Prevalence and causes of visual impairment in The Barbados Eye Study

Trends in the Prevalence of Blindness and Correlation With Health Status in Korean Adults: A 10-Year Nationwide Population-Based Study

BACKGROUND

Contemporary data on vision impairment form an important basis for public health policies. However, most data on the clinical epidemiology of blindness are limited by small sample sizes and focused not on systemic conditions but ophthalmic diseases only. In this study, we examined the ten-year trends of blindness prevalence and its correlation with systemic health status in Korean adults.

METHODS

This study investigated 10,000,000 participants randomly extracted from the entire Korean population (aged ≥ 20 years) who underwent a National Health Insurance Service health checkup between 2009 and 2018. Participants with blindness, defined as visual acuity in the better-seeing eye of ≤ 20/200, were identified. The prevalence of blindness was assessed, and the systemic health status was compared between participants with blindness and without blindness.

RESULTS

The mean prevalence of blindness was 0.473% (47,115 blindness cases) and tended to decrease over ten years (0.586% in 2009 and 0.348% in 2018; P < 0.001). The following factors were significantly associated with blindness: female sex, underweight (body mass index < 18.5), high serum creatinine (> 1.5 mg/dL), and bilateral hearing loss. In addition, except for those aged 30-39 and 40-49 years, high fasting glucose (≥ 126 mg/dL) and low hemoglobin (male: < 12 g/dL, female: < 10 g/dL) were significantly correlated with prevalent blindness.

CONCLUSION

Our ten-year Korean nationwide population-based study suggested a gradual decrease in the prevalence of blindness and its association with specific systemic health status. These conditions might be the cause or consequence of blindness and can be used as a reference for the prevention and/or rehabilitation of blindness to establish public health policies.

Influencing factors of low vision 2 years after vitrectomy for proliferative diabetic retinopathy: an observational study

BACKGROUND

Proliferative diabetic retinopathy (PDR) can seriously affect the vision and quality of life of patients. The present study aimed to evaluate the clinical effect of vitrectomy for PDR by observing visual recovery and postoperative complications and to explore the factors influencing low vision.

METHODS

This was a case series observational study. Consecutive eyes of patients with PDR who underwent 23G vitrectomy in our hospital within one year (2019.11-2020.11) were collected and followed up for more than 2 years. Patients' visual acuity, surgical complications and management were collected before the operation and during the follow-up. Decimal visual acuity was recorded and converted to the logarithm of the minimal angle of resolution (logMAR) for statistical analysis. Excel was used to establish a database, and SPSS 22.0 statistical software was used for data analysis.

RESULTS

A total of 127 patients and 174 eyes were included in the study. The mean age was 57.8 years. The best corrected visual acuity (BCVA) was < 0.3 in 89.7% of eyes before surgery and ≥ 0.3 in 48.3% of eyes after surgery. Among 174 eyes, visual acuity improved in 83.3%. There was no change in 8.6% of eyes, while 8.1% of eyes had decreased visual acuity after surgery. The average logMAR visual acuity was 1.5 ± 0.7 before surgery and 0.7 ± 0.6 after surgery, indicating significant improvement (p < 0.05). Logistic regression analysis showed that intraoperative silicone oil filling and postoperative complication were significant risk factors for postoperative low vision, while preoperative pseudophakic lens and postoperative intra vitreal injection of anti-VEGF were protective factors for vision recovery (p < 0.05). The incidence of postoperative complications was 15.5%, top three of which were vitreous haemorrhage, neovascular glaucoma and traction retinal detachment.

CONCLUSION

Vitrectomy is safe and effective in the treatment of PDR with few complication. Postoperative intra vitreal injection of anti-VEGF is a protective factor for vision recovery.

TRIAL REGISTRATION

The trial registration number is ChiCRT2100051628, and the date of registration was September 28, 2021.

Risk Factors Associated With a Large Vertical Cup-to-Disc Ratio: Korean National Health and Nutritional Examination Survey

PRCIS

Higher intraocular pressure, higher systolic blood pressure, and higher serum aspartate transaminase to alanine aminotransaminase level were risk factors associated with a large vertical cup-to-disk ratio (vCDR).

PURPOSE

To identify risk factors for a large vCDR using data from the Korea National Health and Nutritional Examination Survey (2008-2012).

MATERIALS AND METHODS

Out of the total 29,322 participants aged 20 or older who participated in Korea National Health and Nutrition Survey (KHANES) from the year 2008 to 2012, this study was conducted on 21,780 participants, excluding 1449 of them without fundus photographs and 6093 of them with missing values. To identify the risk factors associated with a large vCDR, the participants were divided into 2 groups: ≥0.6 and <0.6.

RESULTS

Of the 21,780 subjects, 2357 of them had a vCDR ≥0.6 and 19,423 had a vCDR <0.6. There were significant differences in age, sex, and educational levels between the 2 groups. After adjusting age, sex, education level, and survey year by propensity score matching, in the group having vCDR ≥0.6, intraocular pressure (IOP) was high, systolic blood pressure (SBP) was high, and serum aspartate transaminase to alanine aminotransaminase level (AST/ALT ratio) was high ( P <0.001, P <0.001, and P <0.001). The results of multiple logistic regression analyses revealed that high IOP, high SBP, high myopia, and high AST/ALT ratio were risk factors for vCDR ≥0.6 ( P <0.001, P =0.006, P =0.005, P <0.001).

CONCLUSIONS

In this study, risk factors associated with large vCDR were analyzed. Higher IOP, higher SBP, and higher AST/ALT ratio were related to vCDR ≥0.6.

Racial Differences in Detection of Glaucoma Using Retinal Nerve Fiber Layer Thickness and Bruch Membrane Opening Minimum Rim Width

PURPOSE

To compare the sensitivities and specificities of the retinal nerve fiber layer thickness (RNFLT) and Bruch membrane opening minimum rim width (BMO-MRW) reference database-based criteria for detection of glaucoma in individuals of European descent (ED) and individuals of African descent (AD).

DESIGN

Comparative diagnostic analysis by race METHODS: 382 eyes of 255 glaucoma patients (ED = 170, AD = 85) and 94 eyes of 50 healthy individuals (ED = 30, AD = 20) with global and sectoral RNFLT and BMO-MRW measured with Spectralis optical coherence tomography (OCT) were included. Six diagnostic criteria were evaluated: global measurement below the 5th or 1st percentile, ≥1 of the 6 sector measurements below the 5th or 1st percentile, and superotemporal (ST) and/or inferotemporal (IT) measurement below the 5th or 1st percentile. The sensitivities and specificities of these measurements for detection of glaucoma were compared using bootstrapping methods.

RESULTS

ST and/or IT RNFLT below the 5th percentile has the best performance for detection of glaucoma among RNFLT classifications with a sensitivity (95% CI) of 89.5% (86.1, 92.5) and specificity of 87.2% (77.8, 95.1). In AD individuals, sensitivities of ST and IT RNFLT and BMO-MRW measurements below the 5th percentile criteria were lower than in ED individuals (RNFLT: 83.7% vs 92.5%, and BMO-MRW: 72.1% vs 88.5%, respectively), as well as specificities (AD RNFLT: 73.7% and BMO-MRW: 89.5% vs ED RNFLT: 96.4% and BMO-MRW: 98.2%, respectively).

