Pattern of vitreo-retinal diseases at the national referral hospital in Bhutan: a retrospective, hospital-based study

Functional diabetic retinopathy: A new concept to improve management of diabetic retinal diseases

Multifocal functional tests are not routinely performed in diabetic retinopathy (DR) and diabetic macular edema (DME) management. We emphasise their importance and coin the term functional diabetic retinopathy (FDR). We reviewed current guidelines on management of DR/DME, and literature on diabetic retinal neurodegeneration (DRN) and functional deficits in DR/DME. Functional visual loss due to DRN precedes vasculopathy and clinical DR; however, currently the diagnosis and management of DR/DME are based on classical signs of retinal vasculopathy and structural changes shown by funduscopy, fundus photographs, and optical coherence tomography (OCT). Furthermore, DME can mask DRN-based retinal layer thinning by OCT and is focussed on the macular region. The only functional test recommended in national and international guidelines on DR/DME is best-corrected visual acuity, a test of foveal function (<1 % of retina). Multifocal functional tests can objectively characterize both foveal and extrafoveal, localized and global, function. Current recommendations for DR/DME screening are inadequate to detect FDR affecting the greater retina. Early detection of FDR using multifocal functional tests could bring DR/DME management strategies forward enabling prevention of the later stage vision-threatening complications. After all, the end point of patient care is functional outcomes.

Pattern and Prevalence of Retinal Vein Occlusion in Bhutan: A 3-Year National Survey at Vitreoretinal Clinics

Purpose

We conducted this study to determine the pattern and prevalence of retinal vein occlusion (RVO) in Bhutan to inform national health policy as no data has been compiled previously.

Methods

A retrospective cross-sectional survey was conducted over 3 years, including all new RVO cases. For patients with bilateral RVO, one eye was chosen randomly. Demographic, clinical, and diagnostic details, including optical coherence tomography, fluorescein angiography, and fundus photography, were collected.

Results

Of 141 RVO new patients included, aged 50.5 ± 20.2 years, there were more males (62.4%) than females (37.6%) significantly (p = 0.031), and 59.6% of total patients were from an urban setting. Farmers were the most affected group (44, 31.2%), followed by housewives (34, 24.1%), and the working group (33, 23.4%). Blurry vision (64, 45.5%), sudden loss of vision (17, 12.1%), including unsatisfactory cataract surgery (8, 5.7%) were common presenting complaints. Systemic hypertension (HT) (36, 25.5%), and diabetes mellitus (DM) (17, 12.1%), were associated systemic diseases. The prevalence of RVO was 4.8% (141/2913 all new retinal patients over the survey). Branch RVO (BRVO) was the most common type (77, 54.6%), followed by central RVO (CRVO) 56, (39.7%), and hemi-central RVO (HCRVO) (8, 5.7%). Superotemporal BRVO was the most common subtype (30, 39%) followed by inferotempoal (19, 24.7%). Best correct visual acuity (BCVA) was worse than 6/60 in 38 eyes (25.5%). BCVA was not significantly different between BRVO and CRVO eyes. Intraocular pressure was significantly lower in HCRVO eyes (p = 0.015) compared to BRVO and CRVO eyes.

Conclusion

In Bhutan, 8.5% of RVO patients were bilateral. HT was associated significantly as a risk factor. Incidental findings of RVO during routine eye check-up and evaluating for unsatisfactory cataract surgery were common. Therefore, Bhutan needs to control noncommunicable diseases such as diabetes and HT to reduce RVO, and RVO-related blindness and complications.

Comparing 2-dimensional macular pigment optical density with objective and subjective perimetry and visual acuity in age-related macular degeneration

PURPOSE

To compare diagnostic power for different severities of age-related macular degeneration (AMD) of two-dimensional macular pigment optical densities (2D-MPOD) and spatially matched objective perimetry, with standard perimetry and best-corrected visual acuity (BCVA).

