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Stefano Miglior

Publications and source records attributed to Stefano Miglior.

14 recordsLinked to original sources
PubMed2006

Central corneal thickness in the European Glaucoma Prevention Study.

PURPOSE: To measure central corneal thickness (CCT) within the participants of the European Glaucoma Prevention Study (EGPS). This study was designed to test if lowering intraocular pressure (IOP) by means of dorzolamide is able to prevent or delay conversion from ocular hypertension to glaucoma. DESIGN: Randomized, double-masked, controlled, observational clinical trial. PARTICIPANTS: Eight hundred fifty-four of 1077 ocular hypertensive participants within the EGPS were investigated. Four hundred twenty-nine patients were treated with dorzolamide and 425 patients received placebo. INTERVENTION: Treatment with dorzolamide or placebo (the vehicle of dorzolamide) in 1 or both eyes. MAIN OUTCOME MEASURES: Central corneal thickness as measured by ultrasound pachymetry (DGH-500 Pachette; DGH Technologies, Exton, PA). The CCT measurements were obtained in the morning before measuring IOP. Five measurements were taken from each eye of each patient within 5 minutes of application of anesthetic eye drops. RESULTS: Mean CCT was 572.6+/-37.4 microm (range, 458.5-695.6 microm). The CCT was higher in younger patients, male patients, and diabetic patients. Mean CCTs for the 429 patients receiving dorzolamide were 574.2+/-38.48 microm (range, 458.5-695.6 microm) and 571.0+/-36.21 microm (469.7-690.1 microm) for the 425 patients receiving placebo (P = 0.205). Central corneal thickness did not correlate with refraction, baseline IOP, or systemic hypertension. CONCLUSION: Central corneal thickness measurements within the EGPS were greater than those reported in other studies of normal eyes without ocular hypertension. Larger CCT measurements correlated with male gender, younger age, and diabetes.

Adult↗
PubMed2006

Validated prediction model for the development of primary open-angle glaucoma in individuals with ocular hypertension.

OBJECTIVE: To test the validity and generalizability of the Ocular Hypertension Treatment Study (OHTS) prediction model for the development of primary open-angle glaucoma (POAG) in a large independent sample of untreated ocular hypertensive individuals and to develop a quantitative calculator to estimate the 5-year risk that an individual with ocular hypertension will develop POAG. DESIGN: A prediction model was developed from the observation group of the OHTS and then tested on the placebo group of the European Glaucoma Prevention Study (EGPS) using a z statistic to compare hazard ratios, a c statistic for discrimination, and a calibration chi2 for systematic overestimation/underestimation of predicted risk. The 2 study samples were pooled to increase precision and generalizability of a 5-year predictive model for developing POAG. PARTICIPANTS: The OHTS observation group (n = 819; 6.6 years' median follow-up) and EGPS placebo group (n = 500; 4.8 years' median follow-up). TESTING: Data were collected on demographic characteristics, medical history, ocular examination visual fields (VFs), and optic disc photographs. MAIN OUTCOME MEASURE: Development of reproducible VF abnormality or optic disc progression as determined by masked readers and attributed to POAG by a masked end point committee. RESULTS: The same predictors for the development of POAG were identified independently in both the OHTS observation group and the EGPS placebo group-baseline age, intraocular pressure, central corneal thickness, vertical cup-to-disc ratio, and Humphrey VF pattern standard deviation. The pooled multivariate model for the development of POAG had good discrimination (c statistic, 0.74) and accurate estimation of POAG risk (calibration chi2, 7.05). CONCLUSIONS: The OHTS prediction model was validated in the EGPS placebo group. A calculator to estimate the 5-year risk of developing POAG, based on the pooled OHTS-EGPS predictive model, has high precision and will be useful for clinicians and patients in deciding the frequency of tests and examinations during follow-up and advisability of initiating preventive treatment.

Cornea↗
PubMed2006

Predictive factors for open-angle glaucoma among patients with ocular hypertension in the European Glaucoma Prevention Study.

