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Biomedical subjects

M Iester

Publications and source records attributed to M Iester.

At least 37 records · Page 2Linked to original sources
PubMed2000

Improvement of the ocular surface using hypotonic 0.4% hyaluronic acid drops in keratoconjunctivitis sicca.

BACKGROUND: The ocular surface changes of keratoconjunctivitis sicca (KCS) could be the result of the effect of an altered tear film on the epithelial environment. PURPOSE: To evaluate the possibility of improving the environmental conditions of the ocular surface by lowering tear osmolarity, increasing tear film volume and stabilising the tear film. Also, to study the effect of such an improvement on the epithelial cells of the ocular surface. METHODS: One hundred and thirty-five patients with a diagnosis of KCS were treated on a randomised basis with either unpreserved hypotonic 0.4% hyaluronic acid (HHA) eye drops or 0.3% hydroxypropylmethylcellulose plus 0.1% Dextran 70 (HPMC) eye drops 6 times a day for 60 or 90 days. In all patients a Schirmer I test, break-up time (BUT), ocular surface staining with 1% Bengal Rose, or 2% fluorescein, as well as subjective symptoms, were recorded before and 15, 30 and 60 days after the beginning of the study. Patients were divided into three subgroups and the effect of the treatment was studied using three different techniques: the tear ferning test, conjunctival impression cytology and tear osmolarity measurement. RESULTS: Improvements in BUT, vital staining, Schirmer I and symptoms were recorded in both groups of treatment, with significant differences for patients treated with 0.4% HHA. On day 60, 30 min after installation: tear ferning patterns changed from 100% pathological (types III-IV) to 93% physiological (types I-II) in the 0.4% HHA group and from 100% pathological to 78% physiological in the 0.3% HPMC group (p < 0.01 between groups). Tear osmolarity shifted from 353 +/- 23 to 305 +/- 6 mosmol/l in the 0.4% HHA group and from 346 +/- 15 to 336 +/- 8 mosmol/l in the 0.3% HPMC group (p < 0.001 between groups). On day 90, the impression cytology score improved from 1.2 to 1.9 in the 0.4% HHA group while it did not change in the 0.3% HPMC group (p < 0.05 between groups). CONCLUSION: In KCS appropriate treatment with a hypotonic 0.4% HHA tear substitute can change the tear environment and results in improvement of the epithelial conditions of the ocular surface.

Adjuvants, Immunologic↗
PubMed2000

Discriminant analysis models for early detection of glaucomatous optic disc changes.

AIM: To evaluate and compare four different mathematical formulas for the early detection of morphometric optic nerve head changes in chronic open angle glaucoma. METHODS: The optic nerve heads of 161 patients with perimetrically defined glaucomatous optic nerve damage and of 194 normal subjects were examined by confocal laser scanning tomography. Using four formulas of linear discriminant analysis and the optic cup shape measure as the single optic disc variable, the predictive power of each of these methods was examined to differentiate between the normal eyes and the glaucoma eyes. RESULTS: The highest predictive power had an optic disc sector based formula, in particular in eyes with medium and large optic discs. This optic disc sector based formula was the one with the best agreement with the other formulas examined. It achieved a better predictability than any single optic disc variable evaluated. CONCLUSIONS: Combining quantitative optic disc variables by discriminant analysis functions, the predictive power of semiautomatic quantitative optic nerve head evaluation can be improved by providing the ophthalmologist with a diagnostic score for the detection of glaucomatous optic nerve damage. Because of the pattern of glaucomatous neuroretinal rim loss, an optic disc sector based discriminant formula may have a higher diagnostic precision than other formulas in detecting early glaucomatous damage.

Adult↗
PubMed1999

Optic nerve head morphologic characteristics in high-tension and normal-tension glaucoma.

