± 0.34 (p < 0.001). The average preoperative ACD was 2.08 ± 0.35 mm, which increased to 3.59 ± 0.33 mm after surgery (p < 0.001). Visual acuity (converted into logarithm of the minimum angle of resolution [logMAR]) improved from 1.14 ± 0.71 to 0.73 ± 0.53 (p =  0.001).

CONCLUSIONS

Primary phacoemulsification plus intraocular lens implantation lowered IOP, reduced the use of antiglaucoma medications, and improved vision in patients with acute PAC. This is a safe and effective method of IOP control and can be considered a first treatment option in managing patients with acute PAC and coexisting cataract.