METHODS

The ObjectiveField Analyser (OFA) provided objective perimetry, and a Heidelberg Spectralis optical coherence tomography (OCT) measured 2D-MPOD in AMD patients, both completed twice over 0.99 ± 0.16 years. From each 2D-MPOD image, we extracted 20 regions/macula, matched to the 20 OFA stimuli/macula. For each region, we calculated 7 measures from the 2D-MPOD pixel values and correlated those with OFA sensitivities and delays. We quantified 2D-MPOD changes, the ability of 2D-MPOD and OFA to discriminate AMD stages, and the discriminatory power of Matrix perimetry and BCVA using percentage area under receiver operator characteristic plots (%AUROC).

RESULTS

In 58 eyes of 29 subjects (71.6 ± 6.3 years, 22 females), we found significant correlations between 2D-MPOD and OFA sensitivities for Age-Related Eye Disease Studies (AREDS)-3 and AREDS-4 severities. Delays showed significant correlations with AREDS-2. For AREDS-4, correlations extended across all eccentricities. Regression associated with the Bland-Altman plots showed significant changes in 2D-MPOD over the study period, especially variability measures. MPOD per-region medians discriminated AREDS-1 from AREDS-3 eyes at a %AUROC of 80.0 ± 6.3%, outperforming OFA, Matrix perimetry, and BCVA.

CONCLUSIONS

MPOD changes correlated with central functional changes and significant correlations extended peripherally in later-stage AMD. Good diagnostic power for earlier-stage AMD and significant change over the study suggest that 2D-MPOD and OFA may provide effective biomarkers.

Association between HDL cholesterol with diabetic retinopathy in diabetic patients: a cross-sectional retrospective study

OBJECTIVE

Diabetic patients are often comorbid with dyslipidemia, however, the relationship between high-density lipoprotein cholesterol(HDL-C) and diabetic retinopathy (DR) in the adult diabetic population remains to be fully elucidated.The aim of this study is to evaluate the associations between HDL-C and DR in the United States adults with diabetes.

METHODS

A total of 1708 participants from the National Health and Nutrition Examination Survey (NHANES) 2005-2008 were enrolled in the present study. Fundus images of all study subjects were captured and evaluated using a digital camera and an ophthalmic digital imaging system, and the diagnosis of DR was made by the severity scale of the Early Treatment Diabetic Retinopathy Study (ETDRS).Roche Diagnostics were used to measure serum HDL-C concentration. The relationship of DR with HDL-C was investigated using multivariable logistic regression. The potential non-line correlation was explored with smooth curve fitting approach.

RESULTS

The fully-adjusted model showed that HDL-C positively correlated with DR(OR:1.69, 95%CI: 1.25-2.31).However, an inverted U-shaped association between them was observed by applying the smooth curve fitted method. The inflection point of HDL-C(1.99mmol/l) was calculated by utilizing the two-piecewise logistic regression model. In the subgroup analysis, the inverted U-shaped nonlinear correlation between HDL-C and DR was also found in female, Non-Hispanic White, and lower age groups.

CONCLUSION

Our study revealed an inverted U-shaped positive relationship between HDL-C and DR.The findings may provide us with a more comprehensive understanding of the association between HDL-C and DR.

Early diabetic eye damage: Comparing detection methods using diagnostic power

It is now clear that retinal neuropathy precedes classical microvascular retinopathy in diabetes. Therefore, tests that underpin useful new endpoints must provide high diagnostic power well before the onset of moderate diabetic retinopathy. Hence, we compare detection methods of early diabetic eye damage. We reviewed data from a range of functional and structural studies of early diabetic eye disease and computed standardized effect size as a measure of diagnostic power, allowing the studies to be compared quantitatively. We then derived minimum performance criteria for tests to provide useful clinical endpoints. This included the criteria that tests should be rapid and easy so that children with type 1 diabetes can be followed into adulthood with the same tests. We also defined attributes that lend test data to further improve performance using Machine/Deep Learning. Data from a new form of objective perimetry suggested that the criteria are achievable.

