Digital Retinal Camera Research Articles

Evaluation of a combination digital retinal camera with spectral-domain optical coherence tomography (SD-OCT) that might be used for the screening of diabetic retinopathy with telemedicine: A pilot study

AimsPilot study to determine whether an instrument combining a non-mydriatic retinal camera and spectral domain optical coherence tomography (SD-OCT) is effective for screening patients with diabetic retinopathy (DR). MethodsCase series conducted between 2012 and 2013. DR imaged with a retinal camera/SD-OCT instrument viewed remotely was compared to a dilated examination by a retina specialist. ResultsThe combination instrument was better than the retina specialist in detecting more severe retinopathy, primarily because of the SD-OCT. For severe retinopathy (grade ≥ 3), the image grader had better sensitivity (87.3% [95% CI: 75.5%, 94.7%]) than the retina examiner (76.4% [95% CI: 63.0%, 86.8%]). Specificities were similar between the instrument grader (96.0% [95% CI: 86.3%, 99.5%]) and retina examiner (100.0% [95% CI: 92.9%, 100.0%]). When identifying diabetic macular edema (ME), the retina examiner only identified 47.6% (20/42) of eyes with ME detected by SD-OCT. The instrument was better than a dilated retinal examination in detecting ME and not as good at detecting mild or proliferative retinopathy. ConclusionsAs used in this study, the instrument was more effective in identifying DR than was the current recommendation of a dilated and comprehensive eye examination. SD-OCT is needed to accurately identify DR in a screening setting.

Accuracy and reliability of retinal photo grading for diabetic retinopathy: Remote graders from a developing country and standard retinal photo grader in Australia.

BackgroundTo evaluate the accuracy and reliability of fundus retinal photos graded by local graders in Bangladesh with those graded by an expert at the Centre for Eye Research Australia (CERA) in the context of mass scale diabetic retinopathy (DR) screening in Bangladesh.MethodsA population-based cross-sectional study of 3,104 adults identified 213 (7.2%) eligible patients with diabetes of age ≥ 40 years in 2012–2013. Retinal photographs were collected using a non-mydriatic digital fundus retinal camera and a two-field imaging protocol. The photos were graded by two remote graders (G1 and G2) who were trained by a retinal specialist (RS) in Bangladesh, by the RS himself, and by a Centre for Eye Research Australia (CERA) grader. The local graders up skilled their grading ability by comparing 30% of the photos graded by the CERA grader with their own grades. Learning from that exercise was applied to the remaining 70% of photos, which were re-graded. Reliability and accuracy of grading amongst the graders were reported using cross tabulation, inter- and intra-grader reliability, and with sensitivity and specificity.ResultsOf 122 eyes from 61 patients, the mild (R1) DR was estimated to be 14 to 25%, pre-proliferative (R2) DR 4–8%, and proliferative (R3) DR 0.8 to 1.6%, whereas 25%, 8%, 18%, and 15% were found to be ungradable by CERA, RS, G1, and G2, respectively. Of 8 (6.6%) eyes identified as R2 by the CERA grader, 5 (63%), 3 (38%) and 3 (38%) were correctly classified as R2, whereas the rest were classified either as R1 or R3 but none were classified as no DR (R0) or ungradable by the RS, G1 and G2, respectively. After getting experience reviewing the 30% test set graded by the CERA grader, the local graders graded moderate and severe DR with 100% accuracy. After excluding ungradable photos, the sensitivity (specificity) relative to the CERA grader was 82% (88%) before and 80% (93%) after training for G1 and 56% (87%) before and 77% (90%) after training for G2. In case of maculopathy, the CERA grader reported 11.2% eyes with maculopathy, which included 100% of the 4.9% by RS, 6.6% by G1, and 7.4% by G2.ConclusionsLocal graders in Bangladesh are able to grade retinal photos with high accuracy if the DR is at least of a moderate level. With appropriate training and experience, local graders have the ability to contribute significantly to the grading of millions of retinal photos, which required grading in resource- poor countries.

A needs assessment of people living with diabetes and diabetic retinopathy.

