Vision impairment in the Pacific region

Diabetic Retinopathy Screening Using a Portable Retinal Camera in Vanuatu

Background and Objective

Proof-of-concept study to test the feasibility of using an all-in-one portable retinal camera for the screening of diabetic retinopathy in the Pacific Island of Vanuatu, which has a high rate of diabetes and its associated complications and a dearth of ophthalmologists.

Study Design/Materials and methods

From February 10, 2020, through February 28, 2020, 49 patients with diabetes mellitus from three islands in Vanuatu were recruited to participate in the study. Demographics, basic health data and retinal photography were obtained. A non-mydriatic, handheld camera was used (Volk Pictor Plus).

Results

Eleven participants (24%) had referral-warranted diabetic retinopathy. There was moderately high inter-rater reliability for our dependent variables: referral status (κ = 0.62, 95% CI 0.42-0.83), retinopathy severity (κ = 0.76, 95% CI 0.55-0.96), and clinically significant macular edema (κ = 0.50, 95% CI 0.25-0.74).

Conclusion

Our study confirms that portable handheld cameras can be used to obtain retinal images of sufficient quality for diabetic retinopathy screening even in resource limited environments like Vanuatu. Among this cohort, a relatively high (24%) prevalence of referral-warranted diabetic retinopathy was found in Vanuatu.

Evaluation of vision screening of 5-15-year-old children in three Tongan schools: comparison of The Auckland Optotypes and Lea symbols

Background

Comprehensive vision screening programmes for children are an important part of public health strategy, but do not exist in many countries, including Tonga. This project set out to assess: (1) the functional vision of children attending primary schools in Tonga and (2) how a new recognition acuity test (The Auckland Optotypes displayed on a tablet computer) compares to use of a standardised eye chart in this setting.

Methods

Children from three Tongan primary schools were invited to participate. Acuity testing was conducted using a standardised recognition acuity chart (Lea symbols) and the tablet test displaying two formats of The Auckland Optotypes. Measures of ocular alignment, stereo acuity and non‐cycloplegic photorefraction were also taken.

Results

Parents of 249 children consented to participate. One child was untestable. Only 2.8 per cent of testable children achieved visual acuity worse than 0.3 logMAR in the weaker eye. Results from the Spot Photoscreener suggested that no children had myopia or hyperopia, but that some children had astigmatism. The tablet test was practical in a community setting, and showed ±0.2 logMAR limits of agreement with the Lea symbols chart.

Conclusion

The sample of children in Tongan primary schools had good functional vision. A modified version of the tablet acuity test is a promising option for vision screening in this context.

A systematic review of historical and contemporary evidence of trachoma endemicity in the Pacific Islands

INTRODUCTION

Trachoma is endemic in several Pacific Island countries. The aims of this study were to (a) identify future trachoma mapping needs in the Pacific and (b) to examine whether any temporal trends in trachoma prevalence could be ascertained from the historical literature on trachoma in the Pacific Islands.

METHODS

Human studies of trachoma and eye care in the Pacific Islands were identified from a systematic search of PubMed, EMbase, Scopus and Web of Science databases. A published quality assessment system for disease prevalence studies was modified to assess studies for quality and transparency.

RESULTS

Few general ophthalmic studies in the Pacific mention trachoma. In targeted studies of trachoma, cases have consistently been identified throughout the Pacific since the early twentieth century. The largest number of studies come from Papua New Guinea and Fiji, whereas some countries have no published data on trachoma. The majority of studies identified were published before the Alliance for the Global Elimination of Trachoma 2020 was convened, so lack the standardisation of population-based mapping which has been implemented in the past decade.

CONCLUSIONS

Population-based trachoma prevalence estimates have been recently generated in Papua New Guinea, Solomon Islands, Vanuatu, Kiribati and Fiji. There is insufficient evidence to assess whether there has been temporal change in trachoma prevalence in these countries over the past century. Cases of trachoma have been identified in some countries (for example, Nauru and Samoa) which have no recent population-based mapping data, but may be at risk of trachoma endemcitiy. Deployment of appropriate mapping strategies is warranted to identify whether interventions are required.

