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PURPOSE: To evaluate the diagnostic accuracy of artificial intelligence (AI)-based automated diabetic retinopathy (DR) screening in real-world settings. DESIGN: Systematic review and meta-analysis METHODS: We conducted a systematic review of relevant literature from January 2012 to August 2022 using databases including PubMed, Scopus and Web of Science. The quality of studies was evaluated using Quality Assessment for Diagnostic Accuracy Studies 2 (QUADAS-2) checklist. We calculated pooled accuracy, sensitivity, specificity, and diagnostic odds ratio (DOR) as summary measures. The study protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO - CRD42022367034). RESULTS: We included 34 studies which utilized AI algorithms for diagnosing DR based on real-world fundus images. Quality assessment of these studies indicated a low risk of bias and low applicability concern. Among gradable images, the overall pooled accuracy, sensitivity, specificity, and DOR were 81%, 94% (95% CI: 92.0-96.0), 89% (95% CI: 85.0-92.0) and 128 (95% CI: 80-204) respectively. Sub-group analysis showed that, when acceptable quality imaging could be obtained, non-mydriatic fundus images had a better DOR of 143 (95% CI: 82-251) and studies using 2 field images had a better DOR of 161 (95% CI 74-347). Our meta-regression analysis revealed a statistically significant association between DOR and variables such as the income status, and the type of fundus camera. CONCLUSION: Our findings indicate that AI algorithms have acceptable performance in screening for DR using fundus images compared to human graders. Implementing a fundus camera with AI-based software has the potential to assist ophthalmologists in reducing their workload and improving the accuracy of DR diagnosis.
Subject(s)
Artificial Intelligence , Diabetic Retinopathy , Humans , Diabetic Retinopathy/diagnosis , Reproducibility of Results , Sensitivity and Specificity , Mass Screening/methods , AlgorithmsABSTRACT
Background: We aimed to evaluate the cost-effectiveness of an artificial intelligence-(AI) based diabetic retinopathy (DR) screening system in the primary care setting for both non-Indigenous and Indigenous people living with diabetes in Australia. Methods: We performed a cost-effectiveness analysis between January 01, 2022 and August 01, 2023. A decision-analytic Markov model was constructed to simulate DR progression in a population of 1,197,818 non-Indigenous and 65,160 Indigenous Australians living with diabetes aged ≥20 years over 40 years. From a healthcare provider's perspective, we compared current practice to three primary care AI-based screening scenarios-(A) substitution of current manual grading, (B) scaling up to patient acceptance level, and (C) achieving universal screening. Study results were presented as incremental cost-effectiveness ratio (ICER), benefit-cost ratio (BCR), and net monetary benefits (NMB). A Willingness-to-pay (WTP) threshold of AU$50,000 per quality-adjusted life year (QALY) and a discount rate of 3.5% were adopted in this study. Findings: With the status quo, the non-Indigenous diabetic population was projected to develop 96,269 blindness cases, resulting in AU$13,039.6 m spending on DR screening and treatment during 2020-2060. In comparison, all three intervention scenarios were effective and cost-saving. In particular, if a universal screening program was to be implemented (Scenario C), it would prevent 38,347 blindness cases, gain 172,090 QALYs and save AU$595.8 m, leading to a BCR of 3.96 and NMB of AU$9,200 m. Similar findings were also reported in the Indigenous population. With the status quo, 3,396 Indigenous individuals would develop blindness, which would cost the health system AU$796.0 m during 2020-2060. All three intervention scenarios were cost-saving for the Indigenous population. Notably, universal AI-based DR screening (Scenario C) would prevent 1,211 blindness cases and gain 9,800 QALYs in the Indigenous population, leading to a saving of AU$19.2 m with a BCR of 1.62 and NMB of AU$509 m. Interpretation: Our findings suggest that implementing AI-based DR screening in primary care is highly effective and cost-saving in both Indigenous and non-Indigenous populations. Funding: This project received grant funding from the Australian Government: the National Critical Research Infrastructure Initiative, Medical Research Future Fund (MRFAI00035) and the NHMRC Investigator Grant (APP1175405). The contents of the published material are solely the responsibility of the Administering Institution, a participating institution or individual authors and do not reflect the views of the NHMRC. This work was supported by the Global STEM Professorship Scheme (P0046113), the Fundamental Research Funds of the State Key Laboratory of Ophthalmology, Project of Investigation on Health Status of Employees in Financial Industry in Guangzhou, China (Z012014075). The Centre for Eye Research Australia receives Operational Infrastructure Support from the Victorian State Government. W.H. is supported by the Melbourne Research Scholarship established by the University of Melbourne. The funding source had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
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OBJECTIVES: To evaluate the accuracy of tele-ophthalmic examination (TOE) for common ocular conditions in comparison with the gold-standard in-person examination (IPE) for diagnosis and treatment advice. METHODS: In a prospective, diagnostic accuracy validation study, we recruited 339 consecutive new patients, aged ≥16 years, visiting a vision centre (VC) associated with Aravind Eye Hospital in south India during January and February, 2020. All participants underwent the TOE, followed by IPE on the same visit. The in-person ophthalmologist was masked to the TOE diagnosis and treatment advice. Data were analysed via the sensitivity specificity of TOE versus the gold-standard IPE. RESULTS: TOE achieved high sensitivity and specificity for identifying normal eyes with 87.4% and 93.5%, respectively. TOE had high sensitivity for cataracts (91.7%), infective conjunctivitis (72.2%), and moderate sensitivity for pterygium (62.5%), DR (57.1%), non-serious injury (41.7%), but low sensitivity for glaucoma (12.5%). TOE had high specificity ranging from 93.5% to 99.8% for all diagnoses. The sensitivity for treatment advice ranged from 58.1% to 77.2% and specificity from 96.9% to 100%. CONCLUSIONS: The TOE in VCs has acceptable accuracy to an IPE by an ophthalmologist for correctly identifying and treating major eye ailments. Through providing universal eye care to rural populations, this model may contribute to work toward achieving Universal Health Coverage, which is a linchpin of the health-related U.N. Sustainable Development Goals (SDG).
