Apolipoprotein E polymorphism in patients with cataract.
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Aged↗
Biomedical subjects
P Teesalu
Publications and source records attributed to P Teesalu.
Search for an optimal combination of structural and functional parameters for the diagnosis of glaucoma. Multivariate analysis of confocal scanning laser tomograph, blue-on-yellow visual field and retinal nerve fiber layer data.
BACKGROUND: The purpose of this study was to evaluate which of the structural and functional parameters--the Heidelberg Retina Tomograph (HRT), white-on-white (W/W) and blue-on-yellow (B/Y) visual fields and semiquantitative retinal nerve fiber layer (RNFL) scoring parameters--can give the best separation between non-glaucomatous and glaucomatous eyes. METHODS: Fifty-five subjects were included in this study: 32 nonglaucomatous subjects with mean age of 54 years, and 23 patients with ocular hypertension or glaucoma and mean age of 59 years. The HRT with software 1.11, the Humphrey 30-2 W/W and lens coloration-corrected B/Y visual fields, and semiquantitative RNFL scores were utilized. Stepwise logistic regression analysis was used in finding, from a given set of parameters, a best discriminating parsimonious subset to a logistic model, the discriminatory performance of which was evaluated by the area under the ROC curve. RESULTS: When all the structural and functional variables were considered, the RNFL total overall score gave the best separation between glaucomatous and non-glaucomatous eyes (ROC area 0.98). Without the RNFL scores and optic disc size-dependent HRT parameters in the model, the cup shape measure was selected first (ROC area 0.88). In the second step the RNFL thickness was selected (ROC area 0.91), and in the third step the corrected B/Y mean deviation (MD) was selected (ROC area 0.91). With only the HRT parameters in the model, the cup/disc ratio was selected first (ROC area 0.88). However, when the groups were matched for optic disc size, all disc size-dependent HRT variables lost their discriminant power. CONCLUSION: Cup shape measure and RNFL thickness, together with age- and lens coloration-corrected MD of the B/Y perimetry provided good discrimination between healthy individuals and patients with glaucoma.
Adult↗
Optical coherence tomography and localized defects of the retinal nerve fiber layer.
PURPOSE: To test the capability of the optical coherence tomography (OCT) to demonstrate and quantitate retinal nerve fiber layer (RNFL) defects. METHODS: The authors examined 6 eyes of 6 chronic open angle glaucoma patients with the OCT. The patients had abnormal Humphrey 30-2 visual fields which corresponded to RNFL defects visible in monochromatic fundus images taken with a digital imaging system. The RNFL images were used for directing the OCT scans to areas where most information was believed to be obtainable. Several linear scans of different lengths across healthy and abnormal RNFL regions were made. RESULTS: When the OCT images were compared to RNFL photographs, the defective areas showed reduced backscattering with the OCT, being distinctly different from the adjacent normal RNFL. Except for one case the RNFL thickness values were smaller in the areas of abnormal appearance compared to areas of normal appearance. CONCLUSION: This preliminary study suggests that the OCT examination results of the RNFL are in good agreement with the RNFL appearance in monochromatic fundus images.
Axons↗
Blue-on-yellow perimetry in the diagnosis of glaucoma.
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Diagnosis, Differential↗
Hemifield association between blue-on-yellow visual field and optic nerve head topographic measurements.
BACKGROUND: Blue-on-yellow (B/Y) perimetry can reveal visual field defects earlier and larger in extent than white-on-white (W/W) perimetry. The Heidelberg Retina Tomograph (HRT) produces a three-dimensional image of the optic disc. The aim of this study was to compare the strength of the association of the B/Y and W/W visual hemifield mean deviation (HMD) variables with the optic nerve head (ONH) morphological variables of the respective area. METHODS: We evaluated one randomly chosen eye of 40 normal subjects and 37 patients with ocular hypertension and different stages of glaucoma. The B/Y and W/W visual fields (program 30-2) were obtained with a Humphrey perimeter. Results of both visual fields were adjusted for the patient's age and lens transmission index measured with a lens fluorometer. HMD was calculated as the difference between the measured and expected hemifield mean sensitivity values, predicted by the regression model fitted in our nonglaucomatous subject data. The HRT with the software version 1.11 was used to acquire and evaluate the topographic measurements of the optic disc. RESULTS: The B/Y and W/W visual field HMDs showed statistically significant correlation with ONH parameters such as cup shape measure (CSM), rim volume, rim area, mean retinal nerve fiber layer (RNFL) thickness and RNFL cross-sectional area. With forward stepwise logistic regression analysis using B/Y hemifield data 38% of the glaucoma patient's normal W/W hemifields were classified abnormal. With the CSM alone in the model 52% of the cases were classified abnormal. CONCLUSIONS: B/Y visual field hemifield mean deviation values correlate well with ONH parameters examined with the HRT.
Adult↗
Blue-on-yellow visual field and retinal nerve fiber layer in ocular hypertension and glaucoma.
