Search PubMed⌕ Search

Biomedical subjects

M Zingirian

Publications and source records attributed to M Zingirian.

At least 37 records · Page 2Linked to original sources

[New occult choroidal vessels in age-related macular degeneration].

We studied the clinical characteristics and the natural course of occult choroidal new vessels (CNV) in 78 eyes with age-related macular degeneration (AMD). Cases were included in 2 groups characterized respectively by ill-defined subretinal ooze (group 1) and serous detachment of the retinal pigment epithelium (RPE) with adjacent areas of mottled pigmentation (group 2). Both these forms of occult CNV showed to have a slower evolution compared to the classic CNV occurring in AMD, but they also led to disciform scar and severe visual loss. Occult CNV of group 2, contrary to those of group 1, were often multifocal and extrafoveal. They had a greater tendency to hemorrhages and a faster and less gradual progression to fibrovascular scarring and visual loss. Fluorescein angiography showed choroidal filling delay in the macular region of 47% of eyes of group 1. A perfusion defect of the macular choroid could be the basis of the low perfusion pressure and the consequent low activity of CNV with the angiographic pattern of ill-defined ooze.

Aged↗

Perimetric aspects of optic nerve aging.

Perimetry analyzes the efficiency of the entire visual system, but reveals the deterioration of even one of its components. Optic nerve changes, especially those of ischemic nature, which most frequently involve the middle and advanced age, cause typical perimetric findings. Manual kinetic perimetry is particularly indicated for the detection and definition of sectorial and global contractions. Manual static perimetry provides precise information on defect depth. Automated static perimetry quantifies the defect density in a large number of positions and also provides data on the significance of changes recorded during the follow-up. In normal subjects every type of perimetry shows a physiological decay of light sensitivity as a consequence of the aging of the visual system (about 2 dB per decade) and the reduced efficiency of the optic nerve is undoubtedly one of the components of this functional deterioration.

Aging↗

Pattern dystrophy of the retinal pigment epithelium with vitelliform macular lesion: evolution in ten years.

We report an unusual case of primary dystrophy of the retinal pigment epithelium (RPE) in which a vitelliform macular appearance was associated with reticular hyperpigmentation resembling the pattern dystrophies of the RPE. The entire evolution of the disease was observed and documented step-by-step during a 10-year follow-up. During the progressive change of the lesions morphologic characteristics of butterfly, reticular and macroreticular dystrophy as well as Best's macular dystrophy could be seen. Pathogenetic relationships between all of these dystrophies of the RPE can be supposed.

Adult↗

Classification of proliferative diabetic retinopathy.

Using panretinal fluorescein angiography, three patterns (A, B, C) of capillary nonperfusion were identified in 308 eyes with proliferative diabetic retinopathy. Statistical analysis showed that there was a significant association with different retinal complications and clinical parameters. Pattern A (83.7%: midperipheral location of capillary nonperfusion) occurs in type I and II diabetes and is associated with early retinal neovascularization and focal macular edema. Pattern B (8.1%: capillary exclusions disseminated on the whole retina) is typical of young type-I diabetics and is complicated by early disc new vessels and ischemic maculopathy. Pattern C (8.1%: capillary nonperfusion confined to the peripheral retina) is observed in type-I diabetic females and associated with multiple, retinal new vessels, without maculopathy. This study also demonstrated that eyes with pattern B retinal ischemia respond less well to laser treatment than eyes with other pattern types. Various pathogenetic factors could lead to these three distinct types of proliferative diabetic retinopathy.

Capillaries↗

Comparing continuous and stepwise luminance variation in static campimetry using the Grignolo-Tagliasco-Zingirian projection campimeter.

In traditional static perimetry the remarkable precision achieved, resulting mainly from the lack of temporal factors related to latency, largely makes up for the relatively long time required to perform the test. Conversely, the increase in speed of the test and in the information content of the visual field charts counteract the lower precision attained with kinetic perimetry. If the influence of the latency time on responses could be kept at a low value, then adopting a static strategy, based on a continuous rather than discrete target luminance variation for threshold detection, could be justified. For this purpose a luminance variation time sequence designed to reproduce the conditions of the traditional static perimetric test was chosen. The test was performed on the Grignolo-Tagliasco-Zingirian projection campimeter, after comparing its clinical performance with the Goldmann perimeter. These two methods - one based on continuous variation, the other based on discrete target luminance variation - were compared using a 14-subject sample. We conclude that the presentation strategy based on continuous luminance variation can be regarded as a valid alternative to the traditional method.

Adult↗

Tapioca melanoma of the iris: a contribution to the fine structure and its significance.

A case of iris malignant melanoma, macroscopically classified as tapioca melanoma, was studied by electron microscopy. The tumor originated in the left eye of a patient, and a specimen was obtained during iridociclectomy. Two main types of cells were found: the differences between them concerned mainly the Golgi complex, mitochondria, RER and free ribosomes. The melanotic bodies, scantly represented, were carefully examined. The ultrastructural findings enabled us to classify these two types of cells as spindle subtype B and epithelioid types. A comparison of ultrastructural features observed in our case with those of other melanomas of the uveal tract and the skin allowed us further to stress the hypothesis of a nevoblastic origin of the tapioca tumor cells.

