Trained Optometrists Research Articles

Eye disease knowledge and awareness among Iranian population: The Gilan Eye Study

The purpose of this study was to investigate the public knowledge regarding cataract, glaucoma, refractive error, and diabetic retinopathy among Iranian population living in Gilan province. This population-based cross-sectional study was conducted on 2588 individuals aged over 50, living in both urban and rural districts of Gilan. All participants were interviewed to determine their knowledge regarding the mentioned eye diseases. Their source of knowledge was determined whether health care professionals, family or relatives, social media, or publications. Socioeconomic status (SES) of participants was calculated based on the principal component analysis. The presenting visual acuity of all study participants was assessed by a trained optometrist. In this study, total knowledge of cataract, glaucoma, refractive errors and diabetic retinopathy was 52.1%, 2.5%, 15.1%, and 29.7%, respectively. A lower cataract knowledge was found in participants with low (odds ratio [OR] = 0.44; p = .02) and moderate SES (OR = 0.56, p = .02). We also lower knowledge of glaucoma among low (OR = 0.33; p < .001) and moderate SES group (OR = 0.48, p = .002). A higher level of knowledge about refractive error was observed in participants with normal vision (OR = 4.89; p = .011) and mild/moderate visual impairment (OR = 3.69; p = .046). Participants without a history of diabetes mellitus had less knowledge about diabetic retinopathy (DR) (OR = 0.56; p < .001), while those with more than 12 years of education had higher knowledge about DR. In conclusion, lower level of the knowledge was identified among individuals with lower levels of SES and education, while participants with better vision could be benefit from the high levels of knowledge.

Expert-Level Detection of Referable Glaucoma from Fundus Photographs in a Safety Net Population: The AI and Teleophthalmology in Los Angeles Initiative.

To develop and test a deep learning (DL) algorithm for detecting referable glaucoma in the Los Angeles County (LAC) Department of Health Services (DHS) teleretinal screening program. Fundus photographs and patient-level labels of referable glaucoma (defined as cup-to-disc ratio [CDR] ≥ 0.6) provided by 21 trained optometrist graders were obtained from the LAC DHS teleretinal screening program. A DL algorithm based on the VGG-19 architecture was trained using patient-level labels generalized to images from both eyes. Area under the receiver operating curve (AUC), sensitivity, and specificity were calculated to assess algorithm performance using an independent test set that was also graded by 13 clinicians with one to 15 years of experience. Algorithm performance was tested using reference labels provided by either LAC DHS optometrists or an expert panel of 3 glaucoma specialists. 12,098 images from 5,616 patients (2,086 referable glaucoma, 3,530 non-glaucoma) were used to train the DL algorithm. In this dataset, mean age was 56.8 ± 10.5 years with 54.8% females and 68.2% Latinos, 8.9% Blacks, 2.7% Caucasians, and 6.0% Asians. 1,000 images from 500 patients (250 referable glaucoma, 250 non-glaucoma) with similar demographics (p ≥ 0.57) were used to test the DL algorithm. Algorithm performance matched or exceeded that of all independent clinician graders in detecting patient-level referable glaucoma based on LAC DHS optometrist (AUC = 0.92) or expert panel (AUC = 0.93) reference labels. Clinician grader sensitivity (range: 0.33-0.99) and specificity (range: 0.68-0.98) ranged widely and did not correlate with years of experience (p ≥ 0.49). Algorithm performance (AUC = 0.93) also matched or exceeded the sensitivity (range: 0.78-1.00) and specificity (range: 0.32-0.87) of 6 LAC DHS optometrists in the subsets of the test dataset they graded based on expert panel reference labels. A DL algorithm for detecting referable glaucoma developed using patient-level data provided by trained LAC DHS optometrists approximates or exceeds performance by ophthalmologists and optometrists, who exhibit variable sensitivity and specificity unrelated to experience level. Implementation of this algorithm in screening workflows could help reallocate eye care resources and provide more reproducible and timely glaucoma care.