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Cataract , Glaucoma , Telemedicine , Humans , Rural Population , Prospective Studies , Glaucoma/diagnosis , Cataract/diagnosis , IndiaABSTRACT
Purpose: The purpose of this study was to improve the automated diagnosis of glaucomatous optic neuropathy (GON), we propose a generative adversarial network (GAN) model that translates Optain images to Topcon images. Methods: We trained the GAN model on 725 paired images from Topcon and Optain cameras and externally validated it using an additional 843 paired images collected from the Aravind Eye Hospital in India. An optic disc segmentation model was used to assess the disparities in disc parameters across cameras. The performance of the translated images was evaluated using root mean square error (RMSE), peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), 95% limits of agreement (LOA), Pearson's correlations, and Cohen's Kappa coefficient. The evaluation compared the performance of the GON model on Topcon photographs as a reference to that of Optain photographs and GAN-translated photographs. Results: The GAN model significantly reduced Optain false positive results for GON diagnosis, with RMSE, PSNR, and SSIM of GAN images being 0.067, 14.31, and 0.64, respectively, the mean difference of VCDR and cup-to-disc area ratio between Topcon and GAN images being 0.03, 95% LOA ranging from -0.09 to 0.15 and -0.05 to 0.10. Pearson correlation coefficients increased from 0.61 to 0.85 in VCDR and 0.70 to 0.89 in cup-to-disc area ratio, whereas Cohen's Kappa improved from 0.32 to 0.60 after GAN translation. Conclusions: Image-to-image translation across cameras can be achieved by using GAN to solve the problem of disc overexposure in Optain cameras. Translational Relevance: Our approach enhances the generalizability of deep learning diagnostic models, ensuring their performance on cameras that are outside of the original training data set.
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Glaucoma , Optic Disk , Optic Nerve Diseases , Humans , Glaucoma/diagnosis , Optic Disk/diagnostic imaging , Optic Nerve Diseases/diagnosisABSTRACT
BACKGROUND/AIMS: To estimate the annual cataract surgery workload in Theni district, Tamil Nadu, India based on current utilisation of cataract services, prevalence of blindness and vision impairment (VI), and cataract burden-reduction goals. METHODS: We conducted a population-based longitudinal study between January 2016 and April 2018. We recruited 24 327 participants based on a random cluster sampling method; 7127 participants were ≥40 years. During the year following initial enrolment, we tracked utilisation of eye care services; and at the end of the 1-year period, we conducted a detailed eye examination of participants age ≥40. RESULTS: In the sample age ≥40 years, 13.0% had a visually significant cataract, and 17.8% had prior cataract surgery in at least one eye. The prevalence of cataract blindness based on presenting visual acuity in the better eye (PVABE)<3/60 was 0.34% and VI (PVABE<6/12) was 9.92%. 3.10% of the study population had obtained cataract surgery during 1 year, resulting in a cataract surgical rate of 9085. We estimated the effective cataract surgical coverage (eCSC) to be 54.5% and the CSC to be 75.7%, implying a sizeable quality gap. Prevalence, utilisation and coverage varied by age and gender. We estimated that a goal of eliminating the backlog of VI (PVABE<6/12) in 5 years would increase the annual cataract surgery workload by 11.5% from the current level. CONCLUSIONS: Our estimates of cataract surgery workloads under different scenarios can provide a useful input into planning of eye health services in Theni district.
