Non-mydriatic Retinal Camera Research Articles

Prediction of preeclampsia from retinal fundus images via deep learning in singleton pregnancies: a prospective cohort study.

Early prediction of preeclampsia (PE) is of universal importance in controlling the disease process. Our study aimed to assess the feasibility of using retinal fundus images to predict preeclampsia via deep learning in singleton pregnancies. This prospective cohort study was conducted at Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine. Eligible participants included singleton pregnancies who presented for prenatal visits before 14 weeks of gestation from September 1, 2020, to February 1, 2022. Retinal fundus images were obtained using a nonmydriatic digital retinal camera during their initial prenatal visit upon admission before 20 weeks of gestation. In addition, we generated fundus scores, which indicated the predictive value of hypertension, using a hypertension detection model. To evaluate the predictive value of the retinal fundus image-based deep learning algorithm for preeclampsia, we conducted stratified analyses and measured the area under the curve (AUC), sensitivity, and specificity. We then conducted sensitivity analyses for validation. Our study analyzed a total of 1138 women, 92 pregnancies developed into hypertension disorders of pregnancy (HDP), including 26 cases of gestational hypertension and 66 cases of preeclampsia. The adjusted odds ratio (aOR) of the fundus scores was 2.582 (95% CI, 1.883-3.616; P < 0.001). Otherwise, in the categories of prepregnancy BMI less than 28.0 and at least 28.0, the aORs were 3.073 (95%CI, 2.265-4.244; P < 0.001) and 5.866 (95% CI, 3.292-11.531; P < 0.001). In the categories of maternal age less than 35.0 and at least 35.0, the aORs were 2.845 (95% CI, 1.854-4.463; P < 0.001) and 2.884 (95% CI, 1.794-4.942; P < 0.001). The AUC of the fundus score combined with risk factors was 0.883 (sensitivity, 0.722; specificity, 0.934; 95% CI, 0.834-0.932) for predicting preeclampsia. Our study demonstrates that the use of deep learning algorithm-based retinal fundus images offers promising predictive value for the early detection of preeclampsia.

EyeArt artificial intelligence analysis of diabetic retinopathy in retinal screening events.

Early detection and treatment of diabetic retinopathy (DR) are critical for decreasing the risk of vision loss and preventing blindness. Community vision screenings may play an important role, especially in communities at higher risk for diabetes. To address the need for increased DR detection and referrals, we evaluated the use of artificial intelligence (AI) for screening DR. Patient images of 124 eyes were obtained using a 45° Canon Non-Mydriatic CR-2 Plus AF retinal camera in the Department of Endocrinology Clinic (Newark, NJ) and in a community screening event (Newark, NJ). Images were initially classified by an onsite grader and uploaded for analysis by EyeArt, a cloud-based AI software developed by Eyenuk (California, USA). The images were also graded by an off-site retina specialist. Using Fleiss kappa analysis, a correlation was investigated between the three grading systems, the AI, onsite grader, and a US board-certified retina specialist, for a diagnosis of DR and referral pattern. The EyeArt results, onsite grader, and the retina specialist had a 79% overall agreement on the diagnosis of DR: 86 eyes with full agreement, 37 eyes with agreement between two graders, 1 eye with full disagreement. The kappa value for concordance on a diagnosis was 0.69 (95% CI 0.61-0.77), indicating substantial agreement. Referral patterns by EyeArt, the onsite grader, and the ophthalmologist had an 85% overall agreement: 96 eyes with full agreement, 28 eyes with disagreement. The kappa value for concordance on "whether to refer" was 0.70 (95% CI 0.60-0.80), indicating substantial agreement. Using the board-certified retina specialist as the gold standard, EyeArt had an 81% accuracy (101/124 eyes) for diagnosis and 83% accuracy (103/124 eyes) in referrals. For referrals, the sensitivity of EyeArt was 74%, specificity was 87%, positive predictive value was 72%, and negative predictive value was 88%. This retrospective cross-sectional analysis offers insights into use of AI in diabetic screenings and the significant role it will play in automated detection of DR. The EyeArt readings were beneficial with some limitations in a community screening environment. These limitations included a decreased accuracy in the presence of cataracts and the functional cost of EyeArt uploads in a community setting.