Comparison of cycloplegia with atropine 1% versus cyclopentolate 1.

Cycloplegic refraction is mandatory for children to know the eye's refractive status. In this study, we compared cycloplegia induced by cyclopentolate 1% to that induced by atropine 1% by means of retinoscopy. In this parallel-designed interventional study, we included 67 children aged between 4 and 17 years. After the initial retinoscopy under cyclopentolate 1% (used twice in each eye), we repeated it a week later under atropine ointment 1% (used twice a day for 3 days); both were done by the same trained optometrist masked to the drug. Each eye's refraction was converted to spherical equivalents (SEs), and the values averaged between the two eyes of each child under each drug. We compared SE with paired t-test (JASP 16.4). In addition, we performed correlational analysis, and looked for agreement using the Bland-Altman plot. Significance was set at P < 0.05. Wherever possible, 95% confidence intervals (CIs) are quoted. The mean SE with atropine was +1.93 ± 2.0 D, compared to +1.75 ± 1.95 D under cyclopentolate. On average, atropine induced greater cycloplegia by a mere 0.18 D (95% CI: 0.07 to 0.29 D, P value 0.002). The two cycloplegic refractions correlated significantly (Pearson's r: 0.975, P < 0.001). The Bland-Altman plot revealed the limits of agreement as 1.06 and -0.71 D. Our study suggests that cyclopentolate works for the most part as well as atropine to attain cycloplegia. Atropine may be considered for children less than 15 years of age with greater than 5.0 D of hyperopia. Cycloplentolate, with its advantages of quick action and short duration, should form the first go-to topical cycloplegic in busy outpatient clinics.

FREQUENCY OF REFRACTIVE ERROR AND AMBLYOPIA IN STRABISMUS IN PEDIATRIC AGE GROUP

Objective: To see the frequency and compare the type of refractive error and strabismus in amblyopic versus non amblyopic children.&#x0D; Study Design: Comparative cross sectional study.&#x0D; Place and Duration of Study: Armed Forces Institute of Ophthalmology, Rawalpindi, from Jan to Jul 2019.&#x0D; Methodology: The sample population comprised of 250 patients of new or previously diagnosed children with refractive error and strabismus presenting at children eye outdoor patient department of armed forces institute of ophthalmology. Strabismus was diagnosed by the consultant eye specialist on the basis of heterotropia at near or distance fixation. Amblyopia and refracttive error was assessed by a trained optometrist. Patients were classified into amblyopia and non- amblyopia groups. The type of squint and refractive error was noted down along with demographic details. Chi square test was used to assess thesignificance of association between various categorical variables.&#x0D; Results: A total of 250 participants were included with a mean age of 5.00 ± 1.07 years. Out of total, 132 (52.8%) were males while 118 (47.2%) were females. One hundred and fifty (59.5%) patients were suffering from amblyopia while 100 (39.5%) patients were normal with comparable vision in both the eyes. Out of 150 amblyopic patients 134 (89.3%) were suffering from unilateral amblyopia while 16 (10.6%) patients had amblyopia in both the eyes. Out of refractive errors astigmatism was present in 83 (55.3 %) of amblyopia patients while hypermetropia was present in 54 (36%) of the patients. Out of total patients of strabismus, 95 (63.3%) of non-alternating esotropic patients..........

Mohsin's schoolchildren eye screening program - Analysis of the results

Aim of the Study: To determine the prevalence of ocular morbidity among government schoolchildren from Mohsin's Schoolchildren Eye Screening Program. Design: A school-based, observational study design. Participants: Schoolchildren between 1st and 10th standards across various government schools. Materials and Methods: Students of 429 government schools of Visakhapatnam were covered under this eye screening program. It was a three-staged program. In the first stage, 84,727 students were screened for visual impairment and the presence of any abnormality by trained teachers or optometrists. In the second stage, those who were identified were subjected to a detailed ocular examination and refraction in the school premises by trained optometrists. Glasses were dispensed for those who improved to normal visual acuity and treatment was given for minor ailments by optometrists, residents and ophthalmologists requiring further evaluation were referred to the base hospital for examination and appropriate management by an ophthalmologist in the third stage. Results: 84,727 children from 429 schools were screened. Ocular morbidity was 6.07%. Refractive error was the most common ocular disorder identified in 3.74% with a significantly high rate among secondary schoolchildren (P

Effectiveness of Kanna photoscreener in detecting amblyopia risk factors.

