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Biomedical subjects

L Bonomi

Publications and source records attributed to L Bonomi.

At least 55 records · Page 3Linked to original sources
PubMed1991

Erythrocyte and platelet fatty acids in retinitis pigmentosa.

The fatty acid composition and the glutathione-peroxidase activity (GSH-Px) of erythrocytes and platelets, the production of malondialdehyde (MDA) by platelets and the activity of the main systems of transmembrane cation transport in erythrocyte have been studied in 12 patients (5 males and 7 females) affected by retinitis pigmentosa (RP). A remarkable increase of saturated fatty acids (SFA), particularly of stearic acid (C18:0), has been noted in these patients. The reduced unsaturated/saturated fatty acids ratio (PUFA/SFA) observed in both erythrocytes and platelets and the decrease of arachidonic acid in platelets may depend by an active peroxidation process as documented by the increase of MDA. Platelet glutathione-peroxidase (PTL-GSH-PX) and plasma retinol were in the normal range, whereas erythrocyte glutathione-peroxidase (E-GSH-PX), MDA and plasma alfa-toco-pherol were increased in patients with RP. The activities of Na(+)-K+ pump, cotransport and Na(+)-Li+ countertransport were normal in RP erythrocytes.

Adult↗
PubMed1991

Ocular hypotensive activity of pirbuterol eye drops in rabbits.

The IOP-lowering effect of pirbuterol, a beta-2 adrenergic agonist, was studied in rabbits. In normotensive rabbits, pirbuterol 0.5% eye drops reduced IOP by 20-25%. In ocular hypertensive rabbits (by glucose 5% venous infusion), pirbuterol reduced IOP by 20% (0.1% concentration) to 40% (0.5% and 1% concentration). A slight decrease in the effect was noticed after seven days of treatment.

Administration, Topical↗
PubMed1990

Evaluation of the 701 interzeag lens opacity meter.

The Interzeag 701 Lens Opacity Meter was used to study the lenses of 122 cataract eyes and 73 healthy eyes with clear lenses. The readings taken separately in 67 eyes by two different operators did not significantly differ. Statistically significant differences were found between the readings taken by the same operator when the pupil size was different in all types of cataract and also in eyes with transparent lenses. Opacity Meter readings correlate well with the visual acuity of eyes with nuclear and mixed cataracts, but no correlation was found in eyes with cortical or posterior subcapsular cataracts. In healthy eyes with clear lens, a correlation was found between the instrument readings and age.

Adolescent↗
PubMed1989

Comparison of different screening methods for the detection of visual field defects in early glaucoma.

The effectiveness of three different automated perimetry strategies for the screening of glaucomatous visual field defects was studied on 182 eyes of glaucoma suspects. The results were compared with those obtained with the Octopus G1 program. On this particular sample of population the results are as follows. Henson perimeter: sensitivity 59.4%, specificity 88%. Humphrey perimeter (Armaly full field test): sensitivity 64.2%, specificity 64.2%. Perikon perimeter (Genoa glaucoma screening): sensitivity 55%, specificity 90.4%. Octopus perimeter (G1 program): sensitivity 92.1%, specificity 83%.

Glaucoma↗
PubMed1989

Effects of intraocular dapiprazole in the rabbit eye.

Dapiprazole produces miosis by blocking the alpha 1 receptors in the radial muscle of the iris; its intraocular effect has not yet been investigated. In this preliminary experimental animal study, we investigated the intracameral use of 0.2 ml of 0.005%, 0.0075%, 0.01%, and 0.05% dapiprazole to reverse mydriasis by 10% phenylephrine plus 0.5% tropicamide. With the 0.05% dapiprazole concentration, the values (mean +/- S.E.) of pupillary diameter were as follows: prior to the experiment, 5.3 +/- 0.31 mm; after mydriatics, 8.7 +/- 0.22 mm; after intraocular dapiprazole, 5.6 mm +/- 0.29. The results showed a dose-related miotic effect of dapiprazole. No difference in the toxicity parameters (inflammatory score, corneal thickness, endothelial cell counting, aqueous humor protein concentration, and intraocular pressure) was found between dapiprazole-treated eyes and saline-solution-treated eyes. Intraocular 0.01% and 0.05% dapiprazole is an effective miotic agent that may be helpful during surgery when the reversal of sympathomimetic mydriasis is needed.

