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Biomedical subjects

C Azzolini

Publications and source records attributed to C Azzolini.

At least 37 records · Page 2Linked to original sources
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

[A case of transareolar mastocele (tuberous breast) following an early lateral thoracotomy].

The paper reports a rare case of breast anomaly, classified as "tuberous breast", which was of a specific nature since it was the result of a lateral thoracotomy performed at the age of 7 days old to esophageal atresia. The paper analyses the possible etiopathogenetic mechanisms. The use of an original reparative technique enable an adequately shaped and protruding breast to be obtained without the use of prosthesis and without leaving additional scars.

Adolescent↗
PubMed1992

[A rare case of breast ectopy associated with partial agenesis of osteo-muscular structures of the thoracic wall. Proposal of an original reparative technique].

The Authors report a case of chest wall malformation characterized by costal defect (6th and 7th ribs), hypoplasia of the serratus and pectoralis major muscles, left mammary ectopy and mucoviscidosis. The case is reported because of the very singular malformative association and the originality of the reparative procedure. Appearance has been improved and a good shape and breast projection achieved.

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

Differential isotype expression and binding properties of T cell-reactive antibodies in human immunodeficiency virus (HIV) infection.

Isotype and binding characteristics of T cell-reactive antilymphocyte antibodies (ALA) were investigated in 287 human immunodeficiency virus (HIV)+ sera from patients with CDC II to IVC clinical disease. Using purified soluble T-lymphoblast (CEM cell line) membranes and an ELISA method, 29 HIV+ sera showed significant reactions with this substrate and a selective expression of IgG-ALA was detected in 7 HIV+ sera. Subsequent microcytotoxicity assays, utilizing peripheral T lymphocytes and CEM cells as targets, demonstrated no significant cytotoxic capability in such sera, whereas 12 of 17 HIV+ serum samples with IgM-ALA ELISA reactivities showed a significant degree of killing in the Terasaki test. Further experiments of saturation of CD4 molecules on CEM extract by OKT4 monoclonal antibody (MoAb) induced a high inhibition of IgG-ALA binding to the T-cell membranes in only two IgG-ALA+ sera (No. 93, CDC III; No. 179, CDC II stage). Conversely, treatment of CEM membrane lysate with Leu3a MoAb, specific for the gp120 reactive domain of the HIV receptor, failed to prevent membrane binding in all seven of the IgG-ALA+ sera. Following the adsorption of serum 93 on a T-cell membrane antigen affinity column, SDS-PAGE analysis demonstrated that the predominant ALA material reacting with T-cell membranes was IgG with no detectable traces of IgM. These data provide evidence that ALA in HIV+ patients may be simultaneously or selectively expressed as IgG and/or IgM with different properties.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoantibodies↗
PubMed1992

Long-term histopathologic evaluation of human expanded skin.

Forty-two patients operated on by skin expansion have been contacted after a mean time of 25 months from the last surgery. Two biopsies have been taken from the expanded area of each patient. In 12 patients it has been possible to obtain a similar sampling from the opposite, nonexpanded area of the body. The samples underwent optic microscopy and cell kinetic and DNA content investigations. The epidermal structure of the followed-up skin, compared with the skin of the opposite side of the body, looks normal. The mitotic activity of the epidermal cells has returned to the values of preexpanded skin. The dermis shows a low degree of elastosis and zonal fragmentation of elastic fibers. The hypodermis, where the expander capsule was removed during the last surgery, does not show an accentuated fibrosis.

Adolescent↗
PubMed1991

Combined vitrectomy, cataract extraction, and posterior chamber intraocular lens implantation in diabetic patients.

Combined extracapsular cataract extraction, pars plana vitrectomy, and posterior chamber intraocular lens implantation was performed in six eyes with proliferative diabetic retinopathy. These eyes all had minimal iris vascular changes and were at reasonably low risk for developing intraoperative and postoperative complications. The surgery must be relatively brief and the endophotocoagulation accurate. Initial visual acuities ranged from light perception to 4/200. With an average follow-up of 9.7 months, final acuities ranged from 4/200 to 20/40.

