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Biomedical subjects

C E Traverso

Publications and source records attributed to C E Traverso.

At least 19 recordsLinked to original sources
PubMed2006

Corneal thickness and visual field damage in glaucoma patients.

PURPOSE: To verify whether there was a significant correlation between central corneal thickness (CCT) and visual field damage in patients with primary open angle glaucoma (POAG). METHODS: A total of 99 eyes with POAG were consecutively recruited. Patients were classified as glaucomatous based on visual field and optic nerve head damage. All underwent applanation tonometry, Humphrey perimetry, and measurement of CCT with ultrasonic pachymetry. Based on CCT value, the sample was split at the mode in two groups (group 1<535 microm, n=49; group 2>or=535 microm, n=50). RESULTS: Entire cohort: mean CCT 554 microm+/-45.03; mean deviation (MD) -6.68 dB+/-7.32; pattern standard deviation (PSD) 5.33+/-3.75; intraocular pressure (IOP) 17.91+/-4.16 mmHg with treatment. Group 1: CCT was 504.8 microm+/-30.8; MD -9.01 dB+/-8.72; PSD 6.38+/-3.99; IOP 18.02 mmHg+/-4.66. Group 2: mean CCT 574.6 microm+/-35.03; MD -4.39 dB+/-4.70; PSD 4.25+/-3.19; IOP 17.79 mmHg+/-3.57. A significant difference was found between the two groups for both MD and PSD. Linear regression analysis showed a significant correlation between CCT and PSD (P<0.001). CONCLUSIONS: Our data show that patients with a thinner cornea had a worse MD and PSD. As a thinner CCT causes an underestimation of the true IOP, there may be a delay in the diagnosis of POAG or an inadequate estimate of the clinical course despite apparently desirable IOP applanation readings.

Adult↗
PubMed2005

Long term effect on IOP of a stainless steel glaucoma drainage implant (Ex-PRESS) in combined surgery with phacoemulsification.

AIM: To evaluate the efficacy and safety of a stainless steel miniature glaucoma drainage device (Ex-PRESS R50) for the surgical treatment of primary open angle glaucoma (POAG) and cataract when combined with phacoemulsification. METHODS: Clinical, prospective, multicentre, single treatment arm, non-randomised, non-masked study. The Ex-PRESS device was implanted at the limbus under a conjunctival flap. Phacoemulsification cataract extraction and in the bag IOL implantation were performed through clear cornea temporally. PRIMARY OUTCOME: IOP change; secondary outcomes: side effects and VA changes. RESULTS: 26 eyes of 25 patients were implanted with the device. The mean (SD) follow up was 23.9 (10.4) months and the mean age was 75.1 (7.1) years. 17/26 eyes have more than 3 years of follow up. One case was discontinued because of device removal, one because of death, and three were lost to follow up. EFFICACY: preoperative IOP was 21 (4) mm Hg; at 1, 2, and 3 years IOP was 15.3 (3.1) mm Hg (35% reduction), 16.6 (2.7) mm Hg (29% reduction), and 16 (2.6) mm Hg (22% reduction) respectively. Kaplan-Meyer determined overall success rate (IOP < or = 21 mm Hg at the last visit with or without medications) as 76.9%. The number of antiglaucoma medications was reduced by 95% at year 1. Only six patients (23%) were taking IOP lowering treatment at their last visit, five with one medication and one with two medications. Side effects: early postoperative complications were clinically mild and included six cases of hypotony (IOP <5 mm Hg), three cases of hyphaema (<2 mm) with no clinically significant further effects. Long term complications were two cases (7.7%) of device rotation (one treated by reposition) and three cases (11.5%) of conjunctival erosion at 2 and 3 years. CONCLUSIONS: The Ex-PRESS implant, combined with phacoemulsification cataract extraction, is clinically safe and effective, maintaining in the long term a large reduction in IOP and in the number of antiglaucoma medications.

Aged↗
PubMed2005

Direct costs of glaucoma and severity of the disease: a multinational long term study of resource utilisation in Europe.

BACKGROUND: Resource utilisation and direct costs associated with glaucoma progression in Europe are unknown. As population progressively ages, the economic impact of the disease will increase. METHODS: From a total of 1655 consecutive cases, the records of 194 patients were selected and stratified by disease severity. Record selection was based on diagnoses of primary open angle glaucoma, glaucoma suspect, ocular hypertension, or normal tension glaucoma; 5 years minimum follow up were required. Glaucoma severity was assessed using a six stage glaucoma staging system based on static threshold visual field parameters. Resource utilisation data were abstracted from the charts and unit costs were applied to estimate direct costs to the payer. Resource utilisation and estimated direct cost of treatment, per person year, were calculated. RESULTS: A statistically significant increasing linear trend (p = 0.018) in direct cost as disease severity worsened was demonstrated. The direct cost of treatment increased by an estimated 86 for each incremental step ranging from 455 euro per person year for stage 0 to 969 euro per person year for stage 4 disease. Medication costs ranged from 42% to 56% of total direct cost for all stages of disease. CONCLUSIONS: These results demonstrate for the first time in Europe that resource utilisation and direct medical costs of glaucoma management increase with worsening disease severity. Based on these findings, managing glaucoma and effectively delaying disease progression would be expected to significantly reduce the economic burden of this disease. These data are relevant to general practitioners and healthcare administrators who have a direct influence on the distribution of resources.

