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Biomedical subjects

N Orzalesi

Publications and source records attributed to N Orzalesi.

At least 37 records · Page 2Linked to original sources
PubMed1998

Experimental short-term tolerance to perfluorodecalin in the rabbit eye: a histopathological study.

PURPOSE: Perfluorocarbon liquids are largely used in vitreoretinal surgery, but their permanence into the eye is considered harmful and early withdrawal is routinely performed by most of the surgeons. We undertook this investigation to evaluate the effects of Perfluorodecalin (PFD) tamponade following vitrectomy in the rabbit eye. METHODS: Twenty-four rabbits underwent vitrectomy of the right eye according with a standard procedure. Eighteen rabbits received PFD and 6 control rabbits received Balanced Salt Solution (BSS) as vitreous substitute. The eyes were examined with light microscopy and transmission electron microscopy after two, four and six days after tamponade and thirty days after the withdrawal of PFD. RESULTS: The tamponade lasting four or more days caused irreversible retinal damage involving the photoreceptors and retinal pigment epithelium. Peculiar impressions were formed in the inner retina at the site of the gravitational effect of PFD droplets. CONCLUSIONS: Based on the results of this study we suggest that the tamponade with PFD lasting more than two days is detrimental to the retina, at least in the case of the rabbit. Damage seems to be related only to the high specific gravity of PFD.

Animals↗
PubMed1998

Molecular basis of open-angle glaucoma in Italy.

Glaucoma is a group of ocular diseases characterized by an optic neuropathy in which degeneration of retinal ganglion cells leads to a characteristic excavation of the optic nerve head. Primary open-angle glaucoma (POAG) can be subdivided into two groups according to age of onset:- 1. the more common middle- to late-age onset, chronic open-angle glaucoma (COAG) diagnosed after the age of 40 years; 2. the rarer juvenile open-angle glaucoma (JOAG), which is diagnosed between the age of 3 years and early adulthood. Recently, the gene coding for the trabecular meshwork-induced glucocorticoid response protein (TIGR), located in chromosome 1 (1q23-25), was found mutated in patients affected by POAG. In this work we describe the clinical and molecular genetic features of several Italian families affected by autosomal dominant POAG, collected in various regions of Italy.

Adult↗
PubMed1998

A common beta ig-h3 gene mutation (delta f540) in a large cohort of Sardinian Reis Bücklers corneal dystrophy patients. Mutations in brief no. 180. Online.

Reis-Bücklers' corneal dystrophy (RBCD) is a relatively rare autosomal dominant disease originating in the Bowman's membrane, which causes severe visual impairment. Recently RBCD, together with lattice corneal dystrophy type I (LCDI), granular corneal dystrophy (CDGG1) and Avellino stromal dystrophy (ASD), all mapped on 5q31, were found to be associated to four different mutations in the beta ig-h3 gene which codify for kerato-epithelin. We identified several cases of RBCD in Sardinia. We reconstructed through genealogical search two eight generation-families, originating from the same village (Arbus), indicating a common ancestor for RBCD in Sardinia. Linkage studies on these families confirmed the association of the disease with the 5q31 region. Sequence analysis of beta ig-h3 gene revealed a trinucleotide deletion in exon 12, corresponding to the loss of F540 in the protein sequence (delta F540). Our data describe a new mutation in the beta ig-h3 gene causing RBCD. This dominant negative mutation is located in the fourth internal repeat of kerato-epithelin which is a protein domain highly conserved across species. This suggests the basic role of this domain in maintaining the proper kerato-epithelin structure which when altered can cause the typical precipitates in the RBCD cornea.

Chromosomes, Human, Pair 5↗
PubMed1997

Efficacy and safety of combined diclofenac 0.1% and gentamicin 0.3% eyedrops after phacoemulsification.

