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Biomedical subjects

L Mastropasqua

Publications and source records attributed to L Mastropasqua.

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

Intraocular pressure changes after phacoemulsification and foldable silicone lens implantation using Healon GV.

The authors studied the intraocular pressure (IOP) changes after phacoemulsification with two different kinds of foldable silicone lens implantation using Healon GV as viscoelastic substance. One hundred patients undergoing cataract surgery were enrolled in this study. Inclusion criteria were: absence of ocular hypertension or glaucoma. Patients were randomly assigned to plate haptic (Silens PH, Domilens Chiron Vision, Lyon, France) or three-piece (CeeOntrade mark& ;920, Pharmacia spa, Milano, Italia) silicone intraocular lens (IOL) implantation. Following phacoemulsification and cortical aspiration, the capsular bag was reinflated with Healon GV. After foldable silicone IOL insertion residual Healon GV was removed from the anterior chamber. IOP was measured preoperatively and at 6, 24 h and 1 week postoperatively. Six hours postoperatively IOP was higher in the Silens PH group than in the CeeOn group (20. 85+/-5.42 vs. 18.88+/-2.95 mm Hg, p= 0.026). The difference was confirmed after 24 h (21.02+/-5.18 vs. 17.34+/-3.18 mm Hg, p < 0.01). Despite the medical treatment (acetazolamide 250 mg orally every 6 h), at the 24-hour control 2 eyes with plate haptic silicone lens showed IOP values higher than 30 mm Hg. Slitlamp examination showed in both eyes a shallowing of the anterior chamber together with the evidence of capsular bag hyperdistension and capsular block resulting from the occlusion of the circular anterior capsule opening by the plate haptic IOL. Residual Healon GV removal from the anterior chamber was performed. At 1-week control both eyes showed normalization of IOP. The use of a plate haptic silicone lens may be associated with a more consistent retention of Healon GV in the eye with trapping in the capsular bag. Retained viscoelastic may cause either trabecular meshwork blockage by viscoelastic substance or postoperative capsular bag hyperdistension, anteroplacement of the IOL optic and capsular block from occlusion of the circular anterior opening by the IOL optic.

Aged↗
PubMed1998

Echobiometry of the ocular layers at the posterior pole.

The thickness of the retina, choroid and sclera in relation to macular oedema (ME) can be measured using A scan echography. Ninety diabetic patients (180 eyes) divided into two groups with and without ME, respectively, were studied compared to a third group of 73 healthy controls (146 eyes). Statistical analysis of results showed good specificity (80%) and reasonable sensitivity (70%) of the echographic method in showing the presence of ME confirmed by fluorescein angiography.

Adult↗
PubMed1998

Blue-on-yellow and achromatic perimetry in diabetic children without retinopathy.

OBJECTIVE: We compared blue-on-yellow perimetry with achromatic perimetry to determine whether the first was more sensitive in detecting visual field defects. RESEARCH DESIGN AND METHODS: We studied 50 children and adolescents (22 male, 28 female) with IDDM, ranging in age from 10.1 to 16.3 years (mean 13.3+/-2.1 years), with a disease duration of 5.2-10.0 years (mean 7.1+/-1.9 years). Patients were divided into subgroups according to the presence of persistent microalbuminuria. No one had signs of diabetic retinopathy when studied with fluorescein angiography. RESULTS: By achromatic perimetry, the analysis of subareas of the central 30 degrees of the visual field (0-9 degrees; 10-18 degrees; out of 18 degrees) showed no differences between diabetic subgroups in the central 18 degrees of the visual field, while a significant difference between the same subgroups was found outside the 18 degrees of the 24-2 program of the Humphrey perimeter (P = 0.027). By blue-on-yellow perimetry, in all three of the perimetric subareas evaluated, the sensitivity was lower in microalbuminuric patients than in normoalbuminuric ones. The differential sensitivity between the perimetric tests performed with blue-on-yellow and with achromatic stimuli showed statistically significant data, with a higher level of significance in the central 18 degrees (P < 0.0001) than outside the 18 degrees (P = 0.033). CONCLUSIONS: Our study suggests that blue-on-yellow perimetry is more useful and more sensitive than achromatic perimetry in the detection of preclinical visual field defects in diabetic children with microalbuminuria but without clinically detectable retinopathy.

Adolescent↗
PubMed1998

Relationship between contrast sensitivity and metabolic control in diabetics with and without retinopathy.

