European Association for the Study of Diabetic Eye Complications

Annual Meeting Coimbra 27-29th May 2007

Poster Abstract 1 - 9

RELATION BETWEEN DURATION OF TYPE 1 DIABETES MELLITUS WITH FREQUENCY OF DIABETIC EYE COMPLICATIONS IN WARMIA AND MAZURY REGION , POLAND.

E Bandurska-Stankiewicz(1), J Pieczyski(2), D Wiatr(1), L Surdykowski(1) (1) Endocrinology and Diabetology Ward , General District Hospital , Olsztyn , Poland(2) Ophthalmologic Ward, General District Hospital , Olsztyn , Poland

Purpose: Our study was designed to investigate the relation between duration of type 1 diabetes mellitus (T1DM) and frequency of diabetic eye complications.

Methods: 127 T1DM patients diagnosed using Eurodiab and Dia-Mod methods, 62 female and 67 males, aged 1- 40, with 1–10 years diabetes duration were included in the study. Diabetic eye complications were detected by clinical examination (visual acuity, intraocular pressure, eye adnexae status, fundus examination). The retina was examined using Volk's lens and photographed (2-field colour photos) with Nikon AF 505 fundus camera. Retinopathy was graded according to the Early Treatment Diabetes Retinopathy Study grading system. Additionally, the presence of cataract, glaucoma and optic neuropathy was assessed.

Results: Diabetic eye complications were found in 19 patients (14.9 %), 10 females, 9 males, average age 26.6 +/-9.3 yrs, average duration of diabetes: 6.95 +/- 1.3 yrs. Non-proliferative retinopathy was observed in 10 patients (12.7%)– 18 eyes: 6 females – 11 eyes, and 4 males (3.1%) – 7 eyes (2.7%), aged 24.7 +/-4.6 yrs, 7.5 +/- 1.4 diabetes duration. One female (aged 27, 6 yrs of diabetes duration) was diagnosed with both retinopathy and maculopathy after laser theraphy. Cataract was found in 6 patients (4.72%)(3 females, 3 males), aged 23.5 +/- 2.4, 5.3 years of diabetes duration, while glaucoma in 2 patients: 1 female (aged 16, 6 yrs of diabetes) and 1 male (aged 28, 8 yrs of diabetes)

Conclusion: These data suggest that diabetic eye complications occur soon after the diagnosis of T1DM. T1DM patients should have eye examination as soon as the disease is diagnosed, and should be repeated every year.

INCIDENCE OF LOW VISION IN DIABETIC PATIENTS AS ESTIMATED FROM THE NUMBER OF PATIENTS ADMITTED TO A CENTRE OF VISUAL REHABILITATION.

Johan Elvstam, Gun Olsson Dep. of Ophthalmology, Kalmar County Hospital, Länssjukhuset , Sweden

Purpose: To estimate the incidence of diabetic patients suffering from severe loss of visual acuity.

Methods: A population study of diabetic patients referred to the centre of visual rehabilitation in Kalmar, Sweden. In the study the best-corrected visual acuity (VA), as given from the charts at the time of referral, is used.

Results: The centre of visual rehabilitation in Kalmar serves a geographically defined area with approximately 140 000 inhabitants. The study includes all patients referred to the visual rehabilitation centre during the years 1995 – 2004 with diabetic retinopathy as the main diagnosis and with VA of 0,4 or less (Snellen chart). The total number of diabetic patients admitted yearly varied between 6 and 18, ages 31 – 95 (mean 69 years). Only few (0- 3 patients yearly) had at the time of admittance VA of 0.1 (6/60, 20/200) or worse. The incidence of diabetic patients with low vision as defined as VA 0.1 or worse in the southern county of Kalmar in Sweden is approximately 1 per 100 000 inhabitants per year.

Conclusions: The incidence of diabetic patients with low vision in the southern county of Kalmar in Sweden is approximately 1 per 100 000 inhabitants per year, as estimated from the number of patients admitted to the centre of visual rehabilitation.

SYSTEMIC RISK ASSESSMENT IN A DIABETIC EYE CLINIC

Anju Kadyan(1), Maurice P Headon (1), Baldev Singh (2). Wolverhampton Eye Infirmary(1)and Diabetic Centre (2),Royal Wolverhampton Hospitals NHS Trust, UK.

Purpose: To profile the patients attending the diabetic eye clinic in a district general hospital and to do a systemic risk assessment.