Animals↗
PubMed1989

Effects of benzydamine eye drops on the rabbit's eye reaction to surgical, physical, and chemical stimuli.

The effects of benzydamine eye drops on the ocular reaction to different irritating stimuli in rabbits are reported. Benzydamine at the concentration of 0.1% reduces inflammatory tissue changes induced by AgNO3 burning of the cornea and inhibits the blood-aqueous barrier breakdown due to peripheral iridectomy or laser irradiation of the iris. Benzydamine reduces the aqueous PGE2 concentration to a similar extent as a 0.5% commercially available eye drop formulation of piroxicam. This result is in contrast with previous in vitro results demonstrating that benzydamine is devoid of any effects on PG synthesis. The possibility that PGE2 reduction is an indirect effect due to other biochemical activities of benzydamine is discussed. In the normal eye benzydamine manifests a local anaesthetic effect which is not accompanied by irritative changes in the anterior segment of the eye, changes in the intraocular pressure or pupillary size. It is suggested that in the clinical use of benzydamine eye drops the local anaesthetic activity may contribute to reducing both the neurogenic component of ocular inflammation and acute pain following injuries to the eye.

Anesthesia, Local↗
PubMed1988

[Study of color perception using a new color test and desaturated panel D 15 in normal subjects and diabetics].

The authors used two tests (the Lanthony's New Color Test and the desaturated Panel D 15 test) to evaluate color vision in 235 subjects (235 eyes) of which 80 normal and 155 diabetic (85 with background retinopathy and 70 without retinopathy, as demonstrated by fluorescein angiography). The diabetic patients with maculopathy or macular oedema, with mixed or proliferative retinopathy, or with any form of advanced degenerative retinopathy were excluded from this study. The New Color Test was performed in accordance with Lanthony's standardized method, applying only the separation phase (to quantifying the color perception defect, if any) in photopic illuminance conditions at 250 lux. The desaturated Panel D 15 (qualitative classification test) has been performed at illuminance of 500 lux. Both normal and diabetic subjects were divided into two age groups (below and above 45 years) and the discriminatory value of two tests has been assessed in relation to age, diabetes and background retinopathy. The New Color Test showed a highly significant difference between normal subjects and diabetics of comparable age with background retinopathy. There was also a highly significant difference between diabetics with and without retinopathy. On the other hand, the difference between normal subjects and diabetics without retinopathy proved significant in the below-45 age group and no-significant in the above-45 age group. The results obtained in the desaturated Panel D 15 test have been similar: below the 45 years of age all differences among the three subject groups proved significant, whereas in the above-45 age group no significant differences were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Prevention of surgically induced miosis by diclofenac eye drops.

In this investigation, a rabbit model was used to study the effectiveness of topical diclofenac sodium in the prevention of miosis induced by manipulation of the ocular structures. In untreated rabbit eyes, paracentesis of the anterior chamber induced a 25% narrowing of the pupil. In atropine-treated rabbit eyes, the absolute pupil diameters were larger, but the pupil still contracted, resulting in a postoperative diameter of 6.5 mm. Pretreatment with diclofenac 0.1% eye drops effectively inhibited paracentesis-induced miosis; the postoperative pupil narrowing amounted to only 9% of the original diameter in both untreated and atropine-treated eyes. With a combined topical application of atropine and diclofenac, the mean pupil diameters after paracentesis were as large as 8.7 mm. Diclofenac seems to be a promising drug for the maintenance of mydriasis during eye surgery.

Animals↗
PubMed1983

Intraocular-pressure-lowering effect of low-dosage combination of guanethidine and terbutaline in rabbit.

A low dosage combination of terbutaline plus guanethidine was applied topically to the eyes of rabbits with experimentally induced ocular hypertension, markedly lowering intraocular pressure. The effect of this combination is markedly greater than that produced separately by the two components at corresponding dosages and seems to be due to a true synergistic phenomenon. The low-dosage combination of terbutaline and guanethidine appears to be well tolerated, very potent and effective as a topical ocular hypotensive agent.

Animals↗
PubMed1982

Intraocular pressure in myopic anisometropia.

The authors studied the intraocular pressure, scleral rigidity and outflow facility of 137 anisometropic subjects with unilateral high myopia. The contralateral eyes were emmetropic, hyperopic or slightly myopic (less than 5 diopters). No difference was found between the intraocular pressure on the two sides. The scleral rigidity was lower and the outflow facility higher on the myopic side. It is concluded that high myopia is not, in itself, a cause of ocular hypertension, nor is caused by it.