OBJECTIVES: To determine the morphometric parameters in high-tension glaucoma (HTG) and normal-tension glaucoma (NTG) with a confocal scanning laser ophthalmoscope, and to determine the relationship to disc size. METHODS: One hundred eighty-six patients with glaucoma were recruited for this study. For each patient, only one eye was randomly chosen. Patients with NTG and HTG were classified using untreated intraocular pressure (IOP) as the variable; the NTG group had IOP less than 22 mm Hg during a diurnal tension curve, while patients with HTG had IOP greater than 21 mm Hg in at least 3 measurements. All the patients were examined with Humphrey perimeter program 30-2 and a Heidelberg Retina Tomograph. Findings were assessed by t test. Patients were then divided by disc area size into 3 subgroups: small discs with an area less than 2 mm2, midsized discs with an area of 2 to 3 mm2, and large discs with an area greater than 3 mm2. RESULTS: One hundred thirty-two HTG eyes and 50 NTG eyes were assessed. Four eyes were excluded because they were classified as having secondary glaucoma. No significant differences were found between HTG and NTG eyes for any Heidelberg Retina Tomograph morphometric parameters, even when patients were divided into subgroups. CONCLUSION: No differences were apparent between HTG and NTG in morphometric parameters as measured by scanning laser ophthalmoscopy.

Glaucoma, Open-Angle↗
PubMed1999

Optic disc surface smoothness and visual field indices.

BACKGROUND: In order to ascertain whether the optic disc surface smoothness (ODSS) could be used to predict the amount of visual field damage in glaucomatous eyes, the correlations between ODSS and visual field indices were evaluated. METHODS: One eye was randomly chosen from each of 40 normals and 50 patients with glaucoma. The morphology of the optic disc surface was analyzed using the Topcon IMAGEnet X Rev-3.51b. In order to define the level of "smoothness" of the optic disc surface, the differences of the relative position of each surface point was studied by measuring the standard deviation (SD) from the average height of the points (number of points ranged from 623 to 1883 depending on the size of the disc area) that identify the optic disc surface. All the subjects were also examined with the Humphrey perimeter (Program 30-2) and the results were analyzed by Mann-Whitney U-test and Spearman rank correlation coefficient. RESULTS: The difference in ODSS between the glaucomatous and the normal eyes was statistically significant. No significant correlation was found between age and ODSS. A significant correlation was found between ODSS and mean deviation (MD) and between ODSS and corrected pattern standard deviation (CPSD). In the glaucoma group there were significant correlations between ODSS and the perimetric indices MD and CPSD; no correlations were found in the normal group. CONCLUSION: The ability of ODSS to reflect the level of visual field change in glaucomatous eyes appears to be rather limited, even if statistically significant. This fact does not limit the clinical usefulness of ODSS as a diagnostic parameter in consequence of its strong correlations with the other morphometric parameters and its high sensitivity and specificity in separating normal from glaucomatous eyes.

Female↗
PubMed1999

Topographic analysis to discriminate glaucomatous from normal optic nerve heads with a confocal scanning laser: new optic disk analysis without any observer input.

PURPOSE: We evaluated the potential ability of a confocal scanning laser ophthalmoscope to differentiate patients with normal visual fields from those with abnormal visual fields with an optic nerve head topographic map. PATIENTS AND METHODS: Twenty normal eyes with normal visual fields, intraocular pressures of less than 22 mm Hg, and no family history of glaucoma and 20 glaucomatous eyes with abnormal visual fields and open angles were selected. Glaucomatous eyes with advanced visual field damage were not included. One eye was chosen randomly from each patient. All eyes were examined with the Heidelberg Retina Tomograph (HRT [Heidelberg Engineering GMBH, Heidelberg, Germany]) and Humphrey Perimeter, program 30-2 (Humphrey Instruments, Inc., San Leandro, CA, USA). Topographic maps were analyzed with different methods based on contour lines, with use of a program able to differentiate glaucomatous from normal optic disks. Sensitivity, specificity, and diagnostic precision were calculated. RESULTS: The analysis had a sensitivity, specificity, and diagnostic precision of 80%, 100%, and 90%, respectively. CONCLUSION: With the topographic map data and this technique, the HRT's capacity to differentiate normal optic disks from glaucomatous disks was improved. In addition, with this method, we avoided any subjective observer input in drawing the optic nerve head outline.