Purpose:Amblyopia is a significant public health problem. Photoscreeners have been shown to have significant potential for screening; however, most are limited by cost and display low accuracy. The purpose of this study was validate a novel artificial intelligence (AI) and machine learning–based facial photoscreener “Kanna,” and to determine its effectiveness in detecting amblyopia risk factors.Methods:A prospective study that included 654 patients aged below 18 years was conducted in our outpatient clinic. Using an android smartphone, three images of each the participants’ face were captured by trained optometrists in dark and ambient light conditions and uploaded onto Kanna. Deep learning was used to create an amblyopia risk score based on our previous study. The algorithm generates a risk dashboard consisting of six values: five normalized risk scores for ptosis, strabismus, hyperopia, myopia and media opacities; and one binary value denoting if a child is “at-risk” or “not at-risk.” The presence of amblyopia risk factors (ARF) as determined on the ophthalmic examination was compared with the Kanna photoscreener.Results:Correlated patient data for 654 participants were analyzed. The mean age of the study population was 7.87 years. The algorithm had an F-score, 85.9%; accuracy, 90.8%; sensitivity, 83.6%; specificity, 94.5%; positive predictive value, 88.4%; and negative predictive value, 91.9% in identifying amblyopia risk factors. The P value for the amblyopia risk calculation was 8.5 × 10−142 implying strong statistical significance.Conclusion:The Kanna photo-based screener that uses deep learning to analyze photographs is an effective alternative for screening children for amblyopia risk factors.

Depth-resolved variations in visibility of retinal nerve fibre bundles across the retina in enface OCT images of healthy eyes.

Recent developments in optical coherence tomography (OCT) technology enable direct enface visualisation of retinal nerve fibre bundle (RNFB) loss in glaucoma. However, the optimum depth at which to visualise RNFBs across the retina is unknown. We aimed to evaluate the range of depths and optimum depth at which RNFBs can be visualised across the retina in healthy eyes. The central±25° retina of 10 healthy eyes from 10 people aged 57-75years (median 68.5years) were imaged with spectral domain OCT. Slab images of maximum axial resolution (4μm) containing depth-resolved attenuation coefficients were extracted from 0 to 193.5μm below the inner limiting membrane (ILM). Bundle visibility within 10 regions of a superimposed grid was assessed subjectively by trained optometrists (n=8), according to written instructions. Anterior and posterior limits of RNFB visibility and depth of best visibility were identified for each grid sector. Effects of retinal location and individual eye on RNFB visibility were explored using linear mixed modelling with likelihood ratio tests. Intraclass correlation coefficient (ICC) was used to measure overall agreement and repeatability of grading. Spearman's correlation was used to measure correlation between depth range of visible RNFBs and retinal nerve fibre layer thickness (RNFLT). Retinal location and individual eye affected anterior limit of visibility (χ2(9) =58.6 and 60.5, both p<0.0001), but none of the differences exceeded instrument resolution, making anterior limit consistent across the retina and different eyes. Greater differences were observed in the posterior limit of visibility across retinal areas (χ2(9) =1671.1, p<0.0001) and different eyes (χ2(9) =88.7, p<0.0001). Optimal depth for visualisation of RNFBs was around 20µm below the ILM in most regions. It varied slightly with retinal location (χ2(9) =58.8, p<0.0001), but it was not affected by individual eye (χ2(9) =10.7, p=0.29). RNFB visibility showed good agreement between graders (ICC 0.89, 95%CI 0.87-0.91), and excellent repeatability (ICC 0.96-0.99). Depth range of visible RNFBs was highly correlated with RNFLT (ρ=0.9, 95%CI: 0.86-0.95). The range of depths with visible RNFBs varies markedly across the healthy retina, consistently with RNFLT. To extract all RNFB information consistently across the retina, slab properties should account for differences across retinal locations and between individual eyes.