BackgroundThe Kilimanjaro Diabetic Programme was initiated in response to the needs of people living with diabetes (PWLD) to identify barriers to uptake of screening for diabetic retinopathy, to improve management of diabetes, and establish an affordable, sustainable eye screening and treatment programme for diabetic retinopathy. Intervention Mapping was used as the framework for the needs assessment.MethodsA mixed methods approach was used. Five psychometric measures, Diabetes Knowledge Questionnaire, Diabetes Health Beliefs, Self-Efficacy scale, Problem Areas in Diabetes scale, and Hopkins Scale Checklist-25 and a structured interview relating to self-efficacy, addressing disclosure of living with diabetes and life-style changes were used to triangulate the quantitative findings. These were administered to 26 PWLD presenting to rural district hospitals.ResultsThe interviewees demonstrated low levels of perceived stigma regarding disclosure of living with diabetes and high levels of self-efficacy in raising community awareness of diabetes, seeking on going treatment from Western medicine over traditional healers and in seeking care on sick days. Self-efficacy was high for adjusting diet, although comprehensive dietary knowledge was poor. Negative emotions expressed at diagnosis, changes in life style and altered quality of life were reflected in high levels of anxiety and depression.ConclusionsLow levels of stigma surrounding living with diabetes were linked to a desire to raise community awareness of diabetes, help others live with diabetes and to secure social support to access hospital services. Confusion over what constituted a healthy diet showed the importance of comprehensive, accessible diabetes education, essential to ensuring good glycaemic control, and preventing diabetic complications, including diabetic retinopathy. Low levels of self-efficacy along with high levels of anxiety and depression may have a negative impact on the uptake of screening for Diabetic Retinopathy. The findings of this needs assessment led to the planning and delivery of a comprehensive health intervention programme for PLWD in Kilimanjaro Region. The programme has provided them with support, resources, education, and screening for diabetic retinopathy at the regional hospital and at district level with mobile digital retinal cameras, an electronic diabetic database and computerised follow up to ensure continuity of care.

Clinical Validation of a Smartphone-Based Adapter for Optic Disc Imaging in Kenya.

Visualization and interpretation of the optic nerve and retina are essential parts of most physical examinations. To design and validate a smartphone-based retinal adapter enabling image capture and remote grading of the retina. This validation study compared the grading of optic nerves from smartphone images with those of a digital retinal camera. Both image sets were independently graded at Moorfields Eye Hospital Reading Centre. Nested within the 6-year follow-up (January 7, 2013, to March 12, 2014) of the Nakuru Eye Disease Cohort in Kenya, 1460 adults (2920 eyes) 55 years and older were recruited consecutively from the study. A subset of 100 optic disc images from both methods were further used to validate a grading app for the optic nerves. Data analysis was performed April 7 to April 12, 2015. Vertical cup-disc ratio for each test was compared in terms of agreement (Bland-Altman and weighted κ) and test-retest variability. A total of 2152 optic nerve images were available from both methods (also 371 from the reference camera but not the smartphone, 170 from the smartphone but not the reference camera, and 227 from neither the reference camera nor the smartphone). Bland-Altman analysis revealed a mean difference of 0.02 (95% CI, -0.21 to 0.17) and a weighted κ coefficient of 0.69 (excellent agreement). The grades of an experienced retinal photographer were compared with those of a lay photographer (no health care experience before the study), and no observable difference in image acquisition quality was found. Nonclinical photographers using the low-cost smartphone adapter were able to acquire optic nerve images at a standard that enabled independent remote grading of the images comparable to those acquired using a desktop retinal camera operated by an ophthalmic assistant. The potential for task shifting and the detection of avoidable causes of blindness in the most at-risk communities makes this an attractive public health intervention.

Pilot Study on Visual Function and Fundus Autofluorescence Assessment in Diabetic Patients.