Aged↗
PubMed1999

Correlation between high-pass resolution perimetry and standard threshold perimetry in subjects with glaucoma and ocular hypertension.

PURPOSE: To evaluate the correlation between High-Pass Resolution Perimetry (HRP) and standard threshold perimetry in patients with glaucoma or ocular hypertension. METHODS: 31 glaucomatous patients and 37 ocular hypertension subjects with previous perimetric examination experience were consecutively recruited and only one eye for each patient was selected at random. Glaucomatous patients were classified as having primary open angle glaucoma when they had an abnormal visual field and/or an abnormal optic nerve head (ONH)/retinal nerve fiber layer (RNFL) typical of glaucoma, open angle at gonioscopy and no clinically apparent secondary cause for their glaucoma. Ocular hypertension subjects were defined as having intraocular pressure >21 mm Hg on no treatment, normal visual field, normal ONH and RNFL, elevated intraocular pressure without any treatment. All the subjects were examined with Humphrey Field Analyzer (HFA) 640, 'program central 30-2' (Humphrey Systems, San Leandro, CA, USA) and with High-Pass Resolution Perimeter (HRP), Ophthimus version 2.4,'ring program' (Nikon-HighTech Vision, Goteborg, Sweden). Visual field indices were obtained with both systems: for HFA mean deviation (MD), corrected pattern standard deviation (CPSD) and short term fluctuation (SF), while for HRP global deviation (GD), local deviation (LD), form index (FI) and neural capacity (NC). The data were analyzed by descriptive analysis, Student's t test with Bonferroni's correction or Mann-Whitney non-parametric test and Pearson or Spearman's correlation coefficient. RESULTS: A significant correlation was found between MD and GD (r = -0.81), CPSD and LD (r = 0.87), PSD and LD (r = 0.72). NC was significantly correlated with MD (r = 0.76), GD (r = -0.94). FI was significantly correlated with PSD (r = -0.58), CPSD (r = -0.72), LD (r = -0.56). When the same data were analyzed for the glaucomatous group only, similar results were found; in the ocular hypertensive group no significant correlation was found except between NC and MD (r = 0.52). CONCLUSION: HRP indices vary comparably with HFA indices. Parameters as NC and FI were significantly correlated with standard visual field indices of both HFA and HRP. Although the clinical applications for FI are not clear yet, NC could detect both early glaucomatous damage and age related changes.

Disease Progression↗
PubMed1998

A comparative study of computerised visual field testing and optic disc morphometric parameters in the follow-up of primary open angle glaucoma.

