The Primary Eye Care (PEC) model aimed to right-site patients with non-complex eye conditions by upskilling optometrists. However, there is a paucity of studies examining healthcare professionals’ and patients’ perceptions and context that influenced implementation of community-based eye care model. This study aimed to explore contextual factors (e.g., interprofessional relationships, patients’ perceptions) that influenced implementation of PEC and potential strategies to the identified barriers. Qualitative research design was adopted to elicit the experiences of patients and healthcare professionals. Eight focus group discussions (FGDs) and four in-depth interviews (IDIs) were conducted with 32 healthcare professionals, and 12 IDIs were conducted with 14 patients/caregivers between June 2023 to March 2024. Interviews were transcribed and analysed thematically using an inductive approach. Three themes were identified that influenced the implementation of PEC. First, a bidirectional ophthalmologist-optometrists partnership supported implementation and maintenance of high-quality care. PEC’s high-quality care experienced by the ophthalmologists influenced their motivation to refer patients to PEC paving the way for responsibility transfer and role expansion. Second, limited interprofessional interactions between primary care physicians and optometrists impacted the awareness of PEC’s services and quality of care, dampening referral motivation. Third, patients’ awareness of PEC integration with hospital services and optometrists’ capability influenced acceptance of PEC referrals. To enhance primary care physicians’ awareness and address patients’ concern on PEC integration with hospital services, PEC team will need to prioritise active engagement with primary care physicians and dissemination of interactive patient education.

PURPOSE:Primary eye care (PEC) model aims to facilitate right-siting of care for patients with stable and non-complex conditions by upskilling optometrists. However, there is 1) a lack of examination on PEC's quality of care (measured as degree of agreement in plan of care between upskilled optometrists and ophthalmologists) and 2) no comprehensive real-world evaluation on operational viability and stakeholders' perception of the community-based PEC model. Holistic evaluation is important as in-depth understanding of stakeholders' experience in implementation will be key to ensure the long-term sustainability and scalability of this PEC model. This study aims to examine the quality of care provided at PEC as well as the contextual factors, strategies, and processes that influence implementation, sustainability, and scalability of PEC. METHODS:This study will adopt a mixed-method sequential explanatory design, guided by the Practical, Robust Implementation and Sustainability Model framework. First, the quality of care will be assessed by examining the degree of agreement between PEC optometrists and ophthalmologists on patients' plan of care. Second, qualitative research design will be employed to understand the experiences of patients and healthcare professionals. In-depth interviews will be conducted with patients and focused group discussions will be conducted with healthcare professionals. Integration of quantitative and qualitative data will be achieved by employing the building and merging approach. CONCLUSION:This study will identify areas that could be improved to increase PEC's operational efficiency and enhance its service utilisation. Importantly, key lessons and strategies derived from these evaluations will help to facilitate future nationwide implementation of PEC.

Objectives There is a lack of prognostic information to guide the prediction of short-term all-cause mortality in patients with end-stage renal disease (ESRD). The aim was to review the risk factors that influenced the risk of short-term all-cause mortality in patients with ESRD. Methods MEDLINE, Embase, PubMed, CINAHL, the Cochrane Library and Web of Science databases were searched for articles published between 2000 and 2020. Articles describing risk factors predicting short-term mortality (≤ 3 years) in patients with ESRD were included. Four reviewers independently performed title, abstract, full text screening and data extraction. Assessment of risk of bias was assessed using the Quality In Prognosis Studies (QUIPS) tool checklist. Results 20,840 articles were identified and 113 papers were included for this review. Of the 113 papers, 6.2% included only peritoneal dialysis (PD) patients, 67.3% included only hemodialysis (HD) patients, 20.4% included both PD and HD patients, with the remaining papers featuring patients on conservative management or awaiting renal transplant. Risk factors were categorised into 13 domains: 1)demographics/ lifestyle, 2) comorbidities 3)intradialytic blood pressure, 4)biomarkers, 5)cardiovascular measurements, 6)frailty status, 7)medications, 8)treatment related indicators, 9)renal related parameters, 10)health status, 11)cause of ESRD, 12)access to healthcare care/ information and, 13)proxy measures for poor health. C-reactive protein(CRP), age, and functional status were observed to have higher percentage of instances of being significantly associated with all-cause mortality. Conclusion Commonly examined risk factors observed from this review may be used to build a general prognostic model for patients with ESRD, with specific treatment related risk factors added on to enhance the accuracy of the models.

