Archives: Projects/Publication

Comparison of retinal thickness measurements obtained by Retinal Thickness Analyzer (RTA II) and Optical Coherence Tomography (Stratus OCT) in healthy subjects.

Comparison of retinal thickness measurements obtained by Retinal Thickness Analyzer (RTA II) and Optical Coherence Tomography (Stratus OCT) in healthy subjects.

Comparison of retinal thickness measurements obtained by Retinal Thickness Analyzer (RTA II) and Optical Coherence Tomography (Stratus OCT) in healthy subjects.

Nunes S., Baptista P., Bernardes R., Cunha-Vaz J.

In order to compare retinal thickness using the Retinal Thickness Analyzer (RTA II) and the Optical Coherence Tomography (Stratus OCT), 34 eyes from 20 volunteers, aged from 40 to 60 years, were examined in the same session. To allow for a
direct comparison, a new retinal thickness map based on the RTA raw data was developed to produce OCT-like maps. For each area of both maps, the mean, SD and 95% CI of the mean retinal thickness were computed. Statistical significant differences, in the mean retinal thickness obtained by both techniques, were found with the Stratus OCT presenting higher retinal thickness values in all areas. The reliability of the two techniques, assed by the Intra-Class Correlation coefficient (to assess for consistency in retinal thickness measurements) and by the Cohen’s Kappa statistics (to asses for agreement between techniques), is moderate to good. For the agreement analysis we considered absolute agreement when both techniques showed the same behavior (increase or decrease over the 95% CI of the mean retinal thickness or both on the normal range), absolute disagreement when both techniques showed opposite behavior (increase/decrease or decrease/increase over the 95% CI of the mean retinal thickness), and disagreement otherwise. Best ICC consistency of data and agreement between techniques were found on the central 1 mm disc area (ICC = 0.734 and k = 0.686), where the Stratus OCT has higher density of retinal thickness measurements.

Exp. Ophthalmol. 2006, 32 (1): 13-19.

2006

Increased Resolution Macular Thickness Mapping by OCT.

Increased Resolution Macular Thickness Mapping by OCT.

Increased Resolution Macular Thickness Mapping by OCT.

Bernardes R., Santos T., Cunha-Vaz J.

Optical coherence tomography (OCT) poor mapping resolution has been pointed out as the biggest disadvantage of this technique when compared to others, e.g., retinal thickness analyzer. In this work we were able to solve this problem by developing an atlas of macular thickness of the human retina into which OCT scans were thereafter registered. This atlas is used to allow registering OCT scans from the Fast Macular Protocol, thus bringing OCT scans into the atlas coordinates, therefore correcting for misfixations, while simultaneously allowing to perform OCT inter-scan registration. From this initial registration, we were able to compute a thickness map into which Fast RNFL Protocol scans were merged, thus allowing for increased OCT mapping resolution.

Proceedings of the 28th IEEE EMBS Annual International Conference, New York City, USA, Aug 30 – Sept 3, 2006, 4710-4713, ISBN 14244-0033-3.

2006

A Phase II Randomized Double-Masked Trial of Pegaptanib, an Anti-Vascular Endothelial Growth Factor Aptamer, for Diabetic Macular Edema.

A Phase II Randomized Double-Masked Trial of Pegaptanib, an Anti-Vascular Endothelial Growth Factor Aptamer, for Diabetic Macular Edema.

A Phase II Randomized Double-Masked Trial of Pegaptanib, an Anti-Vascular Endothelial Growth Factor Aptamer, for Diabetic Macular Edema.

The Macugen Diabetic Retinopathy Study Group

Ophthalmology 2005, 112:1747-57.

2005

Polypoidal Choroidal Vasculopathy and Photodynamic Therapy with Verteporfin.

Polypoidal Choroidal Vasculopathy and Photodynamic Therapy with Verteporfin.

Polypoidal Choroidal Vasculopathy and Photodynamic Therapy with Verteporfin.

Silva, R.M., Figueira, J.P., Cachulo, M.L., Duarte, L., Faria de Abreu, J.R., Cunha-Vaz, J.G.

Graefe’s Archive for Cinical and Experimental Ophthyalmology. 2005, 243: 973-979.