Adolescent↗
PubMed1982

Effects of dapiprazole on pupillary size and intraocular pressure in rabbits.

The effects of 3-[2-[4-(2-methylphenyl)-1- piperazinyl]ethyl]-5,6,7,8-tetrahydro-1,2,4-triazolo[4,3-a]pyridine HCl (dapiprazole), a new drug with alpha-adrenergic blocking properties, on pupillary diameter and intraocular pressure have been studied in rabbits. Following i.v. administration, a reduction of intraocular pressure is observed at doses devoid of activity on pupillary diameter. Following topical application, a miotic and ocular hypertensive action was observed at the same doses; the hypotensive action is produced in both normal rabbits and in rabbits with water load- or corticosteroid-induced ocular hypertension. Contact lenses increase the duration of effects of dapiprazole. These results suggest a potential interest of dapiprazole in glaucoma, with particular reference to the topical treatment of angle-closure glaucoma.

Administration, Topical↗
PubMed1981

Ocular hypotensive action of labetalol in rabbit and human eyes.

The ocular hypotensive action of labetalol, a drug endowed with alpha- and beta-adrenergic receptor-blocking properties, was studied in both rabbit and human eyes. In the rabbit, using two different models of experimentally induced ocular hypertension, an impressive decrease of IOP was seen after topical administration of the drug. In this species labetalol was found to be at least as effective as timolol and more active than pilocarpine or propranolol. In human eyes suffering from glaucoma, however, its effectiveness was much less evident and clearly inferior to that of timolol.

Animals↗
PubMed1980

Effects of timolol maleate on tear flow in human eyes.

Lacrimal function was studied in 30 patients treated for glaucoma, with 0.25% timolol eye drops. Rose bengal and fluorescein staining disclosed punctate epithelial defects in 11 eyes after one week. During the following weeks there defects disappeared spontaneously in most eyes. Schirmer tests (I and II), tear lysozyme and pre-corneal film break-up time were significantly decreased by the treatment, while tear immunoglobulins were unimpaired. The authors conclude that topical timolol treatment decreases tear production. This effect is quantitatively limited and does not appear dangerous for normal eyes, although it may become so for eyes with an originally low lacrimal secretion.

Administration, Topical↗
PubMed1979

Comparison of the effects of nine beta-adrenergic blocking agents on intraocular pressure in rabbits.

The intraocular pressure lowering effects of nine beta-adrenergic receptor blocking agents were compared using two different models of experimental ocular hypertension in rabbits. All the nine drugs possess, to different extents, a clear pressure-lowering action after topical administration into the conjunctival sac. For potency and duration of action, the best results were obtained with timolol and sotalol. Pindolol, oxprenolol, practolol, and propranolol are also fairly potent while less impressive effects were produced by atenolol, butidrine, and metoprolol. With the exception of propranolol, all the drugs were well tolerated by the ocular tissues.

Adrenergic beta-Antagonists↗
PubMed1979

A critical analysis of the long-term results of trabeculectomy.

We analyzed the long-term results of trabeculectomy in a homogeneous group of 90 eyes (75 patients) followed up one to five years after surgery. The effect on intraocular pressure was considered stable after one year; complete success was achieved in 69 (71%) of cases with a further in 8 (9%) partial success in eight (9%). The pressure-lowering effect was closely related to the presence of a filtering bleb. The main complication was the late appearance of lens opacities, although these seemed less frequent than after other antiglaucoma operations. Lens opacities were particularly frequent in hypotonic eyes and may depend upon the process of aqueous humor filtration itself.

Adolescent↗
PubMed1978

Experimental corticosteroid ocular hypertension in the rabbit.

Weekly subconjunctival injections of 4mg repository betamethasone, repeated over three weeks, produced a sustained increase of intraocular pressure (IOP) in 96% of the treated rabbits. Treatment was generally well tolerated and important systemic toxic effects were present only in a few animals. The ocular hypertension so obtained was constant, well reproducible and sensitive to antiglaucoma drugs. The authors believe they have developed an animal model which is very suitable for testing the pressure-lowering effect of drugs and for other studies on ocular hypertension and glaucoma.

Animals↗