Prenatal and neonatal factors for the development of childhood visual impairment in primary and middle school students: a cross-sectional survey in Guangzhou, China

ObjectivesIn this cross-sectional survey, we sought to determine the prevalence of and the influence of prenatal and neonatal factors on childhood visual impairment without correction (VIUC) in a paediatric population...

Diagnostic Accuracy of Direct Ophthalmoscopy and Non-Mydriatic Retinal Photography by Trained Optometrists for Screening of Diabetic Retinopathy

Purpose: To determine the reliability of direct ophthalmoscopy and Non-Mydriatic fundus photography for screening of Diabetic Retinopathy by optometrist.&#x0D; Study Design: Observational, cross sectional.&#x0D; Place and Duration of Study: Al-Ibrahim eye hospital, Karachi from October to December 2018.&#x0D; Material and Methods: All individuals with type 2 diabetes of≥ 40 years of age were screened for diabetic retinopathy (DR) by two trained optometrists and an ophthalmologist. First Optometrist used Non Mydriatic Fundus Camera (NMFC) and second optometrist used direct ophthalmoscopy (DO) after dilating the pupils. Final examination was done by the Ophthalmologist with slit lamp using Volk fundus lens which was considered as reference standard. Every investigator was kept unaware of the findings of others.&#x0D; Results: A total of 698 eyes of 349 respondents were screened. Ophthalmologist could not make decision by bio microscopy in 44 (6.3%) individuals as compared to 128 (18.3%) by 1st optometrist by NMFC and 142 (20.3%) by 2nd optometrist with DO. Diabetic retinopathy (DR) was diagnosed in 1493 (21.4%) with slit lamp, in 1172 (16.8%) with NMFC and in 1333 (19.1%) with DO. Sensitivity of NMFC was 76% and that of DO was 64.8%. Specificity of NMFC was 97.45% and that of DO was 96.63%. Positive predictive value (PPV) of NMFC was 89.33% and that of DO was 84.3% Negative predictive value (NPV) of NMFC was 93.33% and that of DO was 90.7%.&#x0D; Conclusion: NMFC is recommended tool for DR screening; but DO by well-trained optometrist can be reliable where neither ophthalmologist nor NMFC is available.

Hyderabad Ocular Morbidity in Elderly Study (HOMES) – Rationale, Study Design and Methodology

ABSTRACTPurpose: To describe the study design, interobserver variability of the questionnaires and clinical procedures of Hyderabad Ocular Morbidity in Elderly Study (HOMES) designed to, (a) to investigate the prevalence, causes and risk factors for visual impairment, and (b) to assess the impact of dispensing spectacles and cataract surgery on visual functions, fear of falls (FOF) and depression among the elderly in India.Methods: Individuals aged ≥60 years are considered elderly. The non-clinical protocol was administered by two trained investigators and included collection of personal, sociodemographic information, ocular and systemic history, Indian Visual Function Questionnaire (IND-VFQ33), Patient Health Questionnaire (PHQ9), Mini-Mental State Examination (MMSE) questionnaire, Hearing Handicap Inventory for the Elderly Screening (HHIE), Short Falls Efficacy Scale (SFES) questionnaire. The eye examination was conducted by a trained optometrist and vision technicians in clinics set-up in the homes and included visual acuity (VA) assessment for distance and near, anterior segment examination and fundus examination, and imaging. The reliability assessments were carried out among 138 participants.Result: The intraclass correlation (ICC) coefficients for MMSE, PHQ9, HHIE, SFES was 0.73 (95% CI: 0.62–0.81), 0.67 (95% CI: 0.54–0.77), 0.63 (95% CI: 0.48–0.74) and 0.70 (95% CI: 0.58–0.79) respectively. The ICC for INDVFQ domains ranged from 0.66 (95% CI: 0.55–0.74) for Psychosocial Impact to 0.88 (95% CI: 0.84–0.91) for activity limitation. The ICC for VA was 0.94 (95% CI: 0.92–0.96).Conclusion: All questionnaires demonstrated acceptable reliability and can be applied in the main study. HOMES is expected to provide data that will help plan strategies to contribute towards ‘healthy aging’ in India.

