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Biomedical subjects

E Sellem

Publications and source records attributed to E Sellem.

At least 19 recordsLinked to original sources

Migraine and glaucoma: an epidemiologic survey of French ophthalmologists.

Glaucoma is a common ocular disorder; a high intraocular pressure is observed in the majority of glaucoma (HIOPG) cases, but some patients have low-tension glaucoma (LTG). In the literature, some works link LTG and migraine, which is speculative of a potential role of a vasospastic factor or diathesis common to migraine and LTG. Using a standardized questionnaire based on International Headache Society (IHS) criteria, we investigated 954 glaucoma patients; 320 (33.5%) described a headache (migraine or tension-type headache) and 240 (25.1%) presented the IHS criteria for migraine. Migraine prevalence was not significantly different between HIOPG and LTG patients (22.8% and 32%, respectively) in this study.

Aged

[Psycho-functional and objective tests applied to early diagnosis of POAG, indications for general ophthalmologists and therapeutic incidences].

The early diagnostic of glaucoma (before the appearance of visual field defects) can be made in some cases with the help of certain objective tests and, to a lesser degree, with subjective or psychophysical tests. Retinal nerve fiber layer photography is certainly the most rewarding objective test, providing the technique has been mastered and there is a clear fundus view without chorio-retinal atrophy. The identification of nerve fiber defects is an almost sure sign of glaucomatous damage in the absence of other pathology. An abnormally small neuroretinal rim area can also be an indicator of glaucoma. However, no conclusion can be drawn if the value is within the wide range of normal limits. Electrophysiological tests in glaucoma patients at the present time give results that show too much variability and overlap with those of normals to be of practical value. The same can be said for subjective tests such as spatial and temporal contrast sensitivity (the flicker test, for example). The specificity and sensitivity of the tests are too weak to be useful for the diagnosis of glaucoma in 1992.

Color Perception Tests

Variations of vitamin D-like reactivity in the crustacean Orchestia cavimana during the molt cycle.

An investigation into vitamin D-like molecules has been performed on whole extracts of the terrestrial amphipod Orchestia cavimana, using a sensitive nonequilibrium assay employing 1,25-(OH)2 D receptor from calf thymus. Relatively large amounts of these secosteroid-like molecules were observed and they varied in concentration according to the stages of the molt cycle. The amplitude of these variations reaches a ratio of about 40 from the minimum in premolt to the intermolt sharp peak.

Animals

[Quantitation of the visual field].

With kinetic perimetry, the visual field chart had the appearance of a geographical map. Since the isopters were not geometric, their surfaces were barely measurable. However, with recent three dimensional computerised (or semi-computerised) perimetry quantitative evaluation of the print-out may easily be done. The visual acuity is expressed by a fraction or ratio. In a similar way our deficit ratio gives a percentage score of visual field volume defects. Using the Peritest, it is very easy to establish the field's deficit ratio. All the defects are classified and have a score. Scores are then added up to establish the deficit ratio. (The same procedure may be used with other perimeters like the Visual Field Analyser). Why express field loss as a deficit ratio? In the natural history of a Primary Open Angle Glaucoma (i.e. a disease of the visual field), the comparison between consecutive visual fields may be difficult. Instead of looking at a collection of print outs, it is easier to look at the numbers of the deficit ratio to appreciate if there is evolution of the disease. In discussions with the patient, it sounds better if the ophthalmologist speaks of a "percentage" of visual field loss: the patient may understand his own situation more easily. Each point is tested twice at each examination to give an idea of patient response fluctuation. Before finding progression of the disease, it is necessary to know the range of an individual's variation in answers. The principle of all sciences is to measure what is measurable, and to render measurable that which is not.

Computers

[Problems and their solutions in today's perimetry].

Progress in the development of perimetry has been slow but certain since the first description of the perimeter by Goldmann in 1946. The creation of static perimetry, and of threshold detection with the multiple stimuli analyser of Friedmann, have been important stages in its development. Automatic perimetry (A.P.) is now available, our choice of apparatus being the Peritest, this instrument combining all the possibilities of A.P. with multiple or single manual perimetry in a very flexible manner. The apparatus allows 153 positions to be examined in the central 25 degrees and 55 in the periphery. The examination is conducted at a suprathreshold level (+ 0,6 log. U) after determination of the patient's eye threshold. Results are grouped in classes on a special chart to facilitate assessment. It is now possible, with the same instrument, to perform a detection A.P. (very useful in suspected glaucoma), a confirmative and limited manual study and, if necessary, a consecutive refined analysis.

Glaucoma

[Modern perimetry: automatic or manual?].

The possible applications of computer assisted static perimetry are examined after one and a half year of personal experience. The general advantage of a computer-assisted perimeter may be the elimination of the influence of the perimetrist on the results. We have employed the PERITEST perimeter because this system allows either full automatic perimetry or two types of manual perimetry with presentation of single or multiple stimuli. All perimetric examination is done after the determination of the individual visual retinal threshold. The examination is always performed at a supraliminal level relative to the individual threshold. The following conclusions can be drawn: 1 - Even after complete elimination of the perimetrist's influence fluctuations in results may be observed. Furthermore, the longer examination the more important patient cooperation becomes in automated perimetry as compared to the manual procedure. So we concluded that the best strategy should be related to the studies of the visual field defects. 2 - For perimetry of presupposed normal visual fields, the multiple stimulus procedure is quite adequate. If some problem appears, the flexibility of the PERITEST enables the use of the single manual stimulus mode. The full automatic examination is done only when there are mild field defects and in intelligent patients. 3 - These techniques enable the description of a new presentation of the classical perimetry's signs of early glaucoma: a loss of 0,5 Log. U.L. (which has the same significance as an isolated relative scotoma.

Computers

[So-called ocular hypertension and new signs of primary open-angle glaucoma].

Between normal and glaucomatous subjects, a group with ocular hypertension exists which is not homogeneous as 10 p. cent of these will develop glaucoma. The problem is to select early eyes at risk. Three new methods of examination have been proposed: the response to the test of contrast sensitivity, the pupillary reaction test of Marcus Gunn, and photographic exploration of the nerve fiber layer of the retina.

Adult