ORCID Profile
0000-0002-4916-6074
Current Organisation
UNIVERSIDADE SÃO FRANCISCO
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Publisher: BMJ
Date: 22-05-2020
DOI: 10.1136/BJOPHTHALMOL-2019-314086
Abstract: To compensate the retinal nerve fibre layer (RNFL) thickness assessed by spectral-domain optical coherence tomography (SD-OCT) for anatomical confounders. The Singapore Epidemiology of Eye Diseases is a population-based study, where 2698 eyes (1076 Chinese, 704 Malays and 918 Indians) with high-quality SD-OCT images from in iduals without eye diseases were identified. Optic disc and macular cube scans were registered to determine the distance between fovea and optic disc centres (fovea distance) and their respective angle (fovea angle). Retinal vessels were segmented in the projection images and used to calculate the circumpapillary retinal vessel density profile. Compensated RNFL thickness was generated based on optic disc (ratio, orientation and area), fovea (distance and angle), retinal vessel density, refractive error and age. Linear regression models were used to investigate the effects of clinical factors on RNFL thickness. Retinal vessel density reduced significantly with increasing age (1487±214 µm in 40–49, 1458±208 µm in 50–59, 1429±223 µm in 60–69 and 1415±233 µm in ≥70). Compensation reduced the variability of RNFL thickness, where the effect was greatest for Chinese (10.9% p .001), followed by Malays (6.6% p=0.075) and then Indians (4.3% p=0.192). Compensation reduced the age-related RNFL decline by 55% in all participants (β=−3.32 µm vs β=−1.50 µm/10 years p .001). Nearly 62% of the in iduals who were initially classified as having abnormally thin RNFL (outside the 99% normal limits) were later reclassified as having normal RNFL. RNFL thickness compensated for anatomical parameters reduced the variability of measurements and may improve glaucoma detection, which needs to be confirmed in future studies.
Publisher: BMJ
Date: 28-08-2019
DOI: 10.1136/BJOPHTHALMOL-2018-313308
Abstract: To determine the prevalence and causes of blindness and vision impairment (VI) in East Asia in 2015 and to forecast the trend to 2020. Through a systematic literature review and meta-analysis, we estimated prevalence of blindness (presenting visual acuity /60 in the better eye), moderate-to-severe vision impairment (MSVI 3/60≤presenting visual acuity /18), mild vision impairment (mild VI: 6/18≤presenting visual acuity /12) and uncorrected presbyopia for 1990, 2010, 2015 and 2020. A total of 44 population-based studies were included. In 2015, age-standardised prevalence of blindness, MSVI, mild VI and uncorrected presbyopia was 0.37% (80% uncertainty interval (UI) 0.12%–0.68%), 3.06% (80% UI 1.35%–5.16%) and 2.65% (80% UI 0.92%–4.91%), 32.91% (80% UI 18.72%–48.47%), respectively, in East Asia. Cataract was the leading cause of blindness (43.6%), followed by uncorrected refractive error (12.9%), glaucoma, age-related macular degeneration, corneal diseases, trachoma and diabetic retinopathy (DR). The leading cause for MSVI was uncorrected refractive error, followed by cataract, age-related macular degeneration, glaucoma, corneal disease, trachoma and DR. The burden of VI due to uncorrected refractive error, cataracts, glaucoma and DR has continued to rise over the decades reported. Addressing the public healthcare barriers for cataract and uncorrected refractive error can help eliminate almost 57% of all blindness cases in this region. Therefore, public healthcare efforts should be focused on effective screening and effective patient education, with access to high-quality healthcare.
Publisher: BMJ
Date: 19-03-2021
DOI: 10.1136/BJOPHTHALMOL-2021-318992
Abstract: To provide contemporary longitudinal data on the incidence and progression of diabetic retinopathy (DR) in a multi-ethnic population of whites, African Americans, Chinese and Hispanics in the United States. A prospective, multi-region, multi-ethnic population-based cohort study that included 498 participants with diabetes, aged 45–84 years at baseline, from the Multi-Ethnic Study of Atherosclerosis with retinal images obtained twice, on average 8 years apart. Presence and severity of DR were graded from these retinal images according to the modified Airlie House classification system. Main outcome measures were 8-year incidence, progression and improvement of DR, and their associated risk factors. Over the 8 years, the cumulative rates were 19.2% for incident DR, 17.3% for DR progression, 23.3% for DR improvement, 2.7% for incident vision-threatening DR, 1.8% for incident proliferative DR and 2.2% for incident macular oedema. In multivariate analysis, significant risk factors associated with incident DR were higher glycosylated haemoglobin (relative risk (RR) 1.28 95% CI: 1.16 to 1.41) and higher systolic blood pressure (RR 1.14 95% CI: 1.04 to 1.25). Significant factors associated with DR progression were higher glycosylated haemoglobin (RR 1.20 95% CI: 1.00 to 1.43) and higher low-density lipoprotein cholesterol (RR 1.01 95% CI: 1.00 to 1.03). Over an 8-year period, approximately one in five participants with diabetes developed DR, while almost a quarter of those with DR at baseline showed improvement, possibly reflecting the positive impact of clinical and public health efforts in improving diabetes care in the United States over the last two decades.