OBJECTIVE: To evaluate the predictive factors of open-angle glaucoma (OAG) in patients affected by ocular hypertension enrolled in the European Glaucoma Prevention Study (EGPS). DESIGN: Randomized, double-masked, controlled clinical trial. PARTICIPANTS: One thousand seventy-seven patients, > or =30 years old, were enrolled at 18 European centers. The patients met inclusion criteria: intraocular pressure, 22 to 29 mmHg; 2 normal and reliable visual fields (VFs) (on the basis of mean deviation and corrected pattern standard deviation [PSD]); and a normal optic disc, as determined by an optic disc reading center. INTERVENTION: Treatment with dorzolamide or a placebo (the vehicle of dorzolamide) in one or both eyes. MAIN OUTCOME MEASURES: Efficacy end points were VF and/or optic disc changes. Baseline demographic and clinical data were collected before randomization, except for corneal thickness measurements, which were determined during follow-up. Proportional hazards models were used to identify factors that predicted which participants in the EGPS had developed OAG. RESULTS: In multivariate analyses, factors that predicted the development of OAG included older age (hazard ratio [HR], 1.32; 95% confidence interval [CI], 1.04-1.69), larger vertical cup-to-disc (C/D) ratio (HR, 1.34; 95% CI, 1.14-1.58), larger vertical C/D ratio asymmetry (HR, 1.46; 95% CI, 1.11-1.93), higher PSD (HR, 1.66; 95% CI, 1.15-2.38), and lesser central corneal thickness (HR, 1.32; 95% CI, 1.05-1.67). CONCLUSIONS: Baseline age, vertical C/D ratio, vertical C/D ratio asymmetry, and PSD were good predictors of the onset of OAG in the EGPS. Central corneal thickness was found to be a powerful predictor of the development of OAG. The EGPS results agree with the findings of the Ocular Hypertension Treatment Study and support the need for a thorough evaluation of patients with ocular hypertension.

Antihypertensive Agents↗
PubMed2006

Clinical ability of pattern electroretinograms and visual evoked potentials in detecting visual dysfunction in ocular hypertension and glaucoma.

OBJECTIVE: To assess the presence of normal or abnormal pattern electroretinogram (PERG) and visual evoked potential (VEP) responses in patients with ocular hypertension or open-angle glaucoma (OAG). DESIGN: Retrospective, cross-sectional, case-control study. PARTICIPANTS: Eighty normal control subjects (mean age, 51.77+/-6.04 years; 80 eyes), 68 ocular hypertension patients (mean age, 51.58+/-7.12; 68 eyes; intraocular pressure [IOP] < 18 mmHg under pharmacological treatment; Humphrey field analysis [HFA] 24/2 mean deviation [MD] > -2 decibels [dB]), and 84 OAG patients (mean age, 52.77+/-5.28; 84 eyes; IOP < 18 mmHg under pharmacological treatment; HFA 24/2 mean deviation between -2 and -23 dB) were enrolled. METHODS: Simultaneous recording of PERGs and VEPs using high-contrast (80%) 15' checkerboard stimuli reversed at the rate of 2 reversals per second. MAIN OUTCOME MEASURES: Pattern electroretinogram P50 and VEP P100 implicit times were considered delayed when exceeding the limit of mean values of controls plus 2 standard deviations (SDs). Pattern electroretinogram P50 to N95 and VEP N75 to P100 amplitudes were considered reduced when exceeding the limit of mean values of controls minus 2 SDs. RESULTS: Pattern electroretinogram: P50 implicit times were delayed in 58 of 68 (85.30%) ocular hypertension eyes and 83 of 84 (98.80%) OAG eyes; P50 to N95 amplitudes were reduced in 47 (69.12%) ocular hypertension eyes and 84 (100%) OAG eyes. Visual evoked potential: P100 implicit times were delayed in 58 (85.30%) ocular hypertension eyes and 84 (100%) OAG eyes; reduced N75 to P100 amplitudes were observed in 39 (57.35%) ocular hypertension eyes and 73 (86.90%) OAG eyes. Ocular hypertension eyes showed no significant correlations (Pearson test, P>0.01) between electrophysiological parameters and age, IOP before or under medical treatment, HFA, and corneal thickness values. Significant correlations (P<0.01) were observed in OAG eyes between electrophysiological results and HFA values. Pattern electroretinogram and VEP responses were normal in all control eyes. CONCLUSIONS: Combined PERG/VEP recordings identified a large percentage of ocular hypertension eyes with impairment of the innermost retinal layers, notwithstanding normal optic disc morphology and normal HFA. In OAG eyes, PERG P50 to N95 amplitude and VEP P100 implicit time showed the highest sensitivity/specificity for the detection of a visual dysfunction. The presence of abnormal PERG and/or VEP responses did not allow a clearcut separation between ocular hypertension and OAG eyes.