BACKGROUND AND OBJECTIVE: It has been suggested that the clinically detectable changes of the blue-on-yellow (B/Y) visual field and retinal nerve fiber layer (RNFL) may precede standard white-on-white (W/W) visual field defects in the progression of glaucoma. The aim of this study was to test the relationship between the results of B/Y visual fields and semiquantitative RNFL evaluation in corresponding areas and to determine how the B/Y visual fields and RNFL scores label the normal W/W perimetry hemifields in patients with glaucoma and ocular hypertension. DESIGN: A cohort study. PARTICIPANTS AND METHODS: Monochromatic RNFL photographs of 32 normal subjects and 29 patients with ocular hypertension and different stages of glaucoma were assessed in a masked fashion. The B/Y and W/W visual fields (program 30-2) were examined with a Humphrey perimeter. The results of both visual fields were adjusted for the patients' age and lens transmission index measured with a lens fluorometer. MAIN OUTCOME MEASURE: Mean deviation (MD) of visual field and semiquantitative score of RNFL loss were measured. RESULTS: The total and hemifield MD values of B/Y and W/W visual field showed a statistically significant correlation with diffuse and overall score of RNFL loss in corresponding areas. The hemifield MD values of B/Y perimetry obtained from "normal" W/W hemifields of patients with early glaucoma were well correlated (r = -0.56) with respective RNFL loss scores found to be abnormal in 84% of hemispheres. The difference between the hemifield MD values of B/Y perimetry obtained from normal W/WAN hemifields of patients with ocular hypertension and patients with early glaucoma was not statistically significant (analysis of variance). The respective B/Y hemifield data of normal subjects were statistically significantly different from the data of patients with ocular hypertension and early glaucoma. CONCLUSIONS: The hemifield MD values of B/Y perimetry correlate well with semiquantitative scores of RNFL loss obtained from the corresponding hemisphere. The B/Y perimetry as well as RNFL assessment may show glaucomatous defects in a hemifield found to be normal on W/W perimetry. In subjects with ocular hypertension, the functional damage detected by B/Y perimetry may, in some cases, precede RNFL defects on conversion to glaucoma.
Adult↗
Fluorometry of the crystalline lens for correcting blue-on-yellow perimetry results.
PURPOSE: Optical and neural sources of short wavelength sensitivity should be separated in the assessment of the results of blue-on-yellow (B/Y) perimetry. It has been shown previously that lens autofluorescence is related directly to lens yellowing and age. The aim of this study was to find out if B/Y perimetry results can be better corrected by using lens fluorometry than by age. METHODS: The authors evaluated one randomly chosen eye of 40 normal subjects and 39 age-matched patients with ocular hypertension and different stages of glaucoma. The authors obtained the mean sensitivity (MS) of the 24-2 B/Y visual fields with a Humphrey perimeter and determined the lens transmission index (LTI) from the ratio between posterior and anterior autofluorescence peaks measured with their fluorometer. A multiple regression analysis was used to evaluate the variability of the B/Y MS by age and LTI in normal subjects. RESULTS: The authors found a statistically highly significant linear correlation of B/Y MS to LTI in healthy subjects (R = 0.83; P < 0.0001). The 95% prediction interval of the normal subjects was determined. The majority of the MS values of the ocular hypertensives were inside the prediction limits, whereas approximately half of the patients (4 of 9) with early glaucoma and the majority of patients (14 of 15) with moderate and advanced glaucoma were below the prediction interval. The residual standard deviation of the B/Y MS with age alone was larger than that with LTI alone in the model (3.66 dB and 3.22 dB, respectively). CONCLUSIONS: The interindividual variation of the lens transmission properties increases with age. The reference level for correcting B/Y perimetry results can be determined more precisely using fluorometry of the lens than with age alone.
Adult↗
Correlation of blue-on-yellow visual fields with scanning confocal laser optic disc measurements.
PURPOSE: Visual field defects and changes in the optic nerve head are signs of glaucoma. It has been shown that blue-on-yellow (B-Y) perimetry can reveal visual field defects earlier and shows them larger than does white-on-white (W-W) perimetry. The Heidelberg retina tomograph (HRT) can produce three-dimensional images of the optic disc. The aim of this study was to find out how B-Y perimetry results correlate with optic disc parameters in comparison with W-W perimetry results. METHODS: One randomly chosen eye was evaluated in each of 40 normal subjects and 37 patients with ocular hypertension and different stages of glaucoma. B-Y and W-W visual fields (program 30-2) were obtained with a Humphrey perimeter. B-Y perimetry results were adjusted for the patient's age and lens transmission index measured with a lens fluorometer. The B-Y visual field adjusted mean deviation (MD) was calculated as the difference between the measured and expected mean sensitivity values, predicted by the regression model fitted in normal subjects. The HRT with software version 1.11 was used to acquire and evaluate topographic measurements of the optic disc. RESULTS: The cup shape measure showed strongest correlation with the MD of both the B-Y and W-W visual fields. The multiple correlation coefficients from quadratic regression were 0.65 for both visual fields. Except for peripapillary retinal nerve fiber layer measurements, the statistically significant correlations of the B-Y visual field indexes with other HRT parameters were equal to or better than those of W-W perimetry. CONCLUSIONS: B-Y perimetry MDs are well correlated with optic nerve head parameters measured with the HRT. In early stages of glaucoma, most HRT variables were better correlated with the B-Y MD than with the W-W MD.
Adult↗