Publisher: BMJ
Date: 20-01-2020
DOI: 10.1136/BJOPHTHALMOL-2019-314890
Abstract: To comprehensively examine the association between kidney function and primary open angle glaucoma (POAG) in a large consortium of multiple Asian population-based studies. 28 925 participants (57 340 eyes) from 9 population-based studies (from China, Hong Kong, India, Korea, Russia, Singapore) of the Asian Eye Epidemiology Consortium were included. Across all studies, POAG was defined based on the International Society of Geographical and Epidemiological Ophthalmology criteria. Estimated glomerular filtration rate (eGFR) was calculated from serum creatinine. Chronic kidney disease (CKD) was defined as eGFR mL/min/1.73 m 2 . Eye-specific data were pooled from each study. Multivariable regression analysis with generalised estimating equation models was performed to evaluate the associations between kidney function with POAG and intraocular pressure (IOP). After adjusting for age, gender, study group, hypertension, diabetes, hyperlipidaemia, body mass index, smoking status and IOP, lower eGFR (per 10 mL/min/1.73 m 2 decrease) was not significantly associated with POAG (OR=1.01 p=0.77). Presence of CKD was also not significantly associated with POAG (OR=1.01 p=0.739). Furthermore, lower eGFR and presence of CKD were not associated with IOP (all p≥0.12), However, in the subgroup of combined Korean and Chinese in iduals, significant associations between lower eGFR (OR=1.09 95% CI 1.00 to 1.18 p=0.048) and severe kidney function decline ( mL/min/1.73 m 2 OR=2.57 95% CI 1.34 to 4.93 p=0.004) with POAG, were observed. In this large pooled-analysis of multiple Asian population-based studies, our findings suggest that the association between CKD and POAG may only be present in East Asians specifically but not in the overall Asian population. Further evaluation in Japanese population is warranted to confirm this observation.
Publisher: BMJ
Date: 04-07-2019
DOI: 10.1136/BJOPHTHALMOL-2019-314256
Abstract: To evaluate the association between systemic medications and cortical cataract prevalence in an Asian population. The Singapore Epidemiology of Eye Diseases Study recruited 10 033 Chinese, Malay and Indian residents aged 40+ years living in Singapore. Information on medication use was collected at interview using questionnaires. The presence and severity of cortical cataract were assessed from lens photographs using the modified Wisconsin Cataract Grading System. Associations between medications and the presence of cortical cataract were assessed using logistic regression. Associations between medications and greater severity of cortical cataract (none, minimal, early and late) were assessed using ordinal logistic regression. A total of 8965 participants were included, the mean age was 57.6 (SD=9.8) years, and 4555 (50.8%) were women. After adjusting for age, gender, ethnicity, body mass index, smoking status, socioeconomic status, hypertension, hyperlipidaemia, diabetes, duration of diabetes and cardiovascular disease, ACE inhibitors (OR=1.27 95% CI 1.05 to 1.55), fibrates (OR=1.57 95% CI 1.05 to 2.35), alpha-glucosidase inhibitors (AGIs) (OR=1.85 95% CI 1.13 to 3.02) and insulin (OR=1.80 95% CI 1.11 to 2.93) were significantly associated with the presence of cortical cataract. Further adjusting for concurrent medication use did not alter these associations. Consistently, the four medications were also associated with a greater severity level of cortical cataract. ACE inhibitors, fibrates and AGIs were associated with increased prevalence of cortical cataract in this Asian population, independent of the presence of hypertension, hyperlipidaemia and diabetes, respectively. Whether they contribute to the risk of cortical cataract needs confirmation in longitudinal studies.
