Venous Beading Research Articles

DETECTION OF MICROVASCULAR CHANGES IN EYES OF PATIENTS WITH DIABETES BUT NOT CLINICAL DIABETIC RETINOPATHY USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

To evaluate the ability of optical coherence tomography angiography to detect early microvascular changes in eyes of diabetic individuals without clinical retinopathy. Prospective observational study of 61 eyes of 39 patients with diabetes mellitus and 28 control eyes of 22 age-matched healthy subjects that received imaging using optical coherence tomography angiography between August 2014 and March 2015. Eyes with concomitant retinal, optic nerve, and vitreoretinal interface diseases and/or poor-quality images were excluded. Foveal avascular zone size and irregularity, vessel beading and tortuosity, capillary nonperfusion, and microaneurysm were evaluated. Foveal avascular zone size measured 0.348 mm² (0.1085-0.671) in diabetic eyes and 0.288 mm² (0.07-0.434) in control eyes (P = 0.04). Foveal avascular zone remodeling was seen more often in diabetic than control eyes (36% and 11%, respectively; P = 0.01). Capillary nonperfusion was noted in 21% of diabetic eyes and 4% of control eyes (P = 0.03). Microaneurysms and venous beading were noted in less than 10% of both diabetic and control eyes. Both diabetic and healthy control eyes demonstrated tortuous vessels in 21% and 25% of eyes, respectively. Optical coherence tomography angiography was able to image foveal microvascular changes that were not detected by clinical examination in diabetic eyes. Changes to the foveal avascular zone and capillary nonperfusion were more prevalent in diabetic eyes, whereas vessel tortuosity was observed with a similar frequency in normal and diabetic eyes. Optical coherence tomography angiography may be able to detect diabetic eyes at risk of developing retinopathy and to screen for diabetes quickly and noninvasively before the systemic diagnosis is made.

A Study of Retinal Blood Vessel Extraction from the Retinal Images

Detecting abnormalities such as venous looping or beading sis critical for early treatment as they are in most cases indication of potentially sight-threatening retinopathy. In order to utilize these useful characteristics of retinal blood vessels, it is very important to obtain their locations and shapes accurately. Blood vessels appeared as networks of either deep red or orange-red filaments that originated within the optic disc and were of progressively diminishing width. The major problem of Patients suffering from the disease over a long period of time is more likely to develop eye problems known as diabetic retinopathy. The detection of blood vessels is a major problem in the automatic processing of retinal images. On the one hand, the vessels have certain properties such as diameter which may be the key indicators in the evolution of certain retinopathies. Two major problems in the segmentation of retinal blood vessels are the presence of a wide variety of vessel widths and the heterogeneous background of the retina. The problem is to identify the segmentation of green veins and red veins in retina. Keyword: veins, retina, abnormalities, Blood vessels etc.

An overlap of Coats and Eales diseases or a Coats variant?

To report an association between Coats and Eales diseases, an uncommon presentation. A 21-year-old male presented with gradual visual impairment of two years duration in his left eye. The slit-lamp examination of the affected eye revealed +2 vitreous cells. The other findings were peri-papillary fluid accumulation and extensive macular lipid exudate deposition. Small white vessels were coursing over the macula. The major veins were dilated and tortuous and massive sheathing of both arteries and veins was forming a common sheath. In the mid-periphery and periphery of the retina, discrete hard exudates, tiny superficial retinal hemorrhages and massive vascular sheathing were present. In the inferotemporal region, two intra-retinal macrocysts were located distal to the retinal vasculature. Fluorescein angiography (FA) of the left eye highlighted numerous aneurysmal dilatations throughout the posterior pole. Fluorescein angiography also showed para-foveal telangiectasia and tiny telangiectatic vessels on the optic disk that led to late staining of the macula and optic disk. Hyperfluorescent patches of deep choroiditis were present in the early phases. There was segmental but no diffuse staining of the retinal veins which showed massive sheathing on fundoscopy. In the periphery, segmental venous staining and choroidal leakage to a lesser extent were observed. In the infero-temporal quadrant, a clear-cut zone of non-perfusion and vascular abnormalities (micro-macro aneurysms, veno-venous shunts, venous beading) at the junction between the perfused and non-perfused zones were present. The findings were reminiscent of both Coats and Eales diseases. Though known as two distinct entities, both retinal pathologies may present in a single form.