Methods: We prospectively assessed 88 patients randomly chosen from those attending the diabetic eye clinic over a period of 2 months. Data was collected regarding the ocular status, diabetic control and a systemic risk assessment done to calculate the Coronary Heart Disease (CHD) score using the computerised Framingham equation.

Results: Of the 88 patients studied (age 63.8 +/- 11.6 yrs, 62.5% males), 13.6% were type 1 and 86.4% had type 2 diabetes mellitus (59.2% IDDM and 40.8% NIDDM). Mean duration of diabetes was 14.7 +/- 10.2 yrs. Diabetic retinopathy was graded as background in 52%, pre-proliferative in 12.5% and proliferative in 20.5%, while 16% had clinically significant maculopathy. Their HBA1c was 8.63 +/- 1.88% (mean +/- SD). The diabetic control was worse in the type 1 group (>8 in 100%) and type 2 group on insulin treatment (>8 in 64.4%). Inadequate blood pressure control was noted in 54% patients (systolic pressure >140 mmHg) already on antihypertensive treatment. 3.4% had systolic pressure of >160mm Hg and were not on any antihypertensive treatment. There was established macro vascular disease in 36.4%, persistent smoking in 10%, inadequate foot care in 22%, creatinine >120 in 23% and albumin creatinine ratio >3.5 in 37%. Of those with established macro vascular disease 28% were not on statin and 34.4% were not on aspirin or any other antiplatelet therapy. The mean CHD score calculated for 72/88 (<74 yrs of age) was 17.14 +/- 8.64% with 37.5% having a CHD score of >20%.

Conclusions: Systemic risk assessment in diabetic eye clinics provides a valuable opportunity to detect new and inadequately treated patients and should be encouraged. An integrated care pathway would be useful here.

DIABETIC RETINOPATHY IN A COHORT OF CHILDREN AND ADOLESCENTS FROM FUNEN, DENMARK.

EF Gade (1), ML. Laursen (1), A Green (2), M Hansen (1), AK Sjølie (1) (1) Department of ophthalmology, Odense University Hospital (2) Department of Applied Reserarch and HTA, Odense University Hospital

Purpose: To describe the presence and severity of retinopathy and related risk factors among children and adolescents with diabetes examined at the photographic screening clinic at Odense university Hospital, Denmark.

Methods:From 1999, children and adolescents with diabetes from the county of Funen, Denmark (about 500.000 inhabitants), were included. Fundus Photographs were taken at age 9, 12, 15 and yearly thereafter, and evaluated by retina specialists. Grading of the retinopathy was based on the classification published by Wilkinson et al (Ophthalmology 2003; 110:1677-1682)

Results:147 children, 65 girls (44.2%) and 82 boys (55.8%) were followed from 1999 to 2004. Mean age at diagnosis of diabetes was: 7.4 years (range: 0-16). Mean age at first visit at the screening clinic was 12.6 years (range: 8-17) and mean duration of diabetes was 5.1 years (range: 1-15) and HbA1c was: 8.66 (range: 5.5 – 19.2).Five children had retinopathy (level 1) at the first visit; mean age 16.6 years (range: 15 –17) and mean duration of diabetes was 5.1 years (range: 1-15).Nine children developed some degree of retinopathy. Of these, two patients developed proliferative retinopathy, when they were 19 and 21 years of age, they had a duration of diabetes of 10 and 14 years and a mean value of HbA1c of 11 and 11.2. One of the patients progressed from level 1 to 4 in two years and the other progressed from level 0 to 4 in 3 years.

Conclusions:In our screening clinic we found 14 children with some degree of diabetic retinopathy, out of a total of 147 children followed at the regional photographic screening clinic. Two of these progressed to proliferative retinopathy around the age of twenty. This indicates that it is important to follow young diabetic patients, especially if they have poor glycaemic control.

IS OUR TYPE 1 DIABETIC PATIENT SCREENING SUCCESSFUL?

I Ribeiro, A Lima, R Monteiro, JG. Monteiro, L Costa, P Rodrigues, M Bilhoto Ophthalmology Department - Hospital Pedro Hispano, Matosinhos, Portugal

Purpose: To describe the screening, prevalence and management of eye disease in Type 1 diabetic patients observed in our ophthalmology department.

Methods: Data was collected from the S.E.E. database of W.H.O. and analysed using the Epi Info program.

