Biomedical subjects

E Balestrazzi

Publications and source records attributed to E Balestrazzi.

At least 37 records · Page 2Linked to original sources

PubMed1997

Early detection of P-VEP and PERG changes in ophthalmic Graves' disease.

BACKGROUND: In Graves' disease the optic neuropathy (ON) is due to direct compression of the nerve and/or of its blood supply. The aim of the present study was to detect early changes in the visual functions of patients affected by ophthalmic Graves' disease (OGD) by using electrophysiological tests (P-VEP and PERG). METHODS: We studied 50 OGD patients who were in a range between class 2 and class 5 according to the Donaldson-American Thyroid Association classification, i.e. had no evident ON and normal visual acuity. We recorded transient reversal PERG and P-VEP in response to the stimulation of one eye at three spatial frequencies (2.2, 1.1 and 0.5 c/d). RESULTS: Our results showed a statistically significant reduction in PERG amplitude in class 5, while the P-VEP amplitude was already reduced in class 2. CONCLUSION: The electrofunctional tests were useful to detect small changes in the visual function of patients affected by initial stages of OGD. Therefore, P-VEP and PERG recordings appear to be a useful tool for early diagnosis of the optic nerve involvement in Graves' disease.

Adult↗

PubMed1997

Trans-scleral krypton laser cyclophotocoagulation: our experience of its use on patients with neovascular glaucoma.

Trans-scleral cyclophotocoagulation is an efficacious method in neovascular glaucoma (NVG) treatment. We have used it with krypton laser on 12 eyes of 12 patients affected by NVG with algetic symptoms. Six months after treatment, intraocular pressure was down enough for the pain to disappear. Executional simplicity and the possibility of modulating the intensity of the treatment are grounds for the encouragement of the technique's use in NVG.

Aged↗

PubMed1996

Effect of myopic excimer laser photorefractive keratectomy on the electrophysiologic function of the retina and optic nerve.

PURPOSE: To assess by electrophysiologic testing the effect of photorefractive keratectomy (PRK) on the retina and optic nerve. SETTING: Eye Clinic, S. Salvatore Hospital, L'Aquila University, Italy. METHODS: Standard pattern electroretinograms (P-ERGs) and standard pattern visual evoked potentials (P-VEPs) were done in 25 eyes of 25 patients who had myopic PRK for an attempted correction between 5.00 and 15.00 diopters (D) (mean 8.00 D). Testing was done preoperatively and 3, 6, 12, and 18 months postoperatively. The contralateral eyes served as controls. During the follow-up, 3 patients (12%) developed steroid-induced elevated intraocular pressure (IOP) that resolved after corticosteroid therapy was discontinued. RESULTS: No statistically significant differences were seen between treated and control eyes nor between treated eyes preoperatively and postoperatively. CONCLUSION: Myopic excimer laser PRK did not seem to affect the posterior segment. The transient steroid-induced IOP rise did not seem to cause functional impairment.

Adult↗

PubMed1996

Specular microscopy of the corneal endothelium after excimer laser photorefractive keratectomy.

PURPOSE: To evaluate endothelial cell morphology and density after excimer laser photorefractive keratectomy (PRK). METHODS: We used a noncontact specular microscope to examine the central corneal endothelium of 50 eyes of 50 patients who had PRK for an attempted correction between -2.5 and -17.0 diopters (D) (mean -7.8 D) beginning 18 to 24 hours postoperatively. RESULTS: After a follow-up of 11.4 +/- 6.1 months (mean +/- standard deviation), mean endothelial cell density was 2577.6 +/- 402.0 cells/mm2 with rare signs of polymegathism and pleomorphism. Preoperative and untreated fellow eye endothelial cell density values were used as a control. Paired Student's t-test and analysis of variance results were not significant (P > .05). CONCLUSION: Excimer laser PRK did not significantly change cell density and morphology.

Adult↗

PubMed1996

Penetrating keratoplasty with donor and recipient corneas of the same diameter.