Peripheral Lesions Identified by Mydriatic Ultrawide Field Imaging: Distribution and Potential Impact on Diabetic Retinopathy Severity

To assess diabetic retinopathy (DR) as determined by lesions identified using mydriatic ultrawide field imaging (DiSLO200; Optos plc, Scotland, UK) compared with Early Treatment Diabetic Retinopathy Study (ETDRS) 7-standard field film photography. Prospective comparative study of DiSLO200, ETDRS 7-standard field film photographs, and dilated fundus examination (DFE). A total of 206 eyes of 103 diabetic patients selected to represent all levels of DR. Subjects had DiSLO200, ETDRS 7-standard field film photographs, and DFE. Images were graded for severity and distribution of DR lesions. Discrepancies were adjudicated, and images were compared side by side. Distribution of hemorrhage and/or microaneurysm (H/Ma), venous beading (VB), intraretinal microvascular abnormality (IRMA), and new vessels elsewhere (NVE). Kappa (κ) and weighted κ statistics for agreement. The distribution of DR severity by ETDRS 7-standard field film photographs was no DR 12.5%; nonproliferative DR mild 22.5%, moderate 30%, and severe/very severe 8%; and proliferative DR 27%. Diabetic retinopathy severity between DiSLO200 and ETDRS film photographs matched in 80% of eyes (weighted κ = 0.74,κ = 0.84) and was within 1 level in 94.5% of eyes. DiSLO200 and DFE matched in 58.8% of eyes (weighted κ = 0.69,κ = 0.47) and were within 1 level in 91.2% of eyes. Forty eyes (20%) had DR severity discrepancies between DiSLO200 and ETDRS film photographs. The retinal lesions causing discrepancies were H/Ma 52%, IRMA 26%, NVE 17%, and VB 4%. Approximately one-third of H/Ma, IRMA, and NVE were predominantly outside ETDRS fields. Lesions identified on DiSLO200 but not ETDRS film photographs suggested a more severe DR level in 10% of eyes. Distribution in the temporal, superotemporal, inferotemporal, superonasal, and inferonasal fields was 77%, 72%, 61%, 65%, and 59% for H/Ma, respectively (P<0.0001); 22%, 24%, 21%, 28%, and 22% for VB, respectively (P = 0.009); 52%, 40%, 29%, 47%, and 36% for IRMA, respectively (P<0.0001), and 8%, 4%, 4%, 8%, and 5% for NVE, respectively (P = 0.03). All lesions were more frequent in the temporal fields compared with the nasal fields (P<0.0001). DiSLO200 images had substantial agreement with ETDRS film photographs and DFE in determining DR severity. On the basis of DiSLO200 images, significant nonuniform distribution of DR lesions was evident across the retina. The additional peripheral lesions identified by DiSLO200 in this cohort suggested a more severe assessment of DR in 10% of eyes than was suggested by the lesions within the ETDRS fields. However, the implications of peripheral lesions on DR progression within a specific ETDRS severity level over time are unknown and need to be evaluated prospectively.

VZV multifocal vasculopathy with ischemic optic neuropathy, acute retinal necrosis and temporal artery infection in the absence of zoster rash

We describe a 54-year-old diabetic woman who developed ischemic optic neuropathy followed by acute retinal necrosis and multiple areas of focal venous beading. Vitreous fluid contained amplifiable VZV DNA but not HSV-1, CMV or toxoplasma DNA. The clinical presentation was remarkable for jaw claudication and intermittent scalp pain, prompting a temporal artery biopsy that was pathologically negative for giant cell arteritis, but notable for VZV antigen. The current case adds to the clinical spectrum of multifocal VZV vasculopathy. The development of acute VZV retinal necrosis after ischemic optic neuropathy supports the notion that vasculitis is an important additional mechanism in the development of VZV retinal injury.