Adult↗
PubMed2006

Learning effect of short-wavelength automated perimetry in patients with ocular hypertension.

AIM: To evaluate the learning effect of short-wavelength automated perimetry (SWAP) on a group of patients with ocular hypertension experienced with standard automated perimetry (SAP). METHODS: Thirty patients with ocular hypertension underwent 5 full-threshold SWAP tests at intervals of 7+/-2 days. The parameters investigated to detect a learning effect were duration, the perimetric indices, and the number of points with a P of <5% and 1% in the total and pattern deviation maps. Differences in learning effect were also evaluated by comparing the sensitivities of central, paracentral, and peripheral areas, hemifields and quadrants. RESULTS: Learning effects were demonstrated for mean defect (P<0.0001, analysis of variance), duration (P=0.0001), the number of points with P<5% in the pattern deviation map (P=0.003), and short fluctuations (P=0.03). The effect was greater in the peripheral than in central areas (P=0.04). Mean defect was the most sensitive parameter, for which the learning effect was statistically significant between the first and the fifth test. CONCLUSIONS: The results of this study demonstrate a significant learning effect at full-threshold SWAP. This may limit the efficacy of this kind of perimetry in detecting early glaucoma, and should therefore be carefully considered when creating normative databases for new SWAP strategies.

Female↗
PubMed2006

Sensitivity and specificity of a visual acuity screening protocol performed with the Lea Symbols 15-line folding distance chart in preschool children.

PURPOSE: The aim of this study was to assess the feasibility of a visual acuity (VA) test using the Lea Symbols 15-line folding distance chart and its diagnostic validity in detecting VA deficiency in preschool children. METHODS: A group of 149 children aged 38-54 months underwent VA examination performed with the Lea 15-line folding optotype at a distance of 3 metres, according to a test protocol described in the Methods section. After the VA test, a complete ophthalmological examination, including cycloplegic retinoscopy, a cover test and examination of the anterior and posterior segments, was performed on each child in order to detect any VA-threatening ocular abnormality. The Lea Symbols test's sensitivity, specificity, positive and negative likelihood ratios (LR +, LR -) and the receiver operating characteristic (ROC) curve were calculated by means of standard procedures using each VA level of the chart from 0.1 to 1 (1-0 logMAR) as a cut-off point. RESULTS: The Lea Symbols test could be successfully used in 95.9% of the population. The most useful cut-off points for screening preschool children were found to be 0.8 (LR + 5.73, LR - 0.05) or 0.63 (LR + 11.7, LR - 0.23). CONCLUSION: The Lea Symbols test proved to be clinically useful in detecting VA deficiency in preschool children. The choice between the two best performing cut-off levels should be made according to the expected cost-effectiveness of the screening programme.

Child, Preschool↗
PubMed2005

the impact of definition of primary open-angle glaucoma on the cross-sectional assessment of diagnostic validity of Heidelberg retinal tomography.

