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Biomedical subjects

C Azzolini

Publications and source records attributed to C Azzolini.

At least 19 recordsLinked to original sources
PubMed2001

Florid diabetic retinopathy (FDR): a long-term follow-up study.

PURPOSE: To evaluate efficacy of laser photocoagulation and pars-plana vitrectomy in patients with FDR. METHODS: Eighty-eight patients (155 eyes) with FDR were retrospectively evaluated (mean age 27 +/- 6.0 years; proportion of females 66%; insulin-dependent diabetes 100%; mean duration of diabetes 16.5 +/- 5.8 years; poor metabolic control 83%). The eyes were divided in two groups: group I: 136 eyes amenable to laser photocoagulation and, when necessary, to vitrectomy afterwards (45/136); group II: 19 eyes subjected directly to vitrectomy. RESULTS: In group I (mean follow-up 54.2 +/- 38.7 months) the initial visual acuity (IVA) was 0.61 +/- 0.30 and the final visual acuity (FVA) was 0.47 +/- 0.34; in the 45 vitrectomized eyes IVA was 0.15 +/- 0.24 and FVA was 0.19 +/- 0.25. FDR regressed in 75% and worsened in 25% of the cases. In group II (mean follow-up 46.4 +/- 36.3 months) IVA was 0.1 +/- 0.14 and FVA 0.14 +/- 0.22. FDR regressed in 32% and worsened in 68% of cases. CONCLUSIONS: FDR remains a cause of severe visual impairment in diabetics. Patients at risk of FDR are young females with long-standing, poorly controlled insulin-dependent diabetes. Panretinal laser photocoagulation prior to vitrectomy is beneficial; information on this severe form of retinopathy is essential to ensure prompt diagnosis and improve its unfavorable clinical course.

Adult↗
PubMed2001

Correlation between optical coherence tomography data and biomicroscopic interpretation of idiopathic macular hole.

PURPOSE: This study was designed to assess the new clinical information given by optical coherence tomography in patients with idiopathic macular hole. METHODS: Sixty-one consecutive eyes of 47 patients with idiopathic macular hole at different stages of development were studied clinically. Patients with myopia, epiretinal macular membrane, and any other ocular disease were excluded. Best-refracted visual acuity and biomicroscopic fundus examination with macular contact lens were performed. Optical coherence tomography was performed through a dilated pupil. The optical coherence tomography findings were correlated with the Gass biomicroscopic classification of idiopathic macular hole. RESULTS: Optical coherence tomography provided different or additional information in 22 of 24 eyes (91.7%) biomicroscopically classified in stages 1-A and stage 1-B, according to the Gass macular hole classification, and in seven of 37 eyes (18.9%) biomicroscopically classified in stages 2, 3, and 4. The main difference from Gass biomicroscopic classification was a macular pseudocyst instead of a foveolar detachment in the first stages. The main additional optical coherence tomography observation, not detected biomicroscopically, was the presence of retinal tissue on the bottom of the macular hole. Optical coherence tomography may be particularly useful in evaluation of early stages in development of idiopathic macular hole. CONCLUSIONS: Compared with classic biomicroscopical observation, optical coherence tomography frequently gives different or additional information on idiopathic macular hole, especially in its early stages. Correct diagnosis and surgical indication of idiopathic macular hole may benefit from optical coherence tomography imaging.

Adult↗
PubMed1999

Peribulbar anesthesia with either 0.75% ropivacaine or a 2% lidocaine and 0.5% bupivacaine mixture for vitreoretinal surgery: a double-blinded study.

UNLABELLED: No study has evaluated the efficacy of ropivacaine in peribulbar block for ophthalmic surgery. The purpose of this prospective, randomized, double-blinded study was to compare ropivacaine and a lidocaine-bupivacaine mixture in peribulbar anesthesia. Sixty ASA physical status I or II patients scheduled for elective vitreoretinal surgery were randomized to receive a peribulbar block with 8 mL of either 0.75% ropivacaine (ropivacaine group, n = 30) or a 1:1 mixture of 2% plain lidocaine and 0.5% plain bupivacaine (lido-bupivacaine group, n = 30). Time required for onset of surgical anesthesia, quality of postoperative analgesia, incidence of side effects, and analgesic consumption were recorded. Surgical block was achieved after 8 +/- 5 min in the lido-bupivacaine group and after 10 +/- 5 min in the ropivacaine group (P = 0.23). A 3-mL supplemental injection 15 min after block placement was required in 6 patients in the lido-bupivacaine group (20%) and in 10 patients in the ropivacaine group (33%) due to inadequate motor block (P = 0.38). On Postoperative Day 1, 26 patients in the ropivacaine group (87%) reported no pain at the verbal rating score, compared with 18 patients in the lido-bupivacaine group (60%) (P = 0.005). We conclude that 0.75% ropivacaine may be a suitable choice when performing peribulbar anesthesia for vitreoretinal surgery. IMPLICATIONS: Quick onset of block with prolonged postoperative analgesia is an important goal in regional anesthesia for ophthalmic surgery. Evaluating clinical properties of 0.75% ropivacaine and a 1:1 mixture of 2% lidocaine and 0.5% bupivacaine for peribulbar anesthesia, we demonstrated that ropivacaine has an onset similar to that of the lidocaine-bupivacaine mixture and provides a better quality of postoperative analgesia.

