Detection Of Macular Edema Research Articles

The Diagnostic Function of OCT in Diabetic Maculopathy

Diabetic maculopathy (DM) is one of the major causes of vision impairment in individuals with diabetes. The traditional approach to diagnosis of DM includes fundus ophthalmoscopy and fluorescein angiography. Although very useful clinically, these methods do not contribute much to the evaluation of retinal morphology and its thickness profile. That is why a new technique called optical coherence tomography (OCT) was utilized to perform cross-sectional imaging of the retina. It facilitates measuring the macular thickening, quantification of diabetic macular oedema, and detecting vitreoretinal traction. Thus, OCT may assist in patient selection with DM who can benefit from treatment, identify what treatment is indicated, guide its implementing, and allow precise monitoring of treatment response. It seems to be the technique of choice for the early detection of macular oedema and for the followup of DM.

Netzhautdickenmessung mit dem Heidelberg Retina Tomograph bei Patienten mit Makulaödem und bei Gesunden

This study was carried out to test the reliability of a defined cut-off value for retinal thickness with estimation of the sensitivity, specificity and formation of an edema index in comparison to retinal thickness. This was a single center prospective clinical non-blinded study of 100 eyes, including 22 eyes with central vein or branch vein occlusions, 20 eyes with diabetic macular edema, 6 eyes with postoperative macular edema, 2 eyes with uveitis and 50 healthy eyes. Detection of macular edema was carried out by third generation optical coherence tomography. Using the latest version of the Heidelberg retina tomograph (HRT 3) series of five images were produced and evaluated. The 9-zone circle of the HRT was used as the analysis contour. The reliability of measuring retinal thickness with the HRT in the subjects showed an intraclass correlation between 0.248 and 0.740 and patients with macular edema showed values between 0.515 and 0.949. The reliability of the edema index with the HRT in the subjects showed an intraclass correlation between 0.461 and 0.826 and patients with macular edema showed values between 0.383 and 0.826. The calculated cut-off values were between 285µm and 360µm. The corresponding sensitivity values were between 74.7% and 95.9% with a corresponding specificity of 74.7-90.2%. There was also a highly significant correlation between the edema index and retinal thickness (p < 0.001). The retina module of the latest generation HRT is capable of reproducible measurement of the retinal thickness in micrometers. The defined cut-off values correspond to expectations and can be used in this form in the clinical practice.

Detection and discrimination of disease-related abnormalities based on learning normal cases

Detection of abnormalities from medical images is of key interest in developing computer-aided diagnostic tools. In this paper, we observe the key challenges for representation and feature extraction schemes to be met for detection of abnormalities by learning normal cases. We introduce an image representation, motivated by the effect of motion on perception of structures. This representation is based on a set of patterns called generalized moment patterns (GMP) generated via induced motion over regions of interest, for learning normal. The proposed GMP has been utilized to develop a scheme for addressing two well-known problems: lesion classification in mammograms and detection of macular edema in color fundus images. The strengths of this scheme are that it does not require any lesion-level segmentation and relies largely on normal images for training which is attractive for developing screening tools. The proposed scheme has been assessed on two public domain datasets, namely, MIAS and MESSIDOR. A comparison against the performance of state of the art methods indicates the proposed scheme to be superior.

Uveitic macular oedema: correlation between optical coherence tomography patterns with visual acuity and fluorescein angiography

Aims:(1) To associate optical coherence tomography (OCT) patterns with particular fluorescein angiography (FA) findings in uveitis patients with macular oedema. (2) To investigate the correlation between tomographic features and visual...

DISCREPANCY BETWEEN FLUORESCEIN ANGIOGRAPHY AND OPTICAL COHERENCE TOMOGRAPHY IN DETECTION OF MACULAR DISEASE

To compare high-resolution optical coherence tomography (OCT) and fluorescein angiography (FA) in detection of macular edema (ME) of various etiologies. In a retrospective study over a 12-month period at one retina center, data for consecutive eyes that had undergone simultaneous conventional FA (HRA; Heidelberg Engineering, Vista, CA) and StratusOCT (Carl Zeiss Meditec, Dublin, CA) to rule out ME were reviewed. A subset of patients underwent additional examination with extremely high-resolution (6-microm)/ultrahigh-speed spectral OCT/scanning laser ophthalmoscopy (OTI, Inc., Toronto, Ontario, Canada). Of 1,272 eyes, 1,208 (94.97%) had the finding of ME or subretinal fluid confirmed by both techniques. There were 49 eyes (3.86%) for which FA showed dye leakage in the macular area and OCT showed normal foveal contour. Of 10 eyes in this group that underwent imaging with ultrahigh-speed spectral OCT/scanning laser ophthalmoscopy, 8 had subtle diffuse lucencies in the retina. For 15 eyes (1.17%), OCT showed intraretinal and subretinal fluid, which was missed by FA. Both FA and high-resolution OCT are highly sensitive techniques and correlate well in detection of ME. However, there is a small chance that when performed alone they might miss existing subtle ME.