Contrast sensitivity was studied in diabetic adolescents and young adults with and without retinopathy in order to evaluate their central vision, to analyze the relationship of metabolic control to the presence and severity of retinopathy, and to re-evaluate the response to this test after a significant improvement in metabolic control. Twenty adolescent and young adult diabetics without retinopathy and 40 diabetics with retinopathy of varying degree were enrolled in the study; 20 healthy age and sex-matched subjects served as controls. Contrast sensitivity was assessed with a CSV-1000 contrast testing instrument, testing for four spatial frequencies, 3, 6, 12 and 18 cycles per degree (cpd). Diabetics with no retinopathy showed a weak but significant difference at 18 cpd compared with controls (P = 0.04), while diabetics with background retinopathy showed a significant reduction of contrast sensitivity at 12 and 18 cpd when compared with controls (P < 0.001). In patients with preproliferative/proliferative retinopathy a highly significant reduction of contrast sensitivity at all frequencies was found compared with controls. Furthermore, these patients had a significantly lower mean contrast sensitivity than patients without retinopathy. The patients were re-evaluated after a significant amelioration of metabolic control. An improvement in contrast sensitivity was found in diabetics without retinopathy and with background retinopathy, while there was no change observed in diabetics with severe retinopathy. These results show that diabetic adolescents and young adults with and without signs of retinopathy observed by fluorescein angiography have a reduced contrast sensitivity, which is more severe in patients with preproliferative/proliferative retinopathy. A significant amelioration of metabolic control is associated with an improvement of contrast sensitivity in all patients with the exception of those patients who had signs of preproliferative/proliferative retinopathy observed by fluorescein angiography. In summary, this longitudinal study provides the first evidence that reduced contrast sensitivity is reversible in diabetics with or without background retinopathy only.

Adolescent↗
PubMed1998

Ultrastructural changes in rat cornea after prolonged hypobaric hypoxia.

A study was performed to evaluate the effect of prolonged environmental hypobaric hypoxia on the ultrastructure of rat cornea. 60-day-old female Wistar rats were exposed to a simulated altitude of 5,500 m (350 mmHg) and pO2 of 76 mmHg for 30 days. Control rats were exposed to atmospheric sea level pressure (760 mmHg) and pO2 of 150 mmHg, for the same period. Ultrastructural analysis of the corneal epithelium did not reveal any relevant difference between control and treated rats. In contrast, the corneal stroma of rats subjected to hypoxia showed vascularization with advanced vessel differentiation and signs of active proliferation. The endothelium of hypoxic cornea showed swollen mitochondria and large empty cytoplasmic areas. The endothelial intercellular junctions could hardly be identified in the hypoxic condition. Nevertheless, the most evident change in hypoxic cornea was in Descemet's membrane, which was considerably thickened, to approximately twice that of the control specimen. These results suggest that environmental hypobaric hypoxia induces marked alterations in the corneal stroma and endothelium morphology, probably related to reduced oxygen tension in the aqueous humor, consequent to hypoxemia.

Animals↗
PubMed1997

Ocular hypotensive effect of topical ketanserin in timolol users.

BACKGROUND: Ketanserin is a specific antagonist of 5-HT2 and 5-HT1c receptors. These receptors are linked to the stimulation of phosphoinositide metabolism and are involved in IOP controls. Orally and topically administered ketanserin reduces IOP in normotensive and glaucomatous eyes. METHODS: Ketanserin 0.5% eye drops were administered to 20 patients with primary open-angle glaucoma in a randomised, crossover, double-masked fashion to evaluate the effect of ketanserin in glaucomatous patients already receiving timolol who did not have controlled IOP (> 21 mmHg). Mean and range of IOP curve (8.00 a.m.-8.00 p.m.), pupil diameter, Schirmer I, basal secretion test and BUT values were recorded at baseline and after 2 weeks of topical administration of ketanserin or placebo twice daily. The alternative treatment was given 2 weeks later and the same protocol was repeated. RESULTS: When patients received placebo no significant variations were found in the analysed parameters. Ketanserin significantly reduced mean IOP (19.5%) and was effective for up to 12 h without inducing variations of tear secretion or pupil diameter. No systemic side effects were observed, and no significant variations in ocular symptoms and signs were reported. CONCLUSION: These results indicate that topical administration of ketanserin may be useful to reduce IOP in patients not controlled with beta-blockers.

Administration, Topical↗
PubMed1997

Heparin eyedrops to prevent posterior capsule opacification.

PURPOSE: To evaluate whether heparin eyedrops prevent or reduce posterior capsule opacification (PCO) after extracapsular cataract extraction (ECCE) with intraocular lens (IOL) implantation. SETTING: Institute of Ophthalmology, University G. d'Annunzio, Chieti, Italy. METHODS: This 4 year, prospective, case-controlled study evaluated 200 patients who had ECCE and implantation of the same type of posterior chamber IOL. Patients were randomly assigned to receive topical heparin eyedrops postoperatively (heparin group, n = 100) or not to receive the eyedrops (control group, n = 100). Postoperative cell response, cellular precipitates on the IOL, and presence of PCO were evaluated. RESULTS: There were no significant differences between groups in postoperative inflammation. The incidence of cellular precipitates was significantly lower in the heparin group than in the control group (P < .001). A neodymium:YAG (Nd:YAG) posterior capsulotomy was done in 7 patients in the heparin group and 14 in the control group (P = .15). During the first 24 months after surgery, the heparin group had a significantly lower incidence of Nd:YAG capsulotomy (P < .05) and fibrotic PCO (P = .02). CONCLUSION: Topical heparin eyedrops were effective in reducing fibrotic PCO in the long term, indicating their usefulness in the postoperative management of ECCE.