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Eye care programs, in developing countries, are often planned using the prevalence of blindness and visual impairment, often estimated from Rapid Assessment of Avoidable Blindness (RAAB) surveys. A limitation of this planning approach is that it ignores the annual overall eye care requirements for a given population. Moreover, targets set are arbitrary, often influenced by capacity rather than need. To address this lacunae, we implemented a novel study design to estimate the annual need for comprehensive eye care in a 1.2 million populations. We conducted a population-based longitudinal study in Theni district, Tamil Nadu, India. All permanent residents of all ages were included. We conducted the study in three phases, (i) household-level enumeration and enrollment, (ii) basic eye examination (BEE) at household one-year post-enrollment, and (iii) assessment of eye care utilization and full eye examination (FEE) at central locations. All people aged 40 years and above were invited to the FEE. Those aged <40 years were invited to the FEE if indicated. In the main study, we enrolled 24,327 subjects (58% aged below 40 years and 42% aged 40 years and above). Of those less than 40 years, 72% completed the BEE, of whom 20% were referred for FEE at central location. Of the people aged ≥40 years, 70% underwent FEE. Our study design provides insights for appropriate long-term public health intervention planning, resource allocation, effective service delivery, and designing of eye care services for resource-limited settings.
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Blindness , Workload , Humans , India/epidemiology , Longitudinal Studies , Blindness/diagnosis , Blindness/epidemiology , Comprehensive Health CareABSTRACT
In 2020, the global prevalence of glaucoma was estimated to be 76 million and it was projected to increase to 111.8 million by 2040. Accurate intraocular pressure (IOP) measurement is imperative in glaucoma management since it is the only modifiable risk factor. Numerous studies have compared the reliability of IOP measured using transpalpebral tonometers and Goldmann applanation tonometry (GAT). This systematic review and meta-analysis aims to update the existing literature with a reliability and agreement comparison of transpalpebral tonometers against the gold standard GAT for IOP measurement among individuals presenting for ophthalmic examinations. The data collection will be performed using a predefined search strategy through electronic databases. Prospective methods-comparison studies published between January 2000 and September 2022 will be included. Studies will be deemed eligible if they report empirical findings on the agreement between transpalpebral tonometry and Goldmann applanation tonometry. The standard deviation and limits of agreement between each study and their pooled estimate along with weights and percentage of error will be reported using a forest plot. Cochrane's Q test and the I2 statistic will be used to assess heterogeneity, and the publication bias will be investigated using a funnel plot, Begg's and Egger's tests. The review results will provide additional evidence on the reliability of transpalpebral tonometers that, in turn, could possibly assist practitioners to make informed decision about using it as a screening or diagnostic device for clinical practice, outreach camps, or home-based screening. Institutional Ethics Committee registration number: RET202200390. PROSPERO Registration Number: CRD42022321693.
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Glaucoma , Intraocular Pressure , Humans , Reproducibility of Results , Glaucoma/diagnosis , Tonometry, Ocular/methods , Prospective Studies , Meta-Analysis as Topic , Systematic Reviews as TopicABSTRACT
Purpose: Inadequacy of trained human resources is a critical challenge for eye-care delivery worldwide. Recognizing this, the World Health Organization (WHO) and the International Agency for Prevention of Blindness had identified the development of human resources as one of the focal areas in the global initiative "Vision 2020: The Right to Sight." The global action plan of the WHO also emphasized the need for trained workforce for ensuring comprehensive eye-care services. We aimed to present the uptake pattern of training programs offered at a high-volume training institute in India. Methods: We did a retrospective analysis of data related to training programs conducted between 2000 and 2019. Trainees included ophthalmologists, allied ophthalmic personnel, and eye-care management professionals from all over the world. We analyzed the overall growth over the 20 years in the WHO regions. The uptake patterns were also analyzed across four segments of 5-year-periods by the type of training. Results: Overall, 9091 trainees from 118 countries attended training in over 40 courses that included long- and short-term clinical training for ophthalmologists (54.2%) and short-term training for eye-care managers (29.5%), allied ophthalmic personnel (6.2%), and eye-care technicians (10.2%). The majority of the trainees (81.3%) came from the Southeast Asian region, of which 87.4% were from India. Most (98.3%) of the trainees belonged to developing countries. We found an overall average growth of 4.8% in the training uptake across the four 5-year segments over the 20 years. Conclusion: Comparatively better representation of trainees from the developing countries is encouraging as the prevalence of blindness and visual impairment is higher in those countries, warranting improved eye-care delivery. Given the strong influence of distance and associated costs of accessing training, the development of similar institutes in other regions might help enhance the global efforts to eliminate needless blindness.
