Optometry and Vision Sciences - Research Publications
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ItemEstablishing a method to estimate the effect of antimyopia management options on lifetime cost of myopia(BMJ PUBLISHING GROUP, 2023-08)BACKGROUND: Informed decisions on myopia management require an understanding of financial impact. We describe methodology for estimating lifetime myopia costs, with comparison across management options, using exemplars in Australia and China. METHODS: We demonstrate a process for modelling lifetime costs of traditional myopia management (TMM=full, single-vision correction) and active myopia management (AMM) options with clinically meaningful treatment efficacy. Evidence-based, location-specific and ethnicity-specific progression data determined the likelihood of all possible refractive outcomes. Myopia care costs were collected from published sources and key informants. Refractive and ocular health decisions were based on standard clinical protocols that responded to the speed of progression, level of myopia, and associated risks of pathology and vision impairment. We used the progressions, costs, protocols and risks to estimate and compare lifetime cost of myopia under each scenario and tested the effect of 0%, 3% and 5% annual discounting, where discounting adjusts future costs to 2020 value. RESULTS: Low-dose atropine, antimyopia spectacles, antimyopia multifocal soft contact lenses and orthokeratology met our AMM inclusion criteria. Lifetime cost for TMM with 3% discounting was US$7437 (CI US$4953 to US$10 740) in Australia and US$8006 (CI US$3026 to US$13 707) in China. The lowest lifetime cost options with 3% discounting were antimyopia spectacles (US$7280, CI US$5246 to US$9888) in Australia and low-dose atropine (US$4453, CI US$2136 to US$9115) in China. CONCLUSIONS: Financial investment in AMM during childhood may be balanced or exceeded across a lifetime by reduced refractive progression, simpler lenses, and reduced risk of pathology and vision loss. Our methodology can be applied to estimate cost in comparable scenarios.
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ItemIncidence and correction of vision impairment among elderly population in southern urban China(WILEY, 2019-05)IMPORTANCE: Data on the incidence of presenting vision impairment (PVI) and spectacle coverage rate (SCR) in urban China is limited. BACKGROUND: To estimate the 6-year incidence and risk factors for PVI and the SCR in urban Southern China. DESIGN: Population-based cohort study. PARTICIPANTS: A total of 1817 participants aged ≥35 years were identified from Guangzhou in 2008 at baseline and 1427 attended follow-up examination in 2014. METHODS: Presenting visual acuity (PVA) was measured using the ETDRS chart with habitual spectacles. Participants with PVA ≤20/40 underwent subjective refraction at the follow-up visit. Incidence of PVI was calculated using the WHO and US criteria, respectively. The met-need SCR was defined as the percentage of participants with PVA <20/40 that had been improved to ≥20/40 after correction. MAIN OUTCOME MEASURES: Incidence of PVI and SCR. RESULTS: Incidence of PVI was 8.3% (95%CI, 6.9-9.8) and 12.2% (95%CI, 10.5-14.0) based on the WHO and US definition, respectively. Older age, female, lower education level, more myopic spherical equivalent and worse PVA at baseline were significantly related to a higher PVI incidence based on the WHO criteria, with similar associations identified using the US criteria except for gender. The overall met-need SCR was 42.5%, and was lower among the elderly, more hyperopic participants or participants with lower education level. CONCLUSIONS AND RELEVANCE: The incidence of PVI is high in urban Southern China and spectacle wearing is available in less than half of those in need. This highlights the needs to promote spectacle coverage even in the urban population.
