Lucia Parisi

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

PurposeTo 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 MethodsOne 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. ResultsThe average CCT was 552±39 μm. 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 μm resulted in an ICare reading deviation of 0.7 mm Hg. The Bland-Altman scatter-plot showed a reasonable agreement between the 2 tonometers. ConclusionsThe 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.

Frequency Doubling Technology Perimetry With the Humphrey Matrix 30-2 Test

PurposeTo assess the Humphrey Matrix 30-2 test in detecting functional glaucomatous damage. Patients and MethodsOne eye in each of 60 healthy individuals, 108 patients with ocular hypertension (OHT), and 150 patients with preperimetric (48) or perimetric (102) high-tension primary open-angle glaucoma (POAG) were considered. Visual fields were assessed by the standard automated perimetry (SAP) Humphrey Field Analyzer 30-2, frequency doubling technology (FDT) N-30, and Humphrey Matrix 30-2 tests. Significantly abnormal points in the pattern deviation probability plot, testing time, sensitivity, specificity, and area under the receiver operating characteristic curve of the FDT tests were evaluated. ResultsFDT revealed a significantly greater percentage of depressed points than did SAP in OHT and preperimetric POAG eyes. The FDT-N-30 test showed a significantly greater percentage of areas with P<5% in the OHT, preperimetric POAG, and early POAG groups. The Matrix-30-2 test provided an area under the receiver operating characteristic curve slightly lower than the FDT-N-30 test in the preperimetric POAG group, and significantly greater in the perimetric POAG group. ConclusionsFDT perimetry appeared more sensitive than SAP in detecting early glaucomatous VF loss. The FDT-N-30 test showed a slightly higher ability to detect early glaucomatous damage in patients at risk for the development of glaucoma, whereas the Matrix-30-2 test provided a more detailed characterization of the glaucomatous VF loss pattern, although it required 30% more time.

Comparison between laser scanning in vivo confocal microscopy and noncontact specular microscopy in assessing corneal endothelial cell density and central corneal thickness.

Purpose: To compare central corneal thickness (CCT) and endothelial cell density (ECD) with laser scanning confocal microscope Heidelberg Retina Tomograph (HRT) II Rostock Corneal Module and noncontact specular microscope Tomey EM-3000 and to assess intra- and interobserver agreement in normal corneas. Methods: This prospective study included 48 normals (69.6 ± 7.2 years, range: 55-80 years) who underwent CCT and ECD with both Tomey and HRT 3 times by 2 independent observers. Measurement differences between instruments, agreement between devices, and test-retest variability (TRV) were determined. Results: Mean CCTs with Tomey and HRT were 529.4 ± 35.4 and 536 ± 37.6 μm (P = 0.06), respectively; average ECDs with Tomey and HRT were 2473.5 ± 242.2 and 2539.7 ± 338.6 cells per square millimeter (P = 0.04), respectively. The mean of the differences (HRT minus Tomey) was 6.5 ± 17 μm for CCT and 65 ± 135.1 cells per square millimeter for ECD. Differences between instruments were not related to CCT (P = 0.35), whereas significantly increased with increasing ECD (P = 0.0001). Intraexaminer TRV for Tomey and HRT were 3.9 ± 3.7 and 22.2 ± 18.4 μm for CCT and 73 ± 63.4 and 152.2 ± 148.4 cells per square millimeter for ECD, respectively; interexaminer TRV was 4.6 ± 4.2 and 23.8 ± 17.3 μm for CCT and 84.9 ± 72.3 and 159.8 ± 149.8 cells per square millimeter for ECD. Conclusions: HRT II Rostock Corneal Module and the Tomey EM-3000 showed an overall good intermethod agreement. HRT showed a tendency to slightly overestimate CCT measurements, significantly underestimate ECD measurements in eyes with a reduced cell density (<2290 cells per square millimeter), and overestimate ECD in eyes with a high cell density. Both instruments showed low intra- and interobserver TRV for both CCT and ECD measurements, which tended to be less for Tomey.

Pulsar perimetry in the diagnosis of early glaucoma.

PURPOSE To assess the ability of Pulsar perimetry (Pulsar) in detecting early glaucomatous visual field (VF) damage in comparison with Frequency Doubling Technology (FDT), Scanning Laser Polarimetry (SLP, GDx VCC), and Heidelberg Retina Tomography (HRT). DESIGN Prospective observational cross-sectional case study. METHODS This multicenter study included: 87 ocular hypertensives (OHT); 67 glaucomatous optic neuropathy (GON) patients; 75 primary open-angle glaucoma (POAG) patients; and 90 normals. All patients underwent standard automated perimetry (SAP) HFA 30-2, Pulsar T30W, FDT N-30, HRT II, and GDx VCC. Area under Receiver Operating Characteristic Curves (AROCs) for discriminating between healthy and glaucomatous eyes and agreement among instruments were determined. RESULTS The best parameters for Pulsar, FDT, HRT, and GDx were, respectively: loss variance square root; no. of areas with P< 5%; Cup-Shape-Measure; and Nerve Fiber Indicator (NFI). In detecting POAG eyes, Pulsar (AROC, 0.90) appeared comparable with FDT (0.89) and significantly better than HRT (0.82) and GDx (0.79). For GON, Pulsar ability (0.74) was higher than GDx (0.69) and lower than FDT (0.80) and HRT (0.83). The agreement among instruments ranged from 0.12 to 0.56. Pulsar test duration was significantly shorter than SAP and FDT (P< .001). CONCLUSIONS Pulsar T30W test is a rapid and easy perimetric method, showing higher sensitivity than SAP in detecting early glaucomatous VF loss. Its diagnostic ability is good for detecting early perimetric POAG eyes and fair for GON eyes. Pulsar performance was comparable with FDT, HRT, and GDx, even if the agreement between instruments was poor to fair.