Adult↗
PubMed2000

Learning effect, short-term fluctuation, and long-term fluctuation in frequency doubling technique.

PURPOSE: To evaluate short-term and long-term fluctuations and learning effects in healthy subjects tested with the frequency doubling technique, which is based on a low spatial frequency and a high temporal frequency stimulus. METHODS: Twenty-three healthy adult subjects were consecutively recruited from volunteers, and 20 subjects finished the study. All the visual fields were assessed by the frequency doubling technique, program C-20, full threshold. The frequency doubling technique presents stimuli on a black-and-white video monitor with specialized control circuitry interfaced to a microprocessor. During program C-20, full threshold, 17 points are tested, one round point centrally and 16 square ones in the periphery up to 20 degrees of eccentricity. Each stimulus consists of a 0.25-cycle/degree sinusoidal grating undergoing a 25-Hz counterphase flicker. One eye of each patient was chosen at random. Each subject was tested once in the first session, three times in the second session, and once in the third and fourth sessions. Both short-term and long-term fluctuation were studied either as the average fluctuation value of all the points tested or as a point-to-point fluctuation. To study the learning effect, the results of the first session were compared with those of the second, the third, and the fourth sessions. RESULTS: The average mean sensitivity of the three examinations of the second session was 30.4 +/- 1.24 dB, and the average short-term fluctuation of all the subjects was 2.16 +/- 0.5 dB. The short-term fluctuation of each point tested ranged from 1.4 to 3.4 dB. The average mean sensitivity for all the sessions was 32.4 +/- 1.14 dB, with an average long-term fluctuation of 3.23 +/- 0.5 dB, and the long-term fluctuation of each tested point ranged from 2.5 to 4.4 dB. A mild learning effect was found between the first section and the others. CONCLUSION: Short-term and long-term fluctuations were similar to those known to occur with the conventional threshold perimetry when they were compared with the literature data. A learning effect was also observed and should be taken into account for the clinical use of this test.

Adult↗
PubMed2000

Comparison between relative dispersion analysis of high-pass resolution perimetry and standard threshold perimetry.

PURPOSE: To evaluate the correlation of the dispersion index (DI) of relative dispersion analysis (RDA), a new high-pass resolution perimetry (HRP) index, with other HRP indices and those of the Humphrey standard threshold perimeter (STP) parameters. METHODS: Sixty-eight eyes were randomly recruited. Thirty-one eyes were classified as glaucomatous (high intraocular pressure, abnormal visual field and/or optic disc) and 37 as ocular hypertensives (high intraocular pressure, normal visual field, normal optic disc). All the subjects were examined with Humphrey Perimeter, program 30-2, and HRP. The HRP data were also analysed with the RDA program. Statistical analysis was performed with Student's t-test, Pearson's r correlation coefficient, Mann-Whitney nonparametric test and Spearman correlation coefficient when appropriate. RESULTS: Within the entire sample significant correlations were found between the RDA index (DI) and all the HRP indices (p < 0.001) and corrected pattern standard deviation (p < 0.01), pattern standard deviation (PSD) (p < 0.01), mean deviation (p < 0.05) and short-term fluctuation (p < 0.05) of STP. A stronger correlation was found in glaucomatous patients. In subjects with ocular hypertension DI was only weakly correlated with PSD, local deviation and form index. No difference in DI was found between glaucoma and ocular hypertension. CONCLUSION: The DI of HRP has the theoretical capacity to detect localised inhomogeneity of retinal sensitivity, but at present our data do not support this hypothesis. Before any clinical applications of this index further studies are needed.

Adult↗
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↗
PubMed1999

Reliability of applanation tonometry readings obtained with a disposable latex cap.