Alteraciones retinianas detectadas por screening con cámara retinal no midriática y derivación a oftalmología en una población de alto riesgo cardiovascular

ObjectiveTo describe the main retinal alterations detected by non-mydriatic retinal camera screening and to evaluate factors related to referral to ophthalmology in a population at high cardiovascular risk in Palmira, Colombia. Materials and methodsCross-sectional observational study, which included 11,983 photographic imaging records of patients with hypertension and diabetes mellitus from Gesencro's S.A.S. comprehensive chronic disease care program between 2018 and 2020. Risk factors associated to referral to ophthalmology were evaluated with logistic regression, and crude and adjusted ORs (odds ratios) were obtained. ResultsA total of 11,880 records were analyzed; 67.7±12years old, and 69.5% were women. Among the retinal alterations were patients with diabetic retinopathy classified as more than mild in 10% and gradeI hypertensive retinopathy in 54.9% right eye, 51.9% left eye. Macular edema was also identified. Only 2069 patients (17.4%) required referral to ophthalmology, and for imaging control 82.6%. In the multivariate analysis, the risk factors associated with the probability of being referred were male gender, age 60years and older, glycosylated hemoglobin out-of-target, advanced chronic kidney disease and the microalbumin-to-creatinine ratio moderate to severely elevated. ConclusionThis study makes it possible to determine the importance of screening with a non-mydriatic retinal camera in patients at high cardiovascular risk to detect retinal abnormalities and assess risk factors associated with referral to ophthalmology. Early documentation of ocular compromise in these patients could prevent and avoid visual impairment and blindness.

Retinal microvasculature and risk of spontaneous abortion in multiethnic Southeast Asian women

To better understand the underlying pathogenesis of spontaneous abortion that affects 10%-20% of recognized pregnancies. We used retinal imaging to study the role of systemic microvasculature and the risk of spontaneous abortion. A prospective multiethnic preconception cohort study conducted in Singapore. Hospital-based. A total of 1,032 Southeast Asian women who intended to conceive naturally were screened at study entry, among which 480 women spontaneously conceived within the 12-month observation period. After excluding 24 women who were lost to follow-up, we calculated the spontaneous abortion rate among 456 women. Further, we included 379 women for the final association analysis because 63 women did not undergo preconception retinal imaging examination and 14 had other types of pregnancy loss instead of spontaneous abortion. Trained photographers performed retinal examination using a 45-degree nonmydriatic retinal camera at study entry during the preconception screening. Using a semiautomated, computer-based program, we assessed quantitative retinal microvascular measurements, including caliber, fractal dimension, curvature tortuosity, and branching angle. Clinical research coordinators collected information on sociodemographic status, menstrual characteristics, and lifestyle, and assessed blood pressure and anthropometry at study entry. We performed a modified Poisson regression model to estimate the relative risk (RR) and 95% confidence interval (CI) for each retinal microvascular feature and its association with spontaneous abortion after adjusting for major confounders such as maternal prepregnancy, body mass index, and previous pregnancy loss history. We reported a spontaneous abortion rate of 13.4% (61 out of 456). Among all retinal microvascular features, retinal arteriolar caliber, retinal arteriolar, and venular curvature tortuosity were associated with a high risk of incident spontaneous abortion. In the regression model, per SD increase in retinal curvature tortuosity was associated with a 25%-34% increased risk of incident spontaneous abortion (arteriolar: unadjusted RR, 1.29 [95% CI, 1.06-1.56] and adjusted RR, 1.26 [1.04-1.53]; venule: unadjusted RR, 1.30 [1.08-1.55] and adjusted RR, 1.34 [1.09-1.64]). Our prospective cohort observed an increased risk of spontaneous abortion among Asian women with more tortuous retinal vessels assessed during the preconception phase. Our results indicate a role of vascular inflammatory and oxidative stress in the pathogenesis of spontaneous abortion. ClinicalTrials.gov, NCT03531658.