The association of health-related productivity loss (HRPL) with social isolation and depressive symptoms is not well studied. We aimed to examine the association of social isolation and depressive symptoms with productivity loss. Data on employed adults aged 21 years and above were derived from the Population Health Index (PHI) study conducted by the National Healthcare Group (NHG) on community-dwelling adults, residing in the Central and Northern residential areas of Singapore. The severity of depressive symptoms and social isolation were assessed using the 9-item Patient Health Questionnaire (PHQ-9) and Lubben Social Network Scale-6 (LSNS-6) respectively. Productivity loss was assessed using the Work Productivity and Activity Impairment Questionnaire (WPAI). We used Generalised Linear Models, with family gamma, log link for the analysis. Models were adjusted for socio-demographic variables (including age, gender, ethnicity, employment status, housing type) and self-reported chronic conditions (including the presence of diabetes, hypertension, and dyslipidemia). There were 2,605 working (2,143 full-time) adults in this study. The median reported percentage of unadjusted productivity loss was 0.0%, 10.0% and 20.0% for participants with social isolation, depressive symptoms, and both, respectively. In the regression analysis, mean productivity loss scores were 2.81 times (95% Confidence Interval: 2.12, 3.72) higher in participants with depressive symptoms than those without. On the other hand, social isolation was not found to be associated with productivity loss scores (1.17, 95% Confidence Interval: 0.96, 1.42). The interaction term of depressive symptoms with social isolation was statistically significant, with an effect size of 1.89 (95% Confidence Interval: 1.04, 3.44). It appeared that productivity loss was amplified when social isolation and depressive symptoms were concomitant. Our results suggested significant associations of social isolation and depressive symptoms with productivity loss. These findings highlighted the potential impact of social isolation and depressive symptoms on work performance and drew attention to the importance of having a holistic work support system that promotes social connectedness, mental wellbeing and work productivity.

This experience provided important reminders and lessons for Singapore for managing the effects of future infectious disease outbreaks that might be applied to other countries. First, the outbreaks that occurred within the dormitories were an important caution, in particular to resource limited, low- or middle-income countries with a larger congregation of people living in informal housing [[89]Staff G-i-A. COVID-19: lesson learned? What comes next. 2020 [cited 2020; Available from: https://lkyspp.nus.edu.sg/gia/article/covid-19-lessons-learned-what-comes-next)Google Scholar]. Second, continuous investment in the public health surveillance and health systems, will ensure that the systems are prepared for any future outbreaks. Close collaborative efforts between private and public healthcare institutions during this pandemic demonstrated the importance of enhancing cohesiveness within the local healthcare system. This strong partnership added much-needed bed space and manpower [[90]Vasoo LYSaS. Lessons from a pandemic: How Covid-19 is managed and prevented in Singapore. 2020 [cited 2020; Available from: https://www.straitstimes.com/singapore/lessons-from-a-pandemicGoogle Scholar]. This has been key in keeping COVID-19 death rate low while effectively managing the rate of infection in the community. Third, clear and up-to-date accessible communication between government agencies and the public, had been key in reducing anxiety and confusion about safety measures introduced in the community. Fourth, cultivating a culture of strong community cohesiveness has led to the majority of the public adhering to safe distancing measures and to act in a more sustainable manner, especially during this pandemic [[91]Khalik S. Lessons from one million Covid-19 deaths. 2020 [cited 2020; Available from: https://www.straitstimes.com/singapore/lessons-from-one-millionGoogle Scholar].

Lower extremity muscle strength, and functional limitations are important modifiable predictors of falls, but are often examined using performance based measures. We examined the association between self-reported physical function limitations, determined using Late-Life Function and Disability Instrument(LLFDI) and incident falls in community-dwelling elderly individuals. 283 older adults participants were included in this analysis. Physical function limitations were defined as a person’s difficulty in completing items of the lower extremity function domain and composite scores of the LLFDI. Information on falls was obtained through a standardised questionnaire. At one-year follow-up, 15.2% (43) of the participants experienced their first fall. In the multivariable analysis, individuals who reported difficulties in items of lower extremity function domain were more likely to experience a fall (incidence rate ratio[IRR]: ranging between 2.43 and 7.01; all P ≤ 0.046). In addition, decreasing advanced lower extremity function scores (IRR: 1.70, 95% confidence interval[CI]): 1.04, 2.78) and overall function component score (IRR: 2.05, 95% CI: 1.22, 3.44) were associated with higher risk of incident falls. Physical function limitations, determined using LLFDI, were associated with incident falls. Our findings provide further evidence that the LLFDI function component has the potential to be used as a self-assessment tool for fall risk.