PURPOSE: To study the efficacy of combined diclofenac 0.1% and gentamicin 0.3% (Digen) eyedrops to treat postoperative inflammation and prevent ocular infection in eyes having phacoemulsification. SETTING: Department of Ophthalmology, University of Milan, San Paolo Hospital, Milan; Eye Clinic, University of Verona; and Department of Ophthalmology, University of Palermo, Italy. METHODS: This double-masked, randomized, clinical trial comprised 90 patients; 45 received Digen and 45, gentamicin 0.3% eyedrops. The main outcome measure of the study was the reduction in signs and symptoms of inflammation, graded on a four-point scale. Also assessed were the presence of bacteria in the conjunctival swab and the proportion of patients requiring additional medication. RESULTS: Digen was more effective in reducing postoperative inflammation than gentamicin alone (P < .01). No statistically significant between-group difference was found regarding antibacterial activity. Both treatments were well tolerated throughout the study. CONCLUSION: Digen seemed to maintain the properties and activities of each individual drug, making it a promising treatment for reducing inflammation after phacoemulsification.

Administration, Topical↗
PubMed1997

Temporal corneal phacoemulsification combined with separate-incision superior trabeculectomy vs standard phacotrabeculectomy. A comparative study.

The aim of the study was to compare functional and refractive outcome after temporal approach phacoemulsification combined with superior trabeculectomy against that of standard superior phacotrabeculectomy in patients affected by cataract and uncontrolled glaucoma. Fifty patients undergoing combined surgery were randomly allocated to receive either a standard superior phacotrabeculectomy (group A) or a temporal via clear cornea phacoemulsification combined with a separate superior trabeculectomy (group B). Short-term and long-term mean IOP reductions were similar in the two groups though, at 2 years, more patients in the standard phacotrabeculectomy group had need of medical therapy to control their ocular pressure (p = 0.04). Group B had less surgically induced astigmatism than group A (p = 0.05). There was no significant difference in ocular inflammation and complication rates between the 2 groups.

Adult↗
PubMed1996

Effectiveness of diclofenac eyedrops in reducing inflammation and the incidence of cystoid macular edema after cataract surgery.

PURPOSE: To evaluate the effectiveness of diclofenac eyedrops in reducing inflammation and the incidence of angiographic cystoid macular edema (CME) after cataract surgery and intraocular lens (IOL) implantation. SETTING: Eye Clinic, Institute of Biomedical Sciences, San Paolo Hospital, Milan, Italy. METHODS: Eighty-eight patients having cataract extraction were enrolled in a randomized clinical trial: 42 were given diclofenac eyedrops and 46, placebo. Postoperative inflammation in both groups was graded for 6 months using a dedicated system. RESULTS: Eight patients (9%) had evidence of angiographic CME approximately 1 month after surgery: seven of these were in the placebo group (P = .039). This difference was not significant 3 and 6 months postoperatively. The signs of ocular inflammation were greater in the eyes receiving placebo; the difference was particularly evident up to 1 week after surgery. There was no significant difference in visual acuity between the two groups at any follow-up point, but the contrast sensitivity of the eyes that received diclofenac improved significantly at 10.5 cycles per degree 1 month postoperatively. CONCLUSION: Diclofenac eyedrops effectively reduced ocular inflammation and the occurrence of angiographic CME after cataract surgery.

Administration, Topical↗
PubMed1996

Correlation between the progression of optic disc and visual field changes in glaucoma.

Visual field test and optic disc evaluation are the standard examination techniques used to detect the onset and progression of glaucoma. This explorative study was performed to assess the temporal correlation between visual field and optic disc changes in eyes with ocular hypertension and well-established glaucoma. Eighty-six hypertensive and 16 glaucomatous eyes were followed up for a period of up to 9 years (average 4.4 yrs) using kinetic and computerized static perimetry and optic disc manual morphometry. Perimetric changes were based on a series of strict criteria and optic disc changes were based as a reduction in the baseline rim area/disc area ratio (R/D) measurement exceeding the 99% confidence interval for intraobserver reproducibility (7.7%). Optic disc changes were found prior to visual field changes in four hypertensive eyes, whereas visual field changes were found prior to disc changes in six glaucomatous eyes (p = 0.042). The results of our explorative study suggest that quantitative optic disc analysis may be more sensitive than visual field examination in detecting early glaucomatous changes, whereas visual field examination may be more sensitive than quantitative optic disc analysis in detecting glaucomatous progressions in eyes with well established glaucoma.