Retinal small vessel dilatation in the systemic inflammatory response to surgery

Retinal microvascular calibre has been proposed as a predictor of cardiac events. Surgery is a major stimulus for inflammation which potentially affects small vessel calibre. This study examined the effects of surgery on retinal, and thus systemic, small vessel size, and the potentially confounding effect of surgery when retinal vessel calibre is used to predict cardiac risk in hospital patients. Consecutive participants were recruited from a preoperative assessment clinic at a teaching hospital. They provided demographic and clinical details, and underwent retinal imaging before and again, within 3 days after surgery, with a non-mydriatic retinal camera. Images were graded for vessel calibre using semi-automated software based on the Parr-Hubbard formula with Knudtson’s modification (IVAN, U Wisconsin). Differences were examined using Fisher’s exact test or a paired t-test, and calibre determinants identified from univariate and multiple linear regression analysis (STATA version 11.2). Sixty-eight participants (23 men, 34%) with a mean age of 55 ± 14.5 years, were recruited. Fourteen (21%) underwent a laparotomy which was considered major surgery and 54 (79%) had Other surgery. Mean C-reactive protein (CRP) levels increased post-operatively from 7.8 ± 20.2 mg/L to 43.9 ± 55.1 mg/L (p < 0.01), and mean serum albumin decreased from 38.9 ± 4.4 g/L to 33.9 ± 5.5 g/L (p < 0.01). Mean central retinal arteriole and venular equivalent calibre (CRAE, CRVE) increased post-operatively (142.4 ± 13.3 µm to 146.4 ± 13.0 µm, p < 0.01 and 213.1 ± 16.8 µm to 217.9 ± 18.3 µm, p < 0.01, respectively). The systemic microvasculature dilates post-operatively possibly secondary to inflammation and endothelial dysfunction. These changes were present within 3 days of surgery and may confound the use of small vessel calibre to predict cardiac risk in surgical inpatients. Microvascular dilatation in response to other inflammatory stimuli such as pneumonia is a known potential confounder in hospital patients.

Feasibility of telemedicine program using a hand-held nonmydriatic retinal camera in Panama.

To evaluate the image quality of a telemedicine screening program for retinal disease using a nonmydriatic camera among rural island communities in Bocas del Toro, Panama. In June 2018, a group of three medical students volunteered at clinics operated by the Floating Doctors in the province of Bocas del Toro, Panama. Non-mydriatic images of the retina were obtained using the Pictor Plus (Volk Optical, Mentor OH), randomized, and sent to two board-certified ophthalmologists at the University of California, Irvine for analysis using a modified version of the FOTO-ED scale. Inter-rater reliability was calculated using the kappa statistic. Seventy patients provided a total of 127 images. Average image quality was 3.31, and most frequent image quality was 4/5 on the FOTO-ED scale. Thirty patients had at least one eye image with ideal quality (42.86%), while only one patient had no adequate photos taken (1.43%). However, high quality images were obtained in both eyes in only 12 patients (17.14%). The inter-rater reliability between the two ophthalmologists was 0.614. Further improvements are necessary to acquire higher quality images more reliably. This may include further training and experience or mydriasis.

Efficacy of smartphone-based retinal photography by undergraduate students in screening and early diagnosing diabetic retinopathy

BackgroundTo evaluate the efficacy of retinal photography obtained by undergraduate students using a smartphone-based device in screening and early diagnosing diabetic retinopathy (DR).MethodsWe carried out an open prospective study with ninety-nine diabetic patients (194 eyes), who were submitted to an ophthalmological examination in which undergraduate students registered images of the fundus using a smartphone-based device. At the same occasion, an experienced nurse captured fundus photographs from the same patients using a gold standard tabletop camera system (Canon CR-2 Digital Non-Mydriatic Retinal Camera), with a 45º field of view. Two distinct masked specialists evaluated both forms of imaging according to the presence or absence of sings of DR and its markers of severity. We later compared those reports to assess agreement between the two technologies.ResultsConcerning the presence or absence of DR, we found an agreement rate of 84.07% between reports obtained from images of the smartphone-based device and from the regular (tabletop) fundus camera; Kappa: 0.67; Sensitivity: 71.0% (Confidence Interval [CI]: 65.05–78.16%); Specificity: 94.06% (CI: 90.63–97.49%); Accuracy: 84.07%; Positive Predictive Value (PPV): 90.62%; Negative Predictive Value (NPV): 80.51%. As for the classification between proliferative diabetic retinopathy and non-proliferative diabetic retinopathy, we found an agreement of 90.00% between the reports; Kappa: 0.78; Sensitivity: 86.96%; (CI: 79.07–94.85%); Specificity: 91.49% (CI: 84.95–98.03%); Accuracy: 90.00%; PPV: 83.33%; NPV: 93.48%. Regarding the degree of classification of DR, we found an agreement rate of 69.23% between the reports; Kappa: 0.52. As relating to the presence or absence of hard macular exudates, we found an agreement of 84.07% between the reports; Kappa: 0.67; Sensitivity: 71.60% (CI: 65.05–78.16%); Specificity: 94.06% (CI: 90.63–97.49%); Accuracy: 84.07%; PPV: 90.62%; NPV: 80.51%.ConclusionThe smartphone-based device showed promising accuracy in the detection of DR (84.07%), making it a potential tool in the screening and early diagnosis of DR.