Accurate Cross-Section Estimation of Blood Vessels in Choroidal Haller's Layer: An Iterative Method based on 3D Tensor Voting.

Various eye diseases, including polypoidal choroidal vasculopathy (PCV) and age-related macular degeneration (AMD), affect choroidal vasculature early, but possibly minutely. However, due to the complex networked structure of the vasculature, it becomes hard to visualize, analyze and detect such changes in 2D OCT B-scan images. In contrast, algorithmic evaluation of cross-section facilitates clinicians in tracing minute variations in the vessel network, and quantifying those correlated with pathologies, potentially leading to early diagnosis. In this context, we proposed a novel method of estimating vessel cross-sections in choroidal Haller's layer. Accuracy of our method was evaluated on synthetic as well as clinical data by trained optometrists, and earned a confidence score of 90%, marking about 60% improvement over estimates based on a well-known tree-based method.

Prevalence of amblyopia among preschool children in central south China.

To determine the prevalence and factors associated with amblyopia among children aged 30-83mo in central south of China. A population-based, cross-sectional study was conducted in children aged 30-83mo in Changsha (an urban city) and Zhangjiajie (a rural area) in central south of China. Clinical examinations including ocular alignment, ocular motility, visual acuity (VA), prism cover test, cycloplegic refraction, slit lamp examination and fundus examination were performed by trained study ophthalmologists and optometrists. Unilateral amblyopia was defined as a 2-line difference between eyes with VA<20/32 in the worse eye and with coexisting anisometropia [≥1.00 D spherical eutivalent (SE) for hyperopia, ≥3.00 D SE for myopia, and ≥1.50 D for astigmatism], strabismus, or past or present visual axis obstruction. Bilateral amblyopia was defined as VA in both eyes <20/40 (≥ 48-month-old) and <20/50 (< 48-month-old), with coexisting hyperopia ≥4.00 D SE, myopia ≤-6.00 D SE, and astigmatism ≥2.50 D, or past or present visual axis obstruction. There were 8042 children enrolled and 7713 children were screened. The amblyopia prevalence in children aged 30-83mo was 1.09% (95% confidence interval, 0.86%-1.35%) with no age (P=0.81), gender (P=0.46) or area distribution (P=0.93) differences. Of these, 0.68% were unilateral cases and 0.41% were bilateral cases. Underlying causes included anisometropia (40%), binocular refractive error (36%), strabismus (14%) and deprivation (10%). Hyperopia combined with astigmatism was the frequent refractive error for ametropic and anisometropic amblyopia. In this rural and urban Chinese population, 1.09% of children with 30-83mo of age had amblyopia, a prevalence rate similar to that of many other studies. Anisometropia and refractive error are the most common causes of unilateral and bilateral amblyopia respectively.

Cost-effectiveness of glaucoma screening in cataract camps versus opportunistic and passive screening in urban India: A study protocol.

