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Biomedical subjects

R Brancato

Publications and source records attributed to R Brancato.

At least 91 records · Page 5Linked to original sources
PubMed1994

Echographic diagnosis of Drusen of the optic nerve head in patients with angioid streaks.

A total of 58 patients (116 eyes) with angioid streaks, referred to this department over 2 years (1990-1992), underwent a thorough ophthalmic examination, retinal fluorescein angiography, dermatological visit with skin biopsy, and a series of other examinations (blood and biochemistry, skull X-ray, vascular echo Doppler, abdominal ultrasound) and eye ultrasonography. Fifty patients (100 eyes, 86.2%) had pseudoxanthoma elasticum (PXE). In the whole caselist, 21.6% had drusen compared with 21.0% in the group with PXE. Both these findings are higher than those published elsewhere. Drusen of the optic nerve head were also found in 25% of the 16 eyes (8 patients) with angioid streaks but no PXE. We believe we found a higher prevalence of drusen of the optic nerve head in these patients with angioid streaks because we systematically employed ultrasound.

Adult↗
PubMed1994

Genetic isolate and preserved para-arteriole retinal pigment epithelium.

Preserved para-arteriole retinal pigment epithelium (PPRPE) is an uncommon form of retinitis pigmentosa, with a very peculiar funduscopic appearance. To our knowledge no patient under age ten, affected by PPRPE, has been reported in the literature. The authors present here a seven-year-old boy, whose fundus examination is consistent with the diagnosis of PPRPE. The case report confirms that PPRPE starts early in childhood, and additionally supports the hypothesis of an autosomal recessive inheritance of this condition, since the proband's family lives in a 'genetic isolate'.

Arterioles↗
PubMed1994

Tumors of the optic nerve and chiasm.

Optic nerve gliomas and meningiomas, which remain puzzling to clinicians, are reviewed with special attention to natural history, magnetic resonance findings, and appropriate management. New histopathological insights established the true neoplastic nature of optic nerve gliomas considered by most clinicians to be benign hamartomas. Unusual presenting manifestations and therapeutic alternatives of optic glioma have been also considered. Since the association of optic nerve gliomas and meningiomas with neurofibromatosis has long been recognized, special attention has been drawn to clinical, genetic, and ophthalmologic aspects of neurofibromatosis. New and unusual presenting manifestations, diagnostic and treatment opportunities concerning optic nerve involvement in metastatic disease, and lymphomatous proliferation are also described.

Cranial Nerve Neoplasms↗
PubMed1994

Hypercoagulability and high lipoprotein(a) levels in patients with central retinal vein occlusion.

A series of coagulation parameters and lipoprotein(a) (Lp(a)) were explored in plasma from 40 patients with central retinal vein occlusion (CRVO, non-ischemic type n = 12; ischemic type n = 28) free of local and systemic predisposing factors, 1 to 12 months after the acute event. Forty age- and sex-matched patients with cataract served as controls. Prothrombin fragment 1.2 (F1.2), D-dimer, FVII:C--but not FVII:Ag--were higher and fibrinogen was lower in CRVO patients than in controls. Patients with non-ischemic CRVO had higher F1.2 and FVII:C and lower heparin cofactor II than patients with ischemic CRVO. Lp(a) levels greater than 300 mg/l were observed in 12 patients with CRVO and in 4 controls (30% vs 10%, p < 0.025). Patients with high Lp(a)--consistently associated with the S2 phenotype--had higher FVII:C, FVII:C/Ag ratio, and fibrinogen than the remaining CRVO patients. Plasma F1.2 and D-dimer correlated fairly in controls (r = 0.41) and patients with normal Lp(a) levels (r = 0.55), but they did not in the group of patients with high Lp(a) (r = 0.19), where the latter parameter was negatively related to D-dimer (r = -0.55). There was no dependence of the abnormalities observed on the time elapsed from vein occlusion. The findings of activated FVII and high F1.2, D-dimer, and Lp(a) are not uncommon in patients with CRVO. Increased thrombin formation with fibrin deposition and impaired fibrinolysis may play a role in the pathophysiology of CRVO and require specific treatment.