Direct Observation of Retinal Microvessels in Cancer Patients After Systemic Administration of Bevacizumab and Oxaliplatin.

Antiangiogenic chemotherapy is the backbone of the various anticancer therapies. To date no practical biomarker predicting their antitumor effects and toxicity has been reported. We aimed to determine the feasibility of direct retinal observation as a practical biomarker in antiangiogenic chemotherapy. By direct retinal observation using a nonmydriatic retinal camera, we measured retinal microvessel diameters in 10 patients with colorectal cancer before and after intravenous infusion of bevacizumab and oxaliplatin. All patients also received oral capecitabine during their therapy. Retinal microvessel diameters were decreased from baseline temporarily by 14.5±6.5% after infusion of bevacizumab and oxaliplatin in five patients who responded to treatment and 8.8±6.2% in the other five patients (p=0.008). Measurement of retinal microvessel diameters by direct observation appears to be feasible in patients receiving systemic chemotherapy. The decrease of retinal microvessel diameters might indicate improved tumor response to treatment with bevacizumab-containing systemic chemotherapy.

Retinal Drusen Are More Common and Larger in Systemic Lupus Erythematosus With Renal Impairment

IntroductionComplement has been implicated in systemic lupus erythematosus (SLE) pathogenesis on the basis of the associations with inherited complement defects and genome-wide association study risk alleles, glomerular deposits, reduced serum levels, and occasional reports of retinal drusen. This study examined drusen in SLE and their clinical significance.MethodsThis cross-sectional observational study compared individuals with SLE recruited from renal and rheumatology clinics with hospital controls. Participants were reviewed for clinical features and underwent imaging with a nonmydriatic retinal camera. Deidentified images were examined by 2 trained graders for drusen number and size using a grid overlay.ResultsThe cohort with SLE (n = 65) comprised 55 women (85%) and 10 men (15%) with a median age of 47 years (interquartile range 35–59), where 23 (35%) were of southern European or Asian ancestry, and 32 (49%) had biopsy-proven lupus nephritis. Individuals with SLE had higher mean drusen numbers than controls (27 ± 60, 3 ± 9, respectively, P = 0.001), more drusen counts ≥10 (31, 48% and 3, 5%, respectively, P < 0.001), and more medium-large drusen (14, 22% and 3, 5%, respectively, P < 0.001). In SLE, mean drusen counts were higher, and drusen were larger, with an estimated glomerular filtration rate (eGFR) <90 ml/min per 1.73 m2 (P = 0.02, P = 0.02, respectively) or class IV nephritis (P = 0.03, P = 0.02).ConclusionDrusen composition resembles that of glomerular immune deposits. CFH controls complement activation in the extracellular matrix and CFH risk variants are shared by drusen in macular degeneration and by SLE. CFH represents a possible treatment target for SLE especially with renal impairment.

Use of digital retinal camera to detect prevalence and severity of diabetic retinopathy in a screening program for type 2 diabetic refugees in Palestine

Background: The purpose of this study was to determine the prevalence of diabetic retinopathy among Palestinian refugees serviced by the Diabetic Retinopathy Screening Program in the Occupied Palestinian Territories (DRS-OPT). Material and methods: This is a retrospective study of retinal images of 1891 diabetic patients in 15 urban UNRWA clinics participating in the DRS-OPT program in Palestine over 12 months. A nonmydriatic Canon CR-2 fundus retinal camera was used to capture two 450 non-stereo fundus images for each eye. Qualified graders (nurses) performed the grading based on the DRS-OPT grading system. Results: Out of the 1891 diabetic patients screened, 1694 had at least one gradable eye. 16% of patients had diabetic retinopathy (5.7% had mild nonproliferative diabetic retinopathy, 4.3% had moderate nonproliferative diabetic retinopathy, 1.1% had severe, moderate nonproliferative diabetic retinopathy, and 1.7% had proliferative diabetic retinopathy. Maculopathy without retinopathy amounted to 3%. Other findings included the identification of blinding diseases such as age-related macular degeneration and optic disc glaucomatous cupping. Conclusions: The retinopathy screening program using a nonmydriatic fundus camera identified diabetic retinopathy in 16% of diabetic Palestinian refugees. A total of 72% of these patients were diabetics with nonproliferative retinopathy. This program can be used to prevent progression by facilitating the education of patients and early intervention.