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ItemDistribution and progression of add power among people in need of near correction(WILEY, 2018-11)IMPORTANCE: This study helps to better understand the need and trend in presbyopic add power in the aging society. BACKGROUND: Distribution and progression of presbyopic add power in East Asian population is largely unknown. DESIGN: Prospective cohort study. PARTICIPANTS: About 303 participants from a population-based study of residents aged 35 years and older in Guangzhou, China. METHODS: Visual acuity (VA) test and non-cycloplegic automated refraction were performed at baseline in 2008 and the 6-year follow-up per standardized protocol. Participants with presenting near VA ≤ 20/40 underwent distance subjective refraction and add power measurement by increasing plus lens at a standard distance of 40 cm at each visit. MAIN OUTCOME MEASURES: Add power at baseline and follow-ups. RESULTS: Mean (standard deviation) age of the study participants was 57.6 (11.1) years and 50.2% were female. The mean add power at baseline was 1.43, 1.73, 2.03 and 2.20 diopters (D) for individuals in the age groups of 35-44, 45-54, 55-64 and 65+ years, respectively. Participants with older age and lower educational level had significantly higher add power requirements (P < 0.001). The overall 6-year increase in add power was 0.15D (95% CI: 0.06 to 0.25), and was smaller in myopic subjects (P = 0.03). Baseline age and add power, but not changes in biometric factors, were associated with longitudinal change in add power (P < 0.001). CONCLUSIONS AND RELEVANCE: Distribution and progression of add power in Chinese was different from that previously suggested by Caucasian studies. More studies are needed to establish up-to-date age-related add power prescription norms for population of different ethnicities.
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ItemFeasibility and patient acceptability of a novel artificial intelligence-based screening model for diabetic retinopathy at endocrinology outpatient services: a pilot study(NATURE PORTFOLIO, 2018-03-12)The purpose of this study is to evaluate the feasibility and patient acceptability of a novel artificial intelligence (AI)-based diabetic retinopathy (DR) screening model within endocrinology outpatient settings. Adults with diabetes were recruited from two urban endocrinology outpatient clinics and single-field, non-mydriatic fundus photographs were taken and graded for referable DR ( ≥ pre-proliferative DR). Each participant underwent; (1) automated screening model; where a deep learning algorithm (DLA) provided real-time reporting of results; and (2) manual model where retinal images were transferred to a retinal grading centre and manual grading outcomes were distributed to the patient within 2 weeks of assessment. Participants completed a questionnaire on the day of examination and 1-month following assessment to determine overall satisfaction and the preferred model of care. In total, 96 participants were screened for DR and the mean assessment time for automated screening was 6.9 minutes. Ninety-six percent of participants reported that they were either satisfied or very satisfied with the automated screening model and 78% reported that they preferred the automated model over manual. The sensitivity and specificity of the DLA for correct referral was 92.3% and 93.7%, respectively. AI-based DR screening in endocrinology outpatient settings appears to be feasible and well accepted by patients.
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ItemA Comparison of Perimetric Results from a Tablet Perimeter and Humphrey Field Analyzer in Glaucoma Patients(ASSOC RESEARCH VISION OPHTHALMOLOGY INC, 2016-11)PURPOSE: To determine the correlation between the perimetric outcomes from perimetry software Melbourne Rapid Fields (MRF) run on an Apple iPad tablet and those from the Humphrey Field Analyzer (HFA). METHODS: The MRF software was designed with features including variable fixation and fast thresholding using Bayes logic. Here, we report a cross-sectional study on 90 eyes from 90 participants: 12 had normal optic nerves and 78 had glaucoma with various degrees of visual field loss (41 mild and 37 moderate-severe). Exclusion criteria were patients with worse than 20/40 vision or recent intraocular surgery. The visual field outcomes of MRF were compared against those returned from the HFA 24-2 SITA standard. Participants were tested twice on the MRF to establish test-retest repeatability. RESULTS: The test durations were shorter on MRF than HFA (5.7 ± 0.1 vs. 6.3 ± 0.1 minutes, P < 0.001). MRF showed a high level of concordance in its outcomes with HFA (intraclass coefficient [ICC] = 0.93 for mean defect [MD] and 0.86 for pattern deviation [PD]) although the MRF tended to give a less negative MD (1.4 dB bias) compared with the HFA. MRF also showed levels of test-retest reliability comparable to HFA (ICC = 0.93 for MD and 0.89 for PD, 95% limits of agreement -4.5 to 4.3 dB). CONCLUSION: The perimetry results from the MRF have a strong correlation to the HFA outcomes. MRF also has test-retest reliability comparable to HFA. TRANSLATIONAL RELEVANCE: Portable tablet perimetry may allow accurate assessment of visual field when standard perimetry machines are unavailable or unsuitable.