Aged↗
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↗
PubMed1984

Surgical treatments of proliferative vitreoretinopathy.

Four hundred ten eyes with retinal detachment and proliferative vitreoretinopathy underwent closed vitrectomy with membrane peeling, scleral buckling, and intraocular air injection. The retina was reattached in 243 eyes (59.3%). Useful vision was attained in 223 eyes. The preoperative proliferative vitreoretinopathy was clinically graded in six groups of increasing severity (C-1, C-2, C-3, D-1, D-2, D-3). From grades C-2 to D-3, a significant trend related a decreased rate of retinal reattachment with increased severity. However, grade C-1 showed a significantly lower success rate than did grade C-2. Scleral buckling alone may be the treatment of choice in grade C-1 eyes. Grade D-3 eyes had the worst anatomic and functional results. Preoperatively, there was a significant relationship between increasing severity of proliferative vitreoretinopathy and frequency of aphakia, and aphakic eyes showed a significantly lower rate of retinal reattachment than did phakic eyes.

Adult↗
PubMed1984

Bilateral choroidal osteoma with subretinal neovascularization.

Choroidal osteoma is a rare entity, reported previously mainly in females. We report a case of bilateral choroidal osteoma in a 15-year-old boy. Ultrasonography and computerized tomography findings were key to establishing the diagnosis. During two years' follow-up, there was observable growth in the tumor size. Leakage from subretinal neovascular tufts covering the tumor caused visual deterioration. Photocoagulation of the subretinal new vessels was performed twice, with limited success, but the value of this treatment in choroidal osteomas needs further study.

Adolescent↗
PubMedDate not supplied

Ultrasound biomicroscopy following the intraocular use of silicone oil.

We evaluated the ultrasound biomicroscopy findings and the amount and location of silicone oil residue in anterior structures of the eye before and after silicone oil removal. We examined the anterior structures in 40 silicone oil 1000 cs-filled eyes at the end of silicone oil tamponade time (mean silicone oil tamponade duration 5.1 months), and in the same eyes after silicone oil removal. High resolution ultrasound biomicroscopy, 50 MHz transducer, 50 microns of resolution, was used. Silicone oil droplets--often not ophthalmoscopically visible--appeared as highly reflective images with after ringing effect. They were present in the anterior structures of the eye in up to 95% of eyes with silicone oil in the vitreous cavity, and in up to 87.5% after careful silicone oil removal. With ultrasound biomicroscopy it was possible to identify small silicone oil droplets with a typical morphological appearance. Once silicone oil is used in vitreoretinal surgery, its complete removal from the anterior structures of the eye is very difficult to achieve later on.

Adolescent↗
PubMedDate not supplied

Updating on intraoperative light-induced retinal injury.

We are presenting the state of knowledge concerning intraoperative light-induced retinal injury, considered to be a combination of photic retinopathy and retinal photocoagulation. It may arise from retinal light exposure to the operating microscope or to the fiberoptic endoilluminator. Ultraviolet and short-wavelength visible light are more dangerous than longer wavelength light. Many risk factors may facilitate the onset of this iatrogenic disease following surgery. Many aspects of the retinal damage are still poorly understood. Many mid light-induced retinal injuries probably remain undiagnosed in routine postoperative examination. Current appropriate light filters are not the definitive solution. Appropriate precautions should be taken during both anterior segment and vitreoretinal surgery.

Aged↗
PubMedDate not supplied

Herpes simplex virus type 2 acute retinal necrosis in an immunocompetent patient.