Protocol on a multicentre statistical and economic modelling study of risk-based stratified and personalised screening for diabetes and its complications in India (SMART India)

IntroductionThe aim of this study is to develop practical and affordable models to (a) diagnose people with diabetes and prediabetes and (b) identify those at risk of diabetes complications so...

Age-related features of the organization of the microcirculatory bed of the bulbar conjunctiva

Objective: Analysis of age-related changes of microcirculatory bed of bulbar conjunctiva.Methods: 46 individuals of both sexes, divided into 5 age groups according to WHO recommendations, were examined. Biomicroscopy of bulbar conjunctiva was performed using a non-mydriatic retinal camera TOPCON TRC-NW8F (Japan); the obtained images were processed with a mea‑ suring device of automated analysis system ImageScope (Leica, Germany).Results: The average diameter of arterioles, arterioleto-venule ratio (AVR) and specific density of capillaries were the largest, and the diameter of venules was the smallest among the subjects aged 18–44 years. The most sensitive indicators of the state of microcirculatory bed were AVR and the specific density of capillaries, the values of which in the group of 45–59-year-olds were 10–11% lower than in people aged 18–24 and 25–44 years. Differences in other indicators between people aged 18-24 and 45–59 years were not significant. Between the groups of 60–74 and 75–86-year-old participants of the study, pronounced differences (about 18%) were found only in the specific density of capillaries: compared with 18–24 and 45–59-year-olds, this indicator decreased by almost 1.5 times, AVR – only by a third, and changes in the average diameter of arterioles and venules did not exceed 9–12%. Elderly people more often demonstrated arteriolar spasm, their uneven caliber, avascular fields and other disorders of the structure of the micro‑ circulatory bed.Conclusions: As the body ages, in the microcirculatory bed of the bulbar conjunctiva, the number of atypical vascular formations increases, the diameter of the arterioles decreases, the AVR and the specific density of capillaries decrease, the diameter of the venules increases.

The agreement between optical coherence tomography angiography and non-mydriatic retinal camera in estimating the optic nerve head parameters and relations with the peripapillary vessel density in primary open-angle glaucoma.

To investigate the agreement between optical coherence tomography angiography (OCT-A) and non-mydriatic retinal camera (NMRC) in estimating the optic nerve head (ONH) parameters and evaluate the associations between peripapillary vessel density (VD) with ONH parameters assessed by both devices. The OCT-A and NMRC images of 262 participants (138 eyes were diagnosed with POAG, 63 were glaucoma suspect, and 61 were healthy subjects) were screened retrospectively. The vertical cup-to-disc ratio (VCDR), cup-to-disc area ratio (CDAR), rim area (RA), disc area (DA), and cup volume (CV) were recorded using both devices. Peripapillary VD data were also recorded using OCT-A. The intraclass correlation coefficient (ICC) and Bland-Altman plots were obtained to investigate the agreement between the devices. Age- and intraocular pressure (IOP)-corrected associations between the VD and ONH parameters measured by the two devices were analyzed using linear regression models. ICC revealed excellent agreement for VCDR and CDAR, but poor agreement for RA, DA, and CV (ICC = 0.801, 0.793, 0.445, 0.298, and 0.527, respectively). The Bland-Altman plots showed poor agreement for VCDR and CDAR with a large span of limits of agreement (0.500 and 0.528, respectively) and significant proportional biases (P < 0.05). VD was found to be strongly associated with the VCDR and CDAR measurements of both devices (P < 0.001), but the associations were stronger for the measurements of NMRC. The disagreement between the devices should be considered in clinical practice. The associations between the VD and ONH parameters proved once again the importance of the ONH parameters in terms of the management of glaucoma patients.

Accuracy of the smartphone-based nonmydriatic retinal camera in the detection of sight-threatening diabetic retinopathy.