Individualized optimization of the screening interval for diabetic retinopathy: a new model

Screening programmes for diabetic retinopathy follow guidelines that ensure that vision-threatening complications are detected even when the disease progression is fast. This implies that patients with slow disease progression will be recommended examinations more often than needed. On the basis of previously defined individual risk factors, multiple logistic regression was used to develop a model for individualized determination of the screening interval in diabetic retinopathy, while adjusting for the fact that in the data set used to construct the model, the screening interval acted as a time-dependent confounder. The model was tested on 1372 patients screened during year 2000. It was possible to construct a model for calculating the optimal screening interval in low-risk patients in whom the recommended screening interval was longer than 12 months. When the probability of reaching a treatment requiring event was set to 0.5%, none of the patients reached a treatment end-point in a validation of the model, and the screening interval was prolonged on average 2.9 times in patients with type 1 diabetes and 1.2 times in those with type 2 diabetes. The predictive strength of the model depended on the number of variables included. It is possible to construct a model for optimizing the examination interval during screening for diabetic retinopathy in low-risk patients. The model can potentially be improved by identifying unknown or unmeasured confounders and by including knowledge of risk factors before and after the examination on the basis of which the prediction is made.

Not Only Diabetic Retinopathy - Retinal Vascular Lesions and Signs in Diabetic Patients: Description and Associations

Retinal vascular changes other than diabetic retinopathy (DRP) namely microaneurysms, intraretinal microvascular abnormalities so called IRMA, microinfarctions, hemorrhages, lipid exudates and edema, as well as venous beading and new vessels (NV) on the disk and/or on the retina and their sequalae pre-retinal and vitreous hemorrhages and fibrovascular proliferations and vitreoretinal tractions are common in diabetic patients. These changes are general or focal arteriolar narrowing or arteriolar or venous dilatation, arteriolar sinusoidal elongation or straightening, venous tortuosity, increased arteriolar wall reflex and arterio-venous crossing signs. They reflect cumulative response to aging, cardiovascular risk factors such as hyperglycemia, hypertension and dyslipidemia, as well as inflammation and endothelial dysfunction. Retinal vascular changes are under the influence of both systemic and environmental as well as genetic factors and serve as cardiovascular risk stratification indicator. Furthermore, these changes may cause as such ocular morbidity and threaten vision and influence the occurrence and progression of DRP. Many of these changes were recognized soon after the invention of ophthalmoscope by von Helmholz in 1851 and have since been described in literature. Many of these changes can be accurately measured today.

Panretinal Photocoagulation for Proliferative Diabetic Retinopathy

A 55-year-old man with a 20-year history of type 2 diabetes mellitus was referred to a retina specialist after noticing a few black floaters in his left eye for the preceding week. His glycated hemoglobin level was 8.2%. He had no history of laser treatment for proliferative diabetic retinopathy in either eye. Ophthalmoscopic examination of the right eye showed venous beading, intraretinal microvascular abnormalities, and no macular edema. Ophthalmoscopic examination of the left eye showed extensive neovascularization of the disk, consisting of new vessels extending beyond the optic disk in all directions (Fig. 1A). The retina specialist diagnosed severe nonproliferative diabetic retinopathy in the right eye and high-risk proliferative diabetic retinopathy in the left eye, with no macular edema in either eye. The specialist recommended prompt initiation of panretinal photocoagulation in the left eye.

