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Biomedical subjects

R Brancato

Publications and source records attributed to R Brancato.

At least 163 records · Page 9Linked to original sources
PubMed1989

Histopathology of diode and argon laser lesions in rabbit retina. A comparative study.

Argon lasers are the most frequently used laser source for retinal photocoagulation. These are expensive, bulky and low-efficiency devices. In contrast, diode semiconductor lasers have a number of characteristics that make them attractive for medical application: compact size, high electrical-to-optical efficiency, and long operating lifetime. Comparable irradiance lesions (about 120 Wcm2), ophthalmoscopically similar to those obtained therapeutically in humans, were obtained by a diode and an argon laser. Twenty-four hours after the treatment, a study of these lesions was made by light and electron microscopy. Argon irradiations resulted in damage to both the inner and the outer retinal layers, while the diode laser radiation produced damage to the outer retina and choroid. A sufficient diode laser light passed into the choroid to induce small vessel occlusions and/or edema. The histological characteristics of the lesions produced by the two lasers suggest the use of the diode lasers, as well as argon lasers, in the treatment of retinal and subretinal pathologies.

Animals↗
PubMed1989

Contact transscleral cyclophotocoagulation with Nd:YAG laser in uncontrolled glaucoma.

To evaluate the effectiveness of contact delivery systems, we treated 23 eyes with uncontrolled intraocular pressure using a continuous wave Nd:YAG laser delivered by a fiber optic. With the fiber's tip perpendicular to the surface of the conjunctiva, 1.5 mm from the corneal limbus, we applied 16 laser spots of 2 J/second energy. Patients were followed for at least 6 months (mean, 8.6 +/- 2.4 months). The mean pressure decreased from a pretreatment value of 43.7 mm Hg to a posttreatment value of 24.7 mm Hg (P = 0.000). A total of 66.6% of the treated eyes achieved a pressure on last follow-up visit of 25 mm Hg or less. Pain decreased in all the patients treated (P less than .005). Complications were minimal.

Evaluation Studies as Topic↗
PubMed1988

Dye laser photocoagulation of macular subretinal neovascularization in pathological myopia. A randomized study of three different wavelengths.

The authors present a randomized study of 27 eyes affected by pathological myopia with macular subretinal neovascularization which were treated with a tunable dye laser. The effectiveness of three different wavelengths (577, 590 and 620 nm) in the direct treatment of subretinal neovascularizations was evaluated in 3 groups of 9 patients each. Statistical analysis of both visual and anatomical results did not show significant differences among the three wavelengths used.

Adult↗
PubMed1988

Pneumoretinopexy in the treatment of retinal detachment with macular hole.

Nine eyes of nine patients affected by retinal detachment with macular hole were treated with pneumoretinopexy and postoperative positioning. All the eyes were myopic (mean 13.3 d., sd 3.3), two were amblyopic and one was aphakic. The operative technique included eye softening and intravitreal SF6 gas injection only. Barrage laser photocoagulation was carried out after retinal reattachment. In seven eyes (77.8%) the retina reattached in a mean of three days and the visual acuity improved. No recurrences were observed after a mean of 11.6 months. No severe complications occurred. Vitreous flare was present in 44% and increase of floaters in 55% of the eyes. We believe that pneumoretinopexy can be employed as the first treatment in case of myopic retinal detachment with macular hole.

Aged↗
PubMed1988

Retinal laser photocoagulation in diabetic patients causes prolactin, growth hormone and cortisol release.

Stress of many kinds (psychological, physical, metabolic) is able to induce endocrine modifications in humans, such as growth hormone (GH), prolactin (PRL), luteinizing hormone (LH), glucagon and cortisol release. Argon laser photocoagulation of the retina (RP), the treatment of choice for diabetic retinopathy, is a painful and stressful maneuvre and represents a direct injury onto a nervous tissue. Therefore it was decided to evaluate the possible endocrine modifications induced by RP in diabetic patients affected by retinopathy. In 19 insulin-dependent diabetic patients (12 men and 7 women), RP induced cortisol release in all cases, GH and PRL release in men, but not in women, and no modification of LH and glucagon plasma levels; in 12 similar patients receiving saline infusions without RP, no endocrine modifications were observed. It is concluded that RP elicits GH, PRL and cortisol release in diabetic patients.