Background: Patients with type 2 diabetes mellitus (T2DM) may develop color vision impairment. This study aimed to determine the prevalence and factors associated with impaired color vision in patients with T2DM but without diabetic retinopathy.Methods: Enrolment criteria included multi-ethnic Asian participants, age 21 to 80 years, with known T2DM for a minimum of 2 years. Their diagnoses were affirmed from oral glucose tolerance test results and they were screened for impaired color vision using the Farnsworth D-15 instrument. Demographic characteristics were described and clinical data for the preceding 2 years were analyzed using logistic regression.Results: Twenty-two percent of 849 eligible participants had impaired color vision with higher involvement of the right eye. Impaired blue-yellow color-vision(Tritanomaly) was the commonest impaired color vision. Participants with impaired color vision were significantly associated with age and lower education; longer duration of T2DM (median 6 years vs 4 years); higher HbA1c level and HDL-Cholesterol in 2nd year; lower mean total cholesterol, mean LDL-Cholesterol and mean triglyceride in 2nd year. They also have poorer vision beyond 6/12 in the affected eye. Logistic regression showed that impaired color vision was associated with older patients (OR=1.04), increased duration of T2DM (OR=1.07); prescription of Tolbutamide (OR=3.79) and lower mean systolic blood pressure (OR=0.98).Conclusion: Almost one in four participants with T2DM had impaired color vision, largely with tritanomaly. Color vision screening may be considered for participants who develop T2DM for 6 years or longer, but this requires further cost-effectiveness evaluation.

CVD risk prediction in diabetics is imperfect, as risk models are derived mainly from the general population. We investigate whether the addition of retinopathy and retinal vascular caliber improve CVD prediction beyond established risk factors in persons with diabetes. We recruited participants from the Singapore Malay Eye Study (SiMES, 2004–2006) and Singapore Prospective Study Program (SP2, 2004–2007), diagnosed with diabetes but no known history of CVD at baseline. Retinopathy and retinal vascular (arteriolar and venular) caliber measurements were added to risk prediction models derived from Cox regression model that included established CVD risk factors and serum biomarkers in SiMES, and validated this internally and externally in SP2. We found that the addition of retinal parameters improved discrimination compared to the addition of biochemical markers of estimated glomerular filtration rate (eGFR) and high-sensitivity C-reactive protein (hsCRP). This was even better when the retinal parameters and biomarkers were used in combination (C statistic 0.721 to 0.774, p = 0.013), showing improved discrimination, and overall reclassification (NRI = 17.0%, p = 0.004). External validation was consistent (C-statistics from 0.763 to 0.813, p = 0.045; NRI = 19.11%, p = 0.036). Our findings show that in persons with diabetes, retinopathy and retinal microvascular parameters add significant incremental value in reclassifying CVD risk, beyond established risk factors.

Retinal microvascular changes indicating microvascular dysfunction have been shown to be associated with chronic kidney disease (CKD) in cross-sectional studies, but findings were mixed in prospective studies. We aimed to evaluate the relationship between retinal microvascular parameters and incident CKD in an Asian population. We examined 1256 Malay adults aged 40-80 years from the Singapore Malay Eye Study, who attended both the baseline (2004-07) and the follow-up (2011-13) examinations and were free of prevalent CKD. We measured quantitative retinal vascular parameters (arteriolar and venular calibre, tortuosity, fractal dimension and branching angle) using a computer-assisted program (Singapore I Vessel Assessment, SIVA) and retinopathy (qualitative parameter) using the modified Airlie house classification system from baseline retinal photographs. Incident CKD was defined as an estimated glomerular filtration rate (eGFR) < 60 mL/min/ 1.73 m(2) + 25% decrease in eGFR during follow-up. Over a median follow-up period of 6 years, 78 (6.21%) developed CKD (70.5% had diabetes). In multivariable models, smaller retinal arterioles (hazards ratio [95% confidence interval] = 1.34 [1.00-1.78]), larger retinal venules (2.35 [1.12-5.94] and presence of retinopathy (2.54 [1.48-4.36]) were associated with incident CKD. Our findings suggest that retinal microvascular abnormalities may reflect subclinical renal microvascular abnormalities involved in the development of CKD.

Asian Indians are the fastest growing migration groups in the world. Studies evaluating the impact of migration on disease outcomes in this population are rare.

