Biomedical subjects

V Polo Llorens

Publications and source records attributed to V Polo Llorens.

7 recordsLinked to original sources

PubMed2002

[Cup-to-disk ratio asymmetry: diagnostic value in glaucoma].

PURPOSE: To assess visual field abnormalities in suspected glaucoma patients showing evident asymmetry in cup-to-disk ratio. MATERIAL AND METHOD: Twenty two hypertensive eyes in 11 subjects evidencing lateral differences in cup-to-disk ratio of more than 2/10 were included in the study. Conventional and short wavelength automated perimetry (SWAP) was performed with a Humphrey field analyser. A retinal nerve fiber layer (RNFL) study was also performed. RESULTS: Differences in IOP were 1.23 mmHg (p<0.05). No differences were evidenced in conventional automated perimetry between both eyes. Average sensitivity (SWAP) showed significantly lower (p<0.05) in those ayes with greater cup-to-disk ratio. RNFL showed a higher rate of defects in eyes with a higher cup-to-disk ratio. CONCLUSION: Lateral differences in cup-to-disk ratio indicate structural glaucomatous damage which is related to IOP levels. Associated functional loss was evidenced with SWAP (Arch Soc Esp Oftalmol 2002; 77: 17-22).

Adult↗

PubMed2002

[Glaucomatous damage pattern in swap in the early stages of glaucoma].

PURPOSE: To determine with Short-Wavelength Automated Perimetry (SWAP) the patterns of early glaucomatous damage and to compare frequency of diffuse defects to localized defects. METHODS: One hundred and sixty eyes from 83 ocular hypertensive subjects who met the selection criteria (intraocular pressure greater than 21 mm Hg and normal standard visual fields) were studied. SWAP was performed with a modified Humphrey Field Analyser. Total (TD) and pattern deviation (PD) probability maps were calculated to evaluate the pattern of visual field loss. RESULTS: The frequency of defects was higher in TD than in PD for all levels of defects (p<0.001). There was also a relative topographical distribution of glaucomatous defects. CONCLUSIONS: We documented the existence of predominantly diffuse visual field defects for all depth levels at early glaucoma stages.

Adult↗

PubMed2001

[Predictive value of the pattern-electroretinogram in glaucoma].

PURPOSE: To determine the ability of pattern-electroretinogram (PERG) to discriminate individual evolution of glaucomatous visual field losses in glaucoma suspects. METHODS: We studied 151 eyes of 78 GS, classified depending on their risk to develop glaucomatous damage. The initial visual field was normal. Those eyes showing at least 2 reduced amplitudes in the PERG components (P50, N95 and NP) were considered pathologic. The mean follow-up was 30 months (range: 13-50 months); the VF was evaluated at the end of the study. RESULTS: At the beginning of the study the PERG was pathologic in 65 eyes (43%); in 45 of these eyes (69%) the visual field was pathologic at the end of the study. The positive predictive value of the PERG of visual field glaucomatous changes was 69% and the negative predictive value was 80%. The N95 amplitude showed the best predictive value, with 100% and 77% in the high and medium risk groups, respectively. CONCLUSIONS: The PERG study can discriminate the glaucoma suspects that will develop visual field glaucomatous losses.

Adult↗

PubMed2001

[The Autocad system for planimetric study of the optic disc in glaucoma: technique and reproducibility study].

PURPOSE: To develop a lens planimetry technique for the optic disc using AutoCAD. To determine variability magnitude of the optic disc morphological measurements. METHODS: We employed AutoCAD R.14.0 Autodesk: image acquisition, contour delimitation by multiple lines fitting or ellipse adjustment, image sectorialization and measurements quantification (optic disc and excavation, vertical diameters, optic disc area, excavation area, neuroretinal sector area and Beta atrophy area). Intraimage or operator and interimage o total reproducibility was studied by coefficient of variability (CV) (n=10) in normal and myopic optic discs. RESULTS: This technique allows to obtain optic disc measurement in 5 to 10 minutes time. Total or interimage variability of measurements introduced by one observer presents CV range from 1.18-4.42. Operator or intraimage measurement presents CV range from 0.30-4.21. Optic disc contour delimitation by ellipse adjustment achieved better reproducibility results than multiple lines adjustment in all measurements. CONCLUSIONS: Computer assisted AutoCAD planimetry is an interactive method to analyse the optic disc, feasible to incorporate to clinical practice. Reproducibility results are comparable to other analyzers in quantification optic disc morphology. Ellipse adjustment improves results in optic disc contours delimitation.