Profile of Patients Treated with Intravitreal Anti-Vascular Endothelial Growth Factor Injections in Bhutan

Purpose

Ocular vascular diseases are common causes of visual impairment and blindness, for which anti-vascular endothelial growth factor (anti-VEGF) is the first-line therapy. Current study describes the profile of patients receiving intravitreal anti-VEGF injections (IVI), and gender variation in Bhutan. The study was designed to inform national health policy.

Study Design

Retrospective cross-sectional study.

Methods

We reviewed the surgical registers of the vitreoretinal (VR) units across Bhutan over three years. Patient demography, clinical findings, diagnostic tests performed, and diagnoses or indications for IVI were logged. A descriptive analysis was performed.

Results

Despite limited availability of anti-VEGF, a total of 381 patients received IVI in operating theatres as mandated by the national guidelines. The majority of patients were males (230, 60.4%, p = 0.004). The mean age was 65.2 ± 13.5 years (range 13 years to 90 years), and a median of 69 years. The majority of the treated eyes (117, 30.7%) had BCVA <3/60 to light perception (PL), and another 51 eyes (13.4%) had < 6/60 to 3/60. The most common indication for IVI was neovascular age-related macular degeneration (nAMD) (168 cases, 42.2%), followed by retinal vein occlusion (RVO) (132 cases, 34.6%), diabetic macular oedema (DMO) and retinopathy (DR) (50 cases, 13.1%), and myopic choroidal neovascular membrane (11 cases, 0.03%).

Conclusion

Limited human resources for managing VR diseases in Bhutan are compounded by economic and geographic challenges. With increasing VR diseases such as nAMD and myopia and complications of systemic diseases such as DR, DMO and RVO, there is a need to improve VR services. Currently, anti-VEGF is procured only for a pooled patients requiring IVI, and patients are lost due to longer waiting periods. Bhutan needs to assess if females are reporting less or are not receiving treatment due to cultural barriers and social stigma.

Prevalence and severity of diabetic retinopathy at first presentation to vitreoretinal services in Bhutan: a 3-year national study

PURPOSE

To determine the prevalence and severity of diabetic retinopathy (DR) at first presentation among diabetic patients attending national vitreoretinal (VR) services in Bhutan STUDY DESIGN: Retrospective cross-sectional study METHODS: We included all diabetic patients in Bhutan who presented for retinal evaluation for the first time over a 3-year period (2013-2016). Data including demography, clinical details, diagnostic tests, and clinical staging of DR were analyzed.

RESULTS

A total of 843 diabetic patients, aged 57.2 ± 12.0 (range 18-86) years, were enrolled. The majority were male (452, 53.6%; cumulative frequency [cf] 391, 46.4%; P = .14) and from urban settings (570, 67.6%; cf 273; 32.4%) and did not have modern schooling (555, 65.8%). Hypertension was the most common systemic comorbidity (501, 59.4%). The prevalence of DR was 42.7%, with mild nonproliferative DR (NPDR) being the most common type (187, 51.9%), followed by moderate NPDR (88, 24.4%) and proliferative DR (45, 12.5%). In addition, 120 patients had clinically significant macular edema (CSME), with a prevalence of 14.2%. Best-corrected visual acuity (BCVA) of 6/60 or worse occurred in 231 eyes (13.7%), and 41 patients (4.86%) had BCVA of 6/60 or worse bilaterally due to DR/CSME. A logistic regression model indicated that the major determinant of DR was the duration of diabetes, the odds rising by 1.27× with each year of disease (P < .0001).

CONCLUSION

The prevalence of DR, including CSME, was high. Although a national DR screening program is established in Bhutan, there is a need to accelerate health education, community screening, and referral systems to reduce the prevalence of DR and CSME.

Incidence and Pattern of Neuro-Ophthalmological Disorders Presenting to Vitreoretinal Clinics in Bhutan: A 3-Year National Study

Purpose

To inform national health policy, we quantified the pattern of neuro-ophthalmological disorders (NODs) presenting to the national vitreoretinal clinics in Bhutan.

Study Design

Retrospective cross-sectional study.

Methods

We reviewed all new NODs patients over three years. Demographic data, presenting complaints, treatment history, systemic diseases, diagnostic procedures, and diagnoses were quantified. Logistic regression examined the odds of factors linked to more common NODs.

