Alvarez-Vidal, A. (Aurora)
- Publications
- item.page.relationships.isContributorAdvisorOfPublication
- item.page.relationships.isContributorOfPublication
4 results
Search Results
Now showing 1 - 4 of 4
- Retinal thickness study with optical coherence tomography in patients with diabetes(Association for Research in Vision and Ophthalmology, 2002) Alvarez-Vidal, A. (Aurora); Moreno-Montañes, J. (Javier); Garcia-Layana, A. (Alfredo); Maldonado, M.J. (Miguel J.); Sanchez-Tocino, H. (Hortensia)To quantitatively assess retinal thickness by optical coherence tomography (OCT) in normal subjects and patients with diabetes. This study was intended to determine which retinal thickness value measured with OCT best discriminates between diabetic eyes, with and without macular edema. METHODS: OCT retinal thickness was measured by a manual technique in a total of 26 healthy volunteers (44 control eyes) and 85 patients with diabetes (148 eyes) with the clinical diagnosis of no diabetic retinopathy (45 eyes), nonproliferative diabetic retinopathy without clinically significant macular edema (CSME; 54 eyes), proliferative diabetic retinopathy without CSME (21 eyes), and 28 eyes with diabetic retinopathy with CSME. Independent predictors of the presence of CSME were quantified by using univariate and multivariate logistic regression analyses. Receiver operating characteristic (ROC) curves were generated to evaluate and compare the predictor variables. The correlation of retinal thickness measurements and visual acuity was calculated. RESULTS: There were statistically significant differences in foveal thickness between control eyes and all the other eye groups (P = 0.001). Diabetic eyes with CSME had a statistically significant greater thickness in each of the areas compared with the other groups. In a multivariate logistic regression model, foveal thickness was a strong and independent predictor of CSME (odds ratio [OR], 1.037; 95% confidence interval [CI] 1.02-1.05). The area under the ROC curve of this predictor variable was 0.94 (P = 0.001). For a cutoff point of 180 microm, the sensitivity was 93%, and specificity was 75%. Foveal thickness correlated with visual acuity in a log minimum angle of resolution (logMAR) scale (Spearman's rho = 0.9, P = 0.001). CONCLUSIONS: These results suggest that foveal thickening over 180 microm measured by OCT may be useful for the early detection of macular thickening and may be an indicator for a closer follow-up of the patient with diabetes.
- Objective Quantification of Posterior Capsule Opacification after Cataract Surgery, with Optical Coherence Tomography(Association for Research in Vision and Ophthalmology, 2005) Alvarez-Vidal, A. (Aurora); Moreno-Montañes, J. (Javier); Maldonado, M.J. (Miguel J.)PURPOSE: To evaluate posterior capsule opacification (PCO) in humans after cataract surgery with intraocular lens (IOL) implantation, by using optical coherence tomography (OCT-1). METHODS: Sixty-six eyes with PCO and 20 eyes with a normal posterior capsule were analyzed. A 3-mm-long horizontal scan of the posterior capsule was obtained. Measurements at three points and their average were recorded. Intraoperator and interoperator reliabilities were assessed. Investigated was peak intensity (PI) and posterior capsule thickening (PCT), with PCT indicating the distance between two reflectivity spikes, with an approximate axial resolution of 10 microm. Results were compared with visual acuity (VA) and PCO type. RESULTS: Intraoperator reliability was 0.59 and 0.97 for average PI and PCT, respectively. The interoperator concordance correlation coefficient was 0.70 and 0.82 for average PI and PCT, respectively. Median (interquartile range) intensities of the reflectivity spike were 16.88 (dB) (range, 12.88-20.41) and 11.9 (8.58-14.28), respectively, in the PCO and control eyes (P = 0.001). PCT was found in PCO eyes (median: 86.13 microm; range, 46.33-115.33), whereas no second spike appeared in control eyes (P = 0.001). The area under the receiver operating characteristic curve of the average PCT for differentiating pearl-type from fibrosis-type PCO was 0.87 (P = 0.001). For a cutoff point of 55.3 microm, the sensitivity was 97.5%, and the specificity was 69%. Worse VA correlated significantly only with larger PCT (r(o) = 0.66; P = 0.01). CONCLUSIONS: OCT-1 appears useful to quantitate PCO. In addition, this system seems to discriminate between different types of PCO. PCT may be a previously unrecognized factor in VA degradation.