Clinical features and carotid artery color Doppler imaging in patients with ocular ischemic syndrome

To report the clinical manifestations and results of carotid artery color Doppler imaging (CDI) of ocular ischemic syndrome (OIS). It was a retrospective case series study. Consecutive patients suspected with OIS were retrospectively studied from 1995 to 2009. We evaluated all patients with medical history, visual acuity, slit lamp, direct and indirect funduscopy, Fundus fluorescence angiography. CDI for internal carotid artery (ICA), Diagnostic Cerebral Angiography and magnetic resonance imaging were also performed. 17 patients (20 eyes) with OIS were studied, 13 males and 4 females. The age range of patients was 46 to 83 years old (median 70). 13 right eyes and 7 left eyes (3 bilateral) were involved. (1) SYMPTOMS: 70.6% (12/17) of the patients complained of visual decrease. 17.6% (3/17) had history of repeated amaurosis fugax (transient monocular visual loss); 11.8% (2/17) patients presented with floaters. The course before the first presentation was 2 days to 6 years (median 3 months). (2) Visual Acuity (VA): among the 20 involved eyes, the best corrected VA < 0.05 in 3 eyes (15.0%); 0.05 to < 0.3 in 7 eyes (35.0%); 0.3 to < 0.7 in 7 eyes (35.0%); ≥ 0.7 in 3 eyes (15.0%). (3) Fundus manifestations: 15.0% (3/20) eyes had cotton-wool spots; 25.0% (5/20) had retinal hemorrhages; retinal arterioles and vein became narrow; venous beading could be seen in severe cases. 30.0% (6/20) had microaneurysms in mid-peripheral area. The pressure of central retinal artery decreased; 25.0% (5/20) had optic disc or retinal neovascularization; 10.0% (2/20) had iris neovascularization. 5.0% (1/20) had neovascular glaucoma; 5.0% (1/20) had optic atrophy. (4) Fundus fluorescence angiography: arm-retinal circulation time prolonged to 14.5 to 39.9 seconds, (median 20.9 seconds). The retinal and choroidal circulation time was also prolonged. The wall of artery and venous could be staining. Hyperfluorescence dots indicating microaneurysms could be seen in the mid-peripheral area. Arterio-venous shunts, non-perfusion area and the leakage of new vessels were observed in some cases. (5) Internal carotid artery CDI examination: The ipsilateral ICA of the 19 involved eyes (another patient with pulseless disease had abnormal subclavian arterial flow) showed completely occluded in 5 cases (26.4%), > 80.0% to 95.0% stenosis in 7 cases (36.8%), 52.0% to 80.0% stenosis in 7 cases (36.8%). Among the 14 contralateral eyes of the same group of patients, CDI showed stenosis of 80.0%, 70.0%, 60.0%, 50.0% and 40.0% in 5 eyes, whereas no fundus abnormal was found. Peak of systolic velocity (PSV): Among the 20 involved eyes of the 17 patients, PSV of the ipsilateral ICA was undetectable in 8 cases which occluded completely or stenosis severely. Among the ipsilateral ICA of the other 12 eyes, 11 cases showed abnormal PSV; PSV increased to 92 to 524 cm/s in 9 cases and decreased to 41 cm/s in 1 case. The blood flow of subclavian artery reduced to 20 cm/s in one patient with pulseless disease. The blood flow of subclavian artery reduced to 20 cm/s in one patient with pulseless disease. The patients with OIS are usually older than 60 years of age. It is a chronic disease with unnoticed symptoms. The clinical manifestations may include: amaurosis fugax (transient monocular visual loss), hypoperfusion retinopathy and ischemic optic neuropathy. Internal carotid artery severe stenosis or occlusion are the most frequent cause of this disease. CDI is the best safe, reliable and non-invaded method for carotid artery examination.