India has an estimated 12 million people affected with glaucoma; however, no organised screening programme exists. Cases are usually detected opportunistically. This study documents the protocol for detecting glaucoma in suspects in cataract camps conducted by Shroff Charity Eye Hospital in North India. We report a cost-effectiveness alongside prospective study design of patients attending cataract camps where glaucoma screening will be integrated. The eligible population for glaucoma screening is non-cataract patients. Patients will undergo glaucoma screening by a trained optometrist using a pre-determined glaucoma screening algorithm. Specific diagnostic cut-off points will be used to identify glaucoma suspects. Suspected patients will be referred to the main hospital for confirmatory diagnosis and treatment. This group will be compared to a cohort of patients arriving from cataract camps conducted by the institute in similar areas and undergoing examination in the hospital. The third arm of the study includes patients arriving directly to the hospital for the first time. Cost data will be captured from both the screening components of cataract-only and glaucoma screening-integrated camps for screening invitation and screening costs. For all three arms, examination and treatment costs will be captured using bottom-up costing methods at the hospital. Detection rates will be calculated by dividing the number of new cases identified during the study by total number of cases examined. Median, average and range of costs across the three arms will be calculated for cost comparisons. Finally, cost-effectiveness analysis will be conducted comparing cost per case detected across the three arms from a quasi-societal perspective with a time horizon of 1 year .Ethics approval for the study has been obtained from the institutional ethics committee of the hospital.The study protocol will be useful for researchers and practitioners for conducting similar economic evaluation studies in their context.

Costs, cost-effectiveness and detection rate of glaucoma screening in cataract camps in urban India: A study protocol

India has an estimated 12 million people affected with glaucoma; however, no organised screening programme exists. Cases are usually detected opportunistically. This study documents the protocol for detecting glaucoma in suspects in cataract camps conducted by Shroff Charity Eye Hospital in North India. We report a prospective study design from patients attending cataract camps where glaucoma screening will be integrated. The eligible population for glaucoma screening is non-cataract patients. Patients will undergo glaucoma screening by a trained optometrist using a pre-determined glaucoma screening algorithm. Specific diagnostic cut-off points will be used to identify glaucoma suspects. Suspected patients will be referred to the main hospital for confirmatory diagnosis and treatment. This group will be compared to a cohort of patients arriving from cataract camps conducted by the institute in similar areas and undergoing examination in the hospital. The third arm of the study includes patients arriving directly to the hospital for the first time. Cost data will be captured from both the screening components of cataract-only and glaucoma screening-integrated camps for screening invitation and screening costs. For all three arms, examination and treatment costs will be captured using bottom-up costing methods at the hospital. Detection rates will be calculated by dividing the number of new cases identified during the study by total number of cases examined. Median, average and range of costs across the three arms will be calculated for cost comparisons. Finally, cost-effectiveness analysis will be conducted comparing cost per case detected across the three arms. This is the first such study conducted in India. The study protocol will be useful for researchers and practitioners for conducting similar economic evaluation studies in their context. The protocol publication will be a good step to ensure transparency of methods of reporting of economic evaluation studies in LMICs.

Cost-effectiveness of glaucoma screening in cataract camps versus opportunistic and passive screening in urban India: A study protocol

India has an estimated 12 million people affected with glaucoma; however, no organised screening programme exists. Cases are usually detected opportunistically. This study documents the protocol for detecting glaucoma in suspects in cataract camps conducted by Shroff Charity Eye Hospital in North India. We report a cost-effectiveness alongside prospective study design of patients attending cataract camps where glaucoma screening will be integrated. The eligible population for glaucoma screening is non-cataract patients. Patients will undergo glaucoma screening by a trained optometrist using a pre-determined glaucoma screening algorithm. Specific diagnostic cut-off points will be used to identify glaucoma suspects. Suspected patients will be referred to the main hospital for confirmatory diagnosis and treatment. This group will be compared to a cohort of patients arriving from cataract camps conducted by the institute in similar areas and undergoing examination in the hospital. The third arm of the study includes patients arriving directly to the hospital for the first time. Cost data will be captured from both the screening components of cataract-only and glaucoma screening-integrated camps for screening invitation and screening costs. For all three arms, examination and treatment costs will be captured using bottom-up costing methods at the hospital. Detection rates will be calculated by dividing the number of new cases identified during the study by total number of cases examined. Median, average and range of costs across the three arms will be calculated for cost comparisons. Finally, cost-effectiveness analysis will be conducted comparing cost per case detected across the three arms from a quasi-societal perspective with a time horizon of 1 year . Ethics approval for the study has been obtained from the institutional ethics committee of the hospital. The study protocol will be useful for researchers and practitioners for conducting similar economic evaluation studies in their context.