Subject(s)
Eye Diseases , Ophthalmology , Humans , Ophthalmology/education , Retrospective Studies , Eye , Blindness/prevention & controlABSTRACT
PURPOSE: To validate the fundus image grading results by a trained grader (Non-ophthalmologist) and an ophthalmologist grader for detecting diabetic retinopathy (DR) and diabetic macular oedema (DMO) against fundus examination by a retina specialist (gold standard). METHODS: A prospective diagnostic accuracy study was conducted using 2002 non-mydriatic colour fundus images from 1001 patients aged ≥40 years. Using the Aravind Diabetic Retinopathy Evaluation Software (ADRES) images were graded by both a trained non-ophthalmologist grader (grader-1) and an ophthalmologist (grader-2). Sensitivity, specificity, positive predictive value and negative predictive value were calculated for grader-1 and grader-2 against the grading results by an independent retina specialist who performed dilated fundus examination for every study participant. RESULTS: Out of 1001 patients included, 42% were women and the mean ± (SD) age was 55.8 (8.39) years. For moderate or worse DR, the sensitivity and specificity for grading by grader-1 with respect to the gold standard was 66.9% and 91.0% respectively and the same for the ophthalmologist was 83.6% and 80.3% respectively. For referable DMO, grader-1 and grader-2 had a sensitivity of 74.6% and 85.6% respectively and a specificity of 83.7% and 79.8% respectively. CONCLUSIONS: Our results demonstrate good level of accuracy for the fundus image grading performed by a trained non-ophthalmologist which was comparable with the grading by an ophthalmologist. Engaging trained non-ophthalmologists potentially can enhance the efficiency of DR diagnosis using fundus images. Further study with multiple non-ophthalmologist graders is needed to verify the results and strategies to improve agreement for DMO diagnosis are needed.
Subject(s)
Diabetes Mellitus , Diabetic Retinopathy , Macular Edema , Humans , Female , Male , Diabetic Retinopathy/diagnosis , Macular Edema/diagnosis , Prospective Studies , Photography , Retina , Sensitivity and SpecificityABSTRACT
PURPOSE: To assess the accuracy of refraction measurements by ClickCheckTM compared with the standard practice of subjective refraction at a tertiary level eye hospital. DESIGN: Diagnostic accuracy trial. METHODS: All participants, recruited consecutively, underwent auto-refraction (AR) and subjective refraction (SR) followed by refraction measurement using ClickCheckTM (CR) by a trained research assistant. Eyeglass prescriptions generated using ClickCheckTM and the resulting visual acuity (VA) was compared to SR for accuracy. Inter-rater reliability and agreement were determined using Intra-class correlation and Bland Altman analysis respectively. RESULTS: The 1,079 participants enrolled had a mean (SD) age of 39.02 (17.94) years and 56% were women. Overall, 45.3% of the participants had refractive error greater than ±0.5D. The mean (SD) spherical corrections were -0.66D (1.85) and -0.89D (2.20) in SR and CR respectively. There was high level of agreement between the spherical power measured using SR and CR (ICC: 0.940 (95% CI: 0.933 to 0.947). For the assessment of cylindrical correction, there was moderate level of agreement between SR and CR (ICC: 0.493 (0.100 to 0.715). There was moderate level of agreement between the VA measurements performed by using corrections from SR and CR (ICC: 0.577 (95% CI: 0.521-0.628). The subgroup analysis based on the age categories also showed high level of agreement for spherical corrections between the two approaches (ICC: 0.900). Bland Altman analysis showed good agreement for spherical corrections between SR and CR (Mean difference: 0.224D; 95% LoA: -1.647 D to 2.096 D) without evidence of measurement bias. CONCLUSIONS: There was a high level of agreement for spherical power measurement between CR and SR. However, improvements are needed in order to accurately assess the cylindrical power. Being a portable, low-cost and easy-to-use refraction device, ClickCheckTM can be used for first level assessment of refractive errors, thereby enhancing the efficiency of refractive services, especially in low- and-middle-income countries.
Subject(s)
Refraction, Ocular , Refractive Errors , Adult , Female , Humans , Male , Middle Aged , Refractive Errors/diagnosis , Reproducibility of Results , Vision Tests , Visual AcuityABSTRACT
PURPOSE: To compare patient preferences for eyeglasses prescribed using a low-cost, portable wavefront autorefractor versus standard subjective refraction (SR). DESIGN: Randomized, cross-over clinical trial. PARTICIPANTS: Patients aged 18 to 40 years presenting with refractive errors (REs) to a tertiary eye hospital in Southern India. METHODS: Participants underwent SR followed by autorefraction (AR) using the monocular version of the QuickSee device (PlenOptika Inc). An independent optician, masked to the refraction approach, prepared eyeglasses based on each refraction approach. Participants (masked to refraction source) were randomly assigned to use SR- or AR-based eyeglasses first, followed by the other pair, for 1 week each. At the end of each week, participants had their vision checked and were interviewed about their experience with the eyeglasses. MAIN OUTCOME MEASURES: Patients preferring eyeglasses were chosen using AR and SR. RESULTS: The 400 participants enrolled between March 26, 2018, and August 2, 2019, had a mean (standard deviation) age of 28.4 (6.6) years, and 68.8% were women. There was a strong correlation between spherical equivalents using SR and AR (r = 0.97, P < 0.001) with a mean difference of -0.07 diopters (D) (95% limits of agreement [LoA], -0.68 to 0.83). Of the 301 patients (75.2%) who completed both follow-up visits, 50.5% (n = 152) and 49.5% (n = 149) preferred glasses prescribed using SR and AR, respectively (95% CI, 45.7-56.3; P = 0.86). There were no differences in demographic or vision characteristics between participants with different preferences (P > 0.05 for all). CONCLUSIONS: We observed a strong agreement between the prescriptions from SR and AR, and eyeglasses prescribed using SR and AR were equally preferred by patients. Wider use of prescribing based on AR alone in resource-limited settings is supported by these findings.