- Cirrus high-definition optical coherence tomography compared with Stratus optical coherence tomography in glaucoma diagnosis(Association for Research in Vision and Ophthalmology, 2010) Alvarez-Vidal, A. (Aurora); Moreno-Montañes, J. (Javier); Zarranz-Ventura, J. (Javier); Olmo, N. (Natalia); Garcia, N. (Noelia)To compare the retinal nerve fiber layer (RNFL) evaluation using Cirrus optical coherence tomography (OCT) and Stratus OCT in glaucoma diagnosis. METHODS: One hundred thirty normal and 86 patients with glaucoma were included in this prospective study. The signal strengths of the OCTs were evaluated. The sensitivities and specificities of global RNFL average thickness were compared in the four quadrants and in each clock hour sector. Receiver operating characteristic (ROC) curves, areas under the ROC (AUC), and the likelihood ratio (LR) were plotted for RNFL thickness. Agreement between the OCTs was calculated by using the Bland-Altman method and kappa (kappa) coefficient. RESULTS: Twenty-three percent of all cases examined with Stratus OCT and 1.9% examined with Cirrus OCT had a signal strength below 6 (P = 0.01). In cases with signal strengths > or =6, the mean signal strength was higher with Cirrus OCT than with Stratus OCT (P = 0.01). The RNFL measurements by Cirrus were thicker than those of Stratus OCT (P < 0.05). The AUCs were 0.829 for Stratus and 0.837 for Cirrus OCT (P = 0.706) for global RNFL average. LRs were similar in both OCTs in global RNFL classification but varied in quadrants. The widths of the limits of agreement varied between 42.16 and 97.79 microm. There was almost perfect agreement (kappa = 0.82) in the average RNFL classification. CONCLUSIONS: Cirrus OCT has better scan quality than Stratus OCT, especially in glaucomatous eyes. In cases with good-quality scans, the sensitivity and specificity, and AUCs were similar. The best agreement was in the global average RNFL classification. The widths of limits of agreements exceed the limits of resolution of the OCTs.
- Capa de fibras nerviosas en ojos glaucomatosos. Estudio realizado mediante OCT y su comparación con el campo visual(Elsevier España, 2002) Alvarez-Vidal, A. (Aurora); Moreno-Montañes, J. (Javier); Rodriguez-Conde, R.M. (R. M.); Sainz-Gomez, C. (C.)To investigate the retinal nerve fiber layer (RNFL) thickness in glaucomatous eyes using Optical Coherence Tomography (OCT). To compare the RNFL thickness with visual field damage (Humphrey field analyzer). MATERIAL AND METHODS: The mean RNFL thickness in glaucomatous eyes (n = 80) was compared with age-matched normal eyes (n = 40). Three circular scans were obtained for each eye using OCT (3.4 mm diameter). In each eye, average RNFL, 4 quadrants and 12 meridians were calculated and compared. The superior-inferior asymmetry of RNFL was studied. The average RNFL thickness was compared with mean deviation (MD) and mean standard deviation (MSD) of SITA 24-2 visual field program. RESULTS: Mean RNFL was significantly thinner in glaucomatous eyes than in normal eyes (p<0.001). The RNFL thickness was decrease in the 4 quadrants and 11 of 12 meridians studied in glaucomatous eyes (p<0.05). The superior-inferior asymmetry showed a significant difference in RNFL thickness at 30 degrees central meridian (p<0.05). Mean RNFL thickness was significantly associated with DM and DSM of visual field (p<0.001) in glaucomatous eyes. CONCLUSIONS: OCT revealed significant quantitative differences in RNFL thickness between glaucomatous and normal eyes. OCT showed a considerable measurements overlap between glaucomatous and normal eyes, which can limit the sensitivity and specificity of this instrument