PURPOSE: To evaluate the impact of different definitions of primary open angle glaucoma (POAG) on assessment of the diagnostic validity of Heidelberg Retinal Tomography (HRT). DESIGN: Retrospective, cross-sectional study. METHODS: A search of medline (1992-2003) led to the retrieval of 181 papers containing definitions of POAG, including the eight visual field (VF)-based definitions used for this study. A sample of 193 normal subjects, 222 patients with suspected POAG, and 103 with POAG underwent HRT and the 24 II Humphrey VF examinations to assess the diagnostic validity of HRT. POAG was defined on the basis of Glaucoma Hemifield Test (GHT) "out of normal limits" associated with corrected pattern standard deviation (CPSD) > 2 dB and intraocular pressure (IOP) > or =22 mm Hg. The VFs were re-analyzed and categorized according to the other eight definitions of POAG: IOP formed part of all the definitions, whereas the appearance of the optic disk did not. The sensitivity and specificity of each scenario were calculated by standard procedures. RESULTS: The definitions of POAG found in the literature included 17 IOP criteria, more than 15 optic disk criteria, and more than 30 VF criteria. The sensitivity of HRT ranged from 0.51 to 0.80, and its specificity from 0.94 and 0.95 when the patients with suspected POAG were excluded; diagnostic validity was much lower and still variable when the POAG suspects were included with the normal or the POAG groups. CONCLUSIONS: The most commonly used VF-based definitions of POAG led to substantial differences in the sensitivity and specificity of HRT when using the same large sample of normal subjects and POAG patients. A standard definition of POAG is needed to make diagnostic investigations more accurate and comparable.

Adult↗
PubMed2005

Results of the European Glaucoma Prevention Study.

OBJECTIVE: The European Glaucoma Prevention Study (EGPS) seeks to evaluate the efficacy of reduction of intraocular pressure (IOP) by dorzolamide in preventing or delaying primary open-angle glaucoma (POAG) in patients affected by ocular hypertension (OHT). DESIGN: Randomized, double-masked, controlled clinical trial. PARTICIPANTS: One thousand eighty-one patients (age, > or =30 years) were enrolled by 18 European centers. The patients fulfilled a series of inclusion criteria, including: IOP 22 to 29 mmHg; 2 normal and reliable visual fields (on the basis of mean deviation and corrected pattern standard deviation or corrected loss variance of standard 30/II Humphrey or Octopus perimetry); normal optic disc as determined by the Optic Disc Reading Center. INTERVENTION: Patients were randomized to treatment with dorzolamide or placebo (the vehicle of dorzolamide). MAIN OUTCOME MEASURES: Efficacy end points were visual field, optic disc changes, or both. A visual field change during follow-up had to be confirmed by 2 further positive tests. Optic disc change was defined on the basis of the agreement of 2 of 3 independent observers evaluating optic disc stereo slides. The safety end point was an IOP of more than 35 mmHg on 2 consecutive examinations. RESULTS: During the course of the study, the mean percent reduction in IOP in the dorzolamide group was 15% after 6 months and 22% after 5 years. Mean IOP declined by 9% after 6 months and by 19% after 5 years in the placebo group. At 60 months, the cumulative probability of converting to an efficacy end point was 13.4% in the dorzolamide group and 14.1% in the placebo group (hazard ratio, 0.86; 95% confidence interval [CI], 0.58-1.26; P = 0.45). The cumulative probability of developing an efficacy or a safety end point was 13.7% in the dorzolamide group and 16.4% in the placebo group (hazard ratio, 0.73; 95% CI, 0.51-1.06; P = 0.1). CONCLUSIONS: Dorzolamide reduced IOP by 15% to 22% throughout the 5 years of the trial. However, the EGPS failed to detect a statistically significant difference between medical therapy and placebo in reducing the incidence of POAG among a large population of OHT patients at moderate risk for developing POAG, because placebo also significantly and consistently lowered IOP.

Administration, Topical↗
PubMed2003

Detection of glaucomatous visual field changes using the Moorfields regression analysis of the Heidelberg retina tomograph.