Subject(s)
Eyeglasses , Prescriptions , Refractive Errors/diagnosis , Retinoscopy/economics , Retinoscopy/standards , Adolescent , Adult , Cross-Over Studies , Double-Blind Method , Female , Humans , Male , Patient Acceptance of Health Care , Refraction, Ocular/physiology , Refractive Errors/physiopathology , Refractive Errors/therapy , Reproducibility of Results , Young AdultABSTRACT
PURPOSE: To assess whether routine fundus photography (RFP) to screen for posterior segment disease at community eye clinics (vision centers [VCs]) in India increases referral to centralized ophthalmolic care. DESIGN: Stepped-wedge, cluster-randomized trial. PARTICIPANTS: Patients aged 40 to 75 years and those aged 20 to 40 years with a known history of hypertension or diabetes mellitus presenting to 4 technician-run VCs associated with the Aravind Eye Care System in India. METHODS: VCs (clusters) were randomized to standard care or RFP across five 2-week study periods (steps). Patients in each cluster received standard care initially. At the start of each subsequent step, a randomly chosen cluster crossed over to providing RFP to eligible patients. All clusters took part in RFP during the last step. Standard care involved technician eye exams, optional fundus photography, and teleconsultation with an ophthalmologist. RFP involved eye exams, dilation and 40-degree fundus photography, and teleconsultation with an ophthalmologist. MAIN OUTCOME MEASURES: Standard care and RFP clusters were compared by the proportion of patients referred for in-person evaluation by an ophthalmologist because of fundus photography findings and urgency of referral (urgently in ≤ 2 weeks vs. nonurgently in > 2 weeks). Generalized linear mixed models adjusting for cluster and step were used to estimate the odds of referral due to fundus photography findings compared with standard care. RESULTS: A total of 1447 patients were enrolled across the VCs, including 737 in the standard care group and 710 in the RFP group. Compared with standard care, the RFP group had a higher proportion of referrals due to fundus photography findings (11.3% vs. 4.4%), nonurgent referrals due to fundus photography (9.3% vs. 3.3%), and urgent referrals due to fundus photography (1.8% vs. 1.1%). The RFP intervention was associated with a 2-fold increased odds of being referred because of photography findings compared with standard care (odds ratio, 2.07; 95% confidence interval, 0.98-4.40; P = 0.058). CONCLUSIONS: Adding RFP to community eye clinics was associated with an increased odds of referral compared with standard care. This increase in referral was mostly due to nonurgent posterior segment disease.
Subject(s)
Diagnostic Techniques, Ophthalmological/statistics & numerical data , Photography/statistics & numerical data , Posterior Eye Segment/diagnostic imaging , Retina/diagnostic imaging , Retinal Diseases/diagnosis , Vision Screening/methods , Adult , Aged , Female , Fundus Oculi , Humans , India/epidemiology , Male , Middle Aged , Morbidity/trends , Retinal Diseases/epidemiologyABSTRACT
Purpose: To understand demographic and socioeconomic barriers and treatment-seeking behaviors of patients with infectious keratitis requiring therapeutic penetrating keratoplasty (TPK) in a developing country. Methods: This prospective non-comparative questionnaire- based study included all patients presenting to Aravind Eye Hospital, Madurai with infectious keratitis that eventuated to TPK between November 2015 and October 2016. A structured questionnaire was administered on post-operative day 3 to collect data on the demographic details, predisposing factors, prior treatment received, and treatment expenditures. Results: In total, 227 patients underwent TPK between November 2015 and October 2016 for infectious keratitis. The majority of patients were males (n = 132, 58.1%), illiterate (n = 129, 56.8%), and had a family monthly income of less than INR 6000 (n = 142, 62.5%). Most of the patients (n = 163, 71.8%) had prior treatment with an ophthalmologist before presenting to our hospital. The mean distance travelled to reach our centre was 269.2 ± 298.5 km. The mean duration of disease before the presentation was 20.3 ± 21.1 days. Corneal smear was positive for fungus in 163 (88.1%) and Aspergillus was the most commonly isolated fungi in 55 (41.3%) cultures. The mean total cost of treatment was INR 8752.87 ± 7615.39 per patient. There was a positive correlation between the duration of the disease (rho 0.19, P = 0.0034) and the costs of treatment (rho 0.2, P = 0.0024) with the distance travelled by the patient. Conclusion: Patients who travelled a farther distance had a delayed onset of presentation and spent significantly more than their respective counterparts.