CONCLUSIONS

RNFLT and BMO-MRW had consistently lower diagnostic performance in AD individuals compared with ED individuals. BMO-MRW criteria might fail to detect as many as one-third of eyes with glaucoma, specifically in AD individuals. With the current reference database, RNFLT, and especially BMO-MRW, criteria are not adequate for diagnosing glaucoma in AD individuals.

Geospatial analysis of blindness within rural and urban counties

PURPOSE

To determine the associations of blindness within rural and urban counties using a registry of blind persons and geospatial analytics.

METHODS

We used the Oregon Commission for the Blind registry to determine the number of persons who are legally blind, as well as licensure data to determine the density of eye care providers (optometrists and ophthalmologists) within each county of the State of Oregon. We used geospatial statistics, analysis of variance, and logistic regression to determine the explanatory variables associated with blindness within counties.

RESULTS

We included 8350 individuals who are legally blind within the state of Oregon in the calendar year 2015. The mean observed prevalence of registered blindness was 0.21% and ranged almost 9-fold from 0.04% to 0.58% among counties (p < .001). In univariate models, higher blindness was associated with increasing median age (p = .027), minority race (p < .001), decreased median household income (p < .001), increased poverty within a county (p < .001), and higher density of ophthalmologists (p = .003). Density of optometrists was not associated with prevalence of blindness (p = .89). The final multivariable model showed higher blindness to be associated with lower median household income, higher proportion of black race, and lower proportion of Hispanic race (p < .001 for all).

CONCLUSION

Geospatial analytics identified counties with higher and lower than expected proportions of blindness even when adjusted for sociodemographic factors. Clinicians and researchers may use the methods and results of this study to better understand the distribution of individuals with blindness and the associated factors to help design public health interventions.

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.

Visual Field Progression in Patients with Primary Open Angle Glaucoma, Normal Tension Glaucoma, and Primary Angle Closure Glaucoma

Purpose: We compared visual field progression among patients with primary open-angle glaucoma (POAG), normal tension glaucoma (NTG), and primary angle-closure glaucoma (PACG).Methods: A total of 115 POAG, 123 NTG, and 92 PACG eyes were retrospectively analyzed. Global VF progression was evaluated by calculating the changes of mean deviations. To examine local VF deterioration, scotoma enlargement and deepening were analyzed in the superior, and inferior arcuate, and the central, zones.Results: The mean global rate of change in POAG eyes was -0.52 ± 0.74 dB/year, and -0.35 ± 0.41, and -0.38 ± 0.45 dB/year in NTG and PACG eyes; POAG eyes showed significantly more rapid progression than NTG and PACG eyes (p < 0.01). The superior arcuate zone of POAG eyes, the central zone of NTG eyes, and the inferior arcuate zone of PACG eyes exhibited more scotoma enlargement and scotoma deepening than did other zones.Conclusions: The superior arcuate zone of POAG eyes, the central zone of NTG eyes, and the inferior arcuate zone of PACG eyes showed greater VF progression.

Choroidal Thickness in Advanced Glaucoma Patients

Purpose: We investigated choroidal thickness according to the classification of glaucoma and related factors in patients with advanced glaucoma.Methods: The present study included 133 eyes of 133 advanced glaucoma patients with a mean deviation of <-12 dB. Patients were classified into primary open angle glaucoma (POAG) and normal-tension glaucoma (NTG) groups. Factors related to the subfoveal and peripapillary choroidal thickness were analyzed using linear regression analysis.Results: The mean peripapillary choroid thickness was 99.20 ± 46.85 µm in the NTG group, which was significantly thinner than in the POAG group (121.85 ± 45.39 µm, p = 0.006). Additionally, in the sectoral comparison, the NTG group had thinner choroids than the POAG group in all areas (p < 0.05 for all). In the linear regression analysis, glaucoma class (p = 0.007), age (p = 0.005), and intraocular pressure (IOP) (p = 0.024) significantly affected the peripapillary choroid thickness. Moreover, age (p = 0.029) and macular thickness (p = 0.002) were significantly associated with subfoveal choroid thickness.Conclusions: In advanced glaucoma, low baseline IOP, NTG, and old age were significantly associated with a thin peripapillary choroid, suggesting an association between thin peripapillary choroid and the etiology of NTG. Further studies are needed to clarify the significance of a thin choroid in the pathogenesis of glaucoma.

The Causes and Frequency of Monocular and Binocular Blindness in Adults Applying to the Health Committee of a University Hospital in Central Anatolia

Objectives:

The aim of this study was to investigate the frequency of blindness and the pathologies that cause blindness in the Konya province of Turkey.

Materials and Methods:

The records of individuals over 18 years of age who applied to the health committee of Meram School of Medicine Hospital between January 2015 and December 2018 were evaluated retrospectively.

Results:

After reviewing the records of 4,268 applicants, a total of 222 applicants were included in the study (159 patients with monocular blindness, 63 patients with binocular blindness). The most common causes of monocular blindness were optic atrophy (13%), amblyopia (11%), and phthisis bulbi (10%). The most common causes of binocular blindness were retinitis pigmentosa (28%), proliferative diabetic retinopathy (13%), and unoperated cataract (11%). The frequency of monocular blindness was 3.7% (95% confidence interval [CI]: 3.2-4.3%) and binocular blindness was 1.5% (95% CI: 1.1-1.9%) in the sample. The frequency of blindness increased with age, with a positive correlation between mean age and blindness (p=0.002). Monocular blind applicants had a significantly lower mean age than binocular blind applicants (48.8±13.3 vs. 55.0±13.1 years, p=0.002) and binocular blind women had a significantly higher mean age than binocular blind men (62.7±16.0 vs. 53.2±11.7 years, p=0.023). The prevalence of monocular and binocular blindness was significantly higher in men than women (p=0.032).

Conclusion:

The results of this study show that many of the pathologies that cause blindness are preventable or treatable, and that blindness is associated with age.

A retrospective study of causes of visual impairment and use of low vision devices in the low vision clinic in Trinidad and Tobago

PURPOSE

To determine the causes of visual impairment and the use of low vision devices in patients attending the low vision clinic in Trinidad and Tobago.

METHODS

A retrospective study of the 222 patients attending the low vision clinic at the University of the West Indies, St Augustine Campus was conducted. The presenting visual acuity, causes of low vision and blindness, and prescribed low vision devices were recorded and analysed to determine the major causes of visual impairment and improvement in visual acuity with low vision aids.

RESULTS

Out of the total 222 participants, 66.66% (n = 148) had low vision while the rest (33.33%, n = 74) were legally blind. Glaucoma was the major cause of low vision (31.08%) and blindness (28.38%) followed by diabetic retinopathy (20.94%, low vision and 20.27%, blindness). A total of 193 low vision devices were prescribed, 79.79% (n = 154) near devices and 20.20% (n = 39) distance devices. The low vision devices were effective in improving both near visual acuity (120 participants reading 1M or 2M) and distance visual acuity (VA better than 3/60).