Purpose. Evaluate optimized fundus autofluorescence (FAF) imaging in early stages of diabetic retinopathy (DR) and relate findings with conventional colour fundus imaging and visual function in diabetic patients and control subjects. Materials and Methods. FAF and colour images were obtained using the CR-2 Plus digital nonmydriatic retinal camera in seven diabetic patients and thirteen control subjects. Visual-Functioning Questionnaire-25 (VFQ-25) and Diabetes Self-Management Questionnaire (DSMQ) were used to assess the quality of life and diabetes self-care. Contrast sensitivity function (CSF) was evaluated with the Vistech 6500 chart. Results. FAF and optimized-FAF imaging showed more retinal alterations related to DR than colour imaging. In diabetic patients, compatible signs with microaneurysms, capillary dilations, and haemorrhages were less numerous in colour imaging than optimized-FAF and FAF imaging in areas analysed. Control subjects at risk of developing DM showed more retinal pigment epithelium defects than those without risk in all retinal areas. Significant differences were not found in VFQ-25 and CSF between diabetic patients and control subjects. Conclusions. FAF and optimized-FAF imaging showed significant alterations related to DR not observed in colour imaging. FAF and optimized-FAF images could be a useful complementary tool for detecting early alterations associated with the development and progression of DR.

Results of Automated Retinal Image Analysis for Detection of Diabetic Retinopathy from the Nakuru Study, Kenya

ObjectiveDigital retinal imaging is an established method of screening for diabetic retinopathy (DR). It has been established that currently about 1% of the world’s blind or visually impaired is due to DR. However, the increasing prevalence of diabetes mellitus and DR is creating an increased workload on those with expertise in grading retinal images. Safe and reliable automated analysis of retinal images may support screening services worldwide. This study aimed to compare the Iowa Detection Program (IDP) ability to detect diabetic eye diseases (DED) to human grading carried out at Moorfields Reading Centre on the population of Nakuru Study from Kenya.ParticipantsRetinal images were taken from participants of the Nakuru Eye Disease Study in Kenya in 2007/08 (n = 4,381 participants [NW6 Topcon Digital Retinal Camera]).MethodsFirst, human grading was performed for the presence or absence of DR, and for those with DR this was sub-divided in to referable or non-referable DR. The automated IDP software was deployed to identify those with DR and also to categorize the severity of DR.Main Outcome MeasuresThe primary outcomes were sensitivity, specificity, and positive and negative predictive value of IDP versus the human grader as reference standard.ResultsAltogether 3,460 participants were included. 113 had DED, giving a prevalence of 3.3% (95% CI, 2.7–3.9%). Sensitivity of the IDP to detect DED as by the human grading was 91.0% (95% CI, 88.0–93.4%). The IDP ability to detect DED gave an AUC of 0.878 (95% CI 0.850–0.905). It showed a negative predictive value of 98%. The IDP missed no vision threatening retinopathy in any patients and none of the false negative cases met criteria for treatment.ConclusionsIn this epidemiological sample, the IDP’s grading was comparable to that of human graders’. It therefore might be feasible to consider inclusion into usual epidemiological grading.

Changes in retinal vessels related to varicocele: a pilot investigation.

The aim of this study was to investigate whether retinal vasculature changes had occurred (retinal artery diameter, retinal vein diameter and artery/vein ratio) in patients with varicocele. This pilot study included 50 healthy subjects with any eye disease apart from slight refractive errors and 55 patients with varicocele. Retinal arteriolar and venular diameters were measured and summarised as central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE). Retinal microvascular diameters and the arteriolar-to-venular ratio (AVR) were assessed with a digital retinal camera. All measurements and calculations were performed using a computer-based program. The mean CRAE value was 151.8±3.6μm in the study group and 150.4±4.5μm in the control group. Mean CRVE value was 209.4±5.9μm in the study group and 200.1±8.7μm in the control group. AVR was found 0.72±0.02 in the study group and 0.75±0.03 in the control group. There were significant differences between groups in terms of CRVE and AVR. There were no significant differences between groups in terms of CRAE. The results of this study showed that the patients with varicocele showed significant changes on retinal vascular diameter.

Real-time teleophthalmology in rural Western Australia.