Screening for Diabetic Eye Disease among Samoan Adults: A Pilot Study

Introduction

The purpose of this study was to determine the prevalence of diabetic retinopathy in Samoa by piloting a retinal photography screening programme.

Methods

We performed a cross-sectional study of patients with diabetes who presented to the Tupua Tamasese Meaole eye clinic in Apia, Samoa, between May 2011 and September 2011. Study approval was granted by the National Health Service Board of Samoa, the Monash University Human Research Ethics Committee, and the study adhered to the Tenets of the Declaration of Helsinki. Following informed consent, data collection included patient demographics [age, area of residence (rural or urban)], type of diabetes, length of time since diagnosis, most recent random blood sugar and blood pressure levels. The subjects had three 45-degree retinal photographs taken in each eye with the Canon CR6-45NM camera. All gradable photographs were assessed for the presence of diabetic retinopathy or macular oedema using the International Clinical Diabetic Retinopathy Severity Scale and the International Clinical Diabetic Macular Oedema Severity scale, respectively.

Results

Two hundred and fourteen eyes from 107 subjects were examined during the study period, all of whom had type 2 diabetes mellitus. Diabetic retinopathy was present in 53.3% (114/214) of eyes, with 14.5% having proliferative retinopathy and 7.5% with severe non-proliferative retinopathy. Also, 25.2% (54/214) had some evidence of macular oedema with 11.7% (25/214) requiring treatment. A statistically significant relationship existed between the length of time since diagnosis and the severity of both retinopathy (p < 0.001) and macular oedema (p = 0.031). Blood pressure more than 150/85 mmHg was associated with higher levels of diabetic retinopathy (p = 0.03) and macular oedema (p = 0.02).

Conclusion

A comprehensive diabetic retinopathy screening programme is much needed in Samoa given the high prevalence of diabetic eye disease.

Prevalence and visual risk factors for falls in bilateral cataract patients in Ho Chi Minh City, Vietnam

PURPOSE

To determine the prevalence of falls in the 12 months prior to cataract surgery and examine the associations between visual and other risk factors and falls among older bilateral cataract patients in Vietnam.

METHODS

Data collected from 413 patients in the week before scheduled cataract surgery included a questionnaire and three objective visual tests.

RESULTS

The outcome of interest was self-reported falls in the previous 12 months. A total of 13% (n = 53) of bilateral cataract patients reported 60 falls within the previous 12 months. After adjusting for age, sex, race, employment status, comorbidities, medication usage, refractive management, living status and the three objective visual tests in the worse eye, women (odds ratio, OR, 4.64, 95% confidence interval, CI, 1.85-11.66), and those who lived alone (OR 4.51, 95% CI 1.44-14.14) were at increased risk of a fall. Those who reported a comorbidity were at decreased risk of a fall (OR 0.43, 95% CI 0.19-0.95). Contrast sensitivity (OR 0.31, 95% CI 0.10-0.95) was the only significant visual test associated with a fall. These results were similar for the better eye, except the presence of a comorbidity was not significant (OR 0.45, 95% CI 0.20-1.02). Again, contrast sensitivity was the only significant visual factor associated with a fall (OR 0.15, 95% CI 0.04-0.53).

CONCLUSION

Bilateral cataract patients in Vietnam are potentially at high risk of falls and in need of falls prevention interventions. It may also be important for ophthalmologists and health professionals to consider contrast sensitivity measures when prioritizing cataract patients for surgery and assessing their risk of falls.

Myopia prevention, near work, and visual acuity of college students: integrating the theory of planned behavior and self-determination theory

There has been little research examining the psychological antecedents of safety-oriented behavior aimed at reducing myopia risk. This study utilizes self-determination theory (SDT) and the theory of planned behavior (TPB) to understand the role of motivational and social-cognitive factors on individuals' near-work behavior. Adopting a prospective design, undergraduate students (n = 107) completed an initial questionnaire based on SDT in week 1, a second questionnaire containing measures of TPB variables in week 2, and objective measures of reading distance and visual acuity in week 6. The data were analyzed by variance-based structural equation modeling. The results showed that perceived autonomy support and autonomous motivation from SDT significantly predicted attitude, subjective norm, and perceived behavioral control from the TPB. These social-cognitive factors were significantly associated with intention and intention significantly predicted reading distance. The relationships in the model held when controlling for visual acuity. In conclusion, the integrated model of SDT and the TPB may help explain myopia-preventive behaviors.

