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A Pechereau

Publications and source records attributed to A Pechereau.

At least 37 records · Page 2Linked to original sources
PubMed1981

[Electro-oculographic study of vergence movements (author's transl)].

The study of vergence movements imperatively needs a recording method. Nowadays, in spite of its various drawbacks, electro-oculography is the most accurate method for clinical wants. The authors have studied the refixation vergence along a symmetrical inducing axis. With regard to both eyes in binocular and monocular fixations the analysis of a great lot of recordings in normal patients allows to reveal some phenomena unknown till now. In binocular fixation it is usual to notice a physiologic dyssynergy of vergence movements. The monocular fixations bear out evidence that Hering's Law doesn't apply to vergence movements. On the contrary they are submitted to a complete opto-motor dissociation, because the motor responses fully change according to the modalities of inducing visual inputs. In others respects, the analysis of all recordings proves that a vergence movement is made up with two synkinetic phases: a slow phase which was known for a long time thanks to physiological laboratory works; but also a fast phase having a saccadic feature. The fast vergence is related with a monocular visual attraction reflex and it is not bound only to the macular function.

Accommodation, Ocular↗
PubMed1981

[Electro-oculographie study of vergence movements. II. Asymmetric vergence (author's transl)].

In relation to symmetrical vergence, a study of asymmetrical vergence reveals, in normal cases, particular kinetic phenomena of the most marked degree. In binocular fixation, Johannes Müller's phenomenon is noticed on the axial eye. It exhibits reflex competition between fast and slow vergence, and is always impaired in amblyopias. Monocular fixation with the centered open eye induces a pure and slow consensual vergence on the excentric occluded eye. The movement is mainly be accommodative in nature, and anomalies are shown to very frequent. Monocular fixation with the excentric open eye induces a relative vergence characterized by a fast version phase, limited and corrected by a slow vergence phase. Relative vergence is largely impaired in amblyopias, convergence deficiencies, functional squints and oculo-motor palsies. Generally, the different methods for investigating kinetic vergence patterns reveal a more or less physiological asymmetry in sensori motor potentialities of each eye. This asymmetry strongly increases in nearly all oculo-motor disorders.

Electrooculography↗
PubMed1978

[The new surgery of functional esotropias (Faden operation and classical technics) (author's transl)].

This paper is the second part of a work devoted to the surgery of functional esotropias. The Authors bring a systematic study of fundamental motor impairments, and their particular management. Sucessively they consider the length, the alterations of contractible properties and the visco elastic changes of ocular muscles. Then they point out the partical means to reveal those troubles by clinical examination, electro-oculography, study of eye position during anesthesia and muscular traction test. They underline the advantages, limits and drawbacks of Fadenoperation. Theorically and practically, a too posterior scleral fastening is dangerous. To avoid some complications of Cupper's original technic, they use a personal procedure: the muscle slapping, which seems to give good results. Finally, they analyze central disorders. The electrooculographic recordings prove that motor troubles are certainly related with primitive visual impairments. They note that the frequent surgical cure means the muscle operations have a binding effect of proprioceptive nature on the central motor disorders.

Adult↗
PubMed1978

[New surgical technics in functional esotropias (the thread operation and classical technics)].

The surgical management of functional esotropias is now very different from some years ago with Fadenoperation settled by Cüppers. Indeed this procedure is the only one which can act in a fitted manner on muscular spasms responsible of more than 60% of convergent squints. The simultaneous using of classical technics remains necessary, but in very different way from the custom formely. In the first part of this work, the authors begin to analyze the mechenism of medical rectus recession, and they show that operation doesn't act by a modification in arc of contact as it was always said, but only by a muscular slacking. On the contrary the change in arc of contact is the main factor which intervenes in Fadenoperation, but the muscle exclusion has also an important part. Whereas the effects of Fadenoperation on adduction incomitance are perfectly clear, those on the deviation in primary position still remain very abstruse. A statistical report on 143 cases of operated blocking esotropias shows that often Fadenoperation alone does not bring a complete cure of motor troubles. The authors explain the reasons of these failures and point out the other accurate muscular actions which must be associated to obtain a good result.

Anesthesia, General↗
PubMed1978

[The new surgery of functional esotropias (author's transl)].

In two previous papers published in this journal, mechanic phenomena induced by the surgical procedures and the surgical management of fundamental troubles in esotropias were analyzed fully into details. In this third part, the authors explain the various pratical conclusions which result from their study. They underline that more than 60-70% convergent squints in children have a apastic component, and to overcome it classical procedures alone (resections and recessions) are fully unfitted. Equally, the Fadenoperation cannot by itself make away with motor disorders. Generally, the various technics must be associated to get cure. But to draw up an adequate surgical plan it is necessary to take into account the anaesthetic sign and the muscular traction test. The Authors have settled a pratical surgical scale allowing to know immediatly according to clinical and electro-oculographic findings, and the results to those tests, the particular operating actions which are convenient to do in each case and also their amount.

Electrooculography↗
PubMed1977

[The retro-equatorial muscular strapping. A technical adaptation of Cuppers's Faden-Operation. A preliminary report (author's transl)].

Reckoning up the Balance-sheet of about 300 Faden-operations performed during two years in blocking convergent squints, the Authors note that whether this operation is absolutely appointed in various forms of horizontal incomitances in which the spasmodic factor is prevalent on the other hand in moderate forms it does not seem to give better results than classic muscular surgery. After having detailed the characteristics and technical difficulties of this operation, first they mention that its effects are unforeseeable in spite of a previous careful clinical examination; then moreover, it has a binding character. In many cases reoperations allowed to notice a considerable sclerosis of the formerly operated muscle and neighbouring capsule. To avoid these drawbacks, instead of a muscular fastening, they make a retroequatorial strapping on the sclera. They describe the successive steps in their procedure, which appears having many benefits with regard to the original Faden-operation.

Child↗
PubMedDate not supplied

[Differential photo-oculography of vertical and oblique movements].

Up to now EOG has been the only method used to record ocular movements in daily practice. However such a mean has various drawbacks and limits. It has two main gaps: firstly for vertical movements because the interference discharges related with palpebral movements and blinkings; on the other hand for oblique movements because the unequal transmission of EOG potential towards the orbital rim. The differential photo-oculography perfected by Charlier et Buquet has been fitted and now can be easily used in clinical conditions. With this optical method, it exists a direct relation between the gaze direction and video signals of the eye. The authors point out the reliability of its results not only for horizontal movements, but also for vertical and oblique movements. This method allows a relevant analysis of all kinetic parameters whatever the moving axis may be.

Eye Movements↗