Archives: Projects/Publication

Interpretation of Objectively Acquired Retinal Thickness Values.

Bernardes R., Cunha-Vaz J.

Arch. Ophthalmol. 2003; 121(9):1344-1345.

2003

Alterations of retinal capillary blood flow in preclinical retinopathy in subjects with type 2 diabetes.

Ludovico J., Bernardes R., Pires I., Figueira J., Lobo C., Cunha-Vaz J.

To identify alterations of retinal capillary blood flow in the papillomacular area in preclinical diabetic retinopathy using the Heidelberg scanning laser Doppler flowmeter. METHODS: Ten eyes from ten patients with type 2 diabetes and no lesions visible on fundus photography (level 10 of Wisconsin grading) and ten eyes from ten healthy subjects of similar age range were examined with the HRF. Intravisit reproducibility of retinal capillary blood flow measurements was assessed in normal subjects and in type 2 diabetic patients, comparing different measurement areas and different analysis procedures: (a) 10×10 pixel box with original software, (b) 10×10 pixel box with SLDF software, and (c) whole-scan analysis with SLDF software (automatic full-field perfusion image analysis). RESULTS: Intravisit reproducibility for the whole-scan analysis in the papillomacular area was 3.52%, 4.81% and 4.60% for volume (VOL), flow (FLW) and velocity (VEL) respectively. Using this method, mean and SD values for retinal capillary blood-flow are 13.25+/-2.87, 214.58+/-55.30 and 0.74+/-0.17, for VOL, FLW and VEL for healthy eyes, comparing with 19.85+/-6.22, 360.87+/-158.70 and 1.20+/-0.48 in eyes with preclinical diabetic retinopathy (P<0.010, P<0.019 and P<0.015 respectively). CONCLUSIONS: The HRF shows acceptable reproducibility when using whole-scan analysis in the papillomacular area. Retinal capillary blood VOL, FLW and VEL were particularly increased in five of the ten diabetic eyes examined, with values over the mean + 2SD of the control population, suggesting that eyes showing increased retinal capillary blood flow may indicate risk of progression.

Graefes Arch. Clin. Exp. Ophthalmol. 2003; 41:181-186.

2003

Measurement and mapping of retinal leakage and retinal thickness surrogate – outcomes for the initial stages of diabetic retinopathy.

Cunha-Vaz J

Current Medical Chemistry. 2002; 2: 91-108.

2002

Retinal Thickness in Eyes With Mild Nonproliferative Retinopathy in Patients With Type 2 Diabetes Mellitus: Comparison of Measurements Obtained by Retinal Thickness Analysis and Optical Coherence Tomography.

Pires I., Bernardes R., Lobo C., Soares M., Cunha-Vaz J.

Objective: To compare measurements of retinal thickness in eyes with mild nonproliferative retinopathy in patients with type 2 diabetes mellitus using 2 different techniques: the retinal thickness analyzer (RTA) and optical coherence tomography (OCT).

Methods: Twenty-eight eyes from 28 patients with type 2 diabetes mellitus and mild nonproliferative retinopathy were classified according to the Wisconsin grading system by 7-field stereoscopic fundus photography. Ten eyes were classified as level 10 (absence of visible lesions) and 18 as level 20 or 35 (minimal retinopathy). All eyes were examined by the RTA and OCT. Healthy populations were used to establish reference maps for the RTA (n=14; mean age, 48 years; age range, 42-55 years) and OCT (n=10; mean age, 56 years; age range, 43-68 years). Reference maps were computed using the means + 2 SDs of the values obtained for each location. Increases in thickness were computed as a percentage of increase over these reference maps.

Results: The RTA detected increases in thickness in 1 or more locations in 24 of the 28 diabetic eyes examined, whereas OCT detected increases in only 3 eyes. The percentages of increase detected by the RTA ranged from 0.3% to 73.5%, whereas OCT detected percentages of increase of 0.3% to 4.8%.

Conclusion: Optical coherence tomography is less sensitive than the RTA in detecting localized increases in retinal thickness in the initial stages of diabetic retinal disease.

Arch. Ophthalmol. 2002; 120: 1301-1306.

2002
http://archopht.ama-assn.org/cgi/reprint/120/10/1301?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&author1=Bernardes%2C+R&andorexacttitle=and&andorexacttitleabs=and&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&fdate=1/1/2002&tdate=12

Multimodal Macula Mapping: A new approach to study diseases of the Macula.

Bernardes R., Lobo C., Cunha-Vaz J.

Multimodal macula mapping is presented as a combination of a variety of diagnostic tools and techniques to examine the macular region in order to obtain information on its structure and function in a clinical environment. Foundations of macular mapping are reviewed and discussed. New methodologies for multimodal macula mapping based on a combination of scanning laser angiography, retinal leakage analysis, retinal thickness analysis, and visual field testing are presented, demonstrating the potential of macula mapping. Other available detection devices are briefly reviewed considering their potential to be included and utilized in future developments of multimodal macula mapping. Multimodal macula mapping appears to offer unique perspectives and insights that are expected to contribute to improved diagnosis and better understanding of macular diseases.

Surv. Ophthalmol. 2002, 47:580-589.

2002
http://www.surveyophthalmol.com/article/S0039-6257%2802%2900355-7/abstract