Aged↗
PubMed1994

Reproducibility of retinal nerve fiber layer evaluation by dynamics scanning laser ophthalmoscopy.

Scanning laser ophthalmoscopy is a laser-based image acquisition technique, which greatly improves the quality of the examination of the fundus and the retinal nerve fiber layer. To assess retinal nerve fiber layer imaging by scanning laser ophthalmoscopy and evaluate intra- and interobserver reproducibility in the classification of retinal nerve fiber layer defects, three independent observers evaluated on two separate occasions the videotaped images of 150 eyes of 80 consecutive patients with ocular hypertension or glaucoma. Ophthalmoscopy was performed using argon blue light (488 nm), confocal apertures of 3 to 1 mm, and 40-degree and 20-degree field angles. Of 150 eyes, 20 (13.3%) were excluded from the study because of the poor quality of the images (clinically significant cataract or myopic peripapillary atrophy). The retinal nerve fiber layer was evaluated qualitatively according to a standard classification: normal pattern, slit, wedge, and diffuse defects. Intraobserver reproducibility, evaluated by kappa statistic, was excellent (> or = 0.75): observer A = 0.78 (95% confidence limits, 0.67-0.88); observer B = 0.84 (95% confidence limits, 0.72-0.96); and observer C = 0.79 (95% confidence limits, 0.67-0.91). Interobserver reproducibility was also excellent in all cases: observers A-B = 0.84 (95% confidence limits, 0.71-0.98); observers A-C = 0.76 (95% confidence limits, 0.65-0.87); and observers B-C = 0.80 (95% confidence limits, 0.69-0.92). Kappa values ranged between 0.59 and 0.69 for intraobserver reproducibility and between 0.55 and 0.69 for interobserver reproducibility when using only those eyes in which abnormalities were noted by at least one observer.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Arteriovenous crossing as a risk factor in branch retinal vein occlusion.

To evaluate the importance of the position of the artery anterior to the vein in the arteriovenous crossing to the pathogenesis of first- and second-order branch retinal vein occlusion, we studied the fluorescein angiograms of 65 patients with branch retinal vein occlusion (65 eyes). The corresponding crossing in the opposite arcade (superior or inferior) served as the control. In a statistically significant percentage of crossings, the arteries were anterior to the veins in second-order branches (odds ratio, 6.66; 95% confidence interval, 1.98 to 32.33; chi 2, 12.56; P = .000394). However, their position was not found to be important in the pathogenesis of first-order occlusions (odds ratio, 1.3; 95% confidence interval, 0.23 to 9.01; chi 2, 0.14; P = .708281). These results suggest that some differences may exist in the risk factors for branch retinal vein occlusion depending on the site of the occlusion.

Adult↗
PubMed1994

The efficacy of the combination of l-moprolol and dipivefrin in reducing the intraocular pressure in primary open-angle glaucoma or in ocular hypertension.

BACKGROUND: In this double-blind prospective trial the efficacy of lowering the intraocular pressure of l-moprolol given alone and in combination with dipivefrin was tested. METHODS: Twenty-seven patients with primary open-angle glaucoma or ocular hypertension were randomly assigned to receive twice-daily l-moprolol eye drops or dipivefrin eye drops for 4 weeks; in a second phase of the trial, the combination of the two drugs was administered for 4 weeks. RESULTS: The results of this study indicated that l-moprolol and dipivefrin had an equivalent effect in lowering the intraocular pressure. The association of the two drugs caused a further reduction of intraocular pressure which was significant only in the group previously treated with dipivefrin alone. CONCLUSION: This trial demonstrated that the combination of l-moprolol and dipivefrin is an effective and safe treatment for elevated intraocular pressure.

Adrenergic beta-Antagonists↗
PubMed1994

Performance of diffractive multifocal intraocular lenses in extracapsular cataract surgery.