Adult↗
PubMed1988

Complications of argon laser retinal buckling performed in myopic subjects presenting rhegmatogenous degenerations.

Twenty-two eyes of twenty-two patients suffering from retinal peripheral degenerations underwent preventive equatorial buckling with argon laser photocoagulation. The fellow eye was used as control. We evaluated the effects of laser photocoagulation on corneal sensitivity, on accommodation, on pupillary diameter and light reflex. In the postoperative period, up to the 3rd month, results were significant with respect to the control eye. The mechanisms to which the onset of these undesired alterations is due are discussed.

Accommodation, Ocular↗
PubMed1988

Enucleation after argon laser photocoagulation for choroidal melanoma.

We report the case of a choroidal melanoma 3 disc-diameter in size and 1 mm in thickness located superiorly at 2 disc-diameters from the optic disc. Argon laser photocoagulation was done in 1977. No recurrence was observed for eight years. In 1985, the melanoma suddenly reappeared, invading the posterior pole and causing secondary retinal detachment. The histologic examination after enucleation revealed a spindle-cell melanoma. Considering the fluorescein angiographic findings, we question the effectiveness of argon laser photocoagulation of choroidal melanoma.

Argon↗
PubMed1988

[Fluoroiridographic aspects of iridoschisis].

Iridoschisis is a rare condition of uncertain etiology characterized by a cleavage of the iris layers. We report four cases studied by fluorescein angiography to display possible occurrence of vascular abnormalities in the pathogenesis of the disease. Case 1: 80 year old woman with bilateral schisis of the peripheral iris, in the inferonasal quadrant in RE and inferotemporal in LE. A shallow anterior chamber was present in OU; IOP was 18 in RE and 15 in LE. No corneal abnormalities were present. Fluoroiridography showed a normal pattern filling of the iris vascularity, that was more visible in the schisis area. Case 2: 66 year old man with diabetes and open-angle glaucoma operated on for trabeculectomy five years previously. The examination showed a normal cornea, a shallow anterior chamber and miotic pupils for pilocarpine therapy. IOP was 12 in OU. The iridoschisis was present in RE in the lower sectors which were totally involved from the outer iris to the inner pupillary margin. Fluoroiridography indicated a normal vessel perfusion without any abnormality in the affected sectors. A slight bilateral pupillary dye leakage without any stromal diffusion was attributable to the patient's age. Case 3: 55 year old woman treated with miotics in RE for a glaucoma diagnosed after head trauma twenty years before, after which the vision in LE was reduced to 2/200 for post-traumatic optic nerve atrophy. No corneal abnormality was present. The anterior chamber was shallow and the ocular tension was 14 in RE and 10 in LE.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Eight-year follow-up of central serous chorioretinopathy with and without laser treatment.

A long-term retrospective study was conducted on two groups of patients affected with typical central serous chorioretinopathy (CSCR). One group was not treated and the other was treated by direct argon laser photocoagulation. CSCR shows a long-term good prognosis of visual acuity. The visual acuity of laser-treated eyes improves significantly (P less than or equal to 0.05), particularly in single focus cases (P less than or equal to 0.01). Unfortunately, these results cannot be statistically compared to the natural course of the non-treated patients because of the initial inhomogeneity of the two groups. Laser treatment did not produce any long-term complications. The recurrence rate in treated and untreated eyes was similar.

Adult↗
PubMed1987

Laser treatment of macular subretinal neovascularizations in angioid streaks.