Administration, Topical↗
PubMed1997

Lipids and lipoproteins in diabetic adolescents and young adults with retinopathy.

PURPOSE: To compare serum concentrations of lipoproteins and apolipoproteins in insulin-dependent diabetic patients with and without retinopathy. METHODS: A cross-sectional study was performed on 42 diabetic adolescents and young adults with different degrees of retinopathy. The mean +/- SD age of the patient was 21.1 years (range 12.8-27.9 years); their mean duration of diabetes was 12.3 years (range 7.1-19.9 years). Their glycosylated haemoglobin (HbA1c) and fructosamine were respectively 10.2% (8.2-15.4%) and 280.8 mumol/l (202.1-458.5 mumol/l). Forty-two diabetics without retinopathy similar to the study population as regards age, sex, duration of disease, HbA1c and microalbuminuria values, and 42 healthy subjects, served as controls. RESULTS: Serum lipid and lipoprotein concentrations were not different from those of healthy controls in patients either with or without retinopathy. The diabetic patients were subdivided in two groups according to the degree of their retinopathy: background and preproliferative/proliferative retinopathy. Patients with preproliferative/proliferative retinopathy were found to have significantly higher lipoprotein (a) values than the other group (background, 73.3 IU/l; preproliferative/proliferative, 205.9 IU/l; p < 0.001). CONCLUSION: The increase in lipoprotein (a) levels might play a role in the development of severe retinopathy.

Adolescent↗
PubMed1997

Polycyclic aromatic hydrocarbons in bovine lens.

A study was performed to detect the presence of polycyclic aromatic hydrocarbons (PAHs) in bovine eyes. Twenty fresh bovine eyes were used to detect the presence of PAHs in lens, vitreous and aqueous by HPLC and spectrofluorometer. In lenticular tissue the mean amount of PAHs was 0.0271 microgram/g and the mean level of PAH in each lens was 0.059 microgram. Five types of PAHs (pyrene, fluoranthene, triphenylene, 1.2-benzanthracene and chrysene) were found in the lenses but none in vitreous and aqueous. These data indicate that PAHs are present only in the lens of the bovine eye. The source of these substances in mammalian clear lens is unclear.

Animals↗
PubMed1997

Flicker perimetry in diabetic children without retinopathy.

OBJECTIVE: To determine the flicker fusion frequency in children and adolescents with insulin-dependent diabetes mellitus (IDDM) who did not have fluorescein angiographic signs of retinopathy. DESIGN: Cross-sectional study. SETTING: Antidiabetic Centre, departments of Ophthalmology and Pediatrics, University of Chieti, Chieti, Italy. PATIENTS: Forty-five patients aged 9 to 18 years with IDDM without fluorescein angiographic signs of retinopathy. Forty-five healthy subjects matched for sex and age constituted the control group. The patients were classified into two subgroups according to their metabolic control: good (percentage hemoglobin Alc 9% or less) or poor (percentage hemoglobin Alc greater than 9%). OUTCOME MEASURES: Retinal flicker fusion frequency, evaluated with an automated flicker perimeter in the central 30 degrees of the visual field. RESULTS: The subjects with poor metabolic control had a significantly lower mean flicker fusion frequency than the control subjects (27.43 Hz [standard deviation (SD) 5.16 Hz] vs. 38.72 Hz [SD 4.27 Hz]) and the patients with good metabolic control (33.94 Hz [SD 5.54 Hz]) (p < 0.001). There was a significant relation between flicker fusion frequency and the percentage of hemoglobin Alc (r = -0.533, p < 0.001). CONCLUSIONS: Our results show that children with poorly controlled IDDM without fluorescein angiographic signs of retinopathy have an impairment of retinal flicker sensitivity in the central 30 degrees of the central visual field and that this impairment is related to the degree of metabolic control. Flicker perimetry is a simple, noninvasive tool that may be useful to evaluate the eye function of diabetic children.

Adolescent↗
PubMed1996

Are VEP abnormalities in optic neuritis (ON) dependent on plaque size? A reappraisal of the physiopathology of ON based on improved MRI and multiple-lead recordings.

Twenty patients with optic neuritis (ON) described in the previous study [23] underwent serial VEP recordings (using multiple electrode arrays) for two years. The VEPs could be correlated with the lesions revealed by MRI, Visual Field tests and other clinical findings. On the basis of their scalp distribution, they were classified as "really delayed" VEPs and "pseudo-delayed" VEPs. Real delays could be recorded at the onset of ON or shortly afterwards, and their appearance indicated the recovery of visual function and a good prognosis. Pseudo-delays indicated an alteration in the visual field and, unless a breakthrough of normal or delayed components appeared in the first three months, following acute ON, indicate a poor prognosis for the recovery of visual function. The pseudo-delayed VEPs were mainly observed in patients with longer lesions revealed by means of LTE-STIR MRI [23]; there was no correlation between VEP latency and the length of plaques. Our findings contradict previous theories on the timing of conduction alterations in ON and multiple sclerosis.

Adult↗