Glaucoma↗

PubMed2000

[Variability of sensitivity thresholds in short-wavelength automated perimetry (SWAP) in the central vision field].

PURPOSE: To determine the distribution of sensitivity thresholds of short-wavelength automated perimetry (SWAP) in the central visual field, analysing their variability depending on the eccentricity, in normal subjects. METHODS: 128 eyes of 128 normal subjects were analyzed. They underwent a SWAP examination. A lineal regression model was used to establish a < > (SVF). The SVF determines the threshold distribution and its variability. RESULTS: The regression analysis obtained a SVF, age-corrected, which considers the influence of age in the different points of the visual field. The threshold distribution showed higher inter-subject deviations as eccentricity increased (p<0.001). CONCLUSIONS: The determination of variability of the threshold sensitivity deviations in the different points of the central visual field allows future development of perimetric algorythms for SWAP.

Adult↗

PubMed2000

[Short-wavelength automated perimetry (SWAP) in subjects with suspected glaucoma (I): assessment of sensitivity thresholds].

PURPOSE: To evaluate the threshold values of short-wavelength-sensitive (SWS, or S-cone pathways) mechanisms, throughout the 30 degrees central visual field, in a glaucoma suspect population, and to compare the results with those obtained in the Retinal Nerve Fiber Layer study. METHODS: We studied the central visual field from 288 eyes of 211 subjects classified as ocular hypertensives (160 eyes) or age-matched normal controls (128 eyes). A modified Humphrey Field Analyser was used to isolate and measure the sensitivity of the SWS mechanisms. Monochromatic red-free photographs (RNFL) were taken with a wideangle fundus camera at the same period. RESULTS: Comparing normal and OHT eyes, we found significant differences in sensitivity for SWS cone pathways in the superior and inferior nasal quadrants, paracentral and peripheral region, and in the superior hemifield (p<0.05). Based on the perimetric criteria described, the SWAP was pathological in 57 cases. which represents 35.6% of the total sample. Using RNFL as early glaucoma diagnostic criterion, SWAP sensitivity and specificity values were 62% and a 89% respectively. CONCLUSIONS: SWAP is a useful test for the early detection of visual field losses. It is more sensitive than, standard automated perimetry and gives a high correlation with RNFL assessment, which has proved capable of detecting signs of glaucomatous damage several years before the onset of the typical visual field defects.

Adult↗

PubMed2000

[Short-wavelength automated perimetry (SWAP) in patients with suspected glaucoma (II): correlation with a probabilistic multifactorial model of risk for developing glaucomatous damage].

PURPOSE: To evaluate the efficiency and predictability of a multifactorial probability model to assess the risk of developing glaucomatous visual field defects and to determine the correlation between retinal nerve fiber layer (RNFL) photographs and short-wavelength automated perimetry (SWAP) in a population of patients suspected of having glaucoma. METHODS: One hundred and sixty eyes belonging to 83 patients with ocular hypertension [ocular pressure figures over 21 mmHg and normal conventional automated perimetry (AP) (white-white)] were included in the study. The risk of developing glaucomatous defects was assessed by a multifactorial model that includes intraocular pressure. vertical cup-to-disk ratio, age and family background. RNFL photographs and SWAP tests were also performed. RESULTS: SWAPs were pathological in 57 cases (35.6% of the sample); 23% of the perimetries were abnormal in the low-risk group while the moderate and high risk groups showed abnormal perimetries 38% and 56% respectively. The RNFL defects at the different risk levels were consistent with the SWAP results. The multiple regression analysis of the four variables included in the model showed the relationship among the risk factors, evaluated globally, and the presence of glaucomatous damage evaluated by RNFL and SWAP (p<0.001). CONCLUSIONS: The usefulness of this probability model as predictive indicator of subsequent glaucomatous damage is based on the good correlation between the risk scale and the RNFL and SWAP assessments. These techniques evaluate structural (RNFL) and functional (SWAP) changes in early stages of the glaucomatous disease.

Adult↗