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

Dynamics of Myopia Progression in Ghana-Evidence From Clinical Practice: A Retrospective Cohort Study

Background and Aim

To investigate the pattern of progression of myopia among a Ghanaian clinical cohort.

Methods

A retrospective cohort analysis of a clinical data set of all healthy myopic participants attending a tertiary eye care center was performed. Participants' biennial refraction examinations were tracked for refractive changes 4 years after the date of the first visit. This covered the period from January 2015 to December 2019. Myopia progression was defined as a difference in spherical equivalent between consecutive biennial visits equal to, or greater than -0.50 D of myopia.

Results

The medical records of 169 myopic participants were reviewed, with the majority (53.8%) being female. Most of the participants (51.4%) were younger than 36 years, and at the end of the study period, 96 participants (56.8%), who made up the majority, showed progression of myopia Univariate regression revealed that the 36-59-year-old age range is associated with a 60% [cOR = 0.40, 95% CI: -0.17, 0.97; p = 0.04] reduced likelihood compared to those belonging to the 0-17-year-old age group, and the Mole-Dagbon ethnicity is associated with an almost fourfold [cOR = 3.80; 95% CI: -1.40, 10.316; p = 0.01] increased likelihood of experiencing myopia progression compared to those of Ga-Adangbe ethnicity. Multivariate regression revealed that the Mole-Dagbon ethnicity is associated with an increased likelihood of experiencing myopia progression 4 years after their initial visit [aOR = 3.49; 95% CI: -1.27, 9.63; p = 0.02] compared to those of Ga-Adangbe ethnicity.

Conclusion

Our study provides important insights into myopia progression in Ghana, with findings that are consistent with global trends. The association of myopia progression with age, place of residence, degree of myopia, and ethnicity highlights the need for tailored interventions to manage this growing public health concern in African populations.

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.

Refractive errors in Tianjin youth aged 6-18 years: exploring urban-rural variations and contributing factors

Purpose

Refractive errors, particularly myopia, constitute a significant global public health concern, contributing to morbidity and disability. A more comprehensive understanding of the determinants of refractive errors and the differences between urban and rural areas is essential to develop effective preventive measures for youth. This study aimed to compare the prevalence and risk factors of refractive errors among youth in urban and rural Tianjin, China.

Methods

This school-based cross-sectional study was conducted in 2022. Elementary, middle, and high school students aged 6-18 years from both urban and rural areas of Tianjin were included. All participants underwent visual acuity testing and refractive measurement and completed comprehensive questionnaires.

Results

A total of 346,146 participants (176,628 boys) were included in this investigation (50.36% for urban and 49.64% for rural, respectively). Myopia, hyperopia, astigmatism, and anisometropia were present in 56.8, 9.7, 56.64, and 21.3% of urban students, respectively. Similarly, rural students had a prevalence of 57.6, 11.5, 56.48, and 22.0% for the respective conditions. Compared to rural students, after adjusting for age, sex, and other significant variables, urban students were 1.05 times more likely to have myopia (95% CI: 1.03-1.07, p < 0.0001), 0.71 times less likely to have hyperopia (95% CI: 0.69-0.73, p < 0.0001), and 1.02 times more likely to have astigmatism (95% CI: 0.69-0.73, p < 0.0001). There was no significant association between anisometropia and residence (OR: 1.00, 95% CI: 0.98-1.02, p = 0.9850). Sociodemographic and physiological factors contribute to the disparities in the prevalence of refractive errors between urban and rural areas. Age, increased near-work activities, and Decreased outdoor time were identified as risk factors for myopia, astigmatism, and anisometropia. Conversely, the absence of a parental history of refractive errors emerged as a protective factor for myopia and astigmatism among students. Lower parental education levels were negatively correlated with the risk of myopia and anisometropia in their children. Specifically, the lower the parental education, the greater the risk of myopia in their offspring. For urban students only, lower parental education was associated with an increased risk of astigmatism.

Conclusion

Crude prevalence estimates May not accurately reflect the true burden of refractive error due to confounding factors such as age and sex. Accounting for these factors revealed that urban students were more likely to have myopia and astigmatism but less likely to have hyperopia compared to their rural counterparts. These disparities highlight the importance of considering geographical variations when implementing strategies for myopia control and prevention.

The influence of the environment and lifestyle on myopia

BACKGROUND

Myopia, commonly known as near-sightedness, has emerged as a global epidemic, impacting almost one in three individuals across the world. The increasing prevalence of myopia during early childhood has heightened the risk of developing high myopia and related sight-threatening eye conditions in adulthood. This surge in myopia rates, occurring within a relatively stable genetic framework, underscores the profound influence of environmental and lifestyle factors on this condition. In this comprehensive narrative review, we shed light on both established and potential environmental and lifestyle contributors that affect the development and progression of myopia.