This study aims to assess the current utilisation of a real-time teleophthalmology service for rural Western Australia (WA). Service evaluation by prospective audit. Includes general practices, optometrists, hospitals in rural WA and the Lions Eye Institute in Perth. Eighty-five patients from rural WA participating. Video consultation (VC) with a general ophthalmologist. Number of referring practitioners and their locations, software and imaging equipment used as well as the presentation, working diagnosis and follow-up plan for each consultation. Eighty-five participants took part in a total of 100 VCs in the 5-month data collection period. There were 49 men (58%); age range 7-92 years; 31 identified as Indigenous Australian (37%). Participants were referred by optometrists (59%), hospital district medical officers (23%) and GPs (18%). Karratha (41%), Albany (20%) and Broome (14%) were the main VC locations. There were 31 different eye conditions managed; red eye, acute vision loss, known glaucoma and abnormal retinal photographs were the main presentations. Skype was the commonly used software (71%). Images were provided in 63% of all VCs. The main equipment used included digital retinal cameras (56%), smartphones (25%) and digital slit lamps (13%). An outpatient appointment with the ophthalmologist was recommended following 35 VCs. Optometrists used this service most frequently, despite a lack of financial incentive. Digital retinal cameras and smartphones were the most commonly used imaging modalities. Overall, real-time teleophthalmology was used in the management of a broad range of eye conditions and was a useful supplement to outreach ophthalmology services.

Three Years Follow-Up Incidence of Retinopathy, In Type 1 Diabetic Patients, In a Population-Based Screening Program with Digital Retinal Photographs

Purpose: To determine the incidence of diabetic retinopathy (DR) and risk factors associated with its development in a cohort of patients with type 1 diabetes mellitus (DM 1), after three years of follow up, with annual retinal photograph by teleophthalmological means. Methods: Prospective cohort study of DM 1 patients, medically assisted in the Puerta del Mar Hospital Endocrinology Unit between 2009 and 2010, without DR, or with any degree of retinopathy that requires no treatment. Patients undergo endocrinological study. Control of blood glucose, glycosylated hemoglobin (HbA1c), blood pressure, dyslipidemia, renal dysfunction and smoking were recorded. Annually, three pictures are taken in each eye with a non-mydriatic digital retinal camera and are included in the intranet tool of the Andalusian Integral Diabetes Plan for remote analysis and grading. The cumulative incidence of DR after three years of follow up and the relationship between the recorded risk factors and the onset of DR is analyzed Results: One hundred and forty-three patients were included in the study. The incidence of RD at 3 years followup was 23.1%. Baseline HbA1c showed a clear trend towards significance to the development of the RD (p=0.06). The duration of diabetes and other considered risk factors showed no significant values in the statistical analysis. Conclusions: This study provides the first results of cumulative incidence of DR in a cohort of DM 1 patients, followed-up through the Tele-ophthalmology tool of the Integral Diabetes Plan of Andalusia, which was 23.1%. Only baseline HbA1c showed a trend toward significant association in the development of RD.

Optic Disc Drusen in a Child

To describe a case of bilateral optic nerve head drusen (ONHD) in a pediatric patient and the complementary use of advanced noninvasive imaging techniques to confirm this diagnosis. A 15-year-old female adolescent with type 1 diabetes and no ocular history was seen at a routine screening without complaints. Visual acuity was 20/20 bilaterally, and visual fields using frequency doubling technology (Zeiss Humphrey Systems, Dublin, CA) were within normal limits. Fundus photography (CX-1 Mydriatic/Non-Mydriatic Hybrid Digital Retinal Camera, Canon, Toyko, Japan) showed slight elevation of the left disc margin, with lack of physiologic cup, elevation of the inferior neuroretinal rim, and no swelling of the nerve fiber layer. Fundus autofluorescence image of the left eye showed hyperfluorescence in the inferior optic disc. Red/green/blue channel separation analysis using the blue channel (Eye-Q software, Canon, Irvine, CA) showed elevation of the nerve fiber layer without obscuration of small vessels surrounding the left optic disc. Embossed technique highlighted the drusen in the left disc. B-scan ultrasound (Eye Cubed, Ellex, Adelaide, Australia) showed a hyperechoic focus on the optic disc with posterior shadowing and corresponding spike on A-scan in both eyes, indicative of bilateral drusen. Optical coherence tomography (RTVue, Optovue, Fremont, CA) showed an elevation in the ONH corresponding to the drusen. The complementary use of noninvasive imaging modalities such as fundus autofluorescence, red/green/blue separation, B-scan, and optical coherence tomography is important in confirming the diagnosis of ONHD in pediatric patients. They allow us to rule out more serious conditions and avoid unnecessary, costly, and invasive investigative procedures, relieving young patients and their families of potential financial and emotional burdens.