Results

Of 226 patients, the majority were males (54.0%), farmers (60.2%), and urbanites (55.8%). Loss of vision was the most common presenting complaint (57.9%), followed by head or orbital trauma (19.5%). The best corrected visual acuity (BCVA) of 216 eyes (47.8%) was ≤6/60. Hypertension was the most common systemic disease (16.4%), followed by diabetes (3.5%), and intracranial space-occupying lesions (3.5%). Neuroimaging (37.6%) was the most common diagnostic test performed, followed by visual field testings (VFTs) (22.9%). With a NOD incidence of 7.8% p.a. (226/2913), optic atrophy (OA) was diagnosed in 134 patients (59.3%). Other common NODs were optic neuritis (15.5%), papilloedema (9.3%), and traumatic optic neuropathy (8.4%). Female gender increased the odds for glaucomatous OA by 2.65× (p = 0.044), and age by 1.09× per year (p < 0.001). Being female increased the odds of optic neuritis by 2.57× (p = 0.03).

Conclusion

Over half of the NODs were OA, which could be curable with timely treatment. Improved treatment of glaucoma and non-communicable diseases would reduce the risk of NODs-induced visual loss in Bhutan. The need for improved neuro-ophthalmological assessment and a coordinated multidisciplinary approach to NODs are the highest priorities.

Classification of Seasonal Hyperacute Panuveitis (SHAPU)

INTRODUCTION

Classification are essential part of scientific methodology and has important role in medical reporting system. Even after having 46 years long history, Seasonal Hyperacute Panuveitis (SHAPU), the blinding diseases reported mainly from Nepal lacks a standard classification system. Thus, we aim to contribute in the ophthalmic nosology by purposing a classification system for SHAPU.

METHODOLOGY

The classification is suggested on the background of prolonged experience of this entity by the group of investigators who have dedicated years of research on this topic.

CONCLUSION

We are optimistic that the proposed classification system will help in effective planning and evaluation of this ocular emergency condition and deliver the appropriate and reliable information for timely management and prevention of complications.

Monoclonal Antibodies: A Therapeutic Option for the Treatment of Ophthalmic Diseases of the Eye Posterior Segment

The eye is an organ that allows us to observe the outside world. Pathologies of the eye's posterior segment, such as glaucoma, macular degeneration, diabetic retinopathy, uveitis, and retinoblastoma, cause vision loss. Traditional treatments consist of applying topical medications that do not penetrate properly or using high doses that generate adverse effects. Different laser surgeries stop the pathology's progression but do not allow visual improvement. So, an alternative is to use monoclonal antibodies, proteins produced by different processes that selectively bind to metabolites associated with diseases, reducing the adverse effects of traditional treatments and improving the application of the drug in the area. The two main molecular targets are TNF (adalimumab, infliximab, and certolizumab pegol) and VEGF (bevacizumab and ranibizumab); other possibilities are under investigation.

Severity of age-related macular degeneration at first presentation in Bhutan: a 3-year national study

Background

Medical services are still developing in Bhutan. There is no published national report on age-related macular degeneration (AMD). We therefore aim to determine the demographic characteristics and severity of AMD at first presentation among Bhutanese patients attending their recently inaugurated vitreoretinal (VR) clinics over a 3-year national survey, and to inform national health policy to develop suitable health program to prevent AMD-related blindness and visual impairment.

Methods

A retrospective cross-sectional consecutive case series study was conducted on all new AMD cases in Bhutan. If a patient presented with asymmetrical AMD, the eye with more severe AMD was considered. If both the eyes had the same severity one eye was chosen randomly. Collection of demographic data and clinical details including diagnostic testing (fundus photography, OCT and fluorescent angiography) and clinical staging were performed.