A serous hemorrhagic maculopathy with a subretinal neovascular membrane appears in about 70% of cases of angioid streaks. In this study a series of 60 eyes (31 patients) was reviewed. In 13 eyes macular subretinal neovascularizations were photocoagulated with blue-green argon laser, green argon laser, dye laser (rhodamine 6G) at 590 nm and red krypton laser. The authors present and discuss the results obtained and suggest that photocoagulation of subretinal new vessels not involving the fovea can be worth performing.

Adolescent↗
PubMed1987

Proliferative retinopathy and toxemia of pregnancy.

Retinopathy occurring during toxemia of pregnancy generally shows the features of hypertensive retinopathy. The authors describe the case of a patient with bilateral peripheral neovascularizations following toxemia of pregnancy. The likely pathogenesis is ascribed to the development of ischemic areas, which can be determined by microthrombus formation. Presently, low-grade disseminated intravascular coagulation is considered very important in the pathogenesis of toxemia of pregnancy. After panretinal fluorangiography, a selective photocoagulation of ischemic areas was performed. The regression of neovascularizations was observed after one month. No similar case report could be found in the literature.

Adult↗
PubMed1987

Transscleral contact cyclophotocoagulation with Nd:YAG laser CW: experimental study on rabbit eyes.

The authors suggest a new type of transscleral cyclophotocoagulation by using the Nd:YAG laser. This was done by bringing fibre optics into contact with the sclera. The study illustrates the macroscopic, histologic and scanning electron microscopic changes produced on the ciliary body of rabbit eyes with this technique. The actual possibility and the future prospect of applying this method to the human eye still remain to be investigated.

Animals↗
PubMed1987

[Hyperplastic primary vitreous with persistent hyaloid artery in 2 non-twin brothers].

The authors describe the case of two brothers afflicted with persistent anterior hyperplasic primary vitreous and hyaloid artery. The occurrence of combination in two members of the same family is unusual, also moreover one of the patients was affected by macular retinoschisis. The two cases were clinically different; the first was typical, complicated by cataract; the second presented alterations mostly located in the posterior vitreous. In one eye fluorescein angiography showed a very slow and delayed filling of the hyaloid artery. Blood flow was directed from its anterior portion towards the optic disk. Nd: YAG laser photoresection of the hyaloid artery, performed in order to obtain a better visualization of the macula did not lead to remarkable hemorrhages. In an other eye fluorescein angiography could be performed after Nd: YAG laser photoresection of a vitreous membrane located in front of the posterior pole: remnants of the hyaloid vascular system with retrograde blood filling were present also in this case. The mechanisms leading to this reverse filling of the vessels are discussed.

Adult↗
PubMed1986

Diabetic papillopathy: fluorangiographic aspects.

Diabetic papillopathy is one of the signs of diabetic microangiopathy. Up to now several researchers have taken interest in this disease, providing various and sometimes clashing pathogenetical interpretations. The most plausible gives a major importance to a localized damage of the peripapillary vascular radial network, considering the anatomo-physiological features of this structure. The Authors' survey is presented with particular attention to fluorangiographic aspects of papillary changes.

Adult↗
PubMed1986

[Vascular and rhegmatogenous peripheral retinal changes in essential systemic arterial hypertension].

The authors examined the peripheral retina of 106 patients affected by essential hypertension grading from 1st to 3rd, as classified by WHO. Research of peripheral retinal vascular alterations and of theoretically possible resulting degenerative changes (lattice degeneration, while without pressure and snail tract degeneration) was carried out. The study included a control group of 39 healthy subjects. A statistical analysis of the resulting data was performed. This showed that the frequency of retinal peripheral vasculopathy is higher in the hypertensive group and is significantly related to the severity of hypertensive retinal angiopathy. In the same way, the incidence of peripheral retinal degenerative changes proved to be significantly higher among the hypertensive group than in the control group. However, a correlation between the frequency of retinal degenerative processes and the presence of vascular changes could not be assessed. The results obtained are discussed, suggesting that peripheral retinal angiopathy could act as a risk factor leading to degenerative alterations on a formerly predisposed retinal tissue.

Adult↗