MAIN BODY

Epidemiological and interventional research has consistently revealed a compelling connection between increased outdoor time and a decreased risk of myopia in children. This protective effect may primarily be attributed to exposure to the characteristics of natural light (i.e., sunlight) and the release of retinal dopamine. Conversely, irrespective of outdoor time, excessive engagement in near work can further worsen the onset of myopia. While the exact mechanisms behind this exacerbation are not fully comprehended, it appears to involve shifts in relative peripheral refraction, the overstimulation of accommodation, or a complex interplay of these factors, leading to issues like retinal image defocus, blur, and chromatic aberration. Other potential factors like the spatial frequency of the visual environment, circadian rhythm, sleep, nutrition, smoking, socio-economic status, and education have debatable independent influences on myopia development.

CONCLUSION

The environment exerts a significant influence on the development and progression of myopia. Improving the modifiable key environmental predictors like time spent outdoors and engagement in near work can prevent or slow the progression of myopia. The intricate connections between lifestyle and environmental factors often obscure research findings, making it challenging to disentangle their individual effects. This complexity underscores the necessity for prospective studies that employ objective assessments, such as quantifying light exposure and near work, among others. These studies are crucial for gaining a more comprehensive understanding of how various environmental factors can be modified to prevent or slow the progression of myopia.

Prevalence Trend of Myopia during the Post-COVID-19 Epidemic Period among Preschoolers: A Prospective School-based Study

SIGNIFICANCE

Changes in behavior and lifestyle during the post-coronavirus disease 2019 (COVID-19) epidemic may have some impact on myopia rates in preschoolers, and exploring the changes in myopia rates in preschool children may inform the formulation of myopia prevention and control policies.

PURPOSE

This study aimed to investigate the prevalence of myopia in preschool children during the post-COVID-19 epidemic period in Xuzhou, China.

METHODS

A series of cross-sectional school-based studies was conducted. A total of 117,632 preschool children aged 3 to 6 years were subjected to annual vision screening from 2019 to 2021. Spot photo screening was used to record the spherical equivalent refraction for each child and to analyze the prevalence of myopia by age, sex, and region during the post-COVID-19 epidemic period.

RESULTS

A total of 113,979 preschool children were included in the analysis, of whom 60,784 (53.3%) were male and 53,195 (46.7%) were female. For all children, the mean ± standard deviation spherical equivalent refraction in 2019, 2020, and 2021 was +0.32 ± 0.50, +0.34 ± 0.55, and +0.34 ± 0.54 D, respectively (all P < .05), indicative of a very slight hyperopic shift. In all age groups, the change in mean spherical equivalent refraction and its distribution were relatively stable. From 2019 to 2021, the overall prevalence of myopia in preschool children was 3.1, 3.3, and 3.5%, respectively. The rise in myopia rates was minimal. The largest increase in the annual prevalence of myopia was seen among children aged 6 years, at 0.5%, followed by those aged 5 years (0.4%) and aged 3 years (0.4%). The prevalence was higher in boys than girls and in urban versus rural areas.

CONCLUSIONS

During the post-COVID-19 epidemic period, the refractive status of Xuzhou preschool children remained stable.

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.

Myopia and its associated factors among pregnant women at health institutions in Gondar District, Northwest Ethiopia: A multi-center cross-sectional study

Background

Myopia is the most common form of uncorrected refractive error with a growing burden worldwide. It is the principal complaint of most women during pregnancy. Although myopia has led to several consequences across the standard life of pregnant women, there is no previous study in Ethiopia regarding this topic. Thus, this study determined the prevalence of myopia and identifies its associated factors among pregnant women attending antenatal care units at governmental health institutions in Gondar City District, Northwest Ethiopia.

Methods

An institution-based cross-sectional study design was conducted from 08 February to 08 April 2021. From the selected health centres, study participants were recruited by systematic random sampling technique. A pre-tested, structured-interviewer-administered questionnaire consisting of socio-demographic variables, obstetric and clinical-related variables was used to collect the required data. Non-cycloplegic refraction was performed using trial lenses, trial frames, and retinoscopy in a semi-dark examination room. EpiData 3 and STATA 14 were used for data entry and statistical analysis respectively. Both bivariable and multivariable binary logistic regression analyses were executed to identify associated factors of myopia. Variables with a p-value ≤0.05 in the multivariable logistic regression analysis were declared as statistically significant with myopia. Model fitness was checked by Hosmer and Lemeshow goodness of test (at p > 0.05).