Results

Of 521 new AMD patients aged 71.9 ± 11.3 years, 306/521 (58.7%) were males (p = 0.005). At their first presentation, 234/521 patients (44.9%) already had late-stage AMD. Importantly, 69/234 patients (29.5%), that is half of total neovascular AMD (nAMD) patients, had disciform scars (DS) which were beyond treatment, and 7/234 patients (3.0%) had geographic atrophy (GA). Seven patients had retinal pigment epithelium tear at presentation. Fourteen of nineteen polypoidal choroidal vasculopathy (PCV) patients were younger than 50 years.

Conclusions

Half of nAMD cases presented as DS not amenable to the treatment. Many potentially treatable nAMD patients had already lost central vision and were legally blind. Young people with PCV losing vision early in life with longer morbidity-affected life and socio-economic burden was concerning. GA and DS cases need visual rehabilitation to improve their QoL. Incorporating a screening program for AMD with effective health education, and maintaining a national AMD Registry, would potentially lower AMD-related blindness and visual impairment.

Rapid Objective Testing of Visual Function Matched to the ETDRS Grid and Its Diagnostic Power in Age-Related Macular Degeneration

Purpose

To study the power of an 80-second multifocal pupillographic objective perimetry (mfPOP) test tailored to the ETDRS grid to diagnose age-related macular degeneration (AMD) by Age-Related Eye Disease Study (AREDS) severity grade.

Design

Evaluation of a diagnostic technology.

Methods

We compared diagnostic power of acuity, ETDRS grid retinal thickness data, new 80-second M18 mfPOP test, and two wider-field 6-minute mfPOP tests (Macular-P131, Widefield-P129). The M18 stimuli match the size and shape of bifurcated ETDRS grid regions, allowing easy structure–function comparisons. M18, P129, and P131 stimuli test both eyes concurrently. We recruited 34 patients with early-stage AMD with a mean ± standard deviation (SD) age of 72.6 ± 7.06 years. The M18 and P129 plus P131 stimuli had 26 and 51 control participants, respectively with mean ± SD ages of 73.1 ± 8.17 years and 72.1 ± 5.83 years, respectively. Multifocal pupillographic objective perimetry testing used the Food and Drug Administration-cleared Objective FIELD Analyzer (OFA; Konan Medical USA).

Main Outcome Measures

Percentage area under the receiver operator characteristic curve (AUC) and Hedge’s g effect size.

Results

Acuity and OCT ETDRS grid thickness and volume produced reasonable diagnostic power (percentage AUC) for AREDS grade 4 eyes at 83.9 ± 9.98% and 90.2 ± 6.32% (mean ± standard error), respectively, but not for eyes with less severe disease. By contrast, M18 stimuli produced percentage AUCs from 72.8 ± 6.65% (AREDS grade 2) to 92.9 ± 3.93% (AREDS grade 4), and 82.9 ± 3.71% for all eyes. Hedge’s g effect sizes ranged from 0.84 to 2.32 (large to huge). Percentage AUC for P131 stimuli performed similarly and for P129 performed somewhat less well.

Conclusions

The rapid and objective M18 test provided diagnostic power comparable with that of wider-field 6-minute mfPOP tests. Unlike acuity or OCT ETDRS grid data, OFA tests produced reasonable diagnostic power in AREDS grade 1 to 3 eyes.

Prevalence of diabetic macular edema based on optical coherence tomography in people with diabetes: A systematic review and meta-analysis

Diabetic macular edema (DME) is a leading cause of vision loss among people with diabetes. Optical coherence tomography (OCT) allows for accurate assessment and early detection of DME. Meta-analyses on DME prevalence diagnosed with OCT are lacking. We performed a meta-analysis to assess the global prevalence of OCT-diagnosed DME. We searched five electronic databases (EMBASE, CINAHL, Web of Science, Scopus, and MEDLINE) on May 29, 2020 and updated the search on March 19 and June 22, 2021. The quality of retrieved studies was evaluated using the Joanna Briggs Institute Checklist for Prevalence Studies. A random-effects model was used to pool prevalence estimates. Countries were classified into low-to-middle-income and high-income countries using World Bank data for subgroup analyses. Seven studies were included in this meta-analysis. The pooled prevalence of DME was 5.47% (95% CI: 3.66%-7.62%) overall, 5.81% (95% CI: 0.07%-18.51%) in low-to-middle-income countries and 5.14% (95% CI: 3.44%-7.15%) in high-income countries. We reported approximately 5.5% of people with diabetes have DME, with a statistically non-significantly lower prevalence in high-income countries versus low-to-middle-income countries. Given the global pandemic of diabetes, there is a need to inform physicians and educate people with diabetes regarding early detection and treatment of DME using OCT.