Clinical Pearls

Clinical Pearls

Prevalence of diabetic retinopathy in Peruvian patients with type 2 diabetes: results of a hospital-based retinal telescreening program.

To estimate the prevalence of diabetic retinopathy (DR) in patients with type 2 diabetes and to determine any association with clinical factors. This hospital-based screening project was designed to prospectively detect the presence of DR in patients with type 2 diabetes by grading images acquired with a digital retinal camera. Of 1 311 patients screened, appropriate retinal images were obtained in 1 222 subjects (93.2%). DR was detected in 282 patients (23.1%) [95% confidence interval (CI): 20.71-25.44]; 249 patients (20.4%) (95% CI: 18.1-22.6) had nonproliferative DR and 33 (2.7%) (95% CI: 1.8-3.6) had proliferative DR. In 32 patients (11.3%), DR was unilateral. The frequency of DR was the same in both sexes. Prevalence of blindness was twice as frequent in patients with DR as in those without it (9.4% and 4.6%, respectively) (P = 0.001). The frequency of DR at diagnosis was 3.5% and it increased with the duration of diabetes. DR was more frequent in patients with arterial hypertension, macrovascular or microvascular complications, and hemoglobin A1c (HbA1c) > 7.0% and in those treated with insulin or sulfonylureas. It was less prevalent in those with HbA1c < 7.0%, with greater body mass index, and who had been treated with metformin. The prevalence of DR in these patients with type 2 diabetes was 23.1%. Nonproliferative retinopathy accounted for 77.0% of cases. Although less prevalent than in a previous report, it doubled the frequency of blindness in the people affected. A national screening DR program should be considered in order to detect this prevalent condition early and treat it in a timely fashion.

Relationship between birth weight and retinal microvasculature in newborn infants

Objective:The purposes of this study were to determine the normal retinal microvasculature measurements in human infants who are born at term and to determine whether birth weight influences measurements of retinal microvasculature.Study Design:Retinal arteriole and venule measurements were obtained in a cohort of 24 infants who were born at term. Digital images of both the retinas were obtained using a digital retinal camera after pupillary dilation.Result:In all, 24 newborn infants born at term (12 females and 12 males) were analyzed in this study. The measured retinal arteriole diameters were from 66.8 to 147.8 μm (mean, 94.2±19.6 μm), and the venule diameters were from 102.0 to 167.8 μm (mean, 135.2±19.1 μm). Seven babies in the sample had low birth weight (LBW), while 17 babies were born with normal weight. Babies with lower birth weights had larger arteriole (113.1±17.9 μm vs 86.4±14.4 μm; P=0.0009) and venule diameters (151.7±14.9 μm vs 128.4±16.9 μm; P=0.0040).Conclusion:Retinal venules and arterioles in LBW babies are larger compared with those of normal-birth-weight babies. We postulate that the difference observed in our study was due to in utero pathophysiological changes that occurred in the cerebral circulation of growth-restricted fetuses.

Accuracy and Reliability of Telemedicine for Diagnosis of Cytomegalovirus Retinitis