Results

A total of four-hundred and twenty-three pregnant women participated with a 100% response rate in this study. The overall prevalence of myopia among pregnant women was 26.48% (95% CI: 22.48-30.91). Eighty-Eight (20.81%) and Eighty-Four (19.85%) of the study participants had myopia in their right and left eyes respectively. The prevalence of myopia was significantly associated with age (AOR = 1.17; 95% CI: 1.09-1.28), the third trimester of gestation (AOR = 2.05, 95% CI: 1.08-3.90), multi & grand multipara (AOR = 3.15; 95% CI: 1.59-6.25), and history of contraceptive use (AOR = 3.30; 95% CI: 1. 50-7.28).

Conclusion

The finding of our study shows that there is a higher prevalence of myopia among pregnant women in our study area. Further prospective analytical studies regarding visual systems among pregnant women, particularly as a result of pregnancy, are strongly recommended.

Increasing prevalence of myopia and the impact of education in primary-school students in Xi'an, north-western of China

Purpose

The present study was performed to detect the prevalence of myopia among primary-school students in Xi'an, north-western of China.

Methods

The present study was a school-based study with students aged from 6 to 13 years old. All the individuals underwent ophthalmological examination and spherical equivalent (SE) of refractive error were measured with non-cycloplegic refraction. Myopia was defined as a SE of ≤ -0.5 diopters (D), and further divided into three stratified groups based on SE: low myopia (≤ -0.5 to >-3.0 D), moderate myopia (≤ -3.0 to >-6.0 D), and high myopia (≤ -6.0 D). Relative risk factors, including age, sex, grade and ethnicity were investigated using questionnaire.

Results

A total of 4,680 individuals were eligible for this survey and 4,654 (99.4% participation rate) were finally included (51.2% boys). The mean age of participants was 8.756 ± 1.727 years. The whole city-level prevalence of total myopia was 57.1% (95% CI: 55.7-58.6%). Additionally, the prevalence of low, moderate, and high myopia was 45.0% (95% CI: 43.5-46.4%), 11.1% (95% CI: 10.2-12.0%), and 1.0% (95% CI: 0.7-1.3%), respectively. Moreover, grade (education level) instead of age, sex and ethnicity was the most essential risk factor for prevalence of overall myopia (OR = 1.844, 95% CI: 1.605-2.119), and an increase of prevalence by 84.4% per grade was seen. Furthermore, similar associations of grade were significant with low myopia (OR = 1.613, 95% CI: 1.385-1.877) and moderate myopia (OR = 2.186, 95% CI: 1.693-2.823), meanwhile, prevalence of low myopia and moderate myopia demonstrated an increase of prevalence by 61.3 and 118.6% per grade, respectively. None of the factors included in the present study was significant risk factor for high myopia.

Conclusions

The present study investigated a non-negligible high prevalence of myopia among primary-school students in Xi'an, north-western of China, and a gradual increasing in proportion with education level.

Trends of myopia development among primary and junior school students in the post-COVID-19 epidemic period

Purpose

To investigate the trends of myopia among primary and junior school students in the post-COVID-19 epidemic period.

Method

A prospective of cross-sectional study using spot photoscreenings in 123,538 children among primary and junior school students from 2019 to 2021 was conducted to evaluate the development of myopia in Xuzhou, China in the post-COVID-19 epidemic period. Equivalent refraction and the prevalence of myopia were recorded.

Results

The spherical equivalent refraction of myopia decreased across all grades except grade 1 (0.23 ± 0.56 D in 2019, 0.24 ± 0.63 D in 2020) from 2019 to 2020. However, refraction exhibited a hyperopic shift in 2021 compared to 2020 for grades 1-5 (no significant decreased for grade 4). The prevalence of myopia in all grades increased in 2020 compared to 2019, and the most dramatic changes were observed from grades 2-5 and grades 7-8 (P < 0.05). The changes in myopia prevalence in grades 1-4 were mild, and the reduction in myopia for Grade 5 is significant from 2020 to 2021. Nevertheless, students in grades 6 and 9 exhibited the greatest growth in myopia prevalence (P < 0.01). All grades had higher myopia prevalence in 2021 compared with 2019, except grade 1 (P = 0.25). The prevalence of myopia in girls was higher compared with boys, and the urban myopia prevalence was higher than in rural areas over the 3 years except in 2019 (P = 0.18).

Conclusions

The prevalence of myopia increased during the COVID-19 epidemic. However, the spherical equivalent refraction of lower grade children drifted to hyperopia and the trends of myopia development remained stable in the post-COVID-19 epidemic period. We should be more concerned about the prevalence of myopia in graduating for the primary or junior grades in the future.

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.

Visual impairment and associated factors among pregnant women attending antenatal care units at health institutions in Gondar City Administration, Northwest Ethiopia

Background

Visual impairment is a major public health concern among women of reproductive age groups in Ethiopia, which is getting worse during pregnancy. Though visual impairment has lots of serious consequences across the life course of pregnant women, there is no previous study on this topic in Ethiopia. Thus, this study determined the prevalence of visual impairment and identified associated factors among pregnant women attending antenatal care units at the governmental health institutions in Gondar City Administration, Northwest Ethiopia.