CONCLUSION

The major causes of vision impairment in Trinidad and Tobago were glaucoma and diabetic retinopathy and low vision devices are effective in improving visual acuity. A comprehensive approach to dealing with the causes of low vision and low vision services are required to mitigate the burden of visual impairment in the country.

Causes and Five-Year Proportion of New Irreversible Visual Impairment in Jinshan District, Shanghai, from 2009-2018

Purpose

To describe the age distribution and main causes of new registered irreversible visual impairment (VI) and to compare the five-year proportion of VI in Jinshan district, Shanghai, from 2009 to 2018.

Methods

The new irreversible VI data were collected in the registry system from the Disabled Persons' Federation in Jinshan district from January 1, 2009, to December 31, 2018. Age, gender, and causes of VI were included, and the 5-year proportion of VI was calculated.

Results

The peak occurrence of blindness occurred in the 50–59 yrs group in 2009–2013 and in the ≥70 yrs group in 2014–2018. The peak occurrence of low vision occurred in the 40–49 yrs group in 2009–2013 and in the 50–59 yrs group in 2014–2018. Myopic macular degeneration (MMD, 15.5%), diabetic retinopathy (DR, 14.3%), and other optic nerve atrophy (ONA, 14.3%) were the three leading causes of blindness in 2009-2013, whereas MMD (21.3%), age-related macular degeneration (AMD, 19.6%), ONA (14.9%) were the three leading causes of blindness in 2014–2018. MMD (39.2%), DR (9.6%), ONA (8.8%) were the three leading causes of low vision in 2009–2013, whereas MMD (38.7%), AMD (23.3%), ONA (7.4%) were the three leading causes of low vision in 2014–2018. The proportions of blindness and low vision caused by AMD were higher in 2014–2018 than those in 2009–2013 (P=0.034 and P < 0.001, respectively).

Conclusion

The present study demonstrated an increasing trend in the number of irreversibly visually impaired individuals from 2009 to 2018. More attention should be paid to people with high myopia and old age.

Minimally Invasive Surgery in Mild-to-Moderate Glaucoma Patients in Italy: Is It Time to Change?

Medical therapy is the first treatment choice for most patients with glaucoma; however, in a relevant proportion of patients, intraocular pressure (IOP) reduction is achieved with multi-therapy and/or high therapeutic doses. Conventional surgery is the standard alternative to medical therapy when this is not effective or not tolerated. Recently, selective laser trabeculoplasty (SLT) has been advocated as first-line therapy, and "minimally invasive glaucoma surgery" (MIGS) has been developed as safer and less traumatic surgical intervention for patients with glaucoma. Schlemm's canal surgery has emerged as one of the approaches with the most favorable risk-benefit profile for glaucoma patients in need of cataract surgery. However, despite the promising results, use of MIGS in Italy has been extremely low. We aimed to investigate the reasons of the lower-than-expected use of Schlemm's canal-based MIGS devices in Italy, share our perspective on their potential place in therapy, and give practical suggestions to improve the management of glaucoma patients.

Prevalence and causes of visual impairment in population more than 50 years old: The Shaanxi Eye Study

To assess the prevalence and causes of visual impairment (VI) in the elderly Chinese rural population in Shaanxi Province.A population-based, cross-sectional study design was used to determine the extent of VI in Chinese people over the age of 50 years in Shaanxi Province. Visual acuity and best-corrected visual acuity were measured using the logarithm of minimum angle of resolution chart. Blindness and low vision were defined according to WHO criteria. The major cause of VI was identified for all participants who were visually impaired.A total of 1912 residents completed a standard questionnaire and underwent a detailed eye examination, and the response rate was 90%. The overall prevalence of blindness and low vision were 1.5% and 8.2%. There was no statistically significant differences between genders in the prevalence of blindness and low vision (P > .05). The prevalence of blindness and low vision was higher among older individuals (P < .05) and lower (P < .05) among those with the highest education level. Cataract, corneal opacity, and glaucoma were considered as the main causes of blindness, which accounted for 67.9%, 10.7%, and 7.1%, respectively. Cataract, refractive error, and age-related macular degeneration were always considered as the leading causes of low vision, which accounted for 66%, 14.7%, and 5.8%, respectively.Cataract, corneal opacity, and glaucoma were the main causes of blindness and low vision in the population aged 50 years or more. The prevalence of these diseases that causes blindness and low vision was higher than that reported in other studies.

Estimating Visual Field Mean Deviation using Optical Coherence Tomographic Nerve Fiber Layer Measurements in Glaucoma Patients

To construct an optical coherence tomography (OCT) nerve fiber layer (NFL) parameter that has maximal correlation and agreement with visual field (VF) mean deviation (MD). The NFL_MD parameter in dB scale was calculated from the peripapillary NFL thickness profile nonlinear transformation and VF area-weighted averaging. From the Advanced Imaging for Glaucoma study, 245 normal, 420 pre-perimetric glaucoma (PPG), and 289 perimetric glaucoma (PG) eyes were selected. NFL_MD had significantly higher correlation (Pearson R: 0.68 vs 0.55, p < 0.001) with VF_MD than the overall NFL thickness. NFL_MD also had significantly higher sensitivity in detecting PPG (0.14 vs 0.08) and PG (0.60 vs 0.43) at the 99% specificity level. NFL_MD had better reproducibility than VF_MD (0.35 vs 0.69 dB, p < 0.001). The differences between NFL_MD and VF_MD were -0.34 ± 1.71 dB, -0.01 ± 2.08 dB and 3.54 ± 3.18 dB and 7.17 ± 2.68 dB for PPG, early PG, moderate PG, and severe PG subgroups, respectively. In summary, OCT-based NFL_MD has better correlation with VF_MD and greater diagnostic sensitivity than the average NFL thickness. It has better reproducibility than VF_MD, which may be advantageous in detecting progression. It agrees well with VF_MD in early glaucoma but underestimates damage in moderate~advanced stages.

The Frequency and Causes of Blindness in a Rural Region of Central Anatolia of Turkey

Objective

This study aimed to evaluate the frequency and primary causes of blindness in adults aged 18 years and more in Sarıkaya rural region of Yozgat, Turkey, to contribute to the epidemiologic information about blindness in our country.

Materials and Methods

Patients who were examined between October 2016 and March 2017 in Sarıkaya State Hospital, Clinic of Ophthalmology, were prospectively investigated. Demographic and ophthalmic examination data, presented visual acuities (VA), primary causes of blindness, and monocular blindness were recorded. Blindness was defined as presented visual acuities (VA) definition of World Health Organization criteria.