Results: One hundred forty two Type 1 diabetic patients were evaluated (age range 7-69 years, mean 34+/-15; 57% females) with mean diabetes duration of 19+/-12 years (range 1-56). Corrected visual acuity in the best eye ranged from light perception to 10/10 (mean 0.8+/-0.3). 62 patients did not have diabetic retinopathy (DR). 41 patients (29%) had nonproliferative DR, described as incipient in 18 patients (13%), moderate in 20 (14%) and severe in 3 (2%). Thirty four patients (24%) had proliferative DR, from which 32 were photocoagulated and 2 were referred for photocoagulation. Five patients (3,5%) had advanced disease. The mean age and the mean duration of the disease for the patients without DR and with nonproliferative and proliferative DR were respectively: 23+/-10 and 10+/-6 for the first group, 42+/-15 and 25+/-11 for the second group, 43+/-12 and 27+/-10 for the third. Macular edema was found in 37 patients (26%) and 16 patients (11%) had previous macular edema, successfully treated. The mean age and the mean duration of the disease of the group with macular edema were respectively 41+/-12 and 25+/-11 years. Argon laser panretinal photocoagulation was performed in 87 eyes and grid pattern photocoagulation in 102 eyes (82 eyes underwent both treatments). 49 eyes had nonoperated cataract and cataract surgeries were performed in 11 eyes. 25 eyes (14 patients) had glaucoma. Four patients were found to be legally blind.

Conclusions: The prevalence of nonproliferative and proliferative DR matches with the group characteristics. We therefore conclude that the screening program is being successful.

DIABETIC RETINOPATHY IN TYPE 1 DIABETES: FROM 1985 TO 2004

J. Figueira, T. Torrent, L. Ribeiro, M. Luz, R Silva, J.R. Faria de Abreu, J. G. Cunha-Vaz Ophthalmology Department. Hospitais da Universidade de Coimbra. Coimbra. Portugal, AIBILI. Coimbra. Portugal

Purpose: To study the value of Vitreous Fluorophotometry (PR) in identifying type 1 diabetic adolescents in risk of developing diabetic retinopathy.

Methods: This is a still-going prospective study started in 1985 with a mean follow-up of 11,4 years (in 2004) in which 80 diabetics were enrolled (41 males, 39 females). Initial value of PR was that at puberty, age at diagnostis was 8,5±4,2 years old (Mean ± SD), age in 2004 was 24,5±4,8. All patients underwent several ophthalmological exams (fundus photograph, Fluorescein Angiography, Vitreous Fluorophotometry) as well as biological evaluation (CBC and HbA1c).

Results:After this follow-up 29 patients (34%) showed no retinopathy (ODR), 41 (48%) showed non proliferative forms (NPDR) and 15 (18%) proliferative forms (PDR)

	Duration	HbA1c
ODR	14,5±4,7	8,8±2,4
NPDR	17,4±5,3	9,1±1.8
PDR	18,0±5,5	9,1± 2

Patients without retinopathy had a shorter duration of the disease (p=0,02) but there were no statistically significant differences in terms of HbA1c. PR at puberty was higher in patients with PDR, with 3,5 being a cut-off value.

Conclusion: Deterioration of the blood retina barrier at puberty may be important in the development of Diabetic Retinopathy.

AUTOMATIC ESTABLISHMENT OF MACULAR COORDINATES

Pedro Baptista(1), Rui Bernardes (1), Jorge Dias (2), José Cunha-Vaz(1,3) 1 Association for Innovation and Biomedical Research on Light and Image (AIBILI/CNTM), Coimbra, 2 Institute of Systems and Robotics (ISR), Faculty of Science and Technology, University of Coimbra, Coimbra, Portugal, 3 Institute of Biomedical Research on Light and Image (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal

Purpose: To automatically establish retinal coordinates on high-resolution fundus images.

Methods: High-resolution color fundus images (50 degree retinographies) were taken using a Zeiss fundus camera (Carl Zeiss, Germany), with a Hiko h10 digital camera of 3192x2656 pixels. A template matching algorithm allows to determine the center of the fovea on a multi-resolution approach. A first step to determine the optic disk (OD) center and contour consists in determining a point inside the OD. This is also achieved using a template matching algorithm. Afterwards, the brightness along a set of radial lines crossing at this point are analyzed to determine the location of the OD contour and an ellipse is fitted to that set of points that also acts as a starting point to the active contour algorithm. Based on this set of points along the OD contour, a new center of the OD is computed and a line connecting it to the center of the fovea establishes the x-axis of the macular coordinates system. This process allows to extract the scaling factor as defined by a 2 disc diameter line from the center of the fovea to the OD contour.