PURPOSE: To report a case of acute retinal necrosis caused by herpes simplex virus 2 in an otherwise healthy patient. CASE REPORT: A 45-year-old man presented with one month's history of decreased vision in the right eye. He had previously received a course of intravenous gancyclovir because of a clinical suspicion of cytomegalovirus retinitis. The patient's ocular history was remarkable for a similar episode in the left eye thirty years earlier, resulting in important visual impairment. System and laboratory investigations were unremarkable. Ocular examination showed severe anterior granulomatous uveitis, vitreous haze, areas of necrosis and retinal exudates. The anterior chamber tap disclosed the presence of HSV type 2, and oral steroids and acyclovir were instituted. Two weeks after the patient had been discharged, a retinal detachment occurred in the right eye, necessitating surgical repair. The presence of HSV type 2 was confirmed in the vitreous. Visual acuity recovered completely after surgery and the patient was placed on a maintenance dose of oral acyclovir. CONCLUSIONS: HSV type 2 is a rare cause of acute retinal necrosis in healthy patients. Bilateral involvement can occur in the fellow eye, even with a long delay. Acute retinal necrosis is a severe ocular inflammatory syndrome associated with a very poor visual outcome. It is caused by VZV, HSV type 1 and, less commonly, by HSV type 2. The disease can affect healthy patients and cause bilateral involvement in the fellow eye, even with a long delay.

Anterior Chamber↗
PubMedDate not supplied

Age-related macular degeneration and vitreous hemorrhage.

Age-related macular degeneration led to vitreous hemorrhage (VH) in six eyes of four patients. Macular involvement was bilateral in three patients and fluorescein angiography performed before VH showed extensive subretinal hemorrhage in the macular region in all eyes. We examine the possible causal mechanisms of VH resulting from age-related macular degeneration. Local risk factors, as outlined in our series by fluorescein angiography, are discussed and systemic risk factors are considered. Three out of the six eyes underwent pars plana vitrectomy for removal of intravitreal blood, and had severe inflammatory reactions in the postoperative period. In the three non-operated eyes spontaneous reabsorption of VH was observed at the end of follow-up.

Aged↗
PubMedDate not supplied

Reliability of preoperative ultrasonography evaluation for vitreoretinal surgery.

To evaluate the present level of reliability of common ultrasonography prior to vitreoretinal surgery, we carried out a prospective study to compare preoperative ultrasonography data with direct intraoperative findings. A total of 228 eyes with different vitreoretinal disorders and opaque or clear media were studied. In the group of 187 eyes with tractional retinal detachment (group I), the percentage of agreement between the ultrasonography data and the surgical findings ranged from 77.1% to 92.2%, depending on the pathology. In the group of 41 eyes without retinal detachment (group II), agreement ranged from 90.4% to 100%. The most frequent causes of failure of preoperative ultrasonography were incorrect prediction of macular detachment, partial posterior vitreous detachment, posterior vitreoschisis and vitreoretinal adhesions. The main cause of failure was the presence of multiple complicated echoes in group I, particularly in tractional diabetic retinal detachment. To achieve maximum benefits from ordinary preoperative ultrasonography, the vitreoretinal surgeon must be fully aware of its present level of reliability and general limitations.

Adolescent↗
PubMedDate not supplied

Posterior empty spaces during vitreoretinal surgery.

PURPOSE: To study during vitreoretinal surgery the intravitreal posterior empty spaces caused by different posterior relationships between the retina, posterior hyaloid and posterior vitreous. METHODS: A total of 151 eyes with different vitreoretinal disorders were considered; 97 eyes with retinal detachment (Group I), 54 eyes without retinal detachment (Group II). Intraoperative anatomy was carefully observed. In Group I, intraoperative observations were made with and without the infusion fluid entering the eyes. RESULTS: Different intraoperative posterior empty spaces were found: (i) within the posterior vitreous, (ii) between the detached posterior hyaloid and the retina, (iii) above and below the detached posterior "isolated hyaloid", and (iv) between the more posterior vitreous and the attached posterior hyaloid. The infusion fluid flux may variously change the size and shape of these posterior empty spaces. CONCLUSIONS: Many types of posterior empty spaces were observed intraoperatively. Their correct interpretation was important to well-conducted surgery. Dynamic movements of fluids in the vitreous cavity caused many intraoperative artifacts, making it difficult to understand the empty spaces and the vitreoretinal relationships present before surgery.

Adolescent↗