Retinopathy Signs in People without Diabetes: The Multi-Ethnic Study of Atherosclerosis

To describe the prevalence of retinopathy and associations with cardiovascular risk factors in persons without diabetes in 4 racial/ethnic groups (white, black, Hispanic, and Chinese). Population-based, cross-sectional study. We included 6176 subjects aged 45-84 years without diabetes, selected from 6 United States communities. Fundus images were taken using 45° digital camera through dark-adapted pupils and were graded for retinopathy as defined by the Early Treatment Diabetic Retinopathy Study severity scale: microaneurysms, hemorrhages, cotton wool spots, intraretinal microvascular abnormalities, hard exudates, venous beading, and new vessels. Retinopathy and the association with cardiovascular risk factors. Prevalence rates of retinopathy in persons without diabetes were 12.5% overall, varying from 11.9% (white), 13.9% (black), 12.6% (Hispanic), to 17.2% (Chinese). Hypertension was strongly associated with retinopathy (odds ratio [OR], 1.47; 95% confidence interval [CI], 1.23-1.75). After adjusting for age, gender, race, and other parameters, smoking (OR, 1.50; 95% CI, 1.09-2.06) and increased internal carotid intima media thickness (OR, 1.22; 95% CI, 1.05-1.41) were associated with retinopathy. A range of serum inflammatory factors were examined, but none were found to be significant. Retinopathy in persons without diabetes is common, varies with race/ethnicity, and associated with cardiovascular risk factors, including hypertension, smoking, and carotid artery intima media thickness.

Digital versus Film Fundus Photography for Research Grading of Diabetic Retinopathy Severity

To assess agreement between digital and film photography for research classification of diabetic retinopathy severity. Digital and film photographs from a 152-eye cohort with a full spectrum of Early Treatment Diabetic Retinopathy Study (ETDRS) severity levels were assessed for repeatability of grading within each image medium and for agreement on ETDRS discrete severity levels, ascending severity thresholds, and presence or absence of diabetic retinopathy index lesions, between digital and 35-mm slides (film). Digital photographs were color balanced to match film. There was substantial agreement (κ = 0.61, κ(w) [linear weighted] = 0.87) in classification of ETDRS diabetic retinopathy severity levels between digital images and film. Marginal homogeneity analyses found no significant difference in frequency distributions on the severity scale (P = 0.21, Bhapkar test). The κ results ranged from 0.72 to 0.95 for presence or absence of eight ascending diabetic retinopathy severity thresholds. Repeatability of grading between readers viewing digital images was equal to or better than that obtained with film (pair-wise interreader κ for digital images ranged from 0.47 to 0.57 and for film from 0.43 to 0.57. The κ results for identifying diabetic retinopathy lesions ranged from moderate to almost perfect. Moderate agreement of intraretinal microvascular abnormalities and venous beading between digital images and film accounted for slightly lower concordance for severity thresholds ≥47 and for slightly lower interreader agreement within digital and film images at severity thresholds ≥43 and ≥47. Under controlled circumstances, digital photography can equal the reliability of 35-mm slides for research classification of ETDRS severity level.

GRADING DIABETIC RETINOPATHY SEVERITY FROM COMPRESSED DIGITAL RETINAL IMAGES COMPARED WITH UNCOMPRESSED IMAGES AND FILM

To compare research grading of diabetic retinopathy (DR) severity level from compressed digital images versus uncompressed images and film. Compressed (JPEG2000, 37:1) digital images (C) were compared with uncompressed digital (U) and film (F) stereoscopic photographs from a 152-eye cohort with full-spectrum Early Treatment Diabetic Retinopathy Study severity levels for agreement on severity level, DR presence with ascending severity threshold, presence of DR index lesions, and repeatability of grading. Classification of Early Treatment Diabetic Retinopathy Study severity levels from C images agreed substantially with results from F images (κ = 0.60, κ(w) [linear weighted] = 0.86) and uncompressed digital images (κ = 0.76, κ(w) = 0.92). For agreement of uncompressed digital versus F images, κ = 0.62 and κ(w) = 0.86. Distribution of Early Treatment Diabetic Retinopathy Study levels was not significantly different between C and F images (P = 0.09, Bhapkar's test for marginal homogeneity). For presence/absence of DR at 8 ascending severity thresholds, agreement between C and F was "almost perfect" (κ ≥ 0.8). Agreement on severity level between readers with C images was at least as good as that with uncompressed digital image or F. Repeatability of severity threshold grading between readers was similar using C or F images. For identifying individual DR lesions, agreement between C and F ranged from "moderate" to "perfect." Agreement of grading venous beading from C was slightly lower than from F. Full Early Treatment Diabetic Retinopathy Study scale DR severity level grading using C images is comparable to that using U images or film.