PURPOSE: To evaluate the sensitivity and specificity of optic disk examinations performed using the Moorfields regression analysis (MRA) of the Heidelberg Retina Tomograph (HRT) in differentiating normal from glaucomatous eyes. DESIGN: Retrospective cross-sectional study. METHODS: Five hundred and nineteen patients were included in the study for a total of 193 normal eyes, 213 with suspected glaucoma (primary open-angle glaucoma [POAG]), and 113 with POAG. The intervention consisted of optic disk imaging by means of HRT I. A mean of three repeated images was analyzed using version 2.01 software. The optic disk was classified as "normal/outside normal limits" on the basis of the MRA. The visual field was examined using the DS 24 II program (Humphrey perimeter), with a glaucomatous visual field being defined on the basis of an abnormal Glaucoma Hemifield Test and a statistically significant corrected pattern standard deviation greater than 2 dB. The results obtained with MRA were compared with those obtained using the multivariate discriminant analysis (MDA) provided in the HRT I. The main outcome measures were sensitivity, specificity, and positive and negative predictive values of HRT examination. RESULTS: The sensitivity and specificity of the HRT-MRA examination were, respectively, 74% and 94% (83% and 75% with MDA) when the patients with suspected POAG were excluded from the analysis; the figures were 74% and 85%, and 41% and 94% (83% and 64%, and 60% and 75% with MDA) when the same patients were included as being normal or having POAG. CONCLUSIONS: In a broad clinical setting including normal subjects, patients with suspected POAG, and POAG patients, the HRT-MRA showed a high degree of diagnostic accuracy. The MRA was less sensitive but more specific than MDA. Greater diagnostic ability may be added by HRT-MRA examinations than by HRT-MDA to standard POAG diagnostic studies.

Adult↗
PubMed2003

Reproducibility of evaluation of optic disc change for glaucoma with stereo optic disc photographs.

PURPOSE: To determine the reproducibility of the assessment for glaucomatous change in serial optic disc stereo-slides. DESIGN: Masked interobserver variability study. PARTICIPANTS: Serial optic disc stereo-slides from 40 patients. METHODS: Three independent ophthalmologists evaluated for change a set of two serial 20 degrees optic disc color stereo-slides of 40 patients. This test set was not from European Glaucoma Prevention Study (EGPS) patients. Each observer performed two evaluations at least 30 days apart and was masked from the temporal sequence of the slides and his or her previous evaluation. Each patient was graded as changed or stable by two-out-of-three agreement. A kappa statistic was used to calculate the intra- and interobserver reproducibility as well as the assignment reproducibility (first consensus versus second consensus). The same procedure was followed to test the reproducibility when another experienced ophthalmologist was added to one of the three reading centers. MAIN OUTCOME MEASURES: Reproducibility in evaluating glaucomatous optic disc change. RESULTS: The intraobserver reproducibility (95% confidence interval [CI]) in the evaluation of change ranged between 0.79 (0.45-1.14) and 1.00 (0.69-1.31). The interobserver reproducibility (95% CI) in the evaluation of change ranged between 0.45 (0.15-0.75) and 0.75 (0.44-1.06). The assignment reproducibility (first consensus versus second consensus in the evaluation of change) between the senior EGPS readers was 0.94 (0.63-1.25). The assignment reproducibility when another experienced ophthalmologist replaced one of the readers was 0.94 (0.63-1.25). CONCLUSIONS: The assignment reproducibility of three expert readers looking for glaucomatous change in serial optic disc stereo-slides was excellent. It remained so when one of the three experts was replaced by another experienced reader.

Double-Blind Method↗
PubMed2002

Intraobserver and interobserver reproducibility in the evaluation of optic disc stereometric parameters by Heidelberg Retina Tomograph.