A comparative study of various diagnostic procedures in macular edema

To compare the results for diagnosis of macular edema between Heidelberg retina tomography (HRT-II macular edema module) and optical coherence tomography (OCT). Two hundred and twelve eyes of 106 macular edema patients were diagnosed with fundus fluorescein angiography (FFA). HRT-II was used to obtain Edema Index and OCT was used to measure the retina thickness in the fovea. The results were compared with FFA. As FFA for gold standard, we compared with other diagnosis method. With regard to the diagnosis of macular edema by OCT, the Kappa value was 0.553, the odds ratio (OR) was 8.519. The Kappa value of HRT-II was 0.403 and OR was 3.210. In two groups of patients with and without macular edema, which were diagnosed by FFA, the difference of Macular edema Index P assayed by HRT-II between these two groups was significant (P = 0.00); while the difference of fovea retina thickness P assayed by OCT between these two groups was significant, too (P = 0.00). The best critical value of E was 2.00 and the ROC curve's area was 0.673 in the detection of macular edema by HRT-II. The best critical value of retina thickness for the diagnosis of macular edema was 170 microm and the ROC curve's area was 0.774 in the detection of macular edema by OCT. In regard to the diagnosis of macular edema, the sensitivity of HRT-II is better than that from OCT, with a lower false-negative result. However, HRT-II has a relatively low specialty with a higher false- positive result. As for the localization of macular edema, HRT-II has its advantage. Compared with FFA, the consistence of OCT for the diagnosis of macular edema is better than that of HRT-II. We can conclude from the OR value that OCT has greater influence than HRT-II in the diagnosis of macular edema. In addition, as for the diagnosis and different diagnosis, the clinical value of OCT is higher than that of HRT-II. Combination of these two different diagnostic methods might provide an accurate quantitative analysis of macular edema.

Accuracy and Reliability of Teleophthalmology for Diagnosing Diabetic Retinopathy and Macular Edema: A Review of the Literature

Using teleophthalmology for the delivery of routine eye care for patients with diabetes mellitus is becoming an increasingly common practice. Paramount in the consideration of any new diagnostic test is an analysis of its diagnostic accuracy and reliability and how that compares with conventional care. This review summarizes existing data on the diagnostic accuracy and reliability of teleophthalmology and conventional clinic-based eye care for detecting diabetic retinopathy and diabetes mellitus. The sensitivity of ophthalmoscopy for detecting diabetic retinopathy performed by eye care clinicians has varied widely, with point estimates ranging from 0% to 96%. Alternatively, specificity has been universally high. The sensitivity of teleophthalmology for detecting diabetic retinopathy has been shown to be comparable, if not better, than clinic-based examinations. Sensitivity values have ranged from 50% to 93%. The specificity of teleophthalmology, like clinic-based examinations, has been consistently high. High levels of diagnostic reliability, analyzed by both simple agreement and kappa values, have been found between ophthalmoscopy and teleophthalmology for detecting and classifying diabetic retinopathy. Evaluating the accuracy of macular edema detection requires the use of dual gold standards, the clinical examination using slit-lamp biomicroscopy and stereoscopic photography. Teleophthalmology, compared with both gold standards, has, overall, been a highly sensitive and specific test. Reliability studies that compared the two gold standards with one another have found moderate to substantial levels of agreement. Based on existing data, teleophthalmology appears to be an accurate and reliable test for detecting diabetic retinopathy and macular edema.

Two-field photography can identify patients with vision-threatening diabetic retinopathy: a screening approach in the primary care setting.

To compare the effectiveness of two 45 degrees photographic fields per eye in the screening for diabetic retinopathy with the routine ophthalmologist's examination and to study the effectiveness of visual acuity measurement in the detection of diabetic macular edema. Type 1 and 2 diabetic patients without a known history of more than minimal retinopathy (n = 469) had a routine examination by an ophthalmologist, including visual acuity measurement, indirect retinoscopy, and biomicroscopy. At the same time, two-field nonstereoscopic retinal photographs were made of both eyes and assessed in a masked fashion by a retinal specialist. The results were compared. The prevalence was 4.3% for vision-threatening retinopathy and 24% for any retinopathy. The sensitivity of two-field photography in identifying diabetic patients with sight-threatening retinopathy was 95% (specificity 99%) and sensitivity for detecting any retinopathy was 83% (specificity 88%). The percentage of referrals to an ophthalmologist was 6.2%. All patients with macular edema detected by biomicroscopy were classified as having vision-threatening retinopathy on the photographs. Two-field retinal photography is a promising alternative to the routine ophthalmologist's examination in the screening for diabetic retinopathy. Visual acuity measurement is not a sensitive tool for the detection of macular edema. Screening for diabetic retinopathy using two-field retinal photography is feasible in a primary care setting and can substantially lower the number of ophthalmic referrals.