In a prospective, randomized clinical trial, 42 patients received a monofocal intraocular lens and 38 a multifocal lens after extracapsular cataract extraction. Patients were examined three, six, and 12 months after surgery. Uncorrected visual acuity was 20/40 or better in 57% of monofocal and 58% of multifocal patients; 12% and 52% had near uncorrected visual acuity of J1 to J2, respectively. Best corrected visual acuities were not significantly different. Forty-eight percent of the multifocal and 8% of the monofocal group did not require spectacle correction. On a patient satisfaction questionnaire, 60% of all patients reported discomfort when using spectacles for near vision. Patients in the multifocal group were more satisfied with their near vision than those in the monofocal group. The difference in satisfaction was not significantly different although more multifocal patients reported visual phenomena (e.g., glare, halos). Mean contrast sensitivity for the monofocal group and the multifocal group was 1.73 and 1.70, respectively. At low contrast sensitivities, the difference was not significant although the monofocal patients scored better.

Aged↗
PubMed1994

Relationship between morphometric optic disc parameters, sex and axial length.

Optic disc correlations were evaluated in normal eyes by means of computer-aided morphometry. Two hundred and thirty-five subjects (144 women and 91 men) entered the study. One eye per patient was randomly chosen for statistical analysis. Disc area (P < 0.05) and axial length (P < 0.0001) were statistically different between sexes. There was a correlation between axial length and both disc area (r for females = 0.55, P < 0.00001; r for males = 0.35, P < 0.0007) and refraction (r for females = 0.40, P < 0.00001; r for males = 0.50, P < 0.00001). The main findings of this investigation were that disc area is greater in male than in female eyes (thus clinically confirming the Ishi's and Quigley's previous observations of autopsy eyes) on the basis of axial length difference between the two sexes, and that disc size correlated with axial length. Disagreements in disc measurements reported in previous studies may be caused by differences in the male/female ratios of their samples.

Adult↗
PubMed1994

Risk factors for cortical, nuclear, posterior subcapsular and mixed cataract: a case-control study.

A case-control study was conducted to evaluate risk factors for cortical, nuclear, posterior subcapsular and mixed cataract. The 385 cases and 215 controls (age range 40-75 yrs) included in the study underwent a complete ophthalmological examination and laboratory blood tests, and were interviewed about behavioral variables, environmental exposure and their medical history. Lens opacity was classified using the 'Lens Opacity Classification System II' (LOCS II). On multivariate analysis, the risk factors for cortical cataract were the presence of diabetes for more than five years (OR = 3.7) and increased serum K+ and Na+ levels. A history of surgery under general anesthesia and the use of sedative drugs were associated with reduced risk (OR = 0.4). Posterior subcapsular cataract was associated with the use of steroids (OR = 18.2) and diabetes (OR = 8.1), and nuclear cataract with calcitonin (OR = 5.7) and milk intake (OR = 0.25). Mixed cataract was associated with a history of surgery under general anesthesia (OR = 0.5). Some of these results are consistent with the findings of similar studies performed in different geographical areas, others are not. The results suggest a possible role of electrolyte imbalance in the development of senile cataract.

Adult↗
PubMed1994

Subretinal neovascularization after naphthalene damage to the rabbit retina.