Results

A total of 3423 participants, aged 18-96 years, were examined. Among them, 1887 participants (55%) were female and 1536 (45%) were male. The frequency of blindness was 1.5% (95% CI: 1.1%-2.0%); and cataract was the primary cause of blindness (42%). Age-related macular degeneration (21%) and uncorrected refractive error (13%) were the next main causes of blindness. The frequency of monocular blindness was 4% (95% CI: 3.8%-5.2%), and cataract (27%) followed by phthisis bulbi/evisceration (13%) and glaucoma (12%) were the leading causes of monocular blindness.

Conclusion

In this rural region of Central Anatolia, the primary cause of blindness and monocular blindness was an unoperated cataract. The patterns of age-specific causes of blindness are variable, but most of them are avoidable or treatable. Thus, awareness should be increased in societies, and people should be prevented from blindness with health-care programs in rural regions of developing countries.

Using registry data to characterize the incidence and causes of blindness in Oregon

In the United States, there is no reliable data to describe the prevalence of eye diseases leading to visual impairment and little active surveillance to address this knowledge gap. Data that is readily available from many state blind registries may provide helpful information on trends and causes of blindness. We analyzed new registrations with the Oregon Commission for the Blind (OCB) and Oregon State Department of Administrative Services (DAS) from 1961 to 2016 for causes of and trends in blindness. Persons with blindness self-refer into the OCB registry and the Oregon State Department of Administrative Services (DAS) includes those receiving social security disability financial support and other state services. Data for 9,273 blind persons registered were analyzed. The most frequent causes of blindness were age related macular degeneration (AMD) 3,308 (38%), followed by diabetic retinopathy (DR) 729 (8%), congenital conditions 697 (8%), optic nerve atrophy 611 (7%), glaucoma 549 (6%), retinitis pigmentosa 546 (6%), retinopathy of prematurity192 (2%), cataract 180 (2%), and trauma 174 (2%). The mean age of onset of blindness was younger for Blacks (31 years) and Hispanics (33 years) than for Whites (44 years). Analysis of state-based registries can provide useful and locally relevant vision and eye health data where little information is otherwise available.

Ophthalmologic health status of an aging population-data from the Berlin Aging Study II (BASE-II)

PURPOSE

Vision of the elderly may be affected by typical age-related diseases like cataract and macular degeneration. Little is known about the effect of aging on visual difficulties and vision-related quality of life. This study was conducted to compare the ophthalmological health status of younger and older individuals within a large cohort study of residents of a greater metropolitan area (Berlin Aging Study II [BASE-II]).

METHODS

A total of 1655 participants (805 men) aged 60 years and older and 494 participants (232 men) aged between 22 and 48 years from the Berlin Aging Study II were included in the analysis. The subjects were examined during a 2-day clinical examination period. History of ocular diseases, vision-related quality of life using the visual function questionnaire (VFQ- 25), refraction, distance and near visual acuity, tonometry, and color vision were provided.

RESULTS

Older subjects performed significantly worse concerning distance and near visual acuity, color vision, and vision-related quality of life compared to young subjects. Intraocular pressure showed no significant difference between groups. Individuals are often unaware of existing eye diseases.

CONCLUSION

The prevalence of ocular diseases and the impairment of vision increases with age. Although 98% of elderly subjects have reported to suffer from any ocular disease, subjective quality of life seems to be affected to a lesser extent.

National Eye Survey of Trinidad and Tobago (NESTT): prevalence, causes and risk factors for presenting vision impairment in adults over 40 years

AIM

To estimate the prevalence, causes and risk factors for presenting distance and near vision impairment (VI) in Trinidad and Tobago.

METHODS

This is a national, population-based survey using multistage, cluster random sampling in 120 clusters with probability-proportionate-to-size methods. Stage 1 included standardised, community-based measurement of visual acuity. Stage 2 invited all 4263 people aged ≥40 years for comprehensive clinic-based assessment. The Moorfields Eye Hospital Reading Centre graded fundus photographs and optical coherence tomography images independently.

RESULTS

The response rates were 84.2% (n=3589) (stage 1) and 65.4% (n=2790) (stage 2), including 97.1% with VI. The mean age was 57.2 (SD 11.9) years, 54.5% were female, 42.6% were of African descent and 39.0% were of South Asian descent. 11.88% (95% CI 10.88 to 12.97, n=468) had distance VI (logarithm of the minimum angle of resolution [logMAR] >0.30), including blindness (logMAR >1.30) in 0.73% (95% CI 0.48 to 0.97, n=31), after adjustment for study design, non-response, age, sex and municipality. The leading causes of blindness included glaucoma (31.7%, 95% CI 18.7 to 44.8), cataract (28.8%, 95% CI 12.6 to 45.1) and diabetic retinopathy (19.1%, 95% CI 4.2 to 34.0). The leading cause of distance VI was uncorrected refractive error (47.4%, 95% CI 43.4 to 51.3). Potentially avoidable VI accounted for 86.1% (95% CI 82.88 to 88.81), an estimated 176 323 cases in the national population aged ≥40 years. 22.3% (95% CI 20.7 to 23.8, n=695) had uncorrected near VI (logMAR >0.30 at 40 cm with distance acuity <0.30). Significant independent associations with distance VI included increasing age, diagnosed diabetes and unemployment. Significant independent associations with near VI included male sex, no health insurance and unemployment.

CONCLUSIONS

Trinidad and Tobago's burden of avoidable VI exceeds that of other high-income countries. Population and health system priorities are identified to help close the gap.

ReGAE 12: preventing glaucoma blindness in the Caribbean through implementation of the Moorfields Safer Surgery System and skills transfer from the UK to Trinidad and Tobago

Objective

The objective of the study was to present evidence of successful skills transfer of the Moorfields Safer Surgery System (MSSS) from the UK to Trinidad and Tobago and the safety and efficacy of this technique.

Methods

Hospital-based retrospective, consecutive, non-comparative case series study of 33 eyes (24 African-Caribbean patients; 16 male patients) with primary open-angle glaucoma undergoing trabeculectomy + mitomycin C (MSSS) by a single surgeon with UK Glaucoma Fellowship training. The clinical outcome measures included intraocular pressure (IOP), bleb morphology, postsurgical interventions, postoperative complications, and best-corrected visual acuity (BCVA) at the final follow-up.

Results

All patients were self-identified as African-Caribbean. The median age was 56 years (range 34-79 years). The mean preoperative IOP on maximum tolerated medical treatment was 22.4 mmHg (SD=5.9 mmHg). With or without medication, IOP was ≤21 mmHg in 92.6% at 1 year and 87.5% at 5 years. At 1 year, IOP was ≤18 mmHg in 78%, ≤15 mmHg in 73% and ≤14 mmHg in 52%. Removal of scleral flap releasable suture(s) was performed in 84%, 5-fluorouracil injection(s) in 88% and bleb needling revision in 38%. The most common complication was early transient bleb leak (52%). No patient developed endophthalmitis, hypotony maculopathy, suprachoroidal hemorrhage, or malignant glaucoma. At the final follow-up, 91% had excellent or satisfactory bleb morphology, and 73% had equal or better BCVA.