Purpose:To evaluate the sensitivity and specificity of smartphone-based nonmydriatic (NM) retinal camera in the detection of diabetic retinopathy (DR) and sight-threatening DR (STDR) in a tertiary eye care facility.Methods:Patients with diabetes underwent retinal photography with a smartphone-based NM fundus camera before mydriasis and standard 7-field fundus photography with a desktop mydriatic fundus camera after mydriasis. DR was graded using the international clinical classification of diabetic retinopathy system by two retinal expert ophthalmologists masked to each other and to the patient's identity. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) to detect DR and STDR by NM retinal imaging were assessed.Results:245 people had gradable images in one or both eyes. DR and STDR were detected in 45.3% and 24.5%, respectively using NM camera, and in 57.6% and 28.6%, respectively using mydriatic camera. The sensitivity and specificity to detect any DR by NM camera was 75.2% (95% confidence interval (CI) 68.1–82.3) and 95.2% (95%CI 91.1–99.3). For STDR the values were 82.9% (95% CI 74.0–91.7) and 98.9% (95% CI 97.3–100), respectively. The PPV to detect any DR was 95.5% (95% CI 89.8–98.5) and NPV was 73.9% (95% CI 66.4–81.3); PPV for STDR detection was 96.7% (95% CI 92.1–100)) and NPV was 93.5% (95% CI 90.0–97.1).Conclusion:Smartphone-based NM retinal camera had fairly high sensitivity and specificity for detection of DR and STDR in this clinic-based study. Further studies are warranted in other settings.

The Light and the Dark of Early and Intermediate AMD: Cone- and Rod-Mediated Changes Are Linked to Fundus Photograph and FAF Abnormalities.

The purpose of this paper is to describe the extent to which scotopic and photopic measures of visual function predict color fundus photograph (CFP) and fundus autofluorescence (FAF) changes in early and intermediate nonexudative AMD. Sixty-nine observers were recruited: 56 AMD patients (mean age, 73 ± 12.98 years) and 13 controls (mean age, 67.77 ± 9.72 years). A nonmydriatic retinal camera was used to obtain stereo fundus photographs and FAF images were recorded with a cSLO Heidelberg Spectralis HRA+OCT. Visual acuity (VA) was measured using an Early Treatment of Diabetic Retinopathy Study chart. Contrast sensitivity (CS) was assessed with a Pelli-Robson chart. Dark adaptation (DA) curves were recorded at 3° eccentricity using a PC-based technique. Analysis of these curves yielded five parameters: cone threshold (CT), cone time constant (CC), cone-rod break (α), slope of the second rod component (S2), and rod-rod break (β). Both cone and rod sensitivity recovery were grossly abnormal in the patients. The rod recovery slope (S2) most accurately predicted the fundus photograph-based grade and the FAF classification (ρ = 0.61 and ρ = 0.60, respectively; both P < 0.0001). CS showed a strong association with FAF (ρ = 0.50, P < 0.0001) and with fundus photograph-based grade (ρ = 0.38, P < 0.002). There was no correlation between VA and either imaging method. Dynamic, rod-based measures most accurately reflect the severity of early AMD. Although less specific to AMD than DA changes, static photopic abnormalities such as CS also correspond with morphologic changes. Assessment of function in early AMD should include dynamic rod- and cone-mediated measurements of sensitivity recovery.

Integrated fundal assessment pathway for patients with suspected shunt malfunction via digital retinal images

Introduction: Papilloedema is an important clinical sign in the assessment of neurosurgical patients presenting with suspected shunt malfunction.Methods: We describe our 18-month experience using a newly acquired nonmydriatic digital retinal camera to acquire fundal photographs for this purpose.Results: It was used to take digital photographs in 67 patients presenting with suspected shunt malfunction and 54% of these images were discussed with the on-call ophthalmology team for advice. Of these 81% had instant input provided by ophthalmology and the remainder were sent to the ophthalmology department for formal assessment. Of all shunt related regional referrals in the same time period, we found that only 13% of the referred patients were discussed with the on-call ophthalmology team. The rest had decisions made by the on-call neurosurgical team.Conclusions: We believe this new integrated pathway is clinically and cost-effective and recommend it as a useful tool in other neurosurgical units.