Publisher: Elsevier BV
Date: 06-2021
Publisher: BMJ
Date: 19-01-2022
DOI: 10.1136/BJOPHTHALMOL-2020-318126
Abstract: We described the 6-year incidence and changes of retinopathy, and their associated risk factors in a multi-ethnic Asian population without diabetes. We included 4374 participants with non-diabetes from a population-based cohort, the Singapore Epidemiology of Eye Disease Study, with gradable retinal photographs at baseline and 6-year follow-up visit. Retinopathy was assessed according to the modified Airlie House classification system. Over the 6-year period, the cumulative rates were 2.5% (106/4279) for retinopathy incidence, 1.0% (1/95) for retinopathy progression and 68.4% (65/95) for retinopathy regression. In multivariable analysis, higher diastolic blood pressure (DBP) (risk ratio (RR)=1.02 95% CI: 1.00 to 1.04 per 10 mm Hg increase in DBP) and wider retinal arteriolar calibre (RR=1.36 95% CI: 1.13 to 1.63 per SD increase in central retinal artery equivalent) were associated with higher risk of incident retinopathy, while higher level of high-density lipoprotein (HDL) was associated with lower risk of incident retinopathy (RR=0.56 95% CI: 0.32 to 0.99 per mmol/L increase in HDL). Compared with Chinese, Malays were more likely to have retinopathy regression (RR=1.63 95% CI: 1.20 to 2.22), while overweight (RR=0.47 95% CI: 0.26 to 0.84) and higher glycosylated haemoglobin (HbA1c) level (RR=0.58 95% CI: 0.37 to 0.93 per per cent increase in HbA1c) were associated with lower likelihood of retinopathy regression. Risk of developing retinopathy in Asians without diabetes is generally low. However, regression of retinopathy over time is common, suggesting that these retinopathy signs may reflect subclinical reversible microvascular dysfunction. Several metabolic risk factors are associated with incidence or regression of retinopathy, suggesting that good metabolic control may still be important in the management of non-diabetic retinopathy.
Publisher: BMJ
Date: 20-05-2021
DOI: 10.1136/BJOPHTHALMOL-2020-315840
Abstract: To investigate the determinants of lamina cribrosa depth (LCD) in healthy eyes of Chinese and Indian Singaporean adults. The optic nerve head (ONH) of the right eye of 1396 subjects (628 Chinese and 768 Indian subjects) was imaged with optical coherence tomography (OCT, Spectralis, Heidelberg, Germany). LCD was defined as the distance from the Bruch’s membrane opening (LCD-BMO) or the peripapillary sclera (LCD-PPS) reference plane to the laminar surface. A linear regression model was used to evaluate the relationship between the LCD and its determinants. Both LCDs were significantly different between the two races (LCD-BMO: 421.95 (95% CI 365.32 to 491.79) µm in Chinese vs 430.39 (367.46–509.81) µm in Indians, p=0.021 and LCD-PPS: 353.34 (300.98–421.45) µm in Chinese vs 376.76 (313.39–459.78) µm in Indians, p .001). In the multivariable regression analysis, the LCD-PPS of the whole cohort was independently associated with females (β=−31.93, p .001), Indians subjects (β=21.39, p=0.004) (Chinese as the reference), axial length (Axl) (β=−6.68, p=0.032), retinal nerve fibre layer thickness (RNFL) (β=0.71, p=0.019), choroidal thickness (ChT) (β=0.41, p .001), vertical cup disc ratio (VCDR) (β=24.42, p .001) and disc size (β=−60.75, p=0.001). For every 1 year older in age, the LCD-PPS was deeper on average by 1.95 µm in Chinese subjects (p=0.01) but there was no association in Indians subjects (p=0.851). The LCD was influenced by age, gender, race, Axl, RNFL, ChT, VCDR and disc size. This normative LCD database may facilitate a more accurate assessment of ONH cupping using OCT in Asian populations.
Publisher: BMJ
Date: 10-08-2019
DOI: 10.1136/BJOPHTHALMOL-2018-312447
Abstract: To evaluate racial differences, and ocular and systemic determinants of macular thickness (MT), measured by spectral-domain optical coherence tomography (SD-OCT) in a normal multiethnic Asian population. MT was measured from a 6×6 mm 2 central macular area using the Cirrus high-definition OCT (HD-OCT) (Carl Zeiss Meditec, Dublin, CA). The associations between ocular and systemic factors with MT were evaluated using linear regression analyses with generalised estimating equation models to account for intereye correlation. 7447 healthy eyes (2577 Chinese, 2072 Malays and 2798 Indians) of 4510 subjects were included. Multivariable analysis showed that older age (per decade, β=−4.39), female gender (β=−5.74), diabetes (β=−1.10), chronic kidney disease (CKD) (β=−3.21), longer axial length (per mm, β=−2.34), flatter corneal curvature (per mm, β=−1.79) and presence of cataract (β=−0.94) were associated with thinner overall average MT (OMT) (all p≤0.026) higher total cholesterol (β=0.44 p=0.010) was associated with thicker OMT. All these factors were also associated with thinner central subfield MT (CSMT) (all p≤0.001), except for cataract, total cholesterol and CKD. Meanwhile, longer axial length (β=2.51 p .001) was associated with thicker CSMT. OMT (mean±SD) was thickest in Chinese (279.9±12.5 µm), followed by Malays (276.5±13.7 µm) and Indians (272.4±13.1 µm), with p≤0.003 for all interethnic comparisons. Similar trend was observed for CSMT. There are interethnic differences in MT profile among Asians, particularly between Chinese and Indians. Ocular and systemic factors affect MT measurements as well. This Asian-specific information may be incorporated into existing clinical interpretation of macular OCT scans to aid in improving the diagnostic and monitoring accuracy of macular diseases among Asians.
No related grants have been discovered for Kah Hie Wong.