Results: These procedures were tested in a series of both normal and diseased eyes. The fovea was completely detected in all cases, while the OD detection failed in 8,7% of the cases. OD contour showed was unsuccessfull in 13% of the cases while for the remaning 78,3% the detection was sucessfull. For the sucessfull cases, the RMS error was 16,9 pixels when compared to the contour drawn by manual grading on a computer monitor.

Conclusions: The procedure reported herein allows for automatic determination of the major retinal features and thus to establish absolute macular coordinates corrected for differences in scaling.

RETINAL THICKNESS MEASUREMENTS: RTA II VS. STRATUS OCT IN HEALTHY SUBJECTS.

Sandrina Nunes(1), Rui Bernardes (1), Pedro Baptista (1), José Cunha-Vaz (1,2) (1) Association for Innovation and Biomedical Research on Light and Image (AIBILI/CNTM), Coimbra; 2 Institute of Biomedical Research on Light and Image (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal

Purpose: To compare retinal thickness in eyes of healthy volunteers using the Retinal Thickness Analyzer (RTA II, Talia Technology, Israel) and the Optical Coherence Tomography (Stratus OCT, Humphrey Instruments, USA).

Methods: Thirty-four eyes from 20 healthy volunteers (14 females/6 males), aged from 40 to 60 years-old (mean±SD: 51.5±5.5), were examined in the same session using the RTA II and the Stratus OCT. Using a proprietary software, a new retinal thickness map based on the RTA II data was developed to produce Stratus OCT-like retinal thickness maps (9 areas in all, with a 1 mm diameter central disc area and 8 retinal quadrants (papillo-macular, superior, temporal and inferior) between 1 and 3 mm radii and between 3 and 6 mm radii). For both maps (RTA and OCT) the mean, SD and 95% CI of the mean were computed for each of the 9 areas. Absolute agreement was considered when both techniques showed the same behaviour (increase or decrease for the 95% CI of the mean or both on the normal range). Absolute disagreement was considered when both techniques showed opposite behaviour (increase/decrease or decrease/increase).

Results: All areas for both instruments presented a normal distribution and a statistical significant difference was found between them (p<0.001). The Stratus OCT presents retinal thickness values higher than the RTA II for all areas (21% to 34% higher). Absolute agreement was found in 56% of the cases (areas/eyes) while 8% of the cases showed absolute disagreement. As expected, good agreement was found for the central area (k=0.686,p<0.001) and moderate to poor agreement was found for the remaining areas.

Conclusions: The Stratus OCT presents retinal thickness values higher than the RTA II for all of the 9 areas and the best agreement was found to be in central area, where the Stratus OCT has a higher density of retinal thickness measurements.

EARMARKING RETINAL CHANGES IN A SEQUENCE OF DIGITAL COLOR FUNDUS PHOTOGRAPHS.

João Ferreira(1), Rui Bernardes(1), Pedro Baptista(1), José Cunha-Vaz(1,2). Association for Innovation and Biomedical Research on Light and Image (AIBILI/CNTM), Coimbra (2) Institute of Biomedical Research on Light and Image (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal

Purpose: The aim of the work presented here is to help graders detect changes on digital color photographs time- sequences of the human fundus.

Methods: A sequence of digital color fundus photographs taken every six-months during a two-year follow-up period was available. All images were taken using a Zeiss FF450 fundus camera, using a 3CCD detector to produce RGB color images of 768 x 576 pixels resolution of the central 50 degrees centered on the macula. All images were pre-processed and converted into the HSV color-space. The V-channel was then normalized to correct differences in intensity and non-uniform illumination and the retinal vascular tree detected by means of differential geometry. Vessel bifurcations and intersections are then used as landmarks for image registration using a perspective transformation. Following the registration, the differences between the normalized V- channels of each image in the sequence and their counterpart of the baseline image were computed in a total of 4 difference images per eye sequence. To achieve better representation it is possible to consider each difference as a component of a hyperspectral image, compute the respective principal component analysis (PCA) and therefore represent the projection that shows in the best manner the differences that occurred along the sequence. In order to earmark the differences found in the reference image, the resulting PCA image was projected onto the baseline fundus image by modifying its H-channel to show a light blue shade over the areas where differences were found.

Results: A fully automated procedure was developed to allow mapping of the changes detected over a time- sequence of color fundus images onto a reference image.

Conclusions: This system helps graders in the assessment of retinal changes occurring in a follow-up study by leading their attention to the areas where those changes have occurred.