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Biomedical subjects

E Midena

Publications and source records attributed to E Midena.

At least 37 records · Page 2Linked to original sources
PubMed1989

Studies on the retina of the diabetic db/db mouse. I. Endothelial cell-pericyte ratio.

The genetically diabetic db/db mouse is a model of type-2 diabetes, where nephropathy and neuropathy, but not retinopathy were observed. The authors studied the retinas (trypsin digestion technique) of 16 db/db mice and 16 age-matched litter mates (db/m; controls), divided into five age groups. They noted a marked increase in the ratio of endothelial cells to intramural pericytes in diabetic mice compared to controls. This increase resulted from a selective and highly significant loss of pericytes in db/db mice (p less than 0.05). Some strand-like and relatively acellular capillaries were also observed. The db/db mouse may represent an adequate model for studies on the pathogenesis of retinopathy.

Age Factors↗
PubMed1989

[Sorsby's pseudo-inflammatory macular dystrophy: laser treatment].

In 1949, Sorsby described a familial fundus disease with progressive visual loss and bilateral hemorrhages and exudates of the posterior pole. The dystrophy, whose inheritance was apparently autosomal dominant, was called pseudo-inflammatory macular dystrophy because of extensive macular lesions that could suggest a post-inflammatory change. The ophthalmoscopic signs include the presence of diffuse drusen-like deposits with extensive changes of retinal pigment epithelium and focal atrophy of the choriocapillaris, particularly in the posterior pole. Some eyes grow subretinal neovascularization, which appears associated to retinal edema, deep hemorrhages and hard exudates. These cases ultimately result in a disciform macular scar. Atrophy of peripheral fundus is typical of advanced stages. We present the case of three sisters whose fundus lesions resembled Sorsby's pseudo-inflammatory macular dystrophy. In two of them, where there was a great suspicion of macular subretinal neovascularization, the laser treatment seemed to positively condition the course of the disease. In our opinion, even though a generalized atrophy of the choroid and retina cannot probably be avoidable, laser treatment can delay the loss of central vision, by blocking the capillaries from leaking, thus preventing secondary destruction from bleeding and fibrosis.

Diagnosis, Differential↗
PubMed1989

Psychophysics and visual aging.

Visual psychophysics represent an invaluable way of studying the visual system aging process. First of all, the author considers the modifications induced by aging on the optic characteristics of the human eye. Subsequently, he outlines the specific reduction of visual acuity, contrast sensitivity, flicker fusion and color vision caused by optic nerve and visual pathway aging. He points to the role and importance of psychophysic investigations in the accurate definition of visual system aging.

Aging↗
PubMed1989

The anatomy and physiology of the optic nerve: historical notes.

The authors outline the historical development of anatomical and physiological acquisitions on the optic nerve. From the first descriptions of Alcmaeone of Crotone (6th century B.C.) through the Aristotelean school, we arrive at the systemization of Claudius Galen. After the medioeval parenthesis, it fell to Vesalius to give a new impulse to anatomical research. Varolio and Eustachi describe the exact point of origin of the optic nerves. Later observations involve both anatomists and physiologists. The question of the transmission of sensory messages is described (Willis, von Haller), as is the microscopic structure of the optic nerve (Zinn, von Leeuwenhoek). After the description of the decussation of the fibers of the optic nerve in the optic chiasma, research into this cranial nerve has an increasingly neurophysiological and neurochemical orientation, continuing until the recent discovery of axoplasmic flow.

History, 15th Century↗
PubMed1987

Retinopathy following radiation therapy of paranasal sinus and nasopharyngeal carcinoma.

Radiation retinopathy is a complication of the therapeutic irradiation of orbital and periorbital structures. The authors studied two groups of patients who had orbital (group 1) and periorbital (group 2) external irradiation. Radiation retinopathy occurred in 63.6% of patients in group 1 and 36.3% group 2. Retinal radiation damage showed a different clinical evaluation in the two groups, appearing earlier (mean, 11 versus 55 months) and with greater involvement of the peripheral retina in group 1 (with three cases of neovascular glaucoma). This study demonstrates that radiation retinopathy occurs in a significant number of cases when the eye is not totally involved in the irradiation field and shows at least two different clinical aspects in relation to the radiation treatment. It also suggests that portal design and choroidal circulation damage may represent important factors in the development of radiation retinopathy.

Adolescent↗
PubMed1986

Optic nerve involvement in diabetic retinopathy.

The Authors briefly review the problem of the involvement of optic nerve head in patients affected by diabetic retinopathy. It is suggested that optic nerve damage is always the result of a microvascular disorder involving the optic disc area. Diabetic papillopathy is considered in detail.

Adolescent↗
PubMed1983

Correlation between retinal pigment epitheliitis and central serous chorioretinopathy.

A 37-year-old woman had sudden blurred vision in her right eye due to multifocal disturbances of the macular retinal pigment epithelium. Fluorescein angiography showed multiple pigment epithelial window defects with minimal late hyperfluorescence. The course of the disease, interpreted as retinal pigment epitheliitis, was complicated by a central serous chorioretinopathy. The possible relation between the two entities is discussed.

Adult↗
PubMed1983

Presumed ocular histoplasmosis in Europe: a case report.

A case of presumed ocular histoplasmosis was diagnosed in a diabetic patient, and an angiographic study of the ocular lesions was carried out. Results of histoplasmin skin test and the specific complement fixation test were negative. The epidemiologic aspects of histoplasmosis in Europe are considered.

Complement Fixation Tests↗
PubMedDate not supplied

Fine needle aspiration biopsy in ophthalmology.