PURPOSE: To evaluate the correlation between computerised visual field testing and optic disc morphometric parameters (rim area, rim/disc area ratio, cup/disc area ratio and optic disc surface smoothness (ODSS)) in the follow-up of a group of patients affected by primary open angle glaucoma (POAG). METHODS: Reliable automated perimetry (Humphrey 640 VFA, central 30-2 threshold program) was performed at T0 (the enrollment time), T1 (after 6 +/- 1 months; range 5-7 months), T2 (12 +/- 1 months), T3 (18 +/- 1 months), and T4 (the end of the follow-up period: 24 +/- 2 months) in one eye randomly chosen from each of 30 POAG patients. Computerised optic disc analysis (IMAGEnet X Rev-3-51b, Topcon Europe, The Netherlands) was performed at T0 and T4. To evaluate the correlation between morphometric parameters and computerised visual field testing, the stability or worsening of visual field test was evaluated by means of 'Mean Deviation linear regression analysis' (STATPAC 2 software); that of morphometric parameters was studied using their coefficients of variation. A rank of '0' was assigned to stability and a rank of '1' to worsening. The Spearman rank correlation coefficient was used to evaluate statistically the correlations between visual field analysis and morphometric parameters. Furthermore kappa statistic was used to evaluate the agreement of morphometric parameter changes with visual field progression analysis. RESULTS: According to the MD slope regression analysis, in 18 patients the visual fields were stable while in 12 they were worsening during the follow-up period. In 86.65% of patients (n = 26) the morphometric parameter ODSS and visual field analysis were concordant (p < 0.0001). In 80% of patients (n = 24) the cup/disc area ratio and visual field analysis were concordant (p < 0.001). The other morphometric parameters (rim area, rim/dics area ratio) were less correlated with visual field analysis than ODSS (p < 0.05). The agreement of visual field analysis with all the morphometric parameters was good (kappa = 0.690, 95% confidence interval (CI) of kappa = 0.589-0.790). The agreement of visual field analysis with ODSS and cup/disc area (kappa = 0.688; 95% CI = 0.511-0.864) was better than the agreement of visual field analysis with rim area and rim/disc area ratio (kappa = 0.438; 95% CI = 0.260-0.655). CONCLUSION: Analysis of the progression of visual field damage and optic nerve head morphometric parameters should both be taken into account in glaucoma follow-up. Among the morphometric parameters evaluated by means of Topcon IMAGEnet, ODSS and (to a lesser extent) the cup/disc ratio should have the greatest weight.

Aged↗
PubMed1998

Low spatial-contrast sensitivity in dry eyes.

PURPOSE: Blurred vision in keratoconjunctivitis sicca eyes could be the result of the loss of the glossy surface of the tear film because of changes in composition or thickness irregularities. Spatial-contrast sensitivity in keratoconjunctivitis sicca and normal control eyes was tested before and after a tear substitute. METHODS: Three different groups of subjects were enrolled: one group of dry eyes with nonsignificant signs of epithelial disease (n = 12), the second group of dry eye positive with 1% Bengal rose staining of the cornea and of the conjunctiva (n = 18), and a third of normal eyes as control group (n = 15). In all the 45 eyes, spatial-contrast sensitivity was tested under the best correction by means of the Vistech Multivision Contrast Tester 8000 (Vistech Consultants, Dayton, OH, U.S.A.) before and 15 min after the instillation of a 0.4% Na-hyaluronate tear substitute without preservatives. RESULTS: A significant decrease of spatial-contrast sensitivity ranging from 35 to 70% was present in keratoconjunctivitis sicca eyes compared with a third group of age-matched normal eyes used as control. The spatial-contrast sensitivity was significantly lower also in the presence of preserved corneal surface. The addition of a tear substitute improved spatial contrast-sensitivity thresholds in all groups. CONCLUSION: Tear-film disease can affect the transfer function of modulation of the ocular surface.

Adult↗
PubMed1998

RA/DA cumulative curve analysis of local and diffuse neuroretinal rim area damage in glaucoma patients.

AIM: To evaluate the validity of cumulative rim/disc area (RA/DA) curve analysis as a clinical tool for the identification of glaucoma induced optic disc pathology. METHODS: 71 normal and 83 glaucomatous eyes were evaluated from a series of 154 subjects recruited for this study. For each eye, the cumulative distribution of RA/DA was calculated from 36 equally spaced rim sectors of each optic disc obtained by the automatic evaluation of simultaneous videographics (Image-net X Rev.3/51b). To increase the sensitivity of this analysis in early glaucoma and in normal eyes, these cumulative curves were subsequently divided into two equal segments and the slopes of their respective regression lines compared. RESULTS: The median RA/DA value obtained from the 36 sectors was significantly different in glaucomatous eyes compared with normals (p < 0.001). Nevertheless, the curves (5th-95th percentile of the cumulative curves distribution) of early glaucomatous eyes fell within the normal range. When the cumulative curve of these marginal cases was then divided into two equal segments, the comparison of the slopes of the regression lines showed a significant difference (p < 0.05) in 100% of early glaucomatous eyes. Furthermore, normal eyes were shown to be true negatives in 93% of the cases in which no significant difference between the two slopes was observed. CONCLUSION: Analysis of the RA/DA cumulative curve from 36 sectors of the optic disc was a valid method for the identification of glaucomatous disc pathology; however, a further calculation of the slopes of the two RA/DA regression lines was needed to identify early glaucomatous damage.