Methods

An institution-based cross-sectional study was conducted. A systematic random sampling technique was used to recruit the study participants. We used an interviewer-administered questionnaire comprising of socio-demographic, clinical and pregnancy-related variables to collect the required data. Snellen’s illiterate “E” chart was used to determine visual impairment. EpiData 3 and Stata 14 were used for data entry and statistical analysis, respectively. Both bivariable and multivariable binary logistic regression analyses were executed to identify associated factors of visual impairment. Variables with a p-value ≤0.05 in the multivariable logistic regression analysis were declared as statistically significant with visual impairment.

Results

A total of 417 (response rate = 98.6%) participants were involved in this study, with a median age of 27 years. The overall prevalence of visual impairment was 22.5% (95% CI: 18.5–26.6). Thirty (7.2%) and thirty-two (7.7%) of the study participants had moderate to severe visual impairments in their right and left eyes, respectively. Participants aged from 31 to 49 years (AOR = 2.1; 95% CI: 1.1–4.0), being 3rd trimester (AOR = 2.4; 95% CI: 1.3–4.5), multi & grand multipara (AOR = 2.3; 95% CI: 1.2–4.6), and history of contraceptive use (AOR = 2.7; 95% CI: 1.2–6.3) had higher chance of visual impairment.

Conclusion

The magnitude of visual impairment among pregnant women was high in the study area. Therefore, routine screening and evaluation of pregnant women for visual condition during antenatal care visits is recommended. Further investigations of visual changes, particularly as a result of pregnancy, are warranted.

The effect of spatially-related environmental risk factors in visual scenes on myopia

Myopia, the most common refractive error, is estimated to affect over two billion people worldwide, especially children from East Asian regions. Children with early onset myopia have an increased risk of developing sight threatening complications in later life. In addition to the contribution of genetic factors, of which expression is controversially suggested to be subject to environmental regulation, various environmental factors, such as near-work, outdoor, and living environment, have also been determined to play significant roles in the development of refractive error, especially juvenile myopia. Cues from daily visual scenes, including lighting, spatial frequency, and optical defocus over the field of visual stimuli, are suggested to influence emmetropisation, thereby affecting myopia development and progression. These risk factors in visual scenes of the everyday life may explain the relationship between urbanicity and myopia prevalence. This review first summarises the previously reported associations between myopia development and everyday-life environments, including schooling, urban settings, and outdoors. Then, there is a discussion of the mechanisms hypothesised in the literature about the cues from different visual scenes of urbanicity in relation to myopia development.

Refractive error and its associated factors among pregnant women attending antenatal care unit at the University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia

Background

Refractive error is one of the commonly encountered problems during pregnancy and being the cause of deleterious effects on health. Despite its impacts, there is no evidence on the magnitude and associated factors of refractive error among pregnant women in Ethiopia. This study aimed to determine the prevalence of refractive error and its associated factors among pregnant women attending antenatal care unit at the University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia, 2020.

Methods

An institution-based cross-sectional study was employed. An ocular examination was performed using Retinoscope and Snellen’s illiterate “E” chart. The required data were collected using an interviewer-administered questionnaire which comprised socio-demographic, clinical and pregnancy-related variables. EpiData 3.02 and STATA 14 were used for data entry and analysis respectively. Both bivariable and multivariable binary logistic regression analyses were executed to identify factors associated with refractive error. Variables with a p-value ≤ 0.05 in the multivariable logistic regression analysis were declared as significantly associated factors with refractive error.

Results

A total of 401 pregnant women with a median age of 27 (IQR = 24–31) years participated in this study. The overall prevalence of refractive error among the study participants was 35.66% (95% CI: 30.95–40.37). Of the total study participants, ninety-two (22.90%) of them were myopic, forty-five (11.22%) were hyperopic and the rest were antimetropic. Increased maternal age (AOR = 1.31; 95% CI: 1.16–1.48)), increased parity (AOR = 3.17, 95% CI: 1.92–5.25), increased gestational age (AOR = 1.15, 95% CI: 1.08–1.22), and regular use of computers/ watching television (AOR = 6.19, 95% CI: 2.46–15.59) were significantly associated with refractive error.

Conclusion

The prevalence of refractive error among pregnant women was high where myopia was the most common variety. Advanced maternal age, increased gestational age, increased parity and regular use of computer or watching television were significantly associated with refractive error among pregnant women. Therefore, apart from providing other maternal health services, routine screening and evaluation of pregnant women for refractive error during antenatal care visit is recommended to avoid its negative impacts.

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.