Amides↗
PubMed1999

Ultrasound biomicroscopic evaluation of ciliochoroidal effusion after laser treatment.

We evaluated ciliochoroidal effusion (CE) by ultrasound biomicroscopy (UBM) following diode endophotocoagulation at the end of the vitreoretinal surgery. The aim of our study was to assess any differences in the CE morphology following diode endophotocoagulation or transpupillary krypton photocoagulation, and to demonstrate the influence of diabetes and intravitreal surgery on CE formation. Sixty-six consecutive patients were divided in to four groups. Twenty-nine patients with proliferative retinopathy underwent transpupillary krypton photocoagulation; 11 diabetic patients underwent vitreoretinal surgery and diode endophotocoagulation; 18 nondiabetics underwent vitreoretinal surgery and diode endophotocoagulation; 8 consecutive nondiabetic patients were the control group and underwent vitreoretinal surgery, without laser treatment. UBM was performed in the four groups before and after laser treatment, if performed. We determined, by UBM, not only the presence, but also the thickness of CE. CE was present in all the patients treated by laser, diabetics and nondiabetics, and its thickness was not correlated with the number of laser spots (p = 0.28). CE was seen ultrasonically in all the patients undergoing transpupillary photocoagulation or endophotocoagulation, regardless of diabetes and surgical trauma.

Aged↗
PubMed1999

[Telemedicine in vitreoretinal surgery].

The authors present one-year experience of the multimedia role in ophthalmology with particularly review on example in vitreoretinal surgery. It has been shown goal of the project, methodology, evaluation of one-year work results and possibility of project's expansion.

Europe↗
PubMed1998

Axial length and refraction in retinal vein occlusions.

To assess whether axial length and refraction are risk factors for retinal vein occlusion, we measured these parameters in 88 consecutive patients with unilateral branch retinal vein occlusion (BRVO), in 58 consecutive patients with unilateral central retinal vein occlusion (CRVO) and in 50 patients selected as a control group. Patients and controls were free or affected by systemic or local predisposing factors. We compared eyes with CRVO with control eyes, eyes with BRVO with control eyes, and eyes with CRVO with eyes with BRVO. Comparing CRVO eyes and controls, none of the investigated variables was shown to be significant. From the analysis of BRVO eyes versus controls, it resulted that refraction was the only variable which played the role of an independent prognostic factor. When comparing BRVO eyes with CRVO eyes, we found that age was slightly related to the development of BRVO. In conclusion, faulty refraction appeared to be a risk factor for the development of BRVO. We did not find any influence of axial length on the occlusion of retinal veins.

Adult↗
PubMed1997

Interaction between infrared radiation and vitreous substitutes.

OBJECTIVE: To characterize the interaction between midintrared radiation of cutting lasers used or proposed for vitreoretinal surgery and fluid vitreous substitutes commonly used in vitreoretinal surgery. METHODS: Optical transmittance of vitreous substitutes was measured with a double-beam spectrophotometer. Measurements were performed in a wide spectral range of infrared radiation, including the 2120-nm wavelength of the holmium-YAG laser and the water absorption peaks at 1440, 1930, and 2940 nm. RESULTS: The wavelengths considered have a penetration depth varying from 410 to 1 microns in Ringer's solution, balanced salt citrate-buffered solution, balanced salt bicarbonated-buffered solution, hyaluronate sodium, and hydroxypropyl methylcellulose ophthalmic solution, from 2000 to 13 mm in perfluorocarbon liquid, and from 52 to 2.5 mm in silicone and fluorosilicone oils. CONCLUSIONS: Midinfrared optical radiation exhibits dramatic differences of penetration depth in different vitreous substitutes. High-absorbing liquids should be used mainly with contact laser procedures and could provide a shield for remote structures. Low-absorption vitreous substitutes allow noncontact laser surgical procedures, but they also may cause direct optical damage to remote tissues. The knowledge of wavelength transmittance of vitreous substitutes is necessary to evaluate and optimize the efficacy and safety of cutting laser sources.