Costs, cost-effectiveness and detection rate of glaucoma screening in cataract camps in urban India: A study protocol

India has an estimated 12 million people affected with glaucoma; however, no organised screening programme exists. Cases are usually detected opportunistically. This study documents the protocol for detecting glaucoma in suspects in cataract camps conducted by Shroff Charity Eye Hospital in North India. We report a prospective study design from patients attending cataract camps where glaucoma screening will be integrated. The eligible population for glaucoma screening is non-cataract patients. Patients will undergo glaucoma screening by a trained optometrist using a pre-determined glaucoma screening algorithm. Specific diagnostic cut-off points will be used to identify glaucoma suspects. Suspected patients will be referred to the main hospital for confirmatory diagnosis and treatment. This group will be compared to a cohort of patients arriving from cataract camps conducted by the institute in similar areas and undergoing examination in the hospital. The third arm of the study includes patients arriving directly to the hospital for the first time. Cost data will be captured from both the screening components of cataract-only and glaucoma screening-integrated camps for screening invitation and screening costs. For all three arms, examination and treatment costs will be captured using bottom-up costing methods at the hospital. Detection rates will be calculated by dividing the number of new cases identified during the study by total number of cases examined. Median, average and range of costs across the three arms will be calculated for cost comparisons. Finally, cost-effectiveness analysis will be conducted comparing cost per case detected across the three arms. This is the first such study conducted in India. The study protocol will be useful for researchers and practitioners for conducting similar economic evaluation studies in their context. The protocol publication will be a good step to ensure transparency of methods of reporting of economic evaluation studies in LMICs.

Sensitivity and specificity of teachers for vision screening among primary school children in South India.

AIMS:This study aims to determine the sensitivity and specificity of vision screening by school teachers among primary school children.SETTINGS AND DESIGN:Prospective nonrandomized clinical trial.SUBJECTS AND METHODS:The study was carried in primary school children of Madurai, Tamil Nadu from April 2007 to October 2007. Sixty-five primary school teachers from 57 schools around Madurai, Tamil Nadu, India, underwent a half-day training programme at the hospital. Each teacher on return to the school screened around a hundred children using the tumbling E. All screened children were subsequently screened by a team from the hospital. The optometrists used tumbling E (Snellen's 20/30 and Early Treatment of Diabetic Retinopathy Study (ETDRS) 20/32) to check the vision of all children. Any child complaining of defective vision or noted to have defective vision on screening underwent a comprehensive ophthalmic evaluation. The sensitivity and specificity of teacher screening was assessed based on the data obtained.RESULTS:Screening was completed for 5150 children. The prevalence of vision <20/30 was 2.82%. Teacher screening was noted to have a sensitivity of 24.8% and a specificity of 98.65%. Tumbling E ETDRS screening by the optometrist had the highest sensitivity of 94.48% and specificity of 97.09%.CONCLUSIONS:Our study shows that vision screening by trained optometrists is a very useful tool to identify visual impairment in primary school children. Measures need to be taken to improve the sensitivity of teacher screening before recommending its generalized use.

Effect of central corneal thickness on intraocular pressure and comparison of Topcon CT‐80 non‐contact tonometry with Goldmann applanation tonometry