Use of oral fluorescein angiography in the diagnosis of macular oedema within a diabetic retinopathy screening programme.

To assess if oral fluorescein angiography (OFA) is a suitable screening method to detect macular oedema in diabetic retinopathy. Eighty-four diabetic patients were included in the study. They were from a consecutive series of patients attending the diabetic eye-screening clinic, with retinopathy at the macula requiring ophthalmology assessment. All patients were subsequently examined in the eye hospital, by ophthalmologist slit lamp biomicroscopy assessment as the gold standard, followed by oral fluorescein angiography. This study indicates a sensitivity of 92% and specificity of 81%. Only 4.8% of patients developed a minor reaction to oral fluorescein; 84.5% of images were of good quality. Oral fluorescein angiography is an efficient and highly sensitive tool for the detection of macular oedema. It can be used as an adjunct in the diabetic screening service to identify patients with oedema within a disc diameter of the macula. Ultimately it will ensure that only necessary and smaller numbers of patients are referred to ophthalmologists.

A telemedical approach to the screening of diabetic retinopathy: digital fundus photography.

The importance of screening for diabetic retinopathy has been established, but the best method for screening has not yet been determined. We report on a trial of assessment of digital photographs by telemedicine compared with standard retinal photographs of the same fields and clinical examination by ophthalmologists. A total of 129 diabetic inpatients were screened for diabetic retinopathy by slit-lamp biomicroscopy performed by an ophthalmologist and by two-field 50 degrees non-stereo digital fundus photographs assessed by six screening centers that received the images by electronic mail. Conventional 35-mm transparencies of the same fields as the digital photographs were assessed by a retinal specialist and served as the reference method for detection of diabetic retinopathy. Slit-lamp biomicroscopy was the reference method for the detection of macular edema. The prevalence of any form of diabetic retinopathy was 30% (n = 35); of sight-threatening retinopathy including macular edema, the prevalence was 6% (n = 7). The assessment of digital images by the six screening centers resulted in a median sensitivity of 85% and a median specificity of 90% for the detection of moderate nonproliferative or sight-threatening diabetic retinopathy. Clinically significant macular edema (n = 4) was correctly identified in 15 of the 24 grading reports. An additional seven reports referred the patients for further investigation because of concurrent diabetic retinopathy. Telescreening for diabetic retinopathy by an assessment of two-field 50 degrees non-stereo digital images is a valid screening method. Although detection of clinically significant macular edema using biomicroscopy is superior to digital or standard non-stereo photographs, only few patients with sight-threatening diabetic retinopathy are missed.

Quantitative analysis of diabetic macular edema after scatter laser photocoagulation with the scanning retinal thickness analyzer.

To define the effect of scatter laser photocoagulation on foveal retinal thickness. A commercial scanning retinal thickness analyzer was used to measure retinal thickness. The foveal retinal thickness was measured at the central area of the fundus (0.4 x 0.4 mm). The method was applied to 20 consecutive patients (mean age, 52.4 +/-16.9 years) with diabetic retinopathy. Measurements were performed before and 6 weeks after scatter photocoagulation. Patients were examined by fluorescein angiography and slit-lamp biomicroscopy to detect macular edema. Mean foveal thickness before scatter photocoagulation was 187+/-45 microm, increasing to 221+/-46 microm after the treatment (P = 0.0001). The foveal thickness increased in 12 eyes (60%). Laser treatment increased macular permeability in two eyes (10%). Biomicroscopic examination revealed central macular thickening in one eye (5%). Visual acuity was reduced in four eyes (20%). Our results suggest that subclinical macular edema occurs after scatter laser photocoagulation. The retinal thickness analyzer is a sensitive tool for early detection of macular edema after laser treatment, because increases in retinal thickness as small as 34 microm cannot be assessed by slit-lamp biomicroscopy.

Detection of Diabetic Macular Edema: Ophthalmoscopy Versus Photography—Early Treatment Diabetic Retinopathy Study Report Number 5

Clinical and photographic methods were used to assess retinopathy during the examinations of diabetic patients enrolled in the Early Treatment Diabetic Retinopathy Study (ETDRS). In analyzing available data from eyes randomly selected for deferral of treatment, the authors compare the clinical detection (including contact lens biomicroscopy) with photographic detection (30° stereoscopic color fundus photographs) of diabetic macular edema. Based on clinical detection, 53% (1778 patients) had hard exudates within 1 disc diameter (DD) of the center of macula,, 56% (1868 patients) had retinal thickening within this region, and 31% (1027 patients) had thickening at the center of macula. These analyses show agreements of 83, 78, and 83% between retinal specialists and photographic graders when assessing these three characteristics, respectively. Agreement was 81 % in the detection of macular edema for which treatment is indicated (clinically significant macular edema). Each method has its advantages but in general there was close agreement between these methods, particularly for clinically significant macular edema, which supports the reliability of each method.