BACKGROUND: To verify the accuracy of applanation tonometry through disposable latex caps used to prevent transmission of infectious diseases. METHODS: Tonometry was performed in 80 patients. Each patient underwent two intraocular pressure (IOP) measurements with and without the latex. In group A patients tonometry was performed first without the cap; in group B tonometry was performed first with the cap. Each group was also divided into patients with IOP, >/=20 mm Hg (A1; B1) and patients with IOP <20 mm Hg (A2; B2). RESULTS: The mean difference of tonometry readings was equal to -0.36 +/- 1. 62 mm Hg in group A, -0.03 +/- 1.77 mm Hg in group A1, -0.61 +/- 1. 45 mm Hg in group A2, 0.23 +/- 1.44 in group B, 0.64 +/- 1.41 mm Hg in group B1, 0.05 +/- 1.42 in group B2. A statistically significant correlation was found in group A, in group A2, B, B1 and B2; a less significant correlation was found in group A1. CONCLUSIONS: The use of the latex caps does not alter the reliability of tonometry readings as long as the cap is applied tightly. Measurement variation in our study is comparable to published data on applanation tonometry.

Evaluation Studies as Topic↗
PubMed1997

Long-term restoration of damaged corneal surfaces with autologous cultivated corneal epithelium.

BACKGROUND: Complete loss of the corneal-limbal epithelium leads to re-epithelialisation by bulbar conjunctival cells. Since conjunctival and corneal-limbal epithelial cells represent two different cell lines, this conjunctival healing of the cornea is followed by stromal scarring, decreased visual acuity, and severe discomfort. Unilateral corneal-limbal epithelial defects can be resolved by the transplantation of limbal grafts taken from the uninjured eye. However, this procedure requires a large limbal graft to be taken from the healthy eye, and is not possible for bilateral lesions. We investigated the possibility of restoring the human corneal surface with autologous corneal epithelial sheets generated by serial cultivation of limbal cells. METHODS: Cells were cultivated from a 1 mm2 biopsy sample taken from the limbus of the healthy eye of two patients with severe alkali burns, and thus complete loss of the corneal-limbal surface, of one eye. Normal corneal differentiation was tested with a specific biochemical marker. Autologous cultured corneal sheets were then grafted onto the damaged eyes of the two patients. The patients were followed up at more than 2 years after grafting. FINDINGS: We have shown that corneal progenitor cells are localised in the limbus, that cultured limbal cells generate cohesive sheets of authentic corneal epithelium, and that autologous cultured corneal epithelium restored the corneal surface of two patients with complete loss of the corneal-limbus epithelium. Long-term follow-up showed the stability of regenerated corneal epithelium and the striking improvement in patients' comfort and visual acuity. INTERPRETATION: The cultivation of corneal epithelium might offer an alternative to patients with unilateral lesions and a therapeutic chance to patients with severe bilateral corneal-limbal epithelial defects. Our findings give a new perspective on the treatment of ocular disorders characterised by stem-cell deficiency.

Burns, Chemical↗
PubMed1996

The glaucomas in pseudophakia.

The glaucomas in pseudophakia are not uncommon. Because they can be related to different mechanisms, each case should be evaluated individually. Once glaucoma has been established and medication fails to maintain the intraocular pressure at a safe level, several options are available. As a group, the glaucomas are considered both difficult to manage with medications and also at high risk for failure of filtration surgery. Trabeculectomy adjuvated with anti-metabolites, draining implants, and cyclodestructive procedures are all effective procedures. Although complications and loss of vision as a consequence of glaucoma surgery are not frequent, they were reported by several authors. The likelihood of any given treatment to preserve the quality of life should be discussed with each patient and should be part of the decision-making process. This article reviews studies on the glaucomas in pseudophakia published from October 1994 to September 1995.

Antimetabolites↗
PubMed1995

Study of the correlation between average values of optic disc parameters and their measurement variability using stereovideographic digital analysis.

Purpose of our study was to find whether there is a correlation between average values of optic nerve head parameters and their coefficient of variation for repeated measurements. Disc stereo video images were taken with Topcon Imagenet (IS100) and analyzed with the Optic Disc Analysis program. Eleven normal and 9 glaucomatous eyes were selected. A significant correlation was found for horizontal cup/disc ratio (r = -0.037, p = 0.037) and disc area (r = 0.776, p = 0.027) in intra-observer intra-image repeated measurements. Vertical, horizontal and average cup/disc ratios (r = -0.81, r = -0.74, r = -0.78 p < 0.05) showed a significant correlation for intra-observer inter-image repeated measurements. For inter-observer intra-image measurements, a significant correlation was present for average cup/disc ratio (r = -0.64, p = 0.043). Our data show that bidimensional semiquantitative parameters in use for optic nerve head assessment, analyzed by computerized stereovideography, have an intrinsic measurement variability. The variability is significantly related to the value of the measured parameter only when their reference points are determined manually by the operator.

Adult↗
PubMed1994

Excimer laser photoablative filtration surgery: histology and ultrastructure in 4 human cadaver eyes.