Rapid, bloody, and blinding diabetic retinopathy

Rapid, bloody, and blinding diabetic retinopathy

Screening of diabetic retinopathy: Effect of field number and mydriasis on sensitivity and specificity of digital fundus photography

Purpose To evaluate the sensitivity and specificity of one- and three-field, nonmydriatic and mydriatic, and 45° digital colour photography compared with mydriatic indirect ophthalmoscopy for diabetic retinopathy (DR) screening. Methods A group of 79 patients (158 eyes) were included in this prospective study. Colour fundus photographs were taken with a Topcon TRC-NW6S digital camera, using four different techniques—single-field nonmydriatic; three-field nonmydriatic; single-field mydriatic; and three-field mydriatic—followed by dilated ophthalmoscopy. Two independent ophthalmologists classified blinded photographs according to the presence or absence of specific diabetic retinal findings. The sensitivity, specificity and agreement (kappa analyses) of the four methods were calculated for the presence or absence of DR and for all diabetic retinal findings. Results The sensitivity and specificity of digital photography compared with ophthalmoscopy for detection of DR were, respectively: 77 and 99% using single-field nonmydriatic; 92 and 97% using three-field nonmydriatic; 90 and 98% using single-field mydriatic; 97 and 98% using three-field mydriatic. The degrees of agreement for the four methods were 0.82, 0.90, 0.90 and 0.95, respectively. For specific retinal findings, sensitivity was greater for detection of hard exudates, nerve fibre layer haemorrhage and venous beading, and lower for detection of microaneurysms, dot-blot haemorrhage, cotton wool spots and intraretinal microvascular anomalies. Conclusion The three-field strategy without pupil dilation represents a good compromise, with reasonable sensitivity and good comfort (short examination duration, able to drive after photography) favouring patient compliance with the screening programme.

Retinal Vascular Lesions in Patients of Caucasian and Asian Origin With Type 2 Diabetes

OBJECTIVE—The objective of this study was to describe prevalent vascular retinal lesions among patients with type 2 diabetes enrolled in the ADVANCE Retinal Measurements (AdRem) study, a substudy of the Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation (ADVANCE) trial. RESEARCH DESIGN AND METHODS—Seven-field stereoscopic photographs of both eyes were obtained at the baseline assessment of the ADVANCE trial. All photographs were graded in a central reading center. Gradable retinal images were received from 1,605 patients. RESULTS—The number of patients with any retinopathy (Early Treatment of Diabetic Retinopathy Study [ETDRS] score ≥20) was 645 (40.2% [95% CI 37.8–42.6]); of these, 35 (2.2% [1.6–3.0]) had severe diabetic retinopathy (ETDRS score ≥50). Focal arterial narrowing, venous beading, and arteriovenous nicking were present in 3.8, 5.1, and 9.8% of participants, respectively. Among participants included in this study, Chinese and South-Asian patients had more retinopathy than Caucasians, as defined both by ETDRS score (49.4, 46.0, and 31.3%, respectively; P &amp;lt; 0.001, adjusted for age, sex, A1C, systolic blood pressure, and duration of diabetes) and specific vascular lesions (e.g., arteriovenous nicking 12.3, 8.5, and 7.5%, respectively; adjusted P &amp;lt; 0.005). A1C, duration of diabetes, and systolic blood pressure were similarly associated with increased retinal lesions in Chinese, South-Asian, and Caucasian patients. CONCLUSIONS—Using a sensitive diagnostic procedure, more than one-third of patients with type 2 diabetes enrolled in the AdRem study had retinal lesions at baseline. Despite differences in prevalence and severity of retinopathy among Chinese, South-Asian, and Caucasian patients included in this study, the cross-sectional associations among established risk factors for retinopathy and retinal lesions were similar across ethnic groups.