To determine the feasibility of remote diagnostic screening for cytomegalovirus (CMV) retinitis among HIV patients in northern Thailand. Prospective, observational cross-sectional study. One hundred eighty-two eyes from 94 consecutive patients with HIV seen in 2008 and 2009 at a tertiary university-based medical center were photographed using a digital retinal camera. Individual and composite images were uploaded to a secure web site. Three expert graders accessed the electronic images and graded each image for signs of CMV retinitis. Results of remote expert grading were compared with on-site patient examination by local expert ophthalmologists. On-site ophthalmologists diagnosed CMV retinitis in 89 (48.9%) of 182 eyes. Trained ophthalmic photographers obtained digital retinal images for all 182 eyes. As compared with the on-site examinations, the sensitivity for detecting CMV retinitis by remote readers using composite retinal images ranged from 89% to 91%. The specificity for detecting CMV retinitis by remote readers ranged from 85% to 88%. Intrarater reliability was high, with each grader achieving a κ value of 0.93. Interrater reliability among the 3 graders also was high, with a κ value of 0.86. Remote diagnostic screening for CMV retinitis among HIV-positive patients may prove to be a valuable tool in countries where the burden of HIV exceeds the capacity of the local eye care providers to screen for ocular opportunistic infections.

Project I See in NC: Initial Results of a Program to Increase Access to Retinal Examinations Among Diabetic Individuals in North Carolina

Diabetic retinopathy is the leading cause of preventable blindness in adults. Project I See in NC was begun to determine whether access to eye screening for Medicaid recipients and uninsured patients with diabetes in North Carolina could be improved. We targeted Medicaid recipients and uninsured adults with diabetes for screening in 2 Community Care of North Carolina Networks. Screenings were performed in primary care settings throughout 6 counties in the Northwest Community Care Network and 6 counties in Access III of Community Care of the Lower Cape Fear. Patients were screened using a high-resolution digital retinal camera with images read at a centralized reading center at Wake Forest School of Medicine. A total of 1,688 patients were screened from October 2005 through September 2007. Nearly 15% (282) were found to have mild, nonproliferative-to-proliferative retinopathy, while the majority of patients had no evidence of diabetic retinopathy. Nearly 12% (196) required referral to an ophthalmologist, with 5% (86) requiring urgent referral for potentially sight-threatening retinopathy. We were not able to confirm which patients kept their ophthalmologic appointments; however, we are currently analyzing data from the Medicaid patients in our study who required ophthalmologic referral. Remote digital retinal screening for diabetic retinopathy is feasible in primary care settings in both urban and rural areas of North Carolina, and it may prove to be an effective means of reaching more patients who require annual screening examinations.

Retinal microvasculature measurements in full-term newborn infants

ObjectiveCurrently, there are no published data on retinal microvasculature size in human infants born at term. The purpose of this study was to determine the normal retinal microvasculature measurements in human infants born at term with normal birth weight and to compare these results with measurements in children and adults. MethodsRetinal arteriole and venule measurements were obtained in a cohort of 20 full-term infants. Digital retinal images were obtained from both eyes after pupillary dilation using a digital retinal camera. Measurements of vessel diameter were then obtained using semi-automated software. ResultsTwenty infants (9 female infants and 11 male infants) were analyzed. The retinal arteriole diameter was 66.8–123.0μm (mean, 85.5 (14.3) μm), and the venule diameter was 102.0–167.8μm (mean, 130.0 (16.0) μm). There were no differences in the arterial or venule diameters between the male and female infants (83.2 (12.2) vs. 88.3 (16.9); P=0.4372; 124.3 (16.0) vs. 137.0 (18.0); P=0.08). The arteriovenous ratio was found to be 0.66 (95% CI 0.62–0.71). The coefficient of correlation between the retinal arterioles and venules was 0.56. The retinal arteriole and venule diameters increase as a person matures. The arteriovenous ratio also increases with age. ConclusionIn newborn infants, retinal venules are significantly larger than retinal arterioles. The arteriovenous ratio is smaller in neonates compared to adults indicating the retinal arteriole diameter increases at a different pace compared to retinal venule. Sex does not influence the retinal microvasculature size in infants. The presence of spontaneous retinal hemorrhage and the inability to account for refractive errors were the main limitations of this study.