BackgroundTo compare intraocular pressure (IOP) measurements obtained with the Topcon CT‐80 non‐contact tonometer (NCT) and Goldmann applanation tonometer (GAT), in different ranges of IOP in normal and glaucoma subjects, and to assess the influence of central corneal thickness (CCT) on the IOP measurements in Asian Indian eyes.MethodsFour hundred and two eyes of 402 subjects (193 newly diagnosed primary open angle glaucoma [POAG] and 209 normal) were enrolled for this prospective study. For each eye, IOP was measured with GAT by a glaucoma specialist and NCT by a trained optometrist. The IOP values were compared among the tonometers in the three different IOP ranges (≤ 12 mmHg, 13–20 mmHg and ≥ 21 mmHg) using Bland–Altman graphs. Correlation between GAT and NCT was assessed by Pearson correlation co‐efficient. CCT was measured with ultrasound pachymetry and its correlation with GAT and NCT was analysed using linear regression analysis.ResultsThe mean paired difference of IOP between NCT and GAT was 1.556 ± 2.69 mmHg (r = 0.26, p = 0.006) at IOP range of ≤ 12 mmHg, −1.665 ± 2.6 mmHg (r = 0.51, p < 0.0001) in IOP range of 13–20 mmHg and −2.202 ± 3.44 mmHg (r = 0.82, p < 0.0001) in the IOP range of ≥ 21 mmHg. Linear regression analysis showed a mean IOP variation of 0.27 mmHg per 10 μm change in CCT for NCT (p < 0.0001) and IOP change of 0.19 mmHg per 10 μm change in CCT for GAT (p = 0.01).ConclusionIn this study of normotensive and POAG subjects, the Topcon CT‐80 NCT showed an overestimation of IOP at the lower range and underestimation of IOP in normal and higher ranges of IOP. Clinicians should keep in mind that CCT influences IOP measurement with both types of tonometer and that the IOP readings obtained with these tonometers are not interchangeable.

Diabetic retinopathy screening programme utilising non-mydriatic fundus imaging in slum populations of New Delhi, India.

To develop and implement a community-based programme for screening of diabetic retinopathy (DR) in urban populations of Delhi. Known diabetics (KDs) aged 40 years and older were identified through house-to-house surveys, volunteers and publicity. All KDs were referred to DR screening camps organised locally where procedures included brief medical history, ocular examination and non-mydriatic fundus photography using portable handheld camera. Fundal images were graded on the spot by trained optometrists for DR. Patients with DR were referred to tertiary centre for management. A total of 11 566 KDs were identified, of whom 9435 (81.6%) visited DR screening camps and 8432 (89.4%) had DR gradable images. DR was identified in 13.5% of subjects; 351 cases were mild NPDR, 567 moderate, 92 severe. Seventy-seven had PDR, and 49 had DME, and 2.7% of participants were blind (presenting visual acuity <3/60 in better eye). Non-use of lifestyle management, presence of systemic complications, BMI <18.5 kg/m2 , disease duration of >5 years and uncontrolled diabetes were associated with increased odds of DR. All cases with DR were referred, and 420 (37%) successful referrals to base hospital were observed. The programme of creating awareness about DR, identifying KDs and optometrist-led DR screening using non-mydriatic fundus camera based in slums was successful.

Analysis of yield of retinal imaging in a rural diabetes eye care model.

Purpose:The aim of this study is to analyze the yield of retinal images obtained in a rural diabetes eye care model.Methods:An analysis of a sample of nonmydriatic fundus photography (NMFP) of posterior segment ophthalmic images, obtained by an indigenous equipment (3 nethra-Forus Royal), was done in a district-wide rural diabetic retinopathy (DR) screening program; a trained optometrist did the initial image grading. DR and diabetic macular edema (DME) were classified based on international DR and DME severity scale. The agreement between the optometrist and retina specialist was very good (κ = 0.932; standard error = 0.030; 95% confidence interval = 0.874–0.991).Results:Posterior segment images of 2000 eyes of 1000 people with diabetes mellitus (DM) were graded. The mean age of the participants was 55.7 ± 11.5 standard deviation years. Nearly 42% of the screened participants (n = 420/1000) needed referral. The most common referable posterior segment abnormality was DR (8.2%). The proportion of people with any form of DR was seen in 110/1225 eyes, and sight-threatening DR was seen in 35/1225 eyes. About 62% of posterior segment images were gradable. The reasons for ungradable posterior segment images (34%) were small pupil, unfocused/partially available field of images, and cataract.Conclusion:A NMFP model was able to detect referable posterior segment abnormalities in a rural diabetes eye care program. Reasons found for ungradability of images in the present study can be addressed while designing future DR screening programs in the rural areas.