A randomized, single-center study of equivalence of 2 intraocular lenses used in cataract surgery

PURPOSE

To compare the outcomes of 2 intraocular lenses (IOLs) for the treatment of age-related cataracts.

DESIGN

Prospective, randomized trial.

PARTICIPANTS

Patients with age-related cataracts were recruited and randomized to receive phacoemulsification and implantation of either the AcrySof SA60AT lens (Alcon, Inc, Fort Worth, TX) or the low-cost Tecsoft Flex lens (Fred Hollows Foundation, Tilganga, Nepal). A total of 300 patients were available for description and analysis (148 in the AcrySof group and 152 in the Tecsoft group).

METHODS

Patients underwent phacoemulsification and implantation of the AcrySof SA60AT lens or the Tecsoft Flex lens. They were followed up and examined at baseline, 1 week, 1 month, 6 months, and 12 months after cataract surgery.

MAIN OUTCOME MEASURES

Uncorrected distance visual acuity (UDVA), best-corrected distance visual acuity (BDVA), incidence of posterior capsule opacification (PCO), Visual Function Index questionnaire results, and safety of the implanted IOLs.

RESULTS

No significant difference (P>0.05) was found in UDVA and BDVA after surgery between the 2 groups. The equivalence test of the 95% confidence intervals showed that both lenses had an equal improvement of UDVA and BDVA as well as similar rates of PCO after cataract surgery. There was no significant difference between the 2 groups with regard to visual functioning or the incidence of adverse surgical events during (P>0.05) or after (P>0.05) the surgery.

CONCLUSIONS

The Tecsoft Flex IOL is a low-cost suitable alternative that is similar to the AcrySof IOL in terms of safety and visual outcomes.

Blindness in iraq: leading causes, target patients, and barriers to treatment

Purpose:

To define the main causes of blindness, demographic characteristics and barriers to care of blind patients attending a teaching eye hospital in Iraq.

Material and Method:

Successive new patients, 6 years of age and older, who attended three outpatients clinics at Ibn Al-Haetham Teaching Eye Hospital (IAHTEH), Baghdad, Iraq, from September 1 to November 30, 2007, were included in this study. Inclusion criterion was fulfillment of the World Health Organization's definition of blindness. The cause of blindness was identified and subjects were interviewed for collection of data on demographic characteristics and barriers to treatment.

Results:

Of 18612 consecutive patients who attended the outpatient clinics, 497 (2.7%) patients were blind. Cataract (76.1%), diabetic retinopathy (12.9%), and glaucoma (5%) were the leading causes of blindness. The majority of blind patients had low socioeconomic status and poor educational level. In cases of cataract, the most important barrier to treatment was the waiting list at the hospital (53.7%). A lack of awareness was the most important barrier to treatment for patients with diabetic retinopathy (54.7%) and glaucoma (56%).

Conclusions:

The preliminary data from our study will aid in the development of blindness prevention programs in Iraq. Priorities include decreasing waiting lists for cataract surgeries at governmental hospitals. Active health promotion programs for early detection and treatment of diabetic retinopathy and glaucoma are also warranted.

inVestIgating the pSychologIcal and ecONomic impAct of cataRact surgerY in Vietnam: The VISIONARY observational study protocol

Background

Visual impairment caused by cataracts not only affects an individual's quality of life but can also have a profound impact on other important psychological factors and on the economic circumstances of individuals and their households. Cataract surgery is an effective intervention to restore vision and is also associated with other positive consequences including improvements in quality of life, economic and psychological outcomes. While there has been an increase in the number and quality of cataract surgeries performed in Vietnam, the programs currently in place are still unable to meet the existing demand and need for surgery. Data on both the cost-effectiveness of cataract surgery and the economic and psychological impact of untreated cataract in this setting is lacking.

