Trends in Blind and Low Vision Registrations in Taipei City

Sight impairment registration in Trinidad: trend in causes and population coverage in comparison to the National Eye Survey of Trinidad and Tobago

BACKGROUND

Little was known about the population coverage and causes of sight impairment (SI) registration within the Caribbean, or the extent to which register studies offer insights into population eye health.

METHODS

We compared causes of SI registration in the Trinidad and Tobago Blind Welfare Association (TTBWA) register with findings from the 2014 National Eye Survey of Trinidad and Tobago (NESTT), and estimated registration coverage. Cross-sectional validation studies of registered clients included interviews, visual function and cause ascertainment in July 2013, and interviews and visual function in July 2016.

RESULTS

The TTBWA register included 863 people (all ages, 48.1%(n = 415) male) registered between 1951 and 2015. The NESTT identified 1.1%(75/7158) people aged ≥5years eligible for partial or severe SI registration, of whom 49.3%(n = 37) were male. Registration coverage was approximately 7% of the eligible population of Trinidad. Nevertheless, there was close agreement in the causes of SI comparing the register and population-representative survey. Glaucoma was the leading cause in both the register (26.1%,n = 225) and population-based survey (26.1%, 18/69 adults), followed by cataract and diabetic retinopathy. In the validation studies combined, 62.6%(93/151) clients had severe SI, 28.5%(43/151) had partial SI and 9.9%(15/151) did not meet SI eligibility criteria. SI was potentially avoidable in at least 58%(n = 36/62) adults and 50%(n = 7/14) children.

CONCLUSION

We report very low register coverage of the SI population, but close agreement in causes of SI to a contemporaneous national population-based eye survey, half of which resulted from preventable or treatable eye disease.

Visual Impairment and Blindness in Saudi Arabia's School for the Blind: A Cross-Sectional Study

AIM

Visual impairment and blindness are important global health issues as they are associated with high morbidity, mortality, and decreased quality of life, leading to substantial economic loss and productivity. There are only a few published articles on vision impairment and blindness in Saudi Arabia to compare the range of estimated global prevalence of low vision, blindness, and their causes. This study aims to find out the important causes of vision impairment and blindness in schools for the blind in Qassim province, Saudi Arabia.

METHODS

The cross-sectional study was conducted at the blind schools in Buraidah city of Qassim province. A total of 278 registered cases were included in this study using a systematic random sampling of registered cases. Based on the definitions, the cases were classified as having vision impairment and/or blindness. The data were entered and analyzed using IBM SPSS 25.

RESULTS

The mean age was 30 years (range: 6 to 83 years) and 174 (76.4%) were males and 84 (32.6%) being females. The male:female ratio was 2:1. All the respondents were of Saudi ethnicity. Mild to moderate visual impairment was found in 6%, severe visual impairment in 27%, and blindness was seen in 64% of registered cases. The causes of blindness in these registered cases from blind school were retinitis pigmentosa (26%), optic atrophy (16%), glaucoma (7%), head trauma (6%), nystagmus (6%), retinopathy of prematurity (6%), ocular albinism (4%), corneal opacities (4%), amblyopia (3%) and other causes (22%). Overall, retinal disorders (retinitis pigmentosa and retinopathy of prematurity) were the leading causes of disability followed by optic atrophy.

CONCLUSION

The findings of this study are useful in planning and implementing screening programs in this area for early identification and corrections, thus preventing permanent loss of sight.

Global prevalence of visual impairment associated with myopic macular degeneration and temporal trends from 2000 through 2050: systematic review, meta-analysis and modelling

Purpose

We used systematic review and meta-analysis to identify and assimilate evidence quantifying blindness and visual impairment (VI) associated with myopic macular degeneration (MMD), then derived models to predict global patterns. The models were used to estimate the global prevalence of blindness and VI associated with MMD from 2000 to 2050.

Methods

The systematic review identified 17 papers with prevalence data for MMD VI fitting our inclusion criteria. Data from six papers with age-specific data were scaled to relative age-dependent risk and meta-analysed at VI and blindness levels. We analysed variance in all MMD VI and blindness data as a proportion of high myopia against variables from the place and year of data collection, with a model based on health expenditure providing the best correlation. We used this model to estimate the prevalence and number of people with MMD VI in each country in each decade.

Results

We included data from 17 studies comprising 137 514 participants. We estimated 10.0 million people had VI from MMD in 2015 (prevalence 0.13%, 95% CI 5.5 to 23.7 million, 0.07% to 0.34%), 3.3 million of whom were blind (0.04%, 1.8 to 7.8 million, 0.03% to 0.10%). We estimate that by 2050, without changing current interventions, VI from MMD will grow to 55.7 million people (0.57%, 29.0 to 119.7 million, 0.33% to 1.11%), 18.5 million of whom will be blind (0.19%, 9.6 to 39.7 million, 0.11% to 0.37%).