Subject(s)
Acanthamoeba Keratitis/epidemiology , Corneal Ulcer/epidemiology , Eye Infections, Bacterial/epidemiology , Eye Infections, Fungal/epidemiology , Keratoplasty, Penetrating , Patient Acceptance of Health Care/psychology , Socioeconomic Factors , Acanthamoeba Keratitis/parasitology , Acanthamoeba Keratitis/surgery , Adult , Corneal Ulcer/microbiology , Corneal Ulcer/surgery , Eye Infections, Bacterial/microbiology , Eye Infections, Bacterial/surgery , Eye Infections, Fungal/microbiology , Eye Infections, Fungal/surgery , Female , Graft Survival , Humans , Male , Middle Aged , Prospective Studies , Visual AcuityABSTRACT
OBJECTIVE: To assess the quality of eyeglass prescriptions provided by an affordable wavefront autorefractor operated by a minimally trained technician in a low-resource setting. METHODS AND ANALYSIS: 708 participants were recruited from consecutive patients registered for routine eye examinations at Aravind Eye Hospital in Madurai, India, or an affiliated rural satellite vision centre. Visual acuity (VA) and patient preference were compared between trial lenses set to two eyeglass prescriptions from (1) a novel wavefront autorefractor and (2) subjective refraction by an experienced refractionist. RESULTS: The mean±SD VA was 0.30±0.37, -0.02±0.14 and -0.04±0.11 logarithm of the minimum angle of resolution units before correction, with autorefractor correction and with subjective refraction correction, respectively (all differences p<0.01). Overall, 25% of participants had no preference, 33% preferred eyeglass prescriptions from autorefraction, and 42% preferred eyeglass prescriptions from subjective refraction (p<0.01). Of the 438 patients 40 years old and younger, 96 had no preference and the remainder had no statistically significant difference in preference for subjective refraction prescriptions (51%) versus autorefractor prescriptions (49%) (p=0.52). CONCLUSION: Average VAs from autorefractor-prescribed eyeglasses were one letter worse than those from subjective refraction. More than half of all participants either had no preference or preferred eyeglasses prescribed by the autorefractor. This marginal difference in quality may warrant autorefractor-based prescriptions, given the portable form factor, short measurement time, low cost and minimal training required to use the autorefractor evaluated here.
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Importance: Studies in high-income countries provide limited evidence from randomized clinical trials on the benefits of teleretinal screening to identify diabetic retinopathy (DR). Objective: To evaluate the effectiveness of teleretinal-screening hospital referral (TR) compared with universal hospital referral (UR) in people with diabetes. Design, Setting, and Participants: A cluster randomized clinical trial of 8 diabetes clinics within 10 km from Aravind Eye Hospital (AEH), Madurai, India, was conducted. Participants included 801 patients older than 50 years. The study was conducted from May 21, 2014, to February 7, 2015; data analysis was performed from March 12 to June 16, 2015. Interventions: In the TR cohort, nonmydriatic, 3-field, 45° retinal images were remotely graded by a retinal specialist and patients with DR, probable DR, or ungradable images were referred to AEH for a retinal examination. In the UR cohort, all patients were referred for a retinal examination at AEH. Main Outcomes and Measures: Hospital-diagnosed DR. Results: Of the 801 participants, 401 were women (50.1%) (mean [SD] age, 60.0 [7.3] years); mean diabetes duration was 8.6 (6.6) years. In the TR cohort, 96 of 398 patients (24.1%) who underwent teleretinal imaging were referred with probable DR (53 [13.3%]) or nongradable images (43 [10.8%]). Hospital attendance at AEH was proportionately higher with TR (54 of 96 referred [56.3%]) compared with UR (150 of 400 referred [37.5%]). The intention-to-treat analysis based on all patients eligible for referral in each arm showed that proportionately more patients with TR (36 of 96 [37.5]%) were diagnosed with DR compared with UR (50 of 400 [12.5%]) (unadjusted risk ratio [RR], 3.00; 95% CI, 2.01-4.48). These results were little changed by inclusion of covariates (RR, 2.72; 95% CI, 1.90-3.91). The RR was lower in the per-protocol analysis based on all patients who adhered to referral (covariate-adjusted RR, 1.75; 95% CI, 1.12-2.74). Diagnoses of DR were predominantly mild or moderate nonproliferative DR (36 in TR and 43 in UR). In the UR arm, there were 4 cases of severe nonproliferative DR and 2 cases of proliferative DR. Age (RR, 0.98; 95% CI, 0.95-0.99), female sex (RR, 0.79; 95% CI, 0.64-0.98), and hypertension diagnosis (RR, 0.81; 95% CI, 0.68-0.95) were factors associated with lower attendance. Those with higher secondary educational level or more were twice as likely to attend (RR, 2.00; 95% CI, 1.32-3.03). Conclusions and Relevance: The proportionate yield of DR cases was higher in the TR arm, confirming the potential benefit, at least in the setting of eye hospitals in India, of a targeted referral approach using teleretinal screening to identify patients with DR. Trial Registration: ClinicalTrials.gov identifier: NCT02085681.