Methods/Design

This study, investigating the psychological and economic impact of cataract surgery in Vietnam (VISIONARY), will recruit and interview a sample of adults (18 years or over) who are referred for cataract surgery by one of the following sites and their outreach programs: Hue Eye Hospital; Thai Binh Eye Hospital; Binh Dinh Department of Health Eye Hospital and the Vinh Long Department of Health Social Disease Centre. All participants (those who have cataract surgery and those who do not have surgery) will be followed up at six and 12 months.

Discussion

This study is designed to examine the impact of low vision on household economic circumstances and psychological outcomes as well as to investigate the effectiveness and cost-effectiveness of cataract surgery in Vietnam. It will help to inform international and national non-government organisations working in the country and local policy-makers on priorities for further investment in eye-health services in this setting and their relevance to broader economic development goals.

Prevalence of chronic ocular diseases in a genetic isolate: the Norfolk Island Eye Study (NIES)

PURPOSE

Over 40% of the permanent population of Norfolk Island possesses a unique genetic admixture dating to Pitcairn Island in the late 18(th) century, with descendents having varying degrees of combined Polynesian and European ancestry. We conducted a population-based study to determine the prevalence and causes of blindness and low vision on Norfolk Island.

METHODS

All permanent residents of Norfolk Island aged ≥ 15 years were invited to participate. Participants completed a structured questionnaire/interview and underwent a comprehensive ophthalmic examination including slit-lamp biomicroscopy.

RESULTS

We recruited 781 people aged ≥ 15, equal to 62% of the permanent population, 44% of whom could trace their ancestry to Pitcairn Island. No one was bilaterally blind. Prevalence of unilateral blindness (visual acuity [VA] < 6/60) in those aged ≥ 40 was 1.5%. Blindness was more common in females (P=0.049) and less common in people with Pitcairn Island ancestry (P<0.001). The most common causes of unilateral blindness were age-related macular degeneration (AMD), amblyopia, and glaucoma. Five people had low vision (Best-Corrected VA < 6/18 in better eye), with 4 (80%) due to AMD. People with Pitcairn Island ancestry had a lower prevalence of AMD (P<0.001) but a similar prevalence of glaucoma to those without Pitcairn Island ancestry.

CONCLUSIONS

The prevalence of blindness and visual impairment in this isolated Australian territory is low, especially amongst those with Pitcairn Island ancestry. AMD was the most common cause of unilateral blindness and low vision. The distribution of chronic ocular diseases on Norfolk Island is similar to mainland Australian estimates.

Survey on Visual Impairment and Refractive Errors on Ta'u Island, American Samoa

PURPOSE

To assess the prevalence of presenting visual impairment and refractive errors on the isolated island of Ta'u, American Samoa.

METHODS

Presenting visual acuity and refractive errors of 124 adults over 40 years of age (55 male and 69 female) were measured using the Snellen chart and an autorefractometer. This sample represented over 50% of the island's eligible population.

RESULTS

In this survey, all presenting visual acuity (VA) was uncorrected. Of the included sample, 10.5% presented with visual impairment (visual acuity lower than 6/18, but equal to or better than 3/60 in the better eye) and 4.8% presented with VA worse than 6/60 in the better eye. Overall, 4.0% of subjects presented with hyperopia (+3 D or more), 3.2% were myopic (-1 D or less), and 0.8% presented with high myopia (-5 D or less). There was no significant difference between genders in terms of visual impairment or refractive errors.

CONCLUSION

This study represents the first population-based survey on presenting visual acuity and refractive errors in American Samoa. In addition to providing baseline data on vision and refractive errors, we found that the prevalence of myopia and hyperopia was much lower than expected.

Volunteer-based vision nongovernmental organizations and VISION 2020

BACKGROUND

The World Health Organization and the International Agency for the Prevention of Blindness developed the global initiative, VISION 2020, with the goal of eliminating avoidable blindness by 2020. An unknown number of volunteer-based organizations conduct short-term vision camps as a means of eliminating blindness in developing countries.