Development of Diabetic retinopathy screening guidelines in South-East Asia region using the context, challenges, and future technology

Objective: To formulate guidelines for screening of diabetic retinopathy (DR) for the World Health Organization (WHO) South-East Asia Region (SEAR) aligned with the current infrastructure and human resources for health (HRH).Design: A consultative group discussion of technical experts of the International Agency for the Prevention of Blindness (IAPB) from SEAR.Participants: IAPB country chairs and DR technical experts from SEAR countries.Methods: Data related to DR in SEAR was collected from published literature on available DM and DR guidelines and the participating experts. The 10 SEAR countries (the Democratic Republic of Korea was not included for lack of sufficient data) were divided into 3 resource levels (low, medium, and high) based on gross national income/per capita, cataract service indicators (cataract surgical rate and cataract surgical service), current infrastructure and available HRH. Two countries each were assigned to low (Myanmar, Timor-Leste) and high resource (India, Thailand) levels, and the remaining 6 countries (Bangladesh, Bhutan, Indonesia, Maldives, Nepal, Sri Lanka) were assigned the medium resource level. The DR care system was divided into 3 levels of care (essential, recommended, and desirable) and 3 levels of service delivery (primary, secondary, and tertiary).Main outcome measures: Primary, secondary, and tertiary level guidelines for screening of DRResults: Nine WHO SEAR countries participated in the formulation of the new country-specific DR screening guidelines. The DR screening recommendations were: advocacy at the community level, visual acuity measurement, and non-mydriatic fundus photography at the primary level, comprehensive eye examination and retinal laser at the secondary level, and intravitreal therapy and vitrectomy at the tertiary level. The systemic care of DM and hypertension are recommended at all levels commiserating with their care capabilities.Conclusions: The DR guidelines for the SEAR region are the first region-specific and resource-aligned recommendations for comprehensive DR care in each country of the region. In the future, the new technological advances in retinal camera technology, teleophthalmology, and artificial intelligence should be included within the structure of the public DR care system.

Retinal laser services in Bhutan: a 3-year national survey

BACKGROUND

We conducted this study to report on the indications and types of retinal laser therapy (RLT) performed in Bhutan, knowing which is critical for proper planning and successful delivery of the services.

METHODS

We reviewed the laser registers maintained in the laser rooms and vitreoretinal (VR) operating theatres (including paediatric cases managed under anaesthesia) over three years at the national and the two regional referral hospitals (RRHs). Intraoperative laser treatments (endolaser) were excluded. Patient demography, indications and types of RLT were recorded and quantified. Comparisons of the expected and observed frequencies used Chi-squared tests.

RESULTS

A total of 685 patients, including 8 cases of bilateral retinopathy of prematurity (ROP) received RLT. The majority of patients (411 cases, 60.0%, p < 0.0001) were males. The mean age was 54.1 ± 14.1 years, median 56 years. The most common indications for RLT were diabetic retinopathy (DR) and diabetic macular oedema (DMO) (542 cases, 66.0%), followed by retinal vein occlusion (RVO) (91 cases, 13.3%). Pan-retinal photocoagulation was the most common type of RLT performed (337 cases, 49.2%), followed by modified grid laser (207 cases, 30.2%), sectoral laser (41 cases, 6.0%), and prophylactic laser photocoagulation (33 cases, 4.8%).

CONCLUSIONS

The majority of patients were within working-age. Common indications for RLT were preventable such as DR, DMO and RVO, indicating need to control systemic diseases such as diabetes, hypertension, and dyslipidaemia. Currently, regular RLT is provided only at the national referral hospital in Thimphu, and periodically in the eastern and central RRHs when the retinal specialist visits. There is need to extend the retinal services to the eastern and central RRHs to improve accessibility and patient coverage in these regions challenged with difficult terrain and poor public transport system.