Subject(s)
Diabetic Retinopathy/diagnosis , Diagnostic Imaging/methods , Referral and Consultation , Telemedicine/methods , Vision Screening/methods , Aged , Ambulatory Care Facilities , Cluster Analysis , Diagnostic Tests, Routine , Female , Humans , India , Male , Middle Aged , Odds Ratio , Program EvaluationABSTRACT
PURPOSE: To investigate prevalence and risk factors for myopia, hyperopia and astigmatism in southern India. METHODS: Randomly sampled villages were enumerated to identify people aged ≥40 years. Participants were interviewed for socioeconomic and lifestyle factors and attended a hospital-based ophthalmic examination including visual acuity measurement and objective and subjective measurement of refractive status. Myopia was defined as spherical equivalent (SE) worse than -0.75 dioptres (D), hyperopia as SE ≥+1D and astigmatism as cylinder <-0.5. RESULTS: The age-standardised prevalences of myopia, hyperopia and astigmatism were 35.6% (95% CI: 34.7-36.6), 17.0% (95% CI: 16.3-17.8) and 32.6 (29.3-36.1), respectively. Of those with myopia (n = 1490), 70% had advanced cataract. Of these, 79% had presenting visual acuity (VA) less than 6/18 and after best correction, 44% of these improved to 6/12 or better and 27% remained with VA less than 6/18. In multivariable analyses (excluding patients with advanced cataract), increasing nuclear opacity score, current tobacco use, and increasing height were associated with higher odds of myopia. Higher levels of education were associated with increased odds of myopia in younger people and decreased odds in older people. Increasing time outdoors was associated with myopia only in older people. Increasing age and female gender were associated with hyperopia, and nuclear opacity score, increasing time outdoors, rural residence and current tobacco use with lower odds of hyperopia. After controlling for myopia, factors associated with higher odds of astigmatism were age, rural residence, and increasing nuclear opacity score and increasing education with lower odds. CONCLUSIONS: In contrast to high-income settings and in agreement with studies from low-income settings, we found a rise in myopia with increasing age reflecting the high prevalence of advanced cataract.
Subject(s)
Myopia/epidemiology , Population Surveillance , Refraction, Ocular/physiology , Risk Assessment , Rural Population , Adult , Aged , Female , Humans , India/epidemiology , Male , Middle Aged , Myopia/physiopathology , Prevalence , Refractive Errors/epidemiology , Refractive Errors/physiopathology , Risk FactorsABSTRACT
BACKGROUND: For patient undergoing cataract surgery in India, existing patient-reported outcome (PRO) measures are either not culturally relevant, have not been adequately validated, or are too long to be used in a busy clinical setting. We sought to develop and validate a brief and culturally relevant point-of-care PRO measure to address this need. METHODS: Twelve items from the Indian Visual Functioning Questionnaire (IND-VFQ) were selected based on preliminary data. Patients 18 years and older were prospectively recruited at Aravind Eye Care System in Madurai, India. Clinical and sociodemographic data were collected and the 12-item short-form IND-VFQ (SF-IND-VFQ) was administered pre- and post-operatively to 225 patients; Factor analysis and Rasch modeling was performed to assess its psychometric properties. RESULTS: One item that did not fit a unidimensional scale and had poor fit with the Rasch model was eliminated from the questionnaire. The remaining 11 items represented a single construct (no residual correlations> 0.1) and were largely unaffected by differential item functioning. Five items had disordered thresholds resolved by collapsing the response scale from four to three categories. The survey had adequate reliability (0.80) and good construct (infit range, 0.77-1.29; outfit range, 0.56-1.30) and content (item separation index, 5.87 logits) validity. Measurement precision was fair (person separation index, 1.97). There was evidence that items were not optimally targeted to patients' visual ability (preoperatively, - 1.92 logits; overall, - 3.41 logits), though the survey measured a very large effect (Cohen's d 1.80). In a subset of patients, the average time to complete the questionnaire was 2 min 6.3 s. CONCLUSIONS: The SF-IND-VFQ is a valid, reliable, sensitive, and rapidly administered point-of-care PRO measure to assess changes in visual functioning in patients undergoing cataract surgery in India.