METHODS

VISION 2020 strategies are reviewed and volunteer organizations' understanding of VISION 2020 and methods of service delivery are considered through survey results.

RESULTS

From the surveys it is apparent that volunteer organizations are not aware of the VISION 2020 initiative and do not conduct their projects and programs in a way that is supported by VISION 2020.

CONCLUSION

Volunteer organizations have the skills, resources, and enthusiasm to make an impact on the burden of visual impairment. They do not, however, follow strategies accepted as most appropriate by the larger global eye health care community. Volunteer organizations are encouraged to reprioritize the work they do and change the methods they use.

Eye disease and care at hospital clinics in Cook Islands, Fiji, Samoa and Tonga

PURPOSE

To obtain eye disease and care data to assist with service planning in Cook Islands, Fiji, Samoa and Tonga.

METHODS

A hospital-based rapid assessment including interviews and examination of clinical records.

RESULTS

An overview of equipment, staff and services was attained. Visual impairment was associated with increasing age but not gender of clinic attendees. Cataract was the most common cause of low vision and blindness. A substantial proportion of visually significant cataract, particularly that causing low vision but not blindness, was not offered treatment. The vision outcome of cataract surgery in Fiji was less successful than elsewhere. Only Samoa achieved the World Health Organization suggested outcomes. Refractive error was a significant cause of low vision, but poorly treated. Diabetic retinopathy was a substantial contributor to visual impairment at all locations except the Cook Islands, but not all was treated with laser. Trauma/corneal opacity was an important cause of blindness in Cook Islands and Tonga. Pterygium-induced low vision and glaucoma blindness were diagnosed most frequently in Samoa.

DISCUSSION

This methodology enabled quick and cost-efficient collection of data about hospital eye services, the conditions diagnosed and treated, and the outcome of treatment. It could easily be repeated by local clinicians to measure the impact of service planning and implementation. In the four countries audited, the management of, and intervention outcomes for, cataract, refractive error, diabetic retinopathy and trauma need attention.

Protecting children from myopia: a PMT perspective for improving health marketing communications

This research examined the predictive utility of the protection motivation theory (PMT) model for myopia prevention amongst children. An integrative model for myopia prevention behavior of parents was first developed in the context of theory and survey instruments then refined using information gathered from two focus groups. Empirical data then was collected from parents of primary school children in Singapore, a country with one of the highest rates of myopia in the world, and analyzed using structural equation modeling (SEM). Our findings revealed that coping appraisal variables were more significantly associated with protection motivation, relative to threat appraisal variables. In particular, perceived self-efficacy was the strongest predictor of parental intention to enforce good visual health behaviors, while perceived severity was relatively weak. Health marketing communications and public policy implications are discussed.

An assessment of recycled spectacles donated to a developing country

BACKGROUND

A rapid assessment methodology was used to determine the suitability of donated recycled spectacles for the Pacific nation of Tuvalu.

METHODS

Spectacles (102) from a donated cache were examined. Those with astigmatism of > 1.00 D, anisometropia of > 0.50 D, significant central lens scratches, broken frame, poor cosmetic fit and comfort, or unsuitable frame appearance were excluded. The refractive errors (> or = +/-0.50 D distance or near) of 320 Tuvaluans were determined.

RESULTS

Of the spectacles, 62.7% had > 1.00 DC and/or > 0.50 D anisometropia, 30% were broken and/or scratched and 50% were uncomfortable or cosmetically unacceptable. Only 13% were optically satisfactory, physically intact, and cosmetically appropriate. Of the people, 8.8% had > 1.00 DC and/or > 0.50 D anisometropia, requiring custom-made spectacles. A further 8.1% needed a -0.50 to -2.00 DS correction, for which there were no spectacles in this cache. For the other 83.1% (266), if the cache contained at least 5538 spectacles, each would eventually find a suitable pair.