Prevalence, Pattern and Risk Factors of Retinal Diseases Among an Elderly Population in Nepal: The Bhaktapur Retina Study

Introduction

Retinal diseases are an emerging cause of visual impairment in the developing world. The aim of this study was to explore the prevalence, pattern, and risk factors of retinal diseases in Nepal.

Methods

This is a population-based, cross-sectional study conducted from 2013 to 2015. The sample size was 2100 subjects age 60 years and above from 30 clusters of Bhaktapur district, Nepal. Detailed history, visual acuity, and anterior and posterior segment examinations were performed. Blood sugar and blood pressure were measured.

Results

Complete information was available for 1860 (88.57%) subjects. Mean age was 69.64±7.31 years, ranging from 60 to 95 years. The prevalence of any retinal disorder was 52.37% (95% confidence interval (CI): 50.07–54.66%). The prevalence of retinal disorders increased with ageing: 51.26% between 60 and 69 years and 53.05% among those age 80 years and above. Age-related macular degeneration (AMD) was the most common retinal disease (35.43%), followed by hypertensive retinopathy (4.35%), epiretinal membrane (ERM) (3.66%), branch retinal vein occlusion (BRVO) (2.90%), and diabetic retinopathy (DR) (2.15%). Other rare retinal disorders included myopic fundus (0.86%), chorioretinal scar (0.54%), retinal holes (0.32%), retinitis pigmentosa (0.32%), retinal detachment (0.16%), and coloboma (0.11%). In multivariate logistic regression analysis, those with prior cataract surgery (odds ratio (OR), 1.71; 95% CI: 1.32–2.22, p < 0.001) and systemic hypertension (OR, 1.21; 95% CI: 1.001–1.47, p = 0.049) had significantly increased retinal disorders.

Conclusion

Prevalence of retinal disorder was 52.37% at age 60 years and above. AMD, hypertensive retinopathy, ERM, BRVO, and DR were the most common retinal disorders. Retinal disorders increased with ageing. Retinal disorders were found associated with hypertension and prior cataract surgery. Timely screening, control of blood sugar and high blood pressure, and regular eye check-ups could help to save vision from retinal diseases.

Rural-urban differences in myopia prevalence among myopes presenting to Bhutanese retinal clinical services: a 3-year national study

PURPOSE

To determine the prevalence and demographic characteristics of myopia among patients presenting to the national vitreo-retinal (VR) services in Bhutan.

METHODS

The records of the VR clinic at the apex national referral centre, providing the only VR services in the country, were reviewed to identify all new myopia patients over three years. Thus, we surveyed all referrals nationally. The patients were categorised into urban and rural females and males. We assessed myopia prevalence in each group by occupational and educational categories. We examined univariate prevalence data and a multivariate logistic regression (MLR) identified independent factors.

RESULTS

Of 2913 cases 1544 (53.0%) were males. Females presented earlier (mean ±SD): overall 45.7 ± 21.9 cf. 48.6 ± 21.6 years, p = 0.003, and among myopes 23.9 ± 13.5 cf. 27.6 ± 18.6 years, p = 0.032. Myopia constituted 92.1% of refractive error, an overall prevalence of 12.3%. Myopia was more common among females (p = 0.01) and urbanites (p = 0.02). Myopia prevalence was highest among urban females (20.9%), followed by urban males (11.9%), rural females (6.8%), and rural males (5.2%). Logistic regression revealed that the odds of having myopia were increased by being a student (4.96 ×) or professional (1.96 ×), and decreased by rural living (1.75 ×), all p ≤ 0.038.

CONCLUSIONS

This is the first study on myopia in Bhutan. As observed throughout East and Southeast Asia, the prevalence of myopia was higher in females and urbanites and positively associated with formal education. Given known risk factors, these prevalences may be driven by educational pressures and reduced time spent outdoors.