PURPOSE: To examine the retinotoxic effect of naphthalene, a powerful oxidative agent and a well-known cataractogenic agent. METHODS: A 10% solution of naphthalene dissolved in paraffin oil was given every other day by gavage to 31 pigmented rabbits for 5 weeks, at a dose of 1 g/kg body weight. Four rabbits who received only paraffin oil served as controls. The eyes were clinically followed up by means of ophthalmoscopy and retinal fluorangiography. At selected intervals, the eyes were examined with light microscopy and transmission electron microscopy. RESULTS: The first lesions were focal and appeared in the periphery of the fundus about 3 weeks after the beginning of treatment and tended to spread over the entire retina. Histologically, there was a degeneration of photoreceptors, accompanied by a reaction and proliferation of retinal pigment epithelium (RPE) that phagocytized the damaged visual cells. After about 3 months, the proliferation of RPE was followed by subretinal neovascularization (SRN). Both mature fenestrated and thick-walled non-fenestrated capillaries penetrated Bruch's membrane, enveloped by abundant fibrous extracellular matrix and accompanied by pericytes. As a consequence of this process, the retina was focally transformed into a "neovascular complex" in which a vascular plexus was intermingled with pseudo-acinar cavities lined by RPE. There were no signs of SRN at retinal fluorangiography, possibly because of the dense microenvironment of extracellular matrix and RPE cells of the neovascular complexes. CONCLUSIONS: Naphthalene degeneration of the rabbit retina appears to be a simple model of photoreceptor vulnerability in the first stages of SRN thereafter. The close chronologic and topographic relationship between the appearance of the anomalous vessels and RPE alteration and the close resemblance with previous models of experimental SRN may support the hypothesis of an experimental model of SRN triggered by the RPE.

Animals↗
PubMed1993

Is proper methodology associated with the use of a clinically relevant outcome measure? The case of randomized clinical trials on medical treatment of open-angle glaucoma.

OBJECTIVE: The aim of this study was to assess critically the published literature concerning medical treatment of primary open-angle glaucoma (POAG), and to see whether trial methodologic quality was related to a clinically relevant outcome measure. METHODS: We identified and reviewed the methodologic quality of 102 published randomized clinical trials (RCTs) on treatment of POAG using an explicit protocol and explored the association between selected aspects of design and conduct and the studies' clinical relevance. RESULTS: Our analysis revealed serious methodologic problems with the trials reviewed. Areas of major concern were: use of unsatisfactory or unspecified methods of randomization (89% of the trials reported no information), exclusion of some patients from the analysis (53% of the studies), failure to provide evidence of having estimated the number of patients needed to detect a prespecified treatment difference (96% failed to provide such an estimate), and incomplete description of patient characteristics (in 39% of the RCTs information on this item was insufficient). Within this generally unsatisfactory picture we found, however, that those studies adopting a double-masked design and those not excluding patients after randomization followed patients for longer periods of time and assessed treatment effectiveness using a clinically relevant outcome (that is, visual field changes) compared to other studies. CONCLUSIONS: For clinicians to make use of the results of clinical trials, future studies must be adequately designed and conducted. In particular, proper method of randomization, masking of the observers, and inclusion of all randomized patients in the analysis must be used. Of perhaps even greater importance is the need for trials to measure clinically relevant outcomes.

Clinical Protocols↗
PubMed1993

Randomized clinical trials on medical treatment of glaucoma. Are they appropriate to guide clinical practice?

A systematic quantitative and qualitative overview of published randomized clinical trials was undertaken to assess the yield of medical treatment on the outcome of patients with primary open angle glaucoma. Reports of 102 randomized clinical trials were published between 1975 and 1991, totalling about 5000 patients. Only 16% (16/102) of the trials were, however, properly designed (ie, comparing an active treatment with a placebo-treated or untreated control group) to answer the question of whether any medical treatment can effectively cure patients with primary open angle glaucoma. Pooled analysis showed a moderate yet statistically significant reduction in mean intraocular pressure (-4.9 mm Hg; 95% confidence interval [CI], -7.3 to -2.5 mm Hg); however, data on long-term visual field changes were available in only three randomized clinical trials, and their statistical combination failed to show a significant protective effect of active treatment (odds ratio, 0.75; 95% CI, 0.42 to 1.35). All of the remaining 86 randomized clinical trials looked at the effectiveness of one drug vs another in lowering intraocular pressure and were thus of no use in the overview. Practicing ophthalmologists should be aware that the effectiveness of pressure-lowering agents in the treatment of primary open angle glaucoma is still to be determined and that the vast majority of published trials are not appropriate to guide clinical practice. It is urgent to plan trials with end-point and follow-up duration that is fully relevant for the health of patients.

Clinical Protocols↗