BACKGROUND AND OBJECTIVE: A retrospective study was conducted to investigate the effect of penetrating keratoplasty (PK) with donor and recipient corneas of equal diameter on astigmatism, corneal curvature, and spherical equivalent. PATIENTS AND METHODS: A total of 89 eyes of 86 consecutive patients who underwent PK with donor and recipient corneas of equal diameter were studied. The surgical techniques were performed using the Hanna suction punch block (endothelial cut) with the trephine system, and a single running 16-bite 10-0 nylon suture. Sixteen eyes underwent a triple procedure (PK, extracapsular cataract extraction, and intraocular lens [IOL] insertion) and 14 eyes underwent PK with sulcus fixation of a posterior chamber IOL. Follow-up ranged from 12 to 30 months (mean +/- SD 17.5 +/- 4.7). The sutures were removed at approximately 12 months postoperatively. RESULTS: The postoperative astigmatism ranged from 0.4 to 10.8 D (mean +/- SD 4.5 +/- 2.8), as evaluated by a computer-assisted videokeratograph topography unit. Twenty-seven eyes (30.3%) achieved a refractive error (spherical equivalent) within +/- 1.5 D of emmetropia. The mean postoperative refractive error (spherical equivalent) was -0.1 +/- 3.5 D (range -6.75 to + 7.25). No wound dehiscences or glaucoma was noted during the follow-up. CONCLUSION: The Hanna suction system creates a sharp, deep, and perpendicular cut on both button cornea and host cornea, making it possible to use donor and recipient corneas of the same diameter in PK with good clinical and refractive results, particularly for myopic (keratoconus) patients.

Astigmatism↗

PubMed1994

Electro-oculographic changes after local excision of uveal melanoma.

Standard electro-oculography was performed in 10 patients with malignant unilateral uveal melanoma All eyes were treated by means of surgical local excision. After a mean +/- standard deviation follow-up of 10.5 +/- 5.5 months (range, 6 to 20 months) in the five patients with choroidal melanoma, the electro-oculographic recordings, which had appeared reduced or flat before the surgery, increased significantly just after the local excision. Thereafter the amplitudes of the electro-oculographic light peaks were reduced in all cases up to extinction, possibly because of a retinal detachment. On the contrary, the electro-oculographic value in the five melanomas localized at the iris and ciliary body, normal before the surgery, showed a marked and persistent increase after surgery, probably related to an 'electric hole' in the globe.

Electrooculography↗

PubMed1991

Evaluation of electrofunctional data following argon-laser trabeculoplasty in primary open-angle glaucoma.

To establish whether or not glaucomatous damage is reversible, we obtained pattern-reversal electroretinograms (PERGs) and visual evoked potentials (VEPs) in 25 eyes of 25 patients suffering from bilateral primary open-angle glaucoma (POAG) before and after argon-laser trabeculoplasty. The laser treatment was carried out in only one eye chosen at random, and the fellow eye was used as a control. In the present study we intended to verify the possibility of using electrofunctional techniques to determine the two distinct and, probably, consecutive glaucomatous alterations occurring in ganglion cells: functional (reversible) and anatomical (irreversible). The results obtained indicate that glaucomatous damage is irreversible. We propose that such alterations differ very slightly and that the current electrofunctional techniques may not be sufficiently sophisticated to distinguish between them.

Adult↗

PubMed1989

Metastasis of bronchial carcinoid tumour to choroid.

A rare case of metastatic carcinoid tumour of the choroid is presented. Techniques used to identify the nature of the neoplasm (immunohistochemical or histochemical stains) and the numerous substances possibly secreted by the neoplastic cells (PAP immunocytochemical technique) are discussed.

Adult↗

PubMed1986

Steroids and neuroendocrine hormones detected by the immunoperoxidase technique from malignant melanomas and nevi of the choroid and conjunctiva.

By the peroxidase-antiperoxidase technique, the authors studied 7 malignant choroidal melanomas, 7 conjunctival nevi and 1 malignant conjunctival melanoma with the aim to detect the presence of vasoactive intestinal polypeptide (VIP), adrenocorticotropic hormone (ACTH), gastrin, estradiol and testosterone. Positive staining reaction for VIP, estradiol and testosterone was observed in both malignant melanomas of the choroid and conjunctival nevi. The case of conjunctival melanoma was positive for VIP and ACTH but not for estradiol and gastrin.

Adolescent↗

PubMed1981