The purpose of this study was to verify the feasibility of ab externo layer-by-layer excimer laser photoablative removal of limbal tissue down to the trabecular meshwork and to assess the damage caused by this procedure to the neighbouring structures. Excimer laser photoablation (193 nm) can remove layers of corneal tissue effectively with little or no damage to the adjacent areas. Previous experimental studies have demonstrated a decrease in outflow resistance after ab-externo photoablative removal of juxtacanalicular tissue. We have performed ab-externo photoablative removal of limbal tissue overlying the trabecular meshwork in four freshly enucleated eyes from our Eye Bank. The beam of an excimer laser (wavelength 193 nm; fluence 180 mJ/Sq.cm) was shaped using a metal mask with a rectangular opening of 1.2 x 2.5 mm. After removing the conjunctiva, photoablation was carried out at maximum surgical microscope magnification (40 x) until trabecular meshwork appeared at the bottom of the crater. Light microscopy showed that craters had smooth walls and their base reached the Schlemm's canal area; all structures appeared of normal morphology. Transmission electron microscopy showed a thin layer of amorphous material or pseudomembrane on the side walls of the crater; corneoscleral collagen fibers were abruptly interrupted and undistorted. At the bottom of the crater the trabecular meshwork and Schlemm's canal tissues appeared normal.

Aged↗
PubMed1992

Photoablative filtration surgery with the excimer laser for primary open-angle glaucoma: a pilot study.

We have performed ab-externo photoablative filtration surgery on 19 patients affected by uncontrolled primary open-angle glaucoma. All cases had wide open angles, were previously treated with argon laser trabeculoplasty and were considered good candidates for trabeculectomy. After topical and peribulbar anesthesia, a limbus-based conjunctival flap was dissected. Photoablation of a rectangular area at the limbus was performed with an argon fluoride excimer laser (193 nm), at 180 mJ x sq cm fluence. The beam was shaped in the appropriate fashion using a custom-made metal mask. Photoablation was continued until aqueous appeared percolating through the juxtacanalicular tissue at the bottom of the crater; a water-tight closure of conjunctiva was then performed. Postoperatively, the anterior chamber reaction was minimal; in no case a flat chamber or choroidal detachment was observed. In 18 of the 19 cases the IOP was significantly lowered, and a filtering bleb developed. Mean preoperative IOP was 26.4 (+/- 7) mmHg. At a median follow-up of 9 months (range 4-15) the IOP is < or = 18 mmHg on no medications in 16 (84%) of the eyes, with a mean value of 13.3 (+/- 6) mmHg. Our short-term results support excimer laser photoablative filtration as a relatively safe and effective procedure for primary open-angle glaucoma.

Aged↗
PubMed1991

High expression levels of the "erythroid/brain" type glucose transporter (GLUT1) in the basal cells of human eye conjunctiva and oral mucosa reconstituted in culture.

The expression of the "erythroid/brain" type glucose transporter (GLUT1) seems to be a feature of "barrier" tissues, at least in humans. Recently, we reported that GLUT1 is highly expressed in the basal layers of either "authentic" human epidermis or human epidermis reconstituted in culture and that its expression seems to be related to keratinocyte differentiation. In this paper we demonstrate that GLUT1 is selectively expressed in the basal layers of either eye conjunctiva epithelia or oral mucosa, reconstituted in culture starting from 1-2 mm2 bioptic specimens of normal human tissue. GLUT1 mRNA and protein levels are very high in conjunctiva and oral mucosa, 2-3 times higher than in epidermis reconstituted in culture. Taking into account its localization at the border of tissues not directly vascularized, but metabolically active, GLUT1 could play an important role in controlling the entry of glucose into these firmly guarded tissues.

Blotting, Northern↗
PubMed1989

Neodymium-YAG laser goniotomy vs surgical goniotomy. A preliminary study in paired eyes.

Goniotomy and trabeculotomy are two widely accepted modalities of treatment for primary congenital/infantile glaucoma. Both procedures may be associated with complications. We treated 10 patients with bilateral, symmetrical congenital/infantile glaucoma and clear corneas. One eye of each patient underwent surgical goniotomy under general anesthesia, and the other was treated by neodymium-YAG laser goniotomy under oral chloral hydrate sedation (average energy, 76.6 mJ). Mean pretreatment intraocular pressure in the surgical goniotomy group was 28.4 mm Hg and in the laser goniotomy group it was 29.5 mm Hg, decreasing to 23.6 and 23.1 mm Hg, respectively, following treatment. There was a strong positive correlation (r = .81) between the percent of intraocular pressure change after laser treatment (mean, -14.4%) and that after surgery (mean, -14.3%). Our preliminary results indicate that neodymium-YAG laser goniotomy is an effective, noninvasive alternative to surgical goniotomy.

Female↗