Subject(s)
Cataract Extraction , Patient Reported Outcome Measures , Point-of-Care Systems/standards , Quality of Life , Aged , Female , Humans , India , Male , Middle Aged , Postoperative Period , Prospective Studies , Psychometrics , Reproducibility of ResultsABSTRACT
PURPOSE: To study the optimal method for delivery of spectacles at eye camps to maximize procurement and use. METHODS: A cluster randomized controlled trial, undertaken in the catchment districts of Aravind Eye Hospital - Theni, in the state of Tamil Nadu, India. Community eye camps (n = 21) were allocated to offer one of three types of service for purchase of spectacles to correct refractive error: (1) Issuance of a prescription only; (2) booking orders for spectacles with subsequent delivery; (3) on-the-spot fitting and dispensing of spectacles. Follow-up questionnaires were administered 6 weeks after interventions to assess patient outcomes. The primary outcome measured was spectacle procurement at follow-up 6 weeks post-screening. Secondary outcomes included use of and satisfaction with spectacles. Reasons for purchase/non-purchase were also assessed. RESULTS: Compared to those who were issued only a prescription and adjusting for distance from base hospital, spectacle procurement was significantly higher for those allowed to book spectacles for subsequent delivery (odds ratio, OR, 8.79, 95% confidence interval, CI, 4.61-16.78) and for those receiving spectacles on the spot (OR 13.97, 95% CI 8.12-24.05). Among those with spectacles at 6 weeks, spectacle use was nearly universal and satisfaction with spectacles varied between 92 and 94% among the three different dispensing modalities. CONCLUSION: Making spectacles available on the spot is important to ensure procurement in a context where availability and access to dispensing opticians is poor.
Subject(s)
Community Health Services/supply & distribution , Delivery of Health Care/methods , Eyeglasses/supply & distribution , Health Services Accessibility/statistics & numerical data , Refractive Errors/therapy , Adult , Aged , Cluster Analysis , Female , Humans , India/epidemiology , Male , Middle Aged , Patient Satisfaction/statistics & numerical data , Prescriptions/statistics & numerical data , Young AdultABSTRACT
PURPOSE: To investigate patterns and characteristics of men and women who used different cataract surgery payment streams in a South Indian hospital. METHODS: We randomly sampled patients with age-related cataract aged 40 years and over from three routine cataract surgical service streams: walk-in paying, walk-in subsidized and free camp. Presenting visual acuity (VA) and cataract surgical details were obtained from routine hospital records. Demographic and socioeconomic factors were collected from patient interviews. Multiple logistic regression was used to investigate factors associated with use of different streams with walk-in paying as the reference group. RESULTS: There were 7076 eligible admissions (3742 women and 3334 men). Proportionately more women than men attended the walk-in subsidized (56%) or free camp sections (55%) compared to the walk-in paying stream (42%, odds ratio, OR, 1.40 95% confidence interval, CI, 1.25-1.57 and OR 1.33 95% CI 1.19-1.49, respectively). After adjustment for socioeconomic factors (illiteracy, not being in paid work), rural residence and poor presenting VA, OR for women compared to men for the walk-in subsided stream was 1.02, (95% CI 0.87-1.18) and for the free camp 0.94 (95% CI 0.80-1.11). CONCLUSION: Our results indicate that women are underrepresented in the paying section, reflecting their poorer socioeconomic and educational statuses.
Subject(s)
Cataract Extraction/economics , Cataract Extraction/statistics & numerical data , Cataract/epidemiology , Delivery of Health Care/economics , Health Status Disparities , Interpersonal Relations , Adult , Age Distribution , Aged , Aged, 80 and over , Cross-Sectional Studies , Delivery of Health Care/statistics & numerical data , Female , Financing, Personal/statistics & numerical data , Health Care Costs , Health Services Accessibility/economics , Health Services Accessibility/statistics & numerical data , Humans , India/epidemiology , Male , Middle Aged , Odds Ratio , Rural Population , Sex Distribution , Visual AcuityABSTRACT
The global initiative, "VISION 2020 - The Right to Sight" aims to eliminate avoidable blindness by year 2020. Avoidable blindness by definition are those conditions for which we already have a treatment or a surgical procedure and often a proven strategy to either prevent or cure the condition. Thus, the challenge to realize this goal would be designing the right service delivery systems specific to the local context, organizing the required resources, coordination, and implementing and monitoring these. The key "discipline" that is required to ensure successful implementation is "Management." To be holistic, such management inputs are required both in a program as well as the hospital setting. From a program perspective, the focus will need to be on reaching the unreached, ensuring equity, creating an enabling environment, putting in place the required infrastructure, including that for developing all cadres of the eye care team, and functionally integrating eye care into the general health system and other developmental activities. From a hospital perspective, the management process should manage the internal and external ecosystems as well as all the interfaces to the hospital. It should also put in place systems for ensuring an adequate patient flow, high productivity, quality, sustainability, and accountability. Since in many countries the notion of management in health care or more specifically in eye care is at an early stage or nonexistent, a proactive effort is required to build the management capacity quickly through a structured process.