Conclusion

Skills transfer between different geographical and economic regions contributes to the prevention of avoidable blindness through disease control - one of the core strategies of the World Health Organization's Vision 2020 initiative. In the Caribbean (Trinidad and Tobago), the MSSS was utilized by a surgeon with Glaucoma Fellowship training and achieved outcomes similar to best-published data. This success can be reproduced in other geographic locations.

The African American Eye Disease Study: Design and Methods

PURPOSE

To describe the study design, operational and recruitment strategies, procedures, and baseline characteristics of the African American Eye Disease Study (AFEDS), a population-based assement of the prevalence of visual impairment, ocular disease, visual function, and health-related quality of life in African Americans.

METHODS

This population-based, cross-sectional study included over 6000 African Americans 40 years and older residing in and around Inglewood, California. A detailed interview and eye examination was performed on each eligible participant. The interview included an assessment of demographic, behavioral, and ocular risk factors and health-related and vision-related quality of life. The eye examination included measurements of visual acuity, intraocular pressure, visual fields; fundus and optic disc photography; a detailed anterior and posterior segment examination; and measurements of blood pressure, glycosylated hemoglobin levels, and blood glucose levels.

RESULTS

The AFEDS cohort includes more than 6000 participants that have completed a home questionnaire and a comprehensive eye examination. The majority of participants were female (63%), the average (± standard deviation) overall age was 60.9 (±11.3). Participants are mostly working (40%) or retired (41%), non-smoking (57%), partial drinking (54%), and with at least some college education (38%). A trust-development recruitment strategy was refined in order to overcome challenges in study participation.

CONCLUSION

The AFEDS is the largest epidemiologic eye study among African Americans to date. The AFEDS cohort will provide information about the prevalence and risk factors of ocular disease in the largest ophthalmologic study population of African Americans in the United States.

Prevalence of Diabetic Retinopathy among Subjects with Known Diabetes in China: The Beijing Eye Study

Purpose

To evaluate the prevalence of diabetic retinopathy and risk factors among patients with self-reported diabetes mellitus in China.

Methods

The Beijing Eye Study, a population-based study on inhabitants aged 40+ years, included 4439 subjects. Fundus photographs of the worse eye from participants with self-reported diabetes were graded.

Results

Fundus photographs ready for evaluation and a filled out questionnaire were available for 4127 (93.0%) subjects. The prevalence of self-reported diabetes was 235/4127 (5.7%). Among the subjects with a self-reported diagnosis of diabetes, diabetic retinopathy was detected on the fundus photographs of 86 (37.1%) subjects, with macular edema in 12 (5.2%) subjects, clinically significant macular edema in 6 (2.6%) subjects, and a vision-threatening stage of the retinopathy in 12 (5.2%) subjects. Diabetic retinopathy was associated with rural region (p=0.004), longer duration of diabetes (p=0.009), use of diabetic medications (p=0.02), and lower education background (p=0.003).

Conclusions

Prevalence of diabetic retinopathy among Chinese patients aged 40+ years with a self-reported diagnosis of diabetes is about 37%, with a vision-threatening stage of the retinopathy detected in 5% of the subjects. About 5.7% of the adult Chinese population report on a known diagnosis of diabetes mellitus, with about 15% of these subjects knowing about the presence of diabetic retinopathy. The frequency of known diabetes mellitus is lower in rural regions than in urban regions, while diabetic retinopathy overall and macular edema among the subjects with known diabetes mellitus were significantly more common in the rural group.

Trends in Blind and Low Vision Registrations in Taipei City

Purpose

To determine the overall reported incidence and causes of registrable blindness and low vision in Taipei, Taiwan, that have occurred in the previous 10 years.

Methods

Study data were obtained from disability identification registration forms completed between January 1995 and December 2004. Definitions of low vision and blindness were defined by WHO criteria: low vision included visual acuity worse than 6/18 (20/60) to a lower limit of 3/60 (20/400). Blindness was defined as visual acuity worse than 3/60 (20/400) in the better eye with best possible correction.

Results

There were 3151 registrations for visual impairment during the study period. A total of 239 registrations were excluded due to insufficient data. Of the remaining 2912 (1518 males and 1394 females), 640 males and 647 females were legally blind (44.20%). A total of 878 males and 747 females were partially sighted. The six leading causes of low vision and blindness, in decreasing frequency, were glaucoma, optic neuropathy, diabetic retinopathy, retinitis pigmentosa, age-related macular degeneration, and myopic macular degeneration.

Conclusions

The proportions of new registrations owing to glaucoma, diabetic retinopathy, age-related macular degeneration, and myopic macular degeneration have changed significantly since 2000; the proportion due to diabetic retinopathy has increased.

Reductions in Retrobulbar and Retinal Capillary Blood Flow Strongly Correlate With Changes in Optic Nerve Head and Retinal Morphology Over 4 Years in Open-angle Glaucoma Patients of African Descent Compared With Patients of European Descent

PURPOSE

To investigate the relationship of changes in ocular blood flow with optic nerve head (ONH) and retinal morphology in open-angle glaucoma (OAG) patients of African versus European descent (ED) over 4 years.

MATERIALS AND METHODS

In this study, 112 patients with OAG were examined at baseline, 79 [59 ED, 20 African descent (AD)] of which were followed for 4 years. Retinal capillary blood flow was assessed with Heidelberg retinal flowmetry. Retrobulbar blood flow was measured by color Doppler imaging. Retinal structural changes were examined with optical coherence tomography and Heidelberg retinal tomography-III. Mixed-model analysis of covariance was used to test for the significance of change from baseline to 4-year follow-up, and Pearson correlation coefficients were calculated to evaluate linear associations.

RESULTS

In OAG patients of AD, structural changes of the ONH demonstrated a strong association with the end diastolic velocities and resistive indices of the short posterior ciliary arteries over 4 years. In addition, there was a significantly larger increase in the avascular area of the inferior retina in patients of AD, and this reduction in retinal capillaries strongly correlated with a reduction in macular thickness.

CONCLUSIONS

Reductions in retinal capillary and retrobulbar blood flow strongly correlated with changes in the ONH and macular thickness over 4 years in OAG patients of AD compared with ED. These data suggest that ocular vascular health may be a more influential contributing factor in the pathophysiology of OAG in patients of AD compared with ED.

Long-term Follow-up of Patients receiving Intraocular Pressure-lowering Medications as Cataract Surgery Candidates: A Case-control Study

AIM

In this study, we reviewed demographics and biometric characteristics among patients receiving chronic β-blockers and prostaglandins (PGs) for primary open-angle glaucoma. We compared the age at the time of cataract surgery in different patient groups and in a control group which was not under any medication.

MATERIALS AND METHODS

Retrospective chart review of glau-comatous patients who underwent cataract extraction at the Department of Ophthalmology of the University Hospital of Heraklion, Crete, Greece, between January 1998 and December 2016 was done. Age at cataract surgery, axial length (AL), and preoperative and postoperative best-corrected visual acuities (BCVAs) were recorded. A cohort of patients without glaucoma who were operated for cataract extraction was also evaluated.