Conclusion

The burden of MMD blindness and VI will rise significantly without efforts to reduce the development and progression of myopia and improve the management of MMD.

Acute angle closure following periorbital botulinum toxin injection in a patient with retinitis pigmentosa

A 50-year-old female presented with bilateral retinitis pigmentosa (RP) and acute angle closure (AAC) with fixed mid-dilated pupil and high intraocular pressure (IOP) in the left eye following left side periorbital botulinum toxin A injection for blepharospasm. Glaucomatous optic neuropathy and retinal nerve fiber layer defect were observed in the affected eye using optical coherence tomography although the IOP was maintained at <21 mmHg after the treatment. Botulinum toxin acts at the cholinergic synapse and inhibits acetylcholine release; hence, it can cause transient mydriasis and may lead to AAC in high-risk populations such as patients with RP. Patients should be explained about the possible development of mydriasis associated with botulinum toxin injection, and clinicians must evaluate the level of risk for AAC before administration of botulinum toxin around the eyelid. In cases showing side effects associated with botulinum toxin injection, early diagnosis and treatment is required to prevent blindness.

An Application of NGS for WDR36 Gene in Taiwanese Patients with Juvenile-Onset Open-Angle Glaucoma

Primary open-angle glaucoma (POAG) is one of the most important disease in ophthalmology with high prevalence and risk of irreversible blindness. If diagnosed before the age of 35, it is usually categorized as juvenile open-angle glaucoma (JOAG). The WDR36 gene is reckoned as one of the major causative genes of POAG, and had been studied to be related to the pathogenesis of POAG in the literature. We have selected 61 JOAG patients and 61 JOAG-free individuals, and by next-generation sequencing method, the WDR36 gene of the subjects were analyzed. We identified 26 variations exclusively in JOAG group. Among these 26 variations, there were 3 noteworthy variations. First, a novel variation c.460-650A>G was found in our study which might cause premature termination of splicing of the conserved domain in WDR36; second, c.1494+1111G>T (rs13178997) had significantly different frequency in our JOAG patients compared to the reference frequency on NCBI; third, a variation c.710+30C>T (rs10038177) was found in our study, which had already been reported to be related to high-pressure glaucoma. We offer the profile of WDR36 in JOAG in Taiwan population, and we suggest that WDR36 gene is involved in the pathogenesis of JOAG as a subordinate modifier gene.

Blindness Registers as Epidemiological Tools for Public Health Planning: A Case Study in Belize

For public eye health programs, blindness registers can be an important tool for informing service planning. This study examines how the Belize Council for the Visually Impaired (BCVI) used its blindness register data to drive several public health interventions. Cross-sectional analysis was performed for all active registrants (n=1194) to determine the distribution of causes of registration according to age, sex, and geographical district. Cataract was the leading cause of registration (39.6%), followed by glaucoma (20.8%), diabetic retinopathy (10.2%), and childhood blindness (9.4%). The distribution of the causes of registration was fairly similar between men and women and across the various districts. However, in Stann Creek, whose population is largely of African descent, glaucoma exceeded cataract. For most causes, the majority of registrants were registered at age 50 or older. Follow-up was conducted four years later. Several interventions had been initiated, most notably bolstering cataract surgical services and creating screening programs for glaucoma and diabetic retinopathy. The register itself was also improved to maximize its utility for future use. While standardized surveys may be the most appropriate method of estimating population-based measures such as prevalence or incidence, the blindness register is still a valuable source of data for public health planning.

Analysis of Excess Direct Medical Costs of Vision Impairment in Taiwan

OBJECTIVES

To quantify the annual excess direct medical costs of vision impairment from the perspective of the Bureau of National Health Insurance in Taiwan and to examine whether the costs vary by severity and duration of vision impairment.

METHODS

A retrospective matched cohort analysis was conducted by using data from the Longitudinal Health Insurance Databases between January 1, 2000, and December 31, 2008. All patients newly diagnosed with vision impairment were categorized as having moderate vision loss, severe vision loss, or blindness. Each patient with vision impairment was matched to one randomly selected patient with normal vision by age (±1 year) and sex. At each level of vision impairment, generalized linear models were used to quantify the total annual excess costs and component costs incurred in the first and second years.

RESULTS

Vision impairment was associated with significantly higher crude excess medical costs. At each level of vision impairment, the total crude medical costs were attributable to different resource utilization and dominated by non-eye-related medical care. After adjusting for covariates, the first-year annual excess costs increased with escalating severity of vision impairment: New Taiwan (NT) $9894 for moderate vision loss, NT $22,760 for severe vision loss, and NT $52,687 for blindness. Similarly, the second-year adjusted costs were estimated as NT $3477, NT $19,532, and NT $28,272 for moderate vision loss, severe vision loss, and blindness, respectively.

CONCLUSIONS

Consistent with Western countries, vision impairment is associated with significantly increased health care costs in Taiwan. The excess costs seem to increase with severity of vision impairment and decrease in the second year.