Purpose: Diabetes is a major public health problem affecting 415 million people worldwide. With the increasing prevalence of diabetes, diabetic retinopathy (DR) is emerging as the leading cause of avoidable blindness worldwide.Methods: We reviewed previous and recent literature to provide an overview of emerging trends on the burden, epidemiology, risk factors, and prevention of DR.Results: First, there is clear evidence of a global increase in the prevalence of diabetes. Second, there is a decline in the incidence of blindness due to DR, particularly in developed countries. Third, diabetic macular edema (DME) rather than proliferative diabetic retinopathy (PDR) is the increasingly common cause of visual impairment. Fourth, DR awareness remains patchy and low in most populations. Fifth, hyperglycemia remains the most consistent risk factor for DR in type 1 diabetes across different studies and populations. Sixth, in contrast, blood pressure is an important risk factor for DR in type 2 diabetes. Seventh, the relationship between dyslipidemia and DR remains unclear, with inconsistent results from different studies and trials. Eighth, the utility of predictive models incorporating multiple risk factors for assessing DR risk requires evaluation. Ninth, photographic screening of DR using tele-ophthalmology platforms is increasingly recognized as being feasible and cost-effective. Finally, DR prevention in low-resource settings cannot follow models developed in high-resource countries and requires different strategies.Conclusions: The ten trends we observed in the current review may guide planning of public healthcare strategies for the management of DR and prevention of blindness.

Purpose: To examine the relationship between central aortic systolic pressure (CASP) and intraocular pressure (IOP), and to compare the strength of any association with that of peripheral blood pressure and IOP.Methods: Adults ranging in age from 40 to 80 years were consecutively recruited from the population-based Singapore Chinese Eye Study. We measured CASP using arterial tonometry (BPro) and IOP using Goldmann applanation tonometry. All participants had a standardized examination including a complete ophthalmic and systemic examination. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured using peripheral blood pressure cuff. Univariable and multiple linear regression analyses were performed to examine the relationship between CASP and IOP. Standardized regression coefficients (s beta) were calculated to compare the associations between CASP and SBP with IOP.Results: A total of 372 consecutive Chinese participants were analyzed. After adjusting for age, gender, body mass index, total cholesterol, use of antihypertensive medication and central corneal thickness, each 10mmHg increase in CASP was associated with 0.32mmHg of IOP elevation [ 95% confidence interval (CI): 0.10-0.53, s beta = 0.160, p value = 0.004]. SBP also had a positive relationship with IOP (beta = 0.279, 95% CI: 0.079-0.479, s beta = 0.152, p value = 0.006). Associations between IOP and CASP, SBP and DBP were similar in participants using antihypertensive medication to participant not using antihypertensives.Conclusions: Increased CASP, as measured by arterial tonometry, is associated with higher IOP. Our results strengthen the relationship between systemic blood pressure and IOP.

PURPOSE:To compare three commonly used retinal vessel caliber measurement software systems, and propose an algorithm for conversion between measurement systems. METHODS:We used 120 retinal photographs to evaluate the agreement between three commonly used software (Retinal Analysis [RA], Integrative Vessel Analysis [IVAN], and Singapore I Vessel Assessment [SIVA]). Bland-Altman plots were used to evaluate agreement of retinal arteriolar (central retinal artery equivalent, CRAE) and venular (central retinal vein equivalent, CRVE) calibers. Pearson's correlation was used to assess the associations between systemic factors and retinal vessel calibers, and Z-test was used to compare the strength of the correlation coefficients across the three software systems. An algorithm was created to convert measurements, with paired t-test performed to evaluate the differences between SIVA-measured retinal calibers and SIVA-approximates converted from RA- and IVAN-measurements using the algorithm. RESULTS:Differences between SIVA- and RA-measured calibers (CRAE: mean difference [MD] = -21.8 μm, 95% limits of agreement [LOA], -47.3 to 3.7 μm; CRVE: MD = -7.7 μm, 95% LOA, -28.0 to 12.6 μm), SIVA- and IVAN-measured calibers (CRAE: MD = -6.7 μm, 95% LOA, -23.8 to 10.4 μm; CRVE: MD = -18.2 μm 95% LOA, -36.7 to 0.4 μm) were large. However, the strength of correlations between systemic factors with SIVA-measured retinal calibers was not significantly different to that measured using RA and IVAN (P ≥ 0.332). SIVA-approximates converted from RA and IVAN measurements using the proposed algorithm was not significantly different from SIVA-measured calibers (P ≥ 0.20). CONCLUSION:Absolute measurements of retinal vessel calibers vary between three common software systems but associations with systemic factors were similar. TRANSLATIONAL RELEVANCE:The proposed algorithm allowed conversions of RA and IVAN measurements to SIVA-approximates. This conversion is important for future data pooling and establishment of normative values for retinal vascular caliber measurements.