PURPOSE: To assess intraobserver and interobserver reproducibility of the measurement of stereometric parameters of the optic disc by means of the Heidelberg Retina Tomograph I (HRT). STUDY DESIGN: Observational study, with interobserver variability. PARTICIPANTS: Fifty-five volunteers (healthy subjects and patients with glaucoma). METHODS: HRT examination of the optic disc was repeated on 3 consecutive days on 1 eye of each of the 55 subjects. During each session, five single images were randomly acquired by two independent observers. One mean topography image (MTI), based on three single images, was then built at each session. For the intraobserver intraimage evaluation, the two observers traced their own contour line on one randomly chosen MTI. This procedure was repeated three times. For the intraobserver interimage and interobserver intra/interimage evaluations, the two observers traced their own contour line on the MTI of the first session, which was then automatically superimposed on the MTIs of the other two sessions. MAIN OUTCOME MEASURES: Reproducibility of the 12 stereometric parameters was calculated for each observer by means of the intraclass correlation coefficient (ICC). The expected range of variability between two independent evaluations was calculated by the scatter-plots of each test-retest difference versus their mean. The standard deviation of the mean test-retest score differences was used to describe the spread of score differences. RESULTS: The ICC ranged between 0.79 and 0.99 for intraobserver intraimage and between 0.56 and 1 for intraobserver interimage evaluation. The ICC ranged between 0.54 and 0.99 for interobserver intraimage and between 0.65 and 0.97 for the interobserver interimage evaluation. ICC was almost perfect to perfect for planimetric measures (0.81 < ICC < or = 1), substantial to almost perfect for volumetric and cup measures (0.61 < ICC < or = 0.99), and moderate to almost perfect for retinal nerve fiber layer related measures (0.41 < ICC < 0.99). The expected variability was low (95% confidence interval, < +/-9%). Interimage evaluation showed a higher variability than intraimage evaluation in both of interobserver (P = 0.012) and intraobserver evaluation (P = 0.028 and P = 0.031 for the two observers). CONCLUSIONS: Measurement of optic disc stereometric parameters by HRT is highly reproducible. However, the use of retinal nerve fiber layer-related parameters should be taken cautiously. The image acquisition-induced variability seems larger than the operator-induced variability.

Adult↗
PubMed2002

The European glaucoma prevention study design and baseline description of the participants.

OBJECTIVES: The European Glaucoma Prevention Study seeks to evaluate the efficacy of reducing intraocular pressure (IOP), with dorzolamide to prevent or delay patients affected by ocular hypertension from developing primary open-angle glaucoma. DESIGN: Randomized, double-blinded, controlled clinical trial. PARTICIPANTS: Patients (age > or =30 years) were enrolled from 18 European centers. The patients fulfilled a series of inclusion criteria including the measurements of IOP (22-29 mmHg), two normal and reliable visual fields (VFs) (on the basis of mean defect and corrected pattern standard deviation/corrected loss of variance of standard 30/II Humphrey or Octopus perimetry), and normal optic disc as determined by the Optic Disc Reading Center (vertical and horizontal cup-to-disc ratios; asymmetry between the two eyes < or =0.4). INTERVENTION: Patients were randomized to the treatment with dorzolamide or a placebo. MAIN OUTCOME MEASURES: End points are VF and/or optic disc changes. A VF change during the follow-up must be confirmed by two further positive tests. Optic disc change is defined by the agreement of two out of three independent observers evaluating optic disc stereo-slides. RESULTS: One thousand seventy-seven subjects were randomized between January 1, 1997 and May 31, 1999. The mean age was 57.03 +/- 10.3 years; 54.41% were women and 99.9% were Caucasian. Mean IOP was 23.6 +/- 1.6 mmHg in both eyes. Mean visual acuity was 0.97 +/- 0.11 in both eyes; mean refraction was 0.23 +/- 1.76 diopters in the right eye and 0.18 +/- 1.79 diopters in the left eye. Previous use of medication for ocular hypertension was reported by 38.4% of the patients, systemic hypertension by 28.1%, cardiovascular diseases by 12.9%, and diabetes mellitus by 4.7%. The qualifying VFs were normal and reliable according to protocol criteria. CONCLUSIONS: The mean IOP of the patients enrolled in the European Glaucoma Prevention Study is consistent with the estimated mean IOP (within the range of 22-29 mmHg) found in a large sample of the European population. The European Glaucoma Prevention Study should be able to better address the clinical question of whether pharmacological reduction of IOP (by means of dorzolamide) in ocular hypertension patients at moderate risk for developing primary open-angle glaucoma effectively lowers the incidence of primary open-angle glaucoma.

Adult↗