Adult↗
PubMed1994

Assessment of visual contrast sensitivity in hyperbaric oxygen.

Hyperbaric oxygen therapy is used in ophthalmology in ischemic pathologies of the anterior and posterior segments. Our experiment was done on a healthy group of volunteers aged between 10 and 50 yr. We examined the subject's vision before and after acute HBO exposure (60 min at 2.5 atm abs with pure oxygen) to verify whether vasoconstriction induced by hyperoxemia can influence eyesight. We measured the psychophysical determination of the threshold contrast according to Maione-Maffei's zebra test. The results demonstrated that contrast sensitivity is significantly improved for almost all the studied frequencies in normal subjects after acute HBO exposure. We hypothesize that the visual system has a reserve which is activated by an improvement of retinal oxygenation.

Adolescent↗
PubMed1994

Corneal nerve damage and regeneration after excimer laser photokeratectomy in rabbit eyes.

PURPOSE: To investigate corneal nerve damage and its subsequent regeneration after excimer laser photokeratectomy in rabbit eyes. METHODS: Corneal photokeratectomy was performed on the right eyes of 34 pigmented rabbits, while the left eyes were used as a control. A Summit UV 200 excimer laser (Summit Technology, Waltham, MA) was used to produce a 100 microns depth phototherapeutic keratectomy (4.5 mm diameter). The rabbits were killed at 0, 1, 2, 3, 4, 5, 7, 8, 10, 15, and 20 days and 1, 2, 3, and 4 months after treatment. Corneal nerve regeneration was investigated using a monoclonal antibody directed against a 150 kD subunit of neurofilaments, in combination with acetylcholinesterase staining. RESULTS: At time 0, the subepithelial plexus had disappeared completely from the photoablated area. One day after treatment, some regenerating nerves sprouting within the treated area were visualized by a monoclonal antibody directed against a 150 kD subunit of neurofilaments. Acetylcholinesterase staining was detectable 7 days later. One month after surgery the subepithelial plexus had already reappeared, but was morphologically disorganized. Four months after treatment, the newly formed subepithelial plexus had considerably thickened in comparison with that of the control eye. CONCLUSIONS: This study shows that corneal nerve regeneration after excimer laser photoablation in rabbit eyes, although more intense, is similar to that produced after other surgical procedures involving the epithelium and the anterior stroma or one of the two.

Acetylcholinesterase↗
PubMed1993

Diode versus argon-green laser panretinal photocoagulation in proliferative diabetic retinopathy: a randomized study in 44 eyes with a long follow-up time.

A clinical randomized study using argon-green (532 nm) and diode (810 nm) lasers was carried out on 44 eyes (34 patients) affected by proliferative diabetic retinopathy (PDR), with the aim of evaluating the long-term effects of diode panretinal photocoagulation. Of the total 44 eyes, 22 were randomized to argon laser treatment (ALT) and 22 to diode laser treatment (DLT). The mean follow-up time was 25 +/- 5 months in the ALT group versus 24 +/- 4 months in the DLT group. In the ALT group 20 eyes (91%) showed regression of PDR whereas 2 eyes (9%) deteriorated. In the DLT group regression of neovascularization was observed in 22 eyes (100%). These results show that the long-term efficacy of diode laser PRP in the treatment of PDR is similar to that of argon-green laser PRP.

Adult↗
PubMed1993

Biomicroscopy versus fluorescein angiography of the iris in the detection of diabetic iridopathy.

Iris fluorescein angiography is not commonly employed in clinical practice, but it is the most sensitive technique for the evaluation of iris vessel abnormalities. We used iris fluorescein angiography as the gold standard against which to test the ability of iris biomicroscopy to demonstrate diabetic iridopathy (DI). One hundred and fourteen eyes of 63 diabetic patients affected by preproliferative or proliferative diabetic retinopathy (DR) (the DR groups at high risk of developing DI) were considered. The DI fluorangiographic classification used was: (1) absence of DI; (2) nonproliferative DI; (3) proliferative DI. The sensitivity of biomicroscopy in detecting DI turned out to be 57%, while the specificity was 94%. The positive predictive value was 93% and the negative predictive value 50%. Our study proved that biomicroscopy can accurately judge when DI is absent. When it is present, however, there is a high probability that biomicroscopy will be less precise in the detection of iris lesions.

