Biomedical subjects

Claudia Tosoni

Publications and source records attributed to Claudia Tosoni.

4 recordsLinked to original sources

PubMed2006

Comparison of ICare tonometer with Goldmann applanation tonometer in glaucoma patients.

PURPOSE: To compare the intraocular pressure (IOP) readings taken with the new ICare tonometer and with the Goldmann applanation tonometer (GAT) and to evaluate the influence of central corneal thickness (CCT) on the IOP measurements. PATIENTS AND METHODS: One eye of 178 consecutive patients with primary open-angle glaucoma underwent ultrasonic CCT measurement, followed by IOP evaluation with the GAT and with the ICare tonometer. The deviation of ICare readings from GAT values, corrected according to the Doughty and Zaman formula, was calculated and correlated to CCT by a linear regression model. The agreement between the 2 devices was assessed by use of the Bland-Altman method. RESULTS: The average CCT was 552+/-39 mum. The mean IOP and the mean corrected IOP with GAT were 19.4+/-5.4 mm Hg, and 18.5+/-5.7 mm Hg, respectively. The mean ICare IOP reading was 18.4+/-5.2 mm Hg. The deviations of ICare readings from corrected GAT values were highly correlated with CCT values (r=0.63, P<0.01). Linear regression analysis showed that a CCT change of 10 mum resulted in an ICare reading deviation of 0.7 mm Hg. The Bland-Altman scatter-plot showed a reasonable agreement between the 2 tonometers. CONCLUSIONS: The ICare tonometer can be useful in a routine clinical setting. The IOP readings are quite in accordance with those obtained by GAT. The measurements seemed to be influenced by CCT variations, and thus pachymetry should always be taken into consideration.

Adult↗

PubMed2006

Visual field testing with the new Humphrey Matrix: a comparison between the FDT N-30 and Matrix N-30-F tests.

PURPOSE: To determine if the N-30-F test with the new Humphrey Matrix instrument is comparable to the traditional frequency-doubling technology (FDT) N-30 test. METHODS: A sample of 47 eyes from 47 patients (five normal subjects, 27 with ocular hypertension and 15 with glaucoma) underwent visual field (VF) testing with standard automated perimetry, and with FDT, using the FDT N-30 program, and the Matrix N-30-F program (using the same 19 tested points, full-threshold strategy, but with an enhanced algorithm to reduce testing time). The plots, mean deviation (MD), pattern standard deviation (PSD), defect locations and test time were compared. RESULTS: The agreement between the two tests was shown to be good, except for subjects with large VF defects, in which greater PSD values were observed with the FDT test, whereas the Matrix test gave a higher MD and number of abnormal test locations in the total deviation plot. A lack of agreement was also found for the number of abnormal test locations on the pattern deviation plot at any VF loss severity level. The test time for the Matrix test was significantly shorter. CONCLUSION: The FDT N-30 and Matrix N-30-F tests proved to be comparable in cases of early to moderate VF defects.

Adult↗

PubMed2006

Comparison between GDx VCC scanning laser polarimetry and Stratus OCT optical coherence tomography in the diagnosis of chronic glaucoma.

PURPOSE: To compare the abilities of scanning laser polarimetry with the variable corneal compensator (GDx VCC) with those of optical coherence tomography (Stratus OCT) in discriminating between healthy and early-to-moderate perimetric glaucomatous eyes. METHODS: A total of 95 glaucomatous patients (mean deviation - 3.7 +/- 3.0 dB, pattern standard deviation 4.5 +/- 2.7 dB) and 62 control subjects underwent imaging by the GDx VCC and Stratus OCT using both optic nerve head (ONH) and retinal nerve fibre layer (RNFL) scan protocols. One eye per patient was considered. Sensitivity at > or = 90% specificity and area under the receiver operating characteristic curve (AROC) were calculated for each GDx VCC and Stratus OCT index. RESULTS: The largest AROCs with Stratus OCT were associated with cup : disc area ratio (0.88) for ONH scan indices, and with average thickness (0.84) for RNFL scan indices. The nerve fibre indicator provided the greatest AROC for the GDx VCC indices (0.85). CONCLUSIONS: Both the GDx VCC and Stratus OCT instruments were shown to be useful in the detection of glaucomatous damage. The best performing indices for the GDx VCC and Stratus OCT with both ONH and RNFL scans gave similar AROCs, showing a moderate sensitivity in early-to-moderate glaucoma patients.

Adult↗

PubMed2003

Staging of functional damage in glaucoma using frequency doubling technology.

PURPOSE: To evaluate three new approaches for staging severity of glaucomatous visual field defects using frequency doubling technology. PATIENTS AND METHODS: One hundred and four patients with either ocular hypertension or chronic glaucoma were tested with both standard automated perimetry (SAP, 30-2 Humphrey threshold test) and frequency doubling technology (N-30 threshold test). Standard automated perimetry results were classified into four groups (normal tests, early defects, moderate defects, and severe defects) using the Glaucoma Staging System. Frequency doubling technology tests were also classified in four groups using three different approaches: frequency doubling technology probability map analysis, considering the number and location of disturbed points, frequency doubling technology MD and PSD indices, graphed on a two-axis diagram (FDT Staging System), and an abnormality score, based on both the statistical significance and the spatial location of depressed points. A control group of 20 eyes from 20 normal subjects was also tested and classified in the same way. The Cohen Kappa was used to compare the level of agreement between the three frequency doubling technology methods of classification and the glaucoma staging system. RESULTS: Measure of agreement was 0.679 using probability map assessment, 0.793 using the frequency doubling technology staging system, and 0.663 using the abnormality score. The specificity rate was 95% for all three methods. CONCLUSIONS: All the studied approaches were able to correctly stage the glaucomatous functional damage, but the frequency doubling technology staging system was the easiest and quickest method. Moreover, it is the only method that supplies information on the characteristics of the defect, without requiring any other time-consuming procedures.

Chronic Disease↗