When noninvasive techniques fail to confirm or rule out the suspicion of a malignant lesion, fine needle aspiration biopsy may provide an efficient, economical and relatively safe method of obtaining material for cytological study. The technique may also be valuable for intraoperative morphological evaluation. Traumatic complications produced by fine (21-25 gauge) needles are infrequent and almost never serious, and concerns about tumor seeding through the procedure have been largely dispelled by recent studies. Reliable results require a high level of skill in performing the aspiration procedure and in cytologically examining the small amount of material obtained. The authors review the history, applications, techniques and complications of fine needle aspiration biopsy, presenting guidelines for and illustrations of its use in specific ophthalmic situations.

Animals↗
PubMedDate not supplied

Prevalence of microangiopathic complications in hyperglycemia secondary to pancreatic disease.

Diabetes secondary to pancreatic disease (PD) represents a useful model for the study of the effects of chronic hyperglycemia on microangiopathic complications in the absence of those genetic factors predisposing to Type I diabetes. Our aim was to evaluate the prevalence of nephropathy and retinopathy in a group of 86 patients with PD. The genetic pattern, assessed by the determination of HLA antigens, was different than in patients with Type I diabetes. A family history of diabetes was present in 53% of the patients. The prevalence of retinopathy was 37%. Eighteen percent of the patients with duration of diabetes less than 10 years showed an albumin excretion rate (AER) greater than 40 mg/24 hr. The prevalence of pathologic microalbuminuria (greater than 40 mg/24 hr) was found in 29% of the patients with duration of diabetes greater than 10 years. The prevalence of pathologic microalbuminuria is related to the duration of diabetes. Both diastolic and systolic blood pressure is positively correlated to albumin excretion rate (p less than 0.02), suggesting a possible role of hypertension in the evolution of nephropathy. Sixty-one percent of the patients with AER greater than 40 mg/24 h had retinopathy, thus confirming the close association between renal and ocular complications. Abnormal microalbuminuria and retinopathy were not influenced by a family history of diabetes. We conclude that the prevalence of microangiopathic complications is similar to that seen in Type I diabetes, and the metabolic abnormalities of diabetes can play a direct role in the development of diabetic microangiopathy.

Albuminuria↗
PubMedDate not supplied

Pregnancy does not induce or worsen retinal and peripheral nerve dysfunction in insulin-dependent diabetic women.

In order to verify whether pregnancy induces or worsens diabetic retinopathy or somatic and autonomic neuropathy, 16 insulin-dependent diabetic (IDDM) pregnant women, 14 age-matched nondiabetic pregnant women, and 12 IDDM nonpregnant women matched for age and disease duration were studied. Plasma glucose, HbA1c, and fructosamine were repeatedly assayed during pregnancy. Retinopathic and neuropathic endpoints were evaluated through ophthalmoscopy, electrophysiology of left peroneal and sural nerves (motor and sensory conduction velocities), and cardiovascular autonomic tests (deep breathing, cough test, lying-to-standing). In the IDDM pregnant women, evaluations were performed three times during pregnancy and 6 months after delivery. Good metabolic control was achieved during pregnancy. At baseline, nine IDDM pregnant women did not show signs of retinopathy, and seven had nonproliferative retinopathy. Only one patient showed worsening during pregnancy, but she improved after delivery. Motor conduction velocity, significantly lower in IDDM pregnant women, progressively improved, and, in the third trimester, was not significantly different from that of nondiabetic pregnant women. At baseline, none of the IDDM pregnant women had abnormal responses to cardiovascular autonomic tests. During pregnancy, the response to deep breathing appeared temporarily reduced in all pregnant women, possibly due to lowered ventilatory excursion at the end of pregnancy. In IDDM women with minimal or no retinopathy, and subclinical or no peripheral neuropathy, pregnancy does not appear to induce or worsen these complications.

Adult↗
PubMedDate not supplied

Reconstruction of conjunctiva with amniotic membrane after excision of large conjunctival melanoma: a long-term study.

PURPOSE: To evaluate, on a long- term basis, the role of amniotic membrane in the reconstruction of large conjunctival defects after excision of large conjunctival melanoma. METHODS: Four consecutive patients with diffuse conjunctival melanoma involving both bulbar and palpebral conjunctiva were studied. Conjunctival melanoma was completely excised (with wide clinically disease-free margins) and amniotic membrane immediately sutured to the surrounding conjunctiva and sclera to cover the conjunctival defect. Minimum follow-up was 48 months. RESULTS: Successful conjunctival surface reconstruction and physiologic fornical depth were achieved in all patients within 6 weeks. No recurrence of primary melanoma was observed during long-term follow-up. CONCLUSIONS: Amniotic membrane transplantation is an effective alternative in ocular surface repairing surgery after removal of large conjunctival tumors.

Aged↗
PubMedDate not supplied

In vivo detection of monosomy 3 in eyes with medium-sized uveal melanoma using transscleral fine needle aspiration biopsy.

PURPOSE: Cytogenetic prognostication of choroidal melanoma, particularly monosomy 3 detections, is limited to enucleated eyes or resected tumors. The authors developed an in vivo technique to detect monosomy 3 using transscleral fine needle aspiration biopsy (FNAB). METHODS: Eight eyes with medium-sized choroidal melanoma were included in this prospective study. A 25-gauge transscleral FNAB was performed during surgical procedure for brachytherapy, just before applying the radioactive plaque over the tumor base. Sampled material underwent fluorescence in situ hybridization (FISH) with centromeric probes for chromosome 3. Follow-up was >12 months. RESULTS: Transscleral FNAB yielded sufficient material in 7 of 8 eyes (87.5 %). Five of seven eyes had monosomy 3. No early or late complications were detected. CONCLUSIONS: This study demonstrates that medium choroidal melanomas may be safely sampled by intraoperative transscleral FNAB to detect monosomy 3 in vivo.

Aged↗