Female↗
PubMed1998

Retinal nerve fiber layer height in high-tension glaucoma and healthy eyes.

PURPOSE: To determine the correlations between the retinal nerve fiber layer height measured by Heidelberg Retina Tomograph, version 1.11, and visual field indices in healthy individuals and patients with glaucoma. METHODS: One eye was randomly chosen from 48 patients with glaucoma and 60 healthy individuals. All participants were classified using Humprey visual field, program 30-2 (Humphrey Instruments, Inc., San Leandro, CA, U.S.A.); mean deviation, pattern standard deviation, short-term fluctuation, and corrected pattern standard deviation were measured. Superior and inferior mean deviation were calculated. For each participants the mean Heidelberg Retina Tomograph was generated from three 10 degrees Heidelberg Retina Tomograph pictures. The Student t test was used to compare healthy and glaucomatous retinal nerve fiber layer (RNFL) mean degree values every 5 degrees. A global measurement, superior sector (25 degrees-125 degrees), nasal sector (130 degrees-230 degrees), inferior sector (235 degrees-335 degrees), temporal sector (340 degrees-20 degrees), and polar sector (superior + inferior) were calculated. The global, superior, nasal, inferior, temporal, and polar RNFL height (RNFLH) were compared between healthy individuals and patients with glaucoma. The correlation between global, superior, inferior, and polar retinal nerve fiber layer height and visual field was calculated. RESULTS: A significant difference was found for RNFLH mean from 45 degrees to 330 degrees and for the distribution of the means (as reflected by the standard deviation) from 85 degrees to 100 degrees, 260 degrees to 295 degrees, and 335 degrees to 5 degrees. From these data we created three new sectors: new superior sector (from 85 degrees to 100 degrees), new inferior sector (from 260 degrees to 295 degrees), and new polar sector (combining the new superior and the new inferior sector). Comparing the healthy individuals to the patients with glaucoma, the mean RNFLH values for each sector were found to differ significantly (p < 0.001), with the exception of the temporal sector. Significant correlations (p < 0.001) between the global RNFLH and mean deviation (r = -0.36), pattern standard deviation (r = 0.49), and corrected pattern standard deviation (r = 0.48) were found in healthy participants and those with glaucoma. The strongest correlations (p < 0.001) were found between the pattern standard deviation and the corrected pattern standard deviation with the new polar sector (r = 0.60 and r = 0.59, respectively). CONCLUSIONS: We found that the strongest correlations with the visual field were with the new polar and new inferior sector.

Aged↗
PubMed1997

The effect of optic disc size on diagnostic precision with the Heidelberg retina tomograph.