Aged↗
PubMed1993

Influence of silicone oil on iris microangiopathy in diabetic vitrectomized eyes.

PURPOSE: This study evaluates the influence of intraocular silicone oil on iris diabetic microangiopathy in diabetic vitrectomized eyes. METHODS: The authors examined 20 eyes of 20 patients with diabetes undergoing primary vitrectomy for fractional diabetic retinal detachment, endophotocoagulation, and 1000 centistokes silicone oil tamponade. The vascular status of the iris in these eyes was examined by iris fluorescein angiography once before silicone oil injection and again when it was removed (mean follow-up, 8.3 months). RESULTS: Iris diabetic microangiopathy, including breakdown of the blood-iris barrier and iris neovascularization, improved or remained stable in 40% of eyes. It worsened in 60% of eyes, including all aphakic eyes. Neovascular glaucoma developed in one of them. A significant correlation was found between worsening of iris diabetic microangiopathy and both aphakia (P = 0.01) and severe immediate postvitrectomy inflammation (P = 0.02). Eyes with recurrent retinal detachment (n = 4) showed worsening of iris diabetic microangiopathy, but this was not significantly correlated. CONCLUSION: Aphakic vitrectomized eyes have a higher risk of iris diabetic microangiopathy developing, even after silicone oil tamponade. Immediate postoperative intraocular inflammation also is a risk factor for worsening of iris diabetic microangiopathy in phakic eyes. Recurrence of retinal detachment was not significantly correlated with worsening of iris status.

Adult↗
PubMed1993

Correlation of corneal thickness with blood glucose control in diabetes mellitus.

The aim of this study was to prove the existence of a correlation between corneal thickness and glycaemic control in insulin-dependent patients. Ultrasound pachometry and blood glucose measurements were taken in 87 patients three times a day: fasting, two, and four hours after lunch. The sample was divided into three groups of patients: 30 of them did not have retinopathy, 30 presented background retinopathy and 27 proliferative retinopathy. Thirty normal age-matched subjects were the control group. No correlation was found between pachometry values, blood glucose and duration of diabetes in the three groups (p > 0.05). A significant increase in corneal thickness was found in patients with background and proliferative retinopathy compared to the others (p < 0.01). No corneal thickness differences resulted between background and proliferative retinopathy (p = 0.74).

Adult↗
PubMed1993

Cystoid macular oedema after extracapsular cataract extraction and intraocular lens implantation in diabetic patients without retinopathy.

Postoperative onset or aggravation of cystoid macular oedema (CMO) in diabetic patients after extracapsular cataract extraction (ECCE) with intraocular lens (IOL) implantation is a frequent problem. At present little is known about the occurrence and prognosis of this complication in diabetics with no clinically detectable diabetic retinopathy (DR). Twenty five diabetic eyes (24 subjects) without DR and 45 normal eyes (44 subjects) were studied before surgery and 30, 90, 180, 360 days after ECCE and posterior chamber IOL implantation. Fluorescein angiography was performed at each examination. The frequency of angiographic CMO in the two groups was comparable 30 days after surgery but was significantly higher in diabetic eyes at 90, 180, and 360 days. This finding is probably related to an impairment of the blood-retinal barrier in diabetics. Final visual acuity, however, was similar in the two groups.

Aged↗
PubMed1993

Laser treatment of iris vascular tufts.

We describe a case of iris vascular tufts which came to our attention because of a hyphaema. Laser treatment was carried out for the vascular anomalies. After a period of 3 months, fresh vascular anomalies had appeared in different locations. Further treatment led to permanent obliteration. We emphasize the importance of fluoro-iridography in the monitoring of vascular anomalies as it allows accurate targeting treatment.

Female↗
PubMed1993

Prenatal detection and early diagnosis of hereditary retinoblastoma in a family.