Peripapillary retinal artery in first diagnosed and untreated normal tension glaucoma

BackgroundGlaucoma, an important cause of visual impairment in many countries, remains a common eye condition due to difficulties in its early diagnosis. We analyzed the characteristics of retinal arteries to add a valuable technology for helping the normal tension glaucoma (NTG) diagnosis.MethodsThis study included 51 patients with newly diagnosed NTG with hemifield defects and 60 age-matched controls. Peripapillary retinal arteriolar calibers (PRACs) photoed by non-mydriatic retinal camera were measured using ImageJ by two masked readers. We also performed spectral-domain optical coherence tomography to evaluate retinal nerve fiber layer thickness (RNFLT) and optic disc parameters. Their relations to retinal arteriolar calibers were investigated by univariate and multivariate linear regression. The area under the receiver operating characteristic curve (AUROC) was used to confirm the powers to detect NTG by PRACs.ResultsPRACs in four quadrants were significantly reduced in individuals with first diagnosed NTG (82 ± 15.1 μm, 80 ± 13.6 μm, 71 ± 11.6 μm, and 64 ± 10.0 μm) compared with those in age-matched controls (101 ± 9.8 μm, 105 ± 8.7 μm, 90 ± 7.5 μm, and 82 ± 9.8 μm). Superotemporal and inferotemporal PRACs in the visual field-affected hemifield were narrower than those in the unaffected hemifield in NTG group (P ≤ 0.004). Temporal PRACs in the RNFL unaffected hemifield were significantly narrower than in healthy eyes (P < 0.001). Superotemporal PRAC showed a significant correlation with superior RNFLT (β = 0.659, P < 0.001), and a similar relationship was found between inferotemporal PRAC and inferior RNFLT (β = 0.227, P = 0.015). The diagnostic capability of temporal PRACs was satisfactory (superotemporal PRAC; AUROC 0.983, cut-off value 84.7 μm, inferotemporal PRAC; AUROC 0.946, cut-off value 94.2 μm).ConclusionsPRAC and inferotemporal PRAC are valid parameters for discriminating patients with NTG.

Diagnostic Accuracy of Community-Based Diabetic Retinopathy Screening With an Offline Artificial Intelligence System on a Smartphone

Offline automated analysis of retinal images on a smartphone may be a cost-effective and scalable method of screening for diabetic retinopathy; however, to our knowledge, assessment of such an artificial intelligence (AI) system is lacking. To evaluate the performance of Medios AI (Remidio), a proprietary, offline, smartphone-based, automated system of analysis of retinal images, to detect referable diabetic retinopathy (RDR) in images taken by a minimally trained health care worker with Remidio Non-Mydriatic Fundus on Phone, a smartphone-based, nonmydriatic retinal camera. Referable diabetic retinopathy is defined as any retinopathy more severe than mild diabetic retinopathy, with or without diabetic macular edema. This prospective, cross-sectional, population-based study took place from August 2018 to September 2018. Patients with diabetes mellitus who visited various dispensaries administered by the Municipal Corporation of Greater Mumbai in Mumbai, India, on a particular day were included. Three fields of the fundus (the posterior pole, nasal, and temporal fields) were photographed. The images were analyzed by an ophthalmologist and the AI system. To evaluate the sensitivity and specificity of the offline automated analysis system in detecting referable diabetic retinopathy on images taken on the smartphone-based, nonmydriatic retinal imaging system by a health worker. Of 255 patients seen in the dispensaries, 231 patients (90.6%) consented to diabetic retinopathy screening. The major reasons for not participating were unwillingness to wait for screening and the blurring of vision that would occur after dilation. Images from 18 patients were deemed ungradable by the ophthalmologist and hence were excluded. In the remaining participants (110 female patients [51.6%] and 103 male patients [48.4%]; mean [SD] age, 53.1 [10.3] years), the sensitivity and specificity of the offline AI system in diagnosing referable diabetic retinopathy were 100.0% (95% CI, 78.2%-100.0%) and 88.4% (95% CI, 83.2%-92.5%), respectively, and in diagnosing any diabetic retinopathy were 85.2% (95% CI, 66.3%-95.8%) and 92.0% (95% CI, 97.1%-95.4%), respectively, compared with ophthalmologist grading using the same images. These pilot study results show promise in the use of an offline AI system in community screening for referable diabetic retinopathy with a smartphone-based fundus camera. The use of AI would enable screening for referable diabetic retinopathy in remote areas where services of an ophthalmologist are unavailable. This study was done on patients with diabetes who were visiting a dispensary that provides curative services to the population at the primary level. A study with a larger sample size may be needed to extend the results to general population screening, however.