Fluorocarbons↗
PubMed1996

Double-frequency Nd:YAG laser vs. argon-green laser in the treatment of proliferative diabetic retinopathy: randomized study with long-term follow-up.

BACKGROUND AND OBJECTIVE: A randomized clinical trial using the argon-green (514 nm) and the double-frequency Nd:YAG (532 nm) lasers was carried out on 42 eyes with proliferative diabetic retinopathy (PDR), with the aim of assessing the long-term effects of double-frequency Nd:YAG panretinal photocoagulation (PRP). MATERIALS AND METHODS: Twenty-one eyes were randomized to argon laser treatment (ALT) and 21 to double-frequency Nd:YAG laser treatment (NdLT). The mean follow-up was 28.90 months (+/- 6.13) in the ALT group and 29.57 months (+/- 5.17) in the NdLT group. RESULTS: In the ALT group, 20 eyes (95.2%) showed regression of PDR and one eye (4.8%) enlargement of pre-existing new vessels. In the NdLT group, neovascularization regressed in 20 eyes (95.2%) and increased in one (4.8%). CONCLUSIONS: The long-term efficacy of double-frequency Nd: YAG laser PRP in the treatment of PDR thus appears to be similar to that of argon-green.

Adult↗
PubMed1996

New semiconductor laser for vitreoretinal surgery.

BACKGROUND AND OBJECTIVE: We investigated the potential application in vitreoretinal surgery of a CW diode laser with cutting capabilities. STUDY DESIGN/MATERIALS AND METHODS: A semiconductor CW laser emitting 300 mW optical power at 1.94 microns wavelength was used to perform retinotomies and membrane cutting on rabbit eyes. The device was integrated into a dedicated controller. The laser radiation was delivered through a low attenuation fused silica optical fiber of 200 microns core size, terminating into a 20-gauge endo-ocular handpiece. Histological aspects of threshold lesions obtained on the rabbits' chorioretina were evaluated by light microscopy. RESULTS: We obtained circular and linear full-thickness retinotomies with contact and noncontact procedures using energy of 120 mJ (240 mW x 0.5 s). Using a non-contact procedure, a larger peripheral coagulation halo around the retinotomies was observed, as compared to the contact method. The adjacent zone of thermal damage ranged from 50 to 200 microns. Lower efficacy was obtained on experimentally induced epiretinal membranes, where only superficial ablation was achieved. CONCLUSION: The CW 2 microns diode laser will have a promising future in vitreoretinal surgery when a higher output irradiance is available.

Animals↗
PubMed1996

Vitreous laser absorption following fluorescein angiography in diabetic patients.

BACKGROUND: Sodium fluorescein staining of the vitreous following fluorescein angiography may interact with laser photocoagulation. METHODS: We evaluated the laser absorption by fluorescein in the vitreous when photocoagulation is performed following fluorescein angiography in 15 eyes of nine diabetic patients. Axial fluorescein concentration in the vitreous was measured by a scanning vitreal fluorophotometer. The amount of light absorbed by the fluorescein within the vitreous was calculated according to the Lambert-Beer law. RESULTS: The mean fluorescein concentration ranged from 2.93 ng cm-3 to 105.16 ng cm-3 at 1 h after injection of fluorescein and from 8.03 to 188.56 ng cm-3 after 4 h. Maximum laser absorption at 488 nm ranged from 6.79% (after 1 h) to 14.53% (after 4 h); at 514.5 nm it ranged from 0.96% to 2.14%; at 532 nm it ranged from 0.03% to 0.07%. At lambda > 550 nm, laser absorption was found to be negligible. CONCLUSIONS: In order to optimize the effect of photocoagulation, especially during long photocoagulation sessions, argon blue laser (488 nm) should be avoided following fluorescein angiography. Argon green laser (514.5 nm) should be used within 1 h after fluorescein injection. Frequency-doubled Nd:YAG laser (532 nm), krypton laser (647 nm) or semiconductor diode laser (810 nm) may be used at any time.

Absorption↗
PubMed1996

Automatic centering of the microscope image for vitreoretinal surgery.

PURPOSE: The authors report on their device, the surgical image tracker, which provides automatic compensation for movements of the surgical image within the microscope field of view, during vitreoretinal procedures. METHODS: The authors developed a compact device acting as an automatic image tracker, based on video monitoring of the surgical image and translation of the operating microscope. Basic components are a standard color charge-coupled device camera and a specifically designed frame grabber for discrimination and tracking of the target image. Operation of the device is fully compatible with the usual pedal adjustments. RESULTS: Ready, fast, and correct automatic centering of the microscope field of view has been achieved successfully in all typical operating conditions. Video recording always is equally well centered. System operation also is effective with panoramic optics and diffuse illumination. CONCLUSION: The surgical image tracker appears to be a valuable tool to obtain well auto-centered surgical images, eliminating a bothersome task during vitreoretinal surgery.