A couple asked for prenatal testing, the husband being a retinoblastoma survivor. Family history suggested that the tumor predisposing mutation came from his paternal side. DNA analysis indicated that the foetus had not inherited that mutation. Detection of a regressed retinoblastoma in the husband's mother changed the interpretation of the haplotypes obtained, and it was concluded that the foetus had inherited the mutation. Ultrasonography on the 3rd day of extra-uterine life showed a retinal mass in the newborn's left eye. Two years later, the couple asked for a new prenatal diagnosis. DNA analysis showed that the foetus had inherited the mutant retinoblastoma haplotype from the father. Fundus examination on the 2nd day of extra-uterine life showed a retinal lesion in the newborn's left eye at the posterior pole. This case indicates the necessity of a thorough check on history and an ophthalmological examination of family members.

Adult↗
PubMed1993

Refractive hazards of intraoperative retinal photocoagulation.

The refractions of a laser beam during transpupillary and endo-ocular intraoperative retinal photocoagulation as it passes through vitreous substitutes, with varying refractive indexes, were investigated with the use of mathematical algorithms and ray tracers. The following modifications and potential hazards were noted: 1) deviations of the laser beam (unlikely, however, to cause target error when surgery is properly conducted); 2) variations in laser-beam diameter and power density (up to 60%), easily leading to retinal underexposure or overexposure; and 3) asymmetry in beam distribution at the target site, leading to non-uniform retinal photocoagulation. Proper surgical techniques must be adopted before and during intraoperative photocoagulation to minimize retinal hazards. The relatively short distance between the endolaser probe and the retina means that fewer undesirable refractions occur with endo-ocular photocoagulation than with transpupillary indirect intraoperative photocoagulation.

Algorithms↗
PubMed1992

Corneal endothelial anomalies in the fetal alcohol syndrome.

The fetal alcohol syndrome involves various neural crest-derived structures thus causing systemic and ocular malformations. This study investigated anomalies of the corneal endothelium, a neural crest-derived tissue, in eight children affected by fetal alcohol syndrome without known anterior segment anomalies. We performed specular biomicroscopy on the central corneal endothelium. The data were then compared with those from 80 age-matched healthy children, applying the same methods. Significant differences were found between patients with fetal alcohol syndrome and healthy subjects for mean cell density (P = .032), polymegethism (P = .000), and percentage of hexagonal cells (P = .000). We also found a close correlation between endothelial anomalies and auditory dysfunction in the patients with fetal alcohol syndrome. These alterations may be a consequence of alcohol-induced toxic effects on neural crest cells destined to form both the corneal endothelium and the organ of Corti in the same embryogenic period.

Adolescent↗
PubMed1992

Interactions between light and vitreous fluid substitutes.

To determine the interactions between light and vitreous fluid substitutes, we studied the absorption and fluorescence properties of the following fluids that are commonly used in vitreoretinal surgery: Ringer's solution, balanced salt citrate-buffered solution, balanced salt bicarbonate-buffered solution, hydroxypropyl methylcellulose ophthalmic solution, hyaluronate sodium, perfluorocarbons, silicone oil, and fluorosilicone oil. The absorption spectra for all the fluids peaked in the UV-C (reference range <280 nm) and UV-B (reference range from 315 to 280 nm) regions of the spectrum, with little or no absorption in the visible region of the spectrum (from 400 to 700 nm). Emission of almost all of the fluids occurred mainly in the 300- to 360-nm region, with fairly low-quantum efficiency. The limited light absorption properties of the fluids calls for caution during transpupillary and intraocular laser photocoagulation to avoid excessive retinal damage, mainly when the laser power is increased during treatment. Transmission of incoherent light (environmental and ophthalmic artificial light) through highly transparent vitreous fluid substitutes may lead in time to dangerous light exposure, particularly in aphakic eyes. The emitted fluorescence in these fluids generates a minimal risk of long-term damage.

Absorption↗
PubMed1992

Ocular involvement in acute lymphoblastic leukemia: an echographic study.

We report a case of acute lymphoblastic leukemia (ALL) with ocular involvement in which bilateral swelling of the optic disk head was noticed. Massive direct infiltration of the optic nerve head by leukemic cells can give rise to a clinical picture identical to that of a true papilledema. Ocular echography allowed a better and more complete interpretation of the optic disk involvement. No echographic description of a leukemic infiltration of the optic nerve head has been reported previously.

Adult↗