Microalbuminuria is associated with an increased risk of cardiovascular disease (CVD), but not all individuals require treatment. Retinal microvascular abnormalities and microalbuminuria reflect early systemic microvascular changes. We examined the joint effect of retinal abnormalities and microalbuminuria on CVD risk in an Asian cohort. We conducted a prospective, population-based study. Retinal abnormalities were defined as presence of retinopathy and/or retinal venular widening. Microalbuminuria was defined as urinary albumin: creatinine ratio between 30–300 mg/g. Incident CVD was defined as newly diagnosed clinical stroke, acute myocardial infarction or CVD death. Cox regression models were performed to determine the associations between retinal abnormalities and microalbuminuria with risk of CVD, while controlling for established risk factors. 3,496 participants (aged ≥ 40) were free of prevalent CVD. During the follow-up (5.8 years), 126 (3.60%) participants developed CVD. Persons presenting with both retinal abnormalities and microalbuminuria were 6.71 times (95% CI, 2.68, 16.79) as likely to have incident CVD compared with those without either abnormalities. There was a significant interaction effect between retinal abnormalities and microalbuminuria on incident CVD. Assessment of retinal abnormalities in patients with microalbuminuria may provide additional value in identifying persons at risk of developing CVD.

BACKGROUND:Retinal microvascular signs may provide insights into the structure and function of small vessels that are associated with renal disease. We examined the relationship of retinal microvascular signs with both prevalent and incident end-stage renal disease (ESRD) in a multi-ethnic Asian population.METHODS:A total of 5763 subjects (aged ≥ 40 years) from two prospective population-based studies (the Singapore Malay Eye Study and the Singapore Prospective Study) were included for the current analysis. Retinopathy was graded using the modified Airlie House classification system. Retinal vascular parameters were measured using computer-assisted programs to quantify the retinal vessel widths (arteriolar and venular caliber) and retinal vascular network (fractal dimension). Data on ESRD was obtained by record linkage with the ESRD cases registered by National Registry of Diseases Office, Singapore. Multi-variable adjusted regression analyses were performed to assess the associations of baseline retinal vascular parameters and prevalent and incident ESRD.RESULTS:At baseline, 21(0.36%) persons had prevalent ESRD. During a median follow-up of 4.3 years, 33 (0.57%) subjects developed ESRD. In our analyses, retinopathy was associated with prevalent ESRD (multi-variable adjusted odds ratio [OR], 3.21, 95% confidence interval [CI]: 1.28-8.05) and incident ESRD (multi-variable adjusted hazard ratio [HR], 2.51, 95%CI: 1.14-5.54). This association was largely seen in person with diabetes (HR, 2.60, 95%CI: 1.01-6.66) and not present in persons without diabetes (HR, 1.65, 95%CI: 0.14-18.98). Retinal arteriolar caliber, retinal venular caliber and retinal vascular fractal dimension were not associated with ESRD.CONCLUSION:Retinopathy signs in persons with diabetes are related to an increased risk of ESRD; however, other microvascular changes in the retina are not associated with ESRD.

PURPOSE:To assess the reliability and determinants of retinal vessel oximetry measurements with the Oxymap T1 Retinal Oximeter in normal Asian eyes.METHODS:Subjects older than 40 years without a history of stroke and heart disease were recruited from a community-based clinic. Subjects underwent standardized systemic and ocular examinations. Normal eyes were defined as eyes without major eye diseases such as age-related macular degeneration, glaucoma, or retinopathy. Retinal vessel oximetry levels were measured by using the Oxymap T1 Retinal Oximeter. Intra- and intergrader reliability of retinal vessel oximetry measurements were assessed by using 50 images. Intravisit repeatability of retinal vessel oximetry measurements was assessed by using 20 paired images. Univariable linear regression was performed to examine the associations between retinal vessel oximetry measurements and systemic determinants.RESULTS:A total of 118 retinal oximetry images were included in the final analysis. Intra- (intraclass correlation coefficient [ICC] values: 0.89-0.99) and intergrader (ICC values: 0.77-0.94) reliability, and intravisit (ICC values: 0.85-0.96) repeatability were both high. In the linear regression analysis, older age was associated with reduced overall retinal venular oximetry levels (β: -2.61%; 95% confidence interval [CI]: -4.92 to -0.29) and reduced inferior-nasal retinal venular oximetry levels (β: -3.53%; 95% CI: -6.07 to -0.99).CONCLUSIONS:The Oxymap Retinal Oximeter allows reliable and repeatable retinal vessel oximetry measurements. Age is the main factor that influences retinal venular oximetry levels and should be taken into account when retinal oximetry measurements are interpreted.