Humans↗
PubMed1995

Expression of VE (vascular endothelial)-cadherin and other endothelial-specific markers in haemangiomas.

Haemangiomas are vascular tumours characterized by rapid growth and increased endothelial turnover. VE-cadherin is a recently discovered endothelial cell-specific cadherin located at intercellular junctions. In different types of epithelial tumours, cadherin expression is inversely correlated with invasiveness and metastatic dissemination. In this immunohistochemical study, VE-cadherin expression has been analysed in different types of haemangioma. VE-cadherin is highly expressed in endothelial cells of haemangiomas and is decreased, but still detectable, in some cases of haemangionendothelioma and angiosarcoma. The antigenic profile of most haemangioma cells was similar to that of normal endothelium. CD31, CD34, ICAM-1, von Willebrand factor, and VLA integrins were expressed in haemangioma endothelium; in addition, the major components of vascular basement membrane, namely fibronectin, collagen type IV, and laminin, were correctly expressed and organized. Surprisingly, a marked reactivity for the M form of laminin (merosin) was detected in the basement membranes of two juvenile capillary haemangiomas. Overall, this study shows that, with the exception of angiosarcoma and haemangionendothelioma, vascular tumours maintain most of the differentiation characteristics of normal endothelium. This encourages speculation that in these pathologies, abnormal endothelial proliferation is more related to the release of local factors than to an altered endothelial phenotype.

Basement Membrane↗
PubMed1994

Endophotocoagulation through perfluorodecalin in rabbit eyes.

Retinal laser endophotocoagulation through perfluorodecalin was studied in six eyes of three Dutch-belted rabbits after vitrectomy. Both the energy density threshold (EDT/50) and the energy threshold necessary to obtain a therapeutic lesion were evaluated. Both argon and semiconductor diode laser endophotocoagulators were used. The amount of laser power energy and the histology of chorioretinal lesions were similar when photocoagulating through perfluorodecalin, compared to photocoagulation through balanced salt citrate-buffered solution. This experimental study indicates that no extra care is necessary when retinal endophotocoagulation is performed through perfluorodecalin, as long as circular spots are obtained and energy is delivered symmetrically to the target site.

Animals↗
PubMed1994

Minimal incision palatopharyngoplasty. A preliminary report.

A new palatopharyngoplasty which allows good muscular reorientation as well as elongation of the soft palate with minimal morbidity and scarring has been developed, and 66 selected patients underwent the procedure during the period September 1989 to March 1993. The most important findings were reduced operative bleeding, good length and mobility of the soft palate, and minimal scarring. A total of seven fistulas (11%) developed. Twenty-three patients (mean age 6 years and 2 months at the time of operation) underwent nasopharyngoscopy and multiview videofluoroscopy; velopharyngeal insufficiency was evident in only four (17%). Dental casts were obtained in 14 patients (mean age at the time of the operation 1 year, 3 months) who were followed up for a maximum period of two years. No postoperative orthodontic treatment was required and the width and harmony of the dental arch were maintained in all cases.

Adolescent↗
PubMed1994

[Scrotal reconstruction by cutaneous expansion].

We report on a patient who underwent scrotal reconstruction by cutaneous expansion, a new technique utilized to repair the male genital area. The tissue obtained with this technique permits creating a scrotal pouch and completely free movement of the testes. Unlike the other methods, sufficient skin can be obtained with the exparsion technique. The morphological result achieved with this technique is clearly superior. The absence of scars is underscored.

Adult↗
PubMed1994

[Haemangiomas and vascular malformations of the nose].

After discussing histogenetic, morphologic and evolutive aspects that distinguish haemangiomas from vascular malformations, the Authors affirm the important role that haemodynamic stimuli take on in the evolution of the latter. Vascular malformations are subdivided into capillary, venous and arterial, according to where they originate in the vascular tree. With reference to haemangiomas, the Authors underline the importance of steroid therapy and the necessity to resort to integrative surgical procedure in those cases which do not respond satisfactorily to steroid therapy. The different procedures to be performed, according to dimension and localization of the haemangiomas, are explained in detail. In capillary vascular malformations of small significance from a haemodynamic and evolutionary point of view, comparable to a slightly pathological capillary network, the surgeon often faces complex reconstructive problems which involve, however, only the tegument. These can be resolved using forehead flaps, if necessary, expanded. Arteriovenous vascular malformations are more problematic and therefore require greater surgical skill, prone as they are to progressive expansion and aggravation brought about by haemodynamic mechanisms.

Angiography↗
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↗