RESULTS

In all, 320 patients were reviewed. There were significant results in mean age difference between the beta-antagonist and the PG group [3.05 years, 95% confidence interval (CI) 1.54-4.57] and between the beta-antagonist group with the patients receiving a combined therapy (3.02 years, 95% CI 1.14-4.91). No significant difference was found between the PG and the combination group. All the three treated groups had a significant lower mean age than the control group at the time of cataract surgery.

CONCLUSION

Based on our study, we concluded that there might be a possible association between chronic treatment with beta-antagonist agents and earlier cataract surgical time in the treated eye.

CLINICAL SIGNIFICANCE

Intraocular pressure control is often usually achieved using ophthalmic agents. Their topical and systemic effects should be monitored precisely. Earlier cataract formation might be an important side effect which the physician has to keep in mind before choosing the suitable medication.How to cite this article: Bontzos G, Agiorgiotakis M, Detorakis ET. Long-term Follow-up of Patients receiving Intraocular Pressure-lowering Medications as Cataract Surgery Candidates: A Case-control Study. J Curr Glaucoma Pract 2017;11(3):107-112.

Glaucoma Increases Retinal Surface Contour Variability as Measured by Optical Coherence Tomography

Purpose

We investigated the feasibility of glaucoma detection by measuring retinal surface contour variability (RSCV) using optical coherence tomography (OCT).

Methods

The peripapillary region in one eye of each participant was scanned over an 8 × 8 mm area with a swept source OCT prototype. The retinal surface contour was sampled at approximately 1.5- to 3.5-mm radius circles centered on the optic nerve head. The RSCV is defined as the average log value within a middle spatial frequency band of the Fourier transform to the elevation profile of the inner retinal surface. The spatial frequency band was optimized to distinguish glaucoma from normal. Nerve fiber layer thickness (NFLT) was sampled around a 1.7-mm radius circle. Glaucoma severity was assessed by automated static perimetry.

Results

We enrolled 17 glaucomatous eyes and 17 healthy eyes. A great majority of the glaucoma group were in the early stage (visual field mean deviation average −2.48 ± 3.73 dB). Significant differences were found for RSCV between glaucoma and control eyes (P < 0.003) at all radii. The area under the receiver operating characteristic curve (AROC = 0.90) of RSCV was best at the 3.5-mm radius. This was not significantly better than NFLT (AROC = 0.84). With the 99% specificity, the glaucoma detection sensitivity was 53% for RSCV and 29% for NFLT (P = 0.13).

Conclusions

Retinal surface contour variability was significantly increased in glaucoma patients. The diagnostic accuracy of RSCV was equal to NFLT in early glaucoma. Since the RSCV detects small-scale focal damage and the average NFLT measures global damage, they provide different diagnostic information that may be synergistic.

The National Eye Survey of Trinidad and Tobago (NESTT): Rationale, Objectives and Methodology

PURPOSE

This paper describes the rationale, study design and procedures of the National Eye Survey of Trinidad and Tobago (NESTT). The main objective of this survey is to obtain prevalence estimates of vision impairment and blindness for planning and policy development.

METHODS

A population-based, cross-sectional survey was undertaken using random multistage cluster sampling, with probability-proportionate-to-size methods. Eligible participants aged 5 years and older were sampled from the non-institutional population in each of 120 cluster segments. Presenting distance and near visual acuity were screened in their communities. People aged 40 years and older, and selected younger people, were invited for comprehensive clinic assessment. The interview included information on potential risk factors for vision loss, associated costs and quality of life. The examination included measurement of anthropometrics, blood glucose, refraction, ocular biometry, corneal hysteresis, and detailed assessment of the anterior and posterior segments, with photography and optical coherence tomography imaging. Adult participants were invited to donate saliva samples for DNA extraction and storage.

RESULTS

The fieldwork was conducted over 13 months in 2013-2014. A representative sample of 10,651 individuals in 3410 households within 120 cluster segments identified 9913 people who were eligible for recruitment.

CONCLUSION

The study methodology was robust and adequate to provide the first population-based estimates of the prevalence and causes of visual impairment and blindness in Trinidad and Tobago. Information was also gathered on risk factors, costs and quality of life associated with vision loss, and on normal ocular parameters for the population aged 40 years and older.

Associations between Body Mass Index and Visual Impairment of School Students in Central China

Body Mass Index (BMI) is a risk indicator for some eye diseases. However, the association between BMI and Visual Impairment (VI) was not quite certain in Chinese students. Our aim was to assess the relationship between BMI and VI with a cross-sectional study. A total of 3771 students aged 6–21 years, including 729 with VI, were sampled from 24 schools in Huangpi District of central China to participate in the study. A multistage stratified cluster random sampling was adopted. Each of the students answered a questionnaire and had physical and eye examinations. The association between BMI and VI was examined with logistic regression and threshold effect analysis. The prevalence of VI was 19.33% (729/3771). Compared to normal and underweight, overweight/obese students showed a stronger relation with VI in age- and sex-adjusted (Odds Ratio (OR) = 16.16, 95% Confidence Interval (CI): 12.37–21.09, p < 0.001) and multivariable models (OR = 8.32, 95% CI: 6.13–11.30, p < 0.001). There was a nonlinear dose–response relation between levels of BMI and the prevalence of VI (p < 0.001). A high level of BMI (≥19.81 kg/m²) was associated with a higher VI prevalence (adjusted OR = 1.20, 95% CI: 1.15–1.25, p < 0.001). In conclusion, the study demonstrated BMI levels were significantly associated with the prevalence of VI.

Glaucoma Risk Alleles in the Ocular Hypertension Treatment Study

PURPOSE

Primary open-angle glaucoma (POAG) is a major cause of blindness and visual disability. Several genetic risk factors for POAG and optic nerve features have been identified. We measured the relative risk for glaucoma that these factors contribute to participants in the Ocular Hypertension Treatment Study (OHTS).

DESIGN

Comparative series.

PARTICIPANTS

One thousand fifty-seven of 1636 participants (65%) of the OHTS were enrolled in this genetics ancillary study.

METHODS

Samples of DNA were available from 1057 OHTS participants. Of these, 209 developed POAG (cases) and 848 did not develop glaucoma (controls) between 1994 and 2009. The frequencies of 13 risk alleles previously associated with POAG or with optic disc features in other cohorts were compared between POAG cases and controls in the OHTS cohort using analyses of variance. The 2 largest subgroups, non-Hispanic whites (n = 752; 70.7%) and blacks (n = 249, 23.7%), also were analyzed separately. The probability of glaucoma developing over the course of the OHTS was compared between participants stratified for transmembrane and coiled-coil domains 1 (TMCO1) risk alleles using Kaplan-Meier and Cox proportional hazards analyses.

MAIN OUTCOME MEASURES

Association of POAG with known genetic factors.