CONCLUSION

If the scheme to Tuvalu is typical, refractive error will remain largely uncorrected if only donated recycled spectacles are available. No amount of efficiency and effectiveness in the delivery chain can justify the output and outcome of this recycling scheme.

The prevalence and severity of diabetic retinopathy, associated risk factors and vision loss in patients registered with type 2 diabetes in Luganville, Vanuatu

AIM

To determine the prevalence and severity of diabetic retinopathy in patients with type 2 diabetes in Luganville, the second largest town in Vanuatu. Additionally, to investigate risk factors for retinopathy and the effect of retinopathy on visual acuity (VA) within this group.

METHOD

All 83 registered patients with type 2 diabetes in Luganville, a town of 13 121 people, were invited for an interview and anthropometric measurements. A questionnaire including assessment of hypertension and glycaemic control, which are known risk factors for diabetic retinopathy, was administered. This sample accounted for approximately 1.07% of Luganville's adult population. Presenting VA was measured. The retina was photographed with a non-mydriatic fundus camera and images later independently graded for the extent of retinopathy.

RESULTS

68 (82%) of the 83 patients attended. The mean (SD) age was 54 (11) years and 31 (46%) were male. Diabetic retinopathy was present in 36 (52.9%) of the sample. Sight-threatening retinopathy requiring urgent referral was present in 15 (22.1%) patients. Presenting VA was worse than 6/12 in the better eye in n = 32 (47%) and in up to half of these cases the principal cause was retinopathy. In addition, four people had uniocular blindness resulting from diabetes. The mean body mass index was lower in those patients with diabetes with retinopathy than in those without (p = 0.010), but there were no other significant differences between the two groups and, specifically, no difference in the frequency of retinopathy risk factors. 42 (61.8%) patients had hypertension (>or=135/85 mm Hg) or were taking antihypertensive therapy.

CONCLUSIONS

The prevalence of registered patients with diabetes in Luganville's adult population was 1.07%. Diabetic retinopathy was highly prevalent in the sample (in 36, 52.9%), and in 15 (22.1%) there was a significant threat to sight, with up to 25% of the sample possibly already affected by decreased VA or blindness resulting from diabetes-related eye disease. Retinopathy risk factors were also prevalent. A diabetes screening programme with baseline ophthalmic assessment and follow-up are urgently needed to enable timely intervention and treatment.

Comparison of age-specific cataract prevalence in two population-based surveys 6 years apart

Background

In this study, we aimed to compare age-specific cortical, nuclear and posterior subcapsular (PSC) cataract prevalence in two surveys 6 years apart.

Methods

The Blue Mountains Eye Study examined 3654 participants (82.4% of those eligible) in cross-section I (1992–4) and 3509 participants (75.1% of survivors and 85.2% of newly eligible) in cross-section II (1997–2000, 66.5% overlap with cross-section I). Cataract was assessed from lens photographs following the Wisconsin Cataract Grading System. Cortical cataract was defined if cortical opacity comprised ≥ 5% of lens area. Nuclear cataract was defined if nuclear opacity ≥ Wisconsin standard 4. PSC was defined if any present. Any cataract was defined to include persons who had previous cataract surgery. Weighted kappa for inter-grader reliability was 0.82, 0.55 and 0.82 for cortical, nuclear and PSC cataract, respectively. We assessed age-specific prevalence using an interval of 5 years, so that participants within each age group were independent between the two surveys.

Results

Age and gender distributions were similar between the two populations. The age-specific prevalence of cortical (23.8% in 1^st, 23.7% in 2^nd) and PSC cataract (6.3%, 6.0%) was similar. The prevalence of nuclear cataract increased slightly from 18.7% to 23.9%. After age standardization, the similar prevalence of cortical (23.8%, 23.5%) and PSC cataract (6.3%, 5.9%), and the increased prevalence of nuclear cataract (18.7%, 24.2%) remained.

Conclusion

In two surveys of two population-based samples with similar age and gender distributions, we found a relatively stable cortical and PSC cataract prevalence over a 6-year period. The increased prevalence of nuclear cataract deserves further study.