Influence of Blood Pressure on Retinal Vascular Caliber in Young Children

Prior studies have reported that blood pressure (BP) has a significant influence on retinal vascular caliber both in adults and children aged 6 years and older. This study aimed to examine the association between BP and retinal vascular caliber in Singapore Chinese preschoolers 4 to 5 years of age. Population-based, cross-sectional study. A total of 385 eligible and healthy Singapore Chinese children 4 to 5 years of age who were recruited in The Strabismus, Amblyopia and Refractive Error Study in Singaporean Chinese Preschoolers from May 2006 through October 2008 underwent BP measurements and retinal photography. According to standard protocols, BP was measured with an automatic Omron sphygmomanometer (Omron HEM 705 LP, Omron Healthcare, Inc., Bannockburn, IL) and a retinal photograph was obtained with a Canon 45° digital retinal camera (Model CR6-NM45, Canon, Inc., Tokyo, Japan) after pupil dilation. Anthropometric and optical biometric measurements such as height, weight, and axial length were obtained also. Information regarding sociodemographic status and child birth information was supplied by parents in either English or Chinese questionnaires. The computer imaging program was used to measure the caliber of all retinal arterioles and venules located in zone B. The central retinal arteriolar equivalent and central retinal venular equivalent were estimated by using a revised Knudtson-Parr-Hubbard formula. The mean retinal arteriolar and venular calibers were 156.19 μm and 220.01 μm in boys and 161.97 μm and 224.22 μm in girls. Higher systolic BP was associated with narrower retinal arterioles. After adjusting for age, gender, father's education, body mass index, birth weight, axial length, and caliber of the fellow retinal vessel, each 10-mmHg increase in systolic BP was associated with 2.00 μm (95% confidence interval, 0.39-3.61; P = 0.02) of retinal arteriolar narrowing and 2.51 μm (95% confidence interval, 0.35-4.68; P = 0.02) of retinal venular widening. However, neither diastolic BP nor mean arterial BP was associated with retinal arteriolar or venular caliber. In very young children 4 to 5 years of age, higher systolic BP was associated with narrower retinal arterioles and wider retinal venules. This suggests that elevated BP may affect the retinal microvasculature from early childhood.

Canon CX-1 Combines Mydriatic and Non-mydriatic Multiple-mode Digital Retinal Imaging in One System

Canon’s CX-1 digital retinal camera is the latest innovation in its eye-care portfolio. Incorporating Canon’s electro-optical system (EOS) camera technology, the compact, fully portable system is synergised for mydriatic and non-mydriatic imaging in five modes, including fundus autofluorescence (FAF).

EyePACS: An Adaptable Telemedicine System for Diabetic Retinopathy Screening

Annual retinal screening of patients with diabetes is the standard clinical practice to prevent visual impairment and blindness from diabetic retinopathy. Telemedicine-based diabetic retinopathy screening (DRS) in primary care settings can effectively detect sight-threatening retinopathy and significantly increase compliance with annual retinal exams. EyePACS is a license-free Web-based DRS system designed to simplify the process of image capture, transmission, and review. The system provides a flexible platform for collaboration among clinicians about diabetic retinopathy. Primary clinic personnel (i.e., nursing, technical, or administrative staff) are trained and certified by the EyePACS program to acquire retinal images from standard digital retinal cameras. Relevant clinical data and eight high-resolution images per patient (two external and six retinal images) are encrypted and transmitted to a secure Internet server, using a standard computer and Web browser. Images are then interpreted by certified EyePACS reviewers or local eye care providers who are certified through the EyePACS Retinopathy Grading System. Reports indicating retinopathy level and referral recommendations are transmitted back to primary care providers through the EyePACS Web site or through interfaces between EyePACS and Health Level 7-compliant electronic medical records or chronic disease registries. The pilot phase of the EyePACS DRS program in California (2005-2006) recorded 3562 encounters. Since 2006, EyePACS has been expanded to over 120 primary care sites throughout California and elsewhere recording over 34,000 DRSs. The overall rate of referral is 8.21% for sight-threatening retinopathy and 7.83% for other conditions (e.g., cataract and glaucoma). The use of license-free Web-based software, standard interfaces, and flexible protocols has allowed primary care providers to adopt retinopathy screening with minimal effort and resources.

Use of digital camera imaging of eye fundus for telemedicine in children suspected of abusive head injury

Aim:Pilot study of the role of RetCam imaging for telemedicine in lieu of availability of ophthalmologist examination for cases of suspected abusive head injury.Design:Cross-sectional observational study.Participants:21 children admitted in the...