RESULTS

No association was detected between the known POAG risk alleles when the OHTS cohort was examined as a whole. However, in the subgroup of non-Hispanic whites, allele frequencies at the TMCO1 locus were statistically different between cases and controls (P = 0.00028). By 13 years, non-Hispanic white participants with TMCO1 risk alleles had a 12% higher cumulative frequency of glaucoma developing than participants with no TMCO1 risk alleles. Moreover, the Cox proportional hazard analysis demonstrated that TMCO1 alleles increased relative risk comparable with that of some previously analyzed clinical measures (i.e., intraocular pressure).

CONCLUSIONS

The size of the OHTS cohort and its composition of 2 large racial subgroups may limit its power to detect some glaucoma risk factors. However, TMCO1 genotype was found to increase the risk of glaucoma developing among non-Hispanic whites, the largest racial subgroup in the OHTS cohort, at a magnitude similar to clinical predictors of disease that long have been associated with glaucoma.

Socioeconomic Disparities in Cataract Prevalence, Characteristics, and Management

PURPOSE

To review the current literature on socioeconomic disparities relationship with cataract prevalence, characteristics, and management.

SUMMARY

Cataracts are an important cause of preventable visual impairment in both the developing and industrialized world. Cataract surgery is a highly effective operation with an excellent risk profile. Furthermore, cataract surgery has been shown to have significant positive functional, social, and economic implications for patients. Several medical conditions have been shown to have correlation with socioeconomic factors and cataract is among several forms of visual impairment that demonstrate this relationship. Disparities in prevalence, clinical characteristics, and management are documented in the ophthalmic literature. A better understanding of these socioeconomic factors and their clinical relevance is critical to alleviating the burden of cataract-related visual impairment in an aging population.

Population-based assessment of visual impairment among ethnic Dai adults in a rural community in China

Dai ethnicity is one of the major Chinese ethnic minorities with a population of about 1.2 million. We aimed to determine the prevalence and potential causes of visual impairment (VI) among ethnic Dai adults aged 50 years or older in a rural community in China. A population-based survey including 2163 ethnic Dai people (80.5%) was undertaken using a random cluster sampling strategy. The detailed eye examination was performed after pupil dilation by trained study ophthalmologists and optometrists. Presenting visual acuity (PVA) and best-corrected visual acuity (BCVA) was measured using the Early Treatment Diabetic Retinopathy Study logMAR chart and VI was defined as a VA of less than 20/63 in the better-seeing eye. The overall prevalence of presenting blindness and low vision was 3.0% (95% CI, 2.3-3.7) and 13.3% (95% CI, 11.9-14.8), respectively. The prevalence estimates were reduced to 2.1% (95% CI, 1.5-2.8) and 6.7% (95% CI, 5.7-7.8) when BCVA was considered. Men were more likely to be affected by low vision but less likely to be blind compared with women. Cataract accounted for 62.7% of presenting low vision and 68.8% of presenting blindness, respectively. In conclusion, VI was a significant health concern in Dai Chinese in China.

Increased Difficulties in Managing Stairs in Visually Impaired Older Adults: A Community-Based Survey

Purpose

Managing stairs is a challenging aspect of daily activities of living for older people. We assessed whether older adults with visual impairment (VI) have greater difficulties of managing stairs in daily lives.

Methods

The study was designed as a community-based cross-sectional study based on a Chinese cohort aged 60 years and older in rural China. Visual acuity (VA) was measured in both eyes using a retro-illuminated Snellen chart with tumbling-E optotypes. VI (including blindness) was defined as presenting VA of worse than 20/60 in either eye. Having any difficulties in managing stairs was self-reported based on a question drawn from the Barthel Index. Information on participants’ socioeconomic status, lifestyle-related factors, diseases histories and medication intake was collected using a questionnaire.

Results

The Barthel Index, Activities of Daily Living questionnaire was completed by 4597 (99.7%) participants including 2218 men and 2379 women. The age of the participants ranged from 60 to 93 years with a mean of 67.6 ± 6.3 years. In age and gender adjusted models, adults with VI had a higher likelihood of having difficulties in managing stairs (odds ratio [OR] = 2.7; 95% confidence interval [CI] 2.0, 3.7) compared with those without. The association of VI with the likelihood of having difficulties in managing stairs was stronger in older adults who lived alone (OR = 3.2; 95%CI 1.8, 4.5) compared with those who lived with other family members (OR = 2.0; 95%CI 1.3, 4.3). Compared with hypertension, diabetes, obesity and cognitive dysfunction, VI had the greatest impact on people's abilities of managing stairs.

Conclusion

VI was associated with an increased likelihood of having difficulties in managing stairs, especially in those who lived alone. However, whether the finding could be extrapolated to other populations warrants further studies as different environmental exposures such as illumination and types of stairs may alter the association observed in this study.

Regular Chinese Green Tea Consumption is Protective for Diabetic Retinopathy: A Clinic-Based Case-Control Study

OBJECTIVE

To determine the association between regular Chinese green tea consumption and the risk of diabetic retinopathy (DR) in diabetic patients in China.

METHODS

100 DR patients and 100 age-sex-matched diabetic controls without retinopathy were recruited in a clinic-based, case-control study. DR was defined from retinal photographs and detailed information on Chinese green tea consumption of the participants was collected through a face-to-face interview.

RESULTS

The crude odds ratio [OR] of Chinese green tea consumption for DR was 0.49 (95% confidence interval: 0.26-0.90). When stratified by sex, the protective effect of Chinese green tea consumption on DR was statistically significant in women (P = 0.01) but not in men (P = 0.63). After adjusting for age, sex, and other confounders, DR was significantly associated with Chinese green tea consumption (OR = 0.48; P = 0.04), higher systolic blood pressure (OR = 1.02; P = 0.05), longer duration of diabetes (OR = 1.07; P = 0.02), and the presence of family history of diabetes (OR = 2.35; P = 0.04).

CONCLUSIONS

Diabetic patients who had regularly drunk Chinese green tea every week for at least one year in their lives had a DR risk reduction of about 50% compared with those who had not. Regular Chinese green tea consumption may be a novel approach for the prevention of DR.

Prevalence and causes of reduced visual acuity among children aged three to six years in a metropolis in China

PURPOSE

To determine the prevalence and possible causes for reduced visual acuity (VA) in preschool children in a metropolis in China.

METHODS

A school-based paediatric eye survey including 5862 preschool children aged three to 6 years was conducted from 2011 to 2012 in Yuhuatai District, Nanjing, China, using an age-stratified random sampling procedure. Clinical examinations including ocular alignment, ocular motility, visual acuity, prism cover test, cycloplegic refraction, stereopsis screening, slit lamp examination and fundus examination were performed by trained study ophthalmologists and optometrists. Reduced VA was defined as presenting VA of worse than 0.30 logMAR (Snellen 6/12 or 20/40), for both better and worse eyes.