Identification of diabetic retinopathy by stereoscopic digital imaging via teleophthalmology: a comparison to slide film

Background: Diabetic retinopathy is a leading cause of vision loss in North America. We compared mydriatic seven-field stereoscopic digital imaging to 100 ASA slide film photography for the identification of diabetic retinopathy via teleophthalmology.Methods: Patients from a northern Alberta community with diabetes mellitus diagnosed by a physician were asked to participate in a teleophthalmology pilot project. Patients were enrolled at four different times between October 1999 and June 2000. Seven 30° fields of the retina were photographed with both slide film and digital imaging (resolution 2008 × 3040 pixels) through a dilated pupil. Slide film was developed and reviewed in a masked fashion by a retinal specialist. Digital images for each patient were transmitted by satellite to Edmonton and analysed a minimum of 2 months after the original slide film. Retinal abnormalities were graded with' the use of the Early Treatment Diabetic Retinopathy Study extension of the modified Airlie House classification. We calculated the sensitivity and specificity of digital imaging for the identification of features of diabetic retinopathy as seen on slide film. Pearson's correlation coefficient was also calculated.Results: A total of 121 patients (241 eyes), of whom 114 (94.2%) had non-insulindependent diabetes, participated in the study. The average duration of diabetes was 8.5 years. Of the 121 patients 57 (47. I %) had diabetic retinopathy, 12 (9.9%) had clinically significant macular edema and 2 (1.6%) had neovascularization. Pearson's correlation coefficient for the presence of retinopathy between slide film and stereoscopic digital imaging was 0.92 for microaneurysms, 0.80 for hemorrhages, 0.45 for intraretinal microvascular abnormalities, 0.32 for venous beading, 1.00 for neovascularization of the disc, 1.00 for neovascularization elsewhere in the retina and 0.97 for clinically significant macular edema (p < 0.001). The correlation between the two techniques for severe nonproliferative diabetic retinopathy (NPDR) was 0.86 and for high-risk proliferative diabetic retinopathy 1.00 (p < 0.001).Interpretation: Stereoscopic digital imaging has a high level of correlation with slide film for the identification of most features of diabetic retinopathy, including microaneurysms, hemorrhage, severe NPDR, highrisk proliferative diabetic retinopathy and clinically significant macular edema.

A comparison of digital nonmydriatic fundus imaging with standard 35-millimeter slides for diabetic retinopathy

Purpose The purpose of this study was to compare nonmydriatic digital images with 35-mm slide images for the detection of diabetic retinal findings. Study design Comparative, observational case series. Participants Forty patients with diabetes. Methods Diabetic patients underwent digital (nonmydriatic fundus camera attached to a digital back) and standard dilated 35-mm retinal photography of three areas: posterior pole, nasal retina, and temporal retina. The images were reviewed by a single masked grader for the presence or absence of specific retinal findings. Primary outcome measures Presence or absence of neovascularization of the disc (NVD), neovascularization elsewhere (NVE), venous beading (VB), nerve fiber layer (NFL) hemorrhage, dot–blot hemorrhage, microaneurysm (MA), clinically significant macular edema, cotton wool spot, intraretinal microvascular anomaly (IRMA), hard exudate (HE), and retinal pigment epithelial (RPE) pigmentary changes. Results Forty eyes of 22 patients underwent both imaging procedures. The agreement between image type was highest for IRMA (97.5%) and VB (95%) and lowest for RPE pigmentary changes (65%) and MA (62.5%). Sensitivity ranged from 25% (NVD) to 100% (VB). Specificity ranged from 90% (RPE pigmentary changes) to 100% (NVD, NVE, VB, NFL hemorrhage, HE). Positive predictive value ranged from 50% (IRMA) to 100% (NVD, NVE, HE, NFL, VB). Negative predictive value ranged from 48% (MA) to 100% (IRMA). Conclusions Nonmydriatic digital fundus imaging for detection of diabetic retionopathy has a low sensitivity rate and a high specificity rate and is less clinically useful than standard dilated 35-mm fundus slide images.