2005

Eslicarbazepine acetate (BIA 2-093: Relative bioavailability and bioequivalence of 50 mg/mL oral suspensions and 200 mg and 800 mg tablet formulations.

Eslicarbazepine acetate (BIA 2-093: Relative bioavailability and bioequivalence of 50 mg/mL oral suspensions and 200 mg and 800 mg tablet formulations.

Eslicarbazepine acetate (BIA 2-093: Relative bioavailability and bioequivalence of 50 mg/mL oral suspensions and 200 mg and 800 mg tablet formulations.

Fontes-Ribeiro, C., Nunes, T., Falcão, A., Neta, C., Lima, R., Tavares, S., Almeida, L., Macedo, T., Soares-da-Silva, P.

Abstract:
Objective: To investigate the dosage form proportionality and food effect of the final tablet formulation of eslicarbazepine acetate (ESL) in healthy volunteers.

Methods: This was a randomized, three-way crossover, single-centre study in 18 healthy volunteers. Subjects received a single dose of oral ESL 800 mg following a standard meal in one period, and following 10 hours of fasting in two separate periods (in the form of one 800 mg tablet [reference] or two 400 mg tablets [test]). The statistical method was based upon the 90% confidence interval (CI) of maximum observed plasma drug concentration (Cmax), area under the plasma concentration time curve (AUC) from time zero to the last sampling time at which concentrations were at or above the lower limit of quantification (AUCt) and AUC from time zero to infinity (AUC[infinity]) geometric means ratios (GMRs) of BIA 2-005, the enantiomeric mixture of the ESL active metabolite eslicarbazepine and its enantiomer R-licarbazepine. Bioequivalence was assumed when the 90% CI of the test/reference GMR fell within the bioequivalence acceptance interval (80.00, 125.00).

Results: Following a single dose of ESL 800 mg in the forms of two 400 mg tablets and one 800 mg tablet, the test/reference GMR (%) and 90% CI for Cmax, AUCt and AUC[infinity] were 100.78% (93.91, 108.16), 100.37% (97.82, 102.99) and 100.48% (97.91, 103.13), respectively. Following administration of one 800 mg tablet in fed (test) and fasting (reference) conditions, the test/reference GMR and 90% CI for Cmax, AUCt and AUC[infinity] were 100.96% (94.08, 108.35), 96.79% (94.34, 99.32) and 96.75% (94.27, 99.29), respectively. Treatments were well tolerated.

Conclusions: The bioequivalence criteria between the ESL 400 mg and 800 mg tablets were met and dosage form proportionality was demonstrated. The presence of food had no influence on ESL pharmacokinetics, indicating that ESL can be administered without regard to meals with no significant effects on drug disposition or extent of systemic exposure.

Drugs R D 2005;6(5):253-60.

2005

Mapping the Human Blood-Retinal Barrier Function.

Mapping the Human Blood-Retinal Barrier Function.

Mapping the Human Blood-Retinal Barrier Function.

Bernardes R., Dias J., Cunha-Vaz J.

The aim of the work herein presented is to map blood-retinal barrier function by measuring retinal fluorescein leakage from the blood stream into the human vitreous using a confocal scanning laser ophthalmoscope (CSLO). Existing methods for the assessment of fluorescein leakage into the human vitreous are based on the qualitative evaluation of fluorescein angiographies (FA) and on volume measurements, as performed by the Fluorotron Master. A new procedure is presented capable of measuring fluorescein leakage into the vitreous while simultaneously imaging the retina. The present methodology computes the fluorescein leakage in a fully automated way, based on the three-dimensional fluorescence distribution in the human eye by using a single data acquisition. The processing includes signal filtering, volume alignment and profile deconvolution. The deconvolved profile obeys the established physical model. Representative cases shown are: a healthy eye; an eye with drusen from a nondiabetic person; a photocoagulated eye; and an eye with nonproliferative diabetic retinopathy. The results are in agreement with previous findings and go a step further by making possible its daily usage in a clinical setup based on currently available instrumentation.

IEEE Trans Biomed Eng 2005;52:106-116.

2005
http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1369593