RESULTS

5667 (94.8%) children with complete VA data were included in the data analyses. Among them, 208 and 93 had reduced VA in the worse and better eye, respectively. Reduced VA was detected in 3.7% (95% confidence interval [CI] 3.2%-4.2%) in the worse eye and 1.6% (95% CI 1.3%-2.0%) in the better eye. No significant age and gender differences in reduced VA were observed (p > 0.05). Refractive errors and amblyopia were the principal causes for reduced VA in the worse eye which accounted for 66.8% and 32.7% of the total cases with reduced VA, respectively. Astigmatism and hyperopia were the major types of refractive errors causing reduced VA.

CONCLUSIONS

The burden of reduced VA in preschool children in China was similar to that of Asian children of similar ages in the United States. Uncorrected refractive error and amblyopia were the principal causes for reduced VA among preschoolers (aged three to 6 years) in China.

Awareness and Knowledge of Glaucoma Among Adult Patients at the Eye Clinic of a Teaching Hospital

BACKGROUND

Primary open angle glaucoma (POAG) is an irreversible blinding disease that often presents late because it is symptomless in the early stages. Prognosis depends on early diagnosis and treatment and patient understanding of their condition. Many patients present late because of poor awareness and knowledge. This study was conducted to assess patient's awareness and knowledge of glaucoma in a referral Teaching Hospital.

METHODS

Descriptive cross-sectional study conducted among glaucoma patients aged 40 years and above attending the Komfo Anokye Teaching Hospital (KATH). Patients were selected by simple random sampling. They were recruited after informed consent had been given. A questionnaire on demographics, socio-economics and awareness of glaucoma was administered.

RESULTS

There were a total of 117 participants, 61 males and 56 females. The median and modal age group was 50 and 59 years. Amongst the participants, 74% were aware of glaucoma. There were no significant statistical difference in the various age groups, sex, ethnic group or religion and their awareness of glaucoma (P > 0.05).There were statistically significant differences between those who had higher education and their awareness of glaucoma (P < 0.001). Yet only 27% of these had accurate knowledge of glaucoma.

CONCLUSION

Glaucoma awareness in patients attending Komfo Anokye Teaching Hospital is high. Higher education was associated with higher awareness yet this was not translated into accurate knowledge as there were significant misconceptions. There is the need to review the contents of health education with the aim of reducing dangerous misconception of glaucoma and targeting the lower socioeconomic population.

Different amounts of alcohol consumption and cataract: a meta-analysis

PURPOSE

To evaluate the association between different amounts of alcohol consumption and the risk of age-related cataract.

METHODS

We searched PubMed and Embase from their inception until May 2014 for case-control or cohort studies with data on alcohol consumption and age-related cataract. Heavy alcohol consumption was defined as more than two standard drinks per day, which is equal to a daily intake of 20 g of alcohol or 140 g per week. Moderate consumption was defined as less than 20 g of alcohol per day but more than never any. We performed separate meta-analyses for the associations of moderate or heavy alcohol consumption with age-related cataract under a random-effects model, respectively.

RESULTS

Five case-control and five cohort studies were identified through comprehensive literature search. In the meta-analysis of 10 studies, the associations between moderate alcohol consumption and age-related cataract were marginally nonsignificant (pooled relative risk, 0.88; 95% confidence interval, 0.74 to 1.05; I = 82.1%), whereas heavy alcohol consumption was associated with an increased risk of age-related cataract (pooled relative risk, 1.26; 95% confidence interval, 1.06 to 1.50; I = 58.9%). The association between heavy alcohol consumption and cataract was stronger in case-control than in cohort studies. Adjusting for smoking as a potential confounder attenuated the association between heavy alcohol consumption and cataract.

CONCLUSIONS

Heavy alcohol consumption significantly increased the risk of age-related cataract, whereas moderate consumption may be protective for this ocular condition. Clinically, information on a patient's alcohol drinking history might be valuable to general physicians and ophthalmologists when there is a diagnosis of age-related cataract and should be collected on a routine basis in eye clinics.

Utility of the Tono-Pen in Measuring Intraocular Pressure in Trinidad: A Cross-sectional Study

AIM

To determine the sensitivity and specificity of the Reichert™ Tono-Pen AVIA® when used by novice medical students in an ethnically diverse population in Trinidad.

SUBJECTS AND METHOD

Participants were residents of Trinidad between the ages of 20 and 90 years attending the Ophthalmology Clinic at the Eric Williams Medical Sciences Complex (EWMSC). Intraocular pressure (IOP) was measured using the Goldmann applanation tonometer (the gold standard) for ophthalmology clinic patients as part of their routine care. Intraocular pressure measurements were then taken using the Tono-Pen.

RESULTS

One hundred persons participated, consisting of Indo-Trinidadians (55%), Afro-Trinidadians (36%), Mixed (8%) and 1% of Caucasian descent. Fourteen per cent reported a diagnosis of glaucoma, with 70.6% of these being of African descent. One hundred and ninety-eight readings of IOP were taken. At a cut-off point of 21 mmHg, there were nine true positives, four false positives, seven false negatives and 178 true negatives. The sensitivity and specificity were found to be 56.3% (95% CI 33.2, 76.9) and 97.8% (95% CI 94.5, 99.1), respectively. The positive predictive value was calculated as 69.2% (95% CI 42.4, 87.3) while the negative predictive value was 96.2% (95% CI 92.4, 98.2). The prevalence of elevated IOP in this population was 8.1% (95% CI 4.8, 13.0). The likelihood ratio of a positive result was calculated to be 25.6 (95% CI 8.6, 73.9).

CONCLUSION

The high specificity and negative predictive value suggests that the Tono-Pen can be used with minimal training, and can prove beneficial at the primary care level in the exclusion of increased IOP in an ethnically diverse high-risk Caribbean population.

Differences in ocular blood flow in glaucoma between patients of African and European descent

PURPOSE

To investigate differences in ocular blood flow in individuals of African descent (AD) and European descent (ED) with open angle glaucoma (OAG).

PATIENTS AND METHODS

A retrospective data analysis was performed on OAG patients of AD and ED who were previously examined for ocular blood flow within the Department of Ophthalmology at Indiana University School of Medicine. Data analysis included blood pressure, heart rate, visual fields, intraocular pressure, ocular perfusion pressure, and color Doppler imaging of retrobulbar vessels. Color Doppler imaging measurements were performed on ophthalmic, central retinal, and nasal and temporal short posterior ciliary arteries, with peak systolic (PSV) and end diastolic velocities (EDV) as well as the Pourcelot vascular resistive index calculated for each vessel. Two-sample t tests of unequal variance were performed with P values <0.05 considered statistically significant.

RESULTS

OAG patients of AD had statistically significant lower retrobulbar blood flow values than patients of ED including lower ophthalmic artery PSV (P=0.0001), ophthalmic artery EDV (P=0.0008), central retinal artery PSV (P=0.01), temporal short posterior ciliary artery PSV (P=0.0037), and nasal short posterior ciliary artery PSV (P<0.0001). No significant differences were found in terms of intraocular pressure or visual field parameters.

CONCLUSIONS

Significantly lower blood flow values were identified in all retrobulbar blood vessels in AD compared with ED OAG patients. These findings suggest that the contribution of ocular blood flow to the disease process may be different in AD compared with ED OAG patients.