Computer-aided diagnostic detection system of venous beading in retinal images

The detection of venous beading in retinal images provides an early sign of diabetic retinopathy and plays an important role as a preprocessing step in diagnosing ocular diseases. We present a computer-aided diagnostic system to automatically detect venous bead- ing of blood vessels. It comprises of two modules, referred to as the blood vessel extraction module (BVEM) and the venus beading detection module (VBDM). The former uses a bell-shaped Gaussian kernel with 12 azimuths to extract blood vessels while the latter applies a neural network-based shape cognitron to detect venous beading among the extracted blood vessels for diagnosis. Both modules are fully computer- automated. To evaluate the proposed system, 61 retinal images (32 beaded and 29 normal images) are used for performance evaluation. © 2000 Society of Photo-Optical Instrumentation Engineers. (S0091-3286(00)01305-2) Subject terms: bell-shaped Gaussian matched filter; blood vessel extraction mod- ule; detection; extraction; neural network; retinal images; shape cognitron; venus beading detection module.

The relation of systemic hypertension to changes in the retinal vasculature: the beaver dam eye study: Klein R *, Klein BEK, Moss SE. Trans Am Ophthalmol Soc 1997;95:329–348

The objective was to investigate the relationship of systemic hypertension to the incidence of various retinal vascular lesions in the population-based Beaver Dam Eye Study.Subjects aged 43 through 86 years who lived in Beaver Dam, Wisconsin between 1987 and 1988 were examined between 1988 and 1990 and 5 years later, 1993-1995. Blood pressure was measured using standardized protocols. Stereoscopic color fundus photographs were graded in a masked fashion using standardized protocols to determine the presence of retinopathy (blot hemorrhages, microaneurysms, hard and soft exudates, intraretinal microvascular abnormalities, and venous beading), retinal arteriolar narrowing, and arterio-venous nicking. People with diabetes or retinal vascular occlusions were excluded from the analyses.Among those examined, 2,151 (69.1%) were normotensive and 963 (30.9%) were hypertensive at baseline. Over the five-year period, retinopathy developed in 175 (6.0%), arteriolar narrowing in 282 (9.9%) and arterio-venous nicking in 201 (6.5%) nondiabetic subjects. After adjusting for age, hypertension was associated with the incidence of retinopathy (in men: relative risk [RR] 2.31, 95% confidence interval [CI] 1.54 to 3.48; in women: RR 1.61, 95% CI 1.07 to 2.43) and with arteriolar narrowing (in men: RR 1.82, 95% CI 1.25 to 2.66; in women: RR 1.36, 95% CI 1.05 to 1.77), but not with arterio-venous nicking (in men: RR 1.01, 95% CI 0.69 to 1.48; in women: RR 1.37, 95% CI 0.95 to 1.97). The five-year incidence of retinopathy and of arteriolar narrowing was higher in those subjects whose blood pressure was elevated despite use of antihypertensive medications compared with those subjects whose blood pressure was controlled with antihypertensive medications or those who were normotensive.These data show a relation of hypertension to an increased incidence of retinopathy and arteriolar narrowing. Furthermore, these data suggest that pharmacologic control of blood pressure is related to a lower incidence of these anatomic retinal lesions relative to uncontrolled blood pressure.

Retinal Venous Beading With Recurrent Preretinal Hemorrhage

To report a patient with idiopathic retinal venous beading and recurrent preretinal hemorrhage. Case report of a 17-year-old girl with bilateral retinal venous beading, greater in the left eye than in the right eye, and recurrent preretinal hemorrhage in the left eye. Complete blood cell count, platelet count, blood glucose level, and hemoglobin electrophoresis were normal. Fluorescein angiography showed normal retinal arterial and venous filling with no evidence of retinal capillary nonperfusion or neovascularization. Idiopathic retinal venous beading may be associated with recurrent preretinal hemorrhage, even in the absence of retinal ischemia or neovascularization.