Optic disc damage staging system.

PurposeTo evaluate the optic disc damage staging system (ODDSS); a new clinical method of optic disc (OD) classification based on OD size, neural rim (NR) loss severity and localization. Accuracy, reproducibility, and reliability were studied. Agreement of ODDSS with the Heidelberg-Retina-Tomograph (HRT) results was evaluated. MethodsOne eye of 68 consecutive open-angle glaucoma (POAG) patients and 40 controls underwent standard automated perimetry (SAP), HRT-II, and OD examination using the ODDSS classification by 3 independent graders in this prospective cross-sectional study. Sensitivity, specificity, and area under the receiver operating characteristic curve (AROC) in discriminating between normal and POAG eyes were determined for ODDSS and HRT parameters. ODDSS intraobserver and interobserver agreement and agreement with HRT-Moorfield-Regression-Analysis (MRA) were assessed. ResultsODDSS sensitivity ranged from 72.0% to 89.7%; specificity ranged from 92.5% to 100%. Differences between AROCs for ODDSS (0.89 to 0.94) and for the best-performing HRT parameter (Vertical Cup/Disc Ratio 0.88) were not statistically significant. ODDSS interobserver agreement ranged from 0.33 to 0.78; intraobserver agreement ranged from 0.53 to 0.89. Agreement with HRT-MRA ranged from 0.50 to 0.87. ConclusionsODDSS is a new method for assessing, recording, and sharing information about the clinical OD appearance. Our preliminary results show that it provides good sensitivity and specificity in glaucoma detection. The interobserver and intraobserver agreement ranged from fair to good.

Peripapillary Retinal Nerve Fiber Layer Thickness Analysis With Scanning Laser Polarimetry (GDx VCC) in Normal Children

PurposeTo assess the use of scanning laser polarimeter with variable corneal compensation (GDx VCC) in children; to compare GDx VCC parameters between normal children and adults; and, to evaluate peripapillary retinal nerve fiber layer thickness variation with age in normals. Patients and MethodsNinety-eight normal children (mean age 8.5±2.8 y; range: 3 to 17) and 96 normal adults (mean age of 47.0±20.4 y; range: 18 to 87) underwent GDx VCC testing. Eyes with small or large optic discs were excluded. The “extended parameter table” parameters and mean thickness values of the 4 quadrants and 64 sectors were considered. Differences between age groups, retinal thickness comparisons and age effect were assessed using unpaired t test, analysis of variance, and regression analysis. ResultsGDx VCC parameters in children and adults showed wide intersubject variability. All parameters, excluding Symmetry, were significantly greater in children (P<0.05). TSNIT (temporal, superior, nasal, inferior, temporal) average, superior average and inferior average parameters showed a significant age-related thinning (P<0.01), at a rate of 0.043, 0.057, and 0.121 μm/y, respectively. ConclusionsA significant age-related superior and inferior retinal nerve fiber layer thinning was found using GDx VCC. Considering the significant differences between children and adults for most GDx VCC parameters, the built-in adult normative database cannot be applied in children.

Learning effect and test-retest variability of pulsar perimetry.

Purpose:To assess Pulsar Perimetry learning effect and test-retest variability (TRV) in normal (NORM), ocular hypertension (OHT), glaucomatous optic neuropathy (GON), and primary open-angle glaucoma (POAG) eyes. Methods:This multicenter prospective study included 43 NORM, 38 OHT, 33 GON, and 36 POAG patients. All patients underwent standard automated perimetry and Pulsar Contrast Perimetry using white stimuli modulated in phase and counterphase at 30 Hz (CP-T30W test). The learning effect and TRV for Pulsar Perimetry were assessed for 3 consecutive visual fields (VFs). The learning effect were evaluated by comparing results from the first session with the other 2. TRV was assessed by calculating the mean of the differences (in absolute value) between retests for each combination of single tests. TRV was calculated for Mean Sensitivity, Mean Defect, and single Mean Sensitivity for each 66 test locations. Influence of age, VF eccentricity, and loss severity on TRV were assessed using linear regression analysis and analysis of variance. Results:The learning effect was not significant in any group (analysis of variance, P>0.05). TRV for Mean Sensitivity and Mean Defect was significantly lower in NORM and OHT (0.6±0.5 spatial resolution contrast units) than in GON and POAG (0.9±0.5 and 1.0±0.8 spatial resolution contrast units, respectively) (Kruskal-Wallis test, P=0.04); however, the differences in NORM among age groups was not significant (Kruskal-Wallis test, P>0.05). Slight significant differences were found for the single Mean Sensitivity TRV among single locations (Duncan test, P<0.05). For POAG, TRV significantly increased with decreasing Mean Sensitivity and increasing Mean Defect (linear regression analysis, P<0.01). Conclusions:The Pulsar Perimetry CP-T30W test did not show significant learning effect in patients with standard automated perimetry experience. TRV for global indices was generally low, and was not related to patient age; it was only slightly affected by VF defect eccentricity, and significantly influenced by VF loss severity.