PURPOSE: The authors evaluated the ability of a confocal scanning laser ophthalmoscope to detect glaucomatous visual field loss by using their previously described discriminant formula on a prospectively obtained cohort. The relationship of optic disc size to diagnostic classification was also evaluated. METHODS: One eye was chosen randomly from each of 153 subjects. Sixty control eyes had intraocular pressure less than 21 mmHg and normal visual fields; 93 glaucomatous eyes had intraocular pressure greater than 21 mmHg and abnormal visual fields. The optic disc status purposely was not used for classification purposes. All subjects were examined with the Heidelberg Retina Tomograph (HRT; Heidelberg Engineering GMBH, Heidelberg, Germany) and Humphrey Perimeter, program 30-2 (Humphrey Instruments, Inc., San Leandro, CA). Visual fields were considered abnormal by the authors' previously published criteria. The HRT classification used age, adjusted cup shape measure, rim volume, and height variation contour to classify the optic disc as normal or glaucomatous. Then the authors assessed the sensitivity, specificity, and diagnostic precision for the entire group, and for three subsets classified by disc area: disc area less than 2 mm2, between 2 and 3 mm2, and more than 3 mm2. RESULTS: The entire group had a sensitivity, specificity, and diagnostic precision of 74%, 88%, and 80%, respectively. The specificity was 83% when disc area was less than 2 mm2 and improved to 89% when disc area was more than 2 mm2. The sensitivity tended to improve from 65% to 79%, and to 83% if the disc area increased, but the difference was not statistically significant. CONCLUSIONS: In a prospective cohort of patients, the HRT discriminant analysis formula was capable of detecting glaucomatous visual field loss with good precision. Unusually small optic discs continue to present diagnostic difficulties.

Adult↗
PubMed1997

Intraimage reproducibility of measurements in the macular area using a computerized system.

An accurate analysis of the morphological changes which take place during pathological processes of the posterior pole is important for a correct diagnosis and therapeutic approach. The purpose of the study was to determine the intraobserver and interobserver reproducibility of the Image-net system 100 (Topcon, Japan) to take measurements on the retina. The program 'Linear/Areal Measurement functions' of Image-net system 100 which is an image digitalization technique, was tested. Twelve patients were consecutively selected from the patients of the Retina Center of the Department of Ophthalmology, University of Genoa. Three images of each eye were taken from each subject and only the best image was used in this study. The intraobserver and interobserver reproducibility of both the distance between two pre-set points (linear measurement), and the perimeter and area of preselected retinal zones were calculated. The repeatability (or intraobserver reproducibility) of the linear sizes was measured by the coefficient of variation and ranged from 0.32% to 7.38%, while the interobserver reproducibility ranged from 0.46% to 5.22%. The repeatability and reproducibility of the perimeters ranged from 0.72% to 9.63% and from 0.6% to 5.7%, respectively, while the repeatability and reproducibility of the areas ranged from 0.72% to 9.63% and from 0.6% to 5.7%, respectively. Although the results were quite good, the quality of the image of the fundus and the number of observers influenced the coefficient of variation; furthermore, the anatomy of the areas to be measured and the computer 'mouse' could increase the value of the coefficient of variation.

Angiography, Digital Subtraction↗
PubMed1997

Correlation between the visual field indices and Heidelberg retina tomograph parameters.

PURPOSE: We wished to determine whether a relationship exists between Heidelberg retina tomograph (HRT) parameters and the visual field indices. METHODS: One eye was randomly chosen from 59 normal patients [normal visual field and normal optic nerve head (ONH) and intraocular pressure (IOP) < 21 mm Hg], 64 ocular hypertensive patients (normal visual field and normal OHN and IOP > 22 mm Hg), 124 high-tension glaucoma patients (abnormal visual field and/or abnormal optic nerve and IOP > 22 mm Hg) and 47 low-tension glaucoma patients (abnormal visual field and or optic disc and IOP < 21 mm Hg). All the patients were examined with Humphrey Perimeter, program 30-2, and HRT. Findings were assessed by analysis of variance, Pearson's correlation coefficient, and multiple linear regression. RESULTS: Among all subjects, we noted a statistically significant correlation (Pearson's r, p < 0.001) between cup area, cup/disc area ratio, rim area, rim volume, cup shape measure, and retinal nerve fiber layer cross-section area with mean deviation and corrected pattern SD. Multiple linear regression analysis demonstrated that rim area was the most important predictor of mean deviation and corrected pattern SD. CONCLUSIONS: The presence of significant correlations between some HRT parameters, such as rim area and cup shape measure and visual field indices, suggests that these HRT parameters could be good indicators of the degree of glaucomatous ONH damage.

Glaucoma, Open-Angle↗