Adult↗

Densitometric analysis of macular fluorescein angiography.

The authors analyze the fluorescein angiographic features of the macula by means of an image processor. The densitometric variations occurring during the various angiographic phases, in the various age-groups of the subjects and with different retinal adaptations, are studied.

Adolescent↗

The fellow eye in retinal detachment.

The examination findings of the fellow eye of 534 patients affected by a unilateral retinal detachment are reported. Nearly 90% of these eyes showed degenerative areas and about 20% showed one or more retinal breaks. These findings are quite different from those reported in examinations of 'random eyes' and suggest that fellow eyes are 'high risks' that often need prompt prophylactic treatment.

Adult↗

The nasal step in normal and glaucomatous visual fields.

We used an original method of kinetic and static analysis to examine the nasal visual field. When the nasal step is less than 4 degrees wide and its depth is less than 0.5 log units it may be merely a physiological sign of the anatomic and functional asymmetry of the retina. Sometimes it is an artifact. The nasal step can also be a glaucomatous defect. In this case it is often an early sign and it is wider than 4 degrees and its depth is greater than 0.5 log units. Because of its typical shape and invariable location it is easy to discover by kinetic perimetry and easy to check by static perimetry. If it is an early glaucomatous defect, it can be reversed. In practice the nasal step is an early and characteristic glaucomatous field defect like the isolated scotomas in the Bjerrum area, and it is easily detected and can be used as a sensitive marker in the follow up of glaucomatous damage.

Glaucoma↗

The visual field examination and its automation.

An automated system for examination of the visual fields is described. The entire campimetric examination was simulated in order to enable an in-depth analysis of actual examinations. The program runs on a HP2100 computer with a 16K core. The main advantages of the system are: greater speed, less patient fatigue, greater reliability, repeatability and accuracy.

Diagnosis, Computer-Assisted↗

[Problems of automated perimetry (author's transl)].

The choice of the most convenient computer, the strategies for stimulus presentation, the fixation control, the presentation of results and the response objectivation are the main problems of automated perimetry, some of which are already solved, others are likely to be solved in the near future. The authors present their experiences on automation of perimetry and indicate future perspectives of this procedure.

Computers↗

[Chronic mucosynechial pemphigoid: so-called ocular pemphigus].

The so-called ocular pemphigus is an oculocutaneomucosal disease, the clinical manifestations of which have been recognized for over a century while its recognition as a nosological and histopathological unit is quite recent. The clinical picture in the eye consists essentially of progressive scar contraction which, preceded by a transient bullous phase, leads to symblepharon, entropion and trichiasis. Corneal complications, such as bullous eruption, erosions, proliferation of vasculoconnective tissue, supervene later. The final appearance is that of complete xerosis with total symblepharon producing a typical 'statute eye'. This local process may be accompanied by bullous lesions of the skin and mucous membranes but the general condition of the patient invariably remains good. In the advanced stages of the disease the appearance is described as 'pemphigoid facies'. The nosological place of ocular pemphigus has been a matter of debate. At various times it has been identified with pemphigus vulgaris, dermatitis herpetiformis of Duhring-Brocq, erythema multiforme of Hebra, Stevens-Johnson syndrome, syphilitic dermatitis bullosa and other bullous dermatoses. At present the condition is universally recognized as a clinical entity, referred to as chronic mucosynechial pemphigoid (CMSP). The anatomopathological picture is quite peculiar. The elementary lesion is a sub-epidermic bulla, hence easily distinguished from that of pemphigus vulgaris, which is situated in the Malpighian layer. This difference applies to the lesions of the skin as well as to those of the mucous membranes including the conjuctiva. In the conjunctiva, epithelial changes suggestive of its epidermization were demonstrated. The Malpighian layer shows a high glycogen and DNA content with overall reduction in enzyme activity. The dermis shows infiltration by lymphocytes, histiocytes and plasma cells, and a considerable increase in hyaluronic acid content. There are many areas of dermoepidermal separation with formation of bullae and the basal membrane is often missing. In some cases, in the centre of the bullae, we were able to demonstrate one or more lumps, consisting almost exclusively of hyaluronic acid, probably filtered in from the dermis across the altered basal membrane. Similar changes are met with also in other mucous membranes, that of buccal cavity in particular, even in ostensibly healthy areas. The histological and histochemical findings are sufficiently typical to justify early diagnostic biopsy in all suspected cases. The aetiology of the CMSP still remains debated. Two theories are under consideration at the moment, viral and autoimmune. The main argument in favour of the viral theory is that a cytopathogenic agent can be isolated from the blood of patients with different dermatoses of the pemphigus group, including the CMSP, whose cytotoxic activity can be passed through and potentiated by passage in cell cultures...

Adrenal Cortex Hormones↗

Preliminary results about a new remotely controlled projection campimeter.

A newly remotely controlled projection campimeter is described. The instrument can be remotely controlled either automatically by a minicomputer or manually by an operator. The introduction of the computer allows the elimination of the systematic errors due to the operator. Moreover, the campimeter is enabled to choose the optimal strategy for target presentations. The last task of the computer consists in the memorization of the graphical results, their comparison and their quantification.

Automation↗