Diagnostic test accuracy of diabetic retinopathy screening by physician graders using a hand-held non-mydriatic retinal camera at a tertiary level medical clinic

BackgroundThe evidence on diagnostic test accuracy (DTA) of diabetic retinopathy (DR) screening utilising photographic studies by non-ophthalmologist personnel in low and middle-income country (LMIC) settings is scarce. We aimed to assess DTA of DR screening using a nonmydriatic hand-held digital camera by trained general physicians in a non-ophthalmic setting.MethodsThis study is a validation of a screening intervention. We selected 700 people with diabetes (PwDM) > 18 years of age, not previously screened or treated for DR, presenting at a tertiary medical clinic in Sri Lanka. Two-field retinal imaging was used to capture fundus images before and after pupil dilatation, using a hand-held non-mydriatic (Visuscout 100®-Germany) digital retinal camera. The images were captured and graded by two trained, masked independent physician graders. The DTA of different levels of DR was assessed comparing physician’s grading with a retinologist’s clinical examination by mydriatic bio-microscopy, according to a locally adopted guideline.ResultsSeven hundred eligible PwDM were screened by physician graders. The mean age of participants was 60.8 years (SD ±10.08) and mean duration of DM was 9.9 years (SD ±8.09). Ungradable image proportion in non-mydriatic imaging was 43.4% (either eye-31.3%, both eyes 12.1%). This decreased to 12.8% (either eye-11.6%, both eyes-1.2%) following pupil dilatation. In comparison to detection of any level of DR, a referable level DR (moderate non-proliferative DR and levels above) showed a higher level of DTA. The sensitivity of the defined referable DR was 88.7% (95% CI 81.7–93.8%) for grader 1 (positive predictive value [PPV] 59.1%) and 92.5% (95% CI 86.4–96.5%) for grader 2 (PPV 68%), using mydriatic imaging, after including ungradable images as screen positives. The specificity was 94.9% (95% CI 93.6–96.0%) for grader 1 (negative predictive value [NPV] 99%) and 96.4% (95% CI 95.3–97.3%) for grader 2 (NPV 99.4%).ConclusionsThe Physicians grading of images from a digital hand-held non-mydriatic camera at a medical clinic, with dilatation of pupil of those who have ungradable images, provides a valid modality to identify referable level of DR. This could be a feasible alternative modality to the existing opportunistic screening to improve the access and coverage.Trial registrationCurrent Controlled Trials ISRCTN47559703. Date of Registration 18th March 2019, Retrospectively registered.

Development and Validation of a Diabetic Retinopathy Screening Modality Using a Hand-Held Nonmydriatic Digital Retinal Camera by Physician Graders at a Tertiary-Level Medical Clinic: Protocol for a Validation Study

BackgroundVisual impairment and blindness from diabetic retinopathy (DR), which can be reduced by early screening and treatment, is an emerging public health concern in low-income and middle-income countries (LMICs) owing to the increasing prevalence of diabetes mellitus (DM). However, no systematic screening exists in most LMIC settings. The Western province of Sri Lanka has the highest prevalence of DM (18.6%) in the country. A situational analysis identified a marked gap in DR screening (DRS) and treatment services uptake in this region; only opportunistic screening is practiced currently.ObjectiveThe aim of this protocol is to describe the methods of development and validation of a DRS intervention using a hand-held nonmydriatic digital camera by physician graders in a non-ophthalmological setting at a tertiary-level medical clinic to propose a valid and feasible modality to improve uptake.MethodsDRS modality was developed after assessing barriers and identifying the most appropriate personnel, methods, and location for screening services, following formative research work. The validation will be conducted in a public sector tertiary care center in the Western province of Sri Lanka. The selected physicians will be trained on capturing and grading images according to a valid locally adopted protocol. Two physicians rated high on training will screen a sample of 506 people with DM at a medical clinic. They will use nonmydriatic and mydriatic 2-field imaging strategy. The validity of the proposed screening procedure will be assessed and compared with the mydriatic indirect biomicroscopic examination by a senior retinologist.ResultsThe validity of screening by physician graders will be analyzed and the sensitivity, specificity, and predictive values (with 95% CIs) calculated by the dilation status and for each grader. The diagnostic accuracy at each level of severity of DR will be assessed to define the most appropriate referable criteria. Data is currently being collected.ConclusionsThe outcome of this study will be useful for the detection of a defined level of DR at non-ophthalmological setting to filter the people with DM before referral to an eye clinic. This will be helpful to improve the uptake and identify risk groups in advance to prevent sight-threatening DR. Furthermore, evidence from this study will be useful for the implementation of a DRS program in this region and in similar communities.International Registered Report Identifier (IRRID)PRR1-10.2196/10900