PubMed Health⌕ Search

Biomedical subjects

W A Houtman

Publications and source records attributed to W A Houtman.

9 recordsLinked to original sources
PubMed1992

Late consecutive exodeviations.

A retrospective study was made of the case-histories of 48 patients with late consecutive exodeviations, which had occurred after surgical treatment of a primary convergent squint. An evident predisposition towards the late appearance of the exodeviation could not be demonstrated. In some cases there seemed directly to have been a slight overcorrection, within the limits of operative success. In spite of the attempted overcorrection in a second operation on account of 'exodrift', recurrence of the exodeviation often occurs.

Adolescent↗
PubMed1991

Alternating hyperphoria. Dissociated vertical deviation (DVD) 'occlusion hyperphoria'.

Alternating hyperphoria (synonyms: dissociated vertical deviation (DVD) or occlusion hyperphoria) and variants like 'unilateral patching hyperphoria' ('periodic vertical squint') and monocular vertical nystagmus, which may arise after strabismus operations or loss of the function of one of the eyes, have dynamic properties which differ from those of the vertical vergences or fusional movements in normal binocular vision. Alternating hyperphoria is the result of an early intense disturbance of binocular vision, leading to the absence of vertical fusional vergence or the detection of disparity necessary for this. Vertical disparity vergence is essentially a stabilizing and adaptive system.

Adolescent↗
PubMed1990

Reaction of the rabbit corneal endothelium to nylon sutures. A SEM study.

Nylon and stainless steel sutures separately placed deeply into rabbit corneas by splitting the stroma for a few millimeters, without closing sutures, remained in the cornea for two, four and six weeks respectively. In contrast to the stainless steel sutures an extensive tissue reaction could be observed clinically around the nylon sutures within a few days and was still present after 4-6 weeks. On the endothelial side, covering of the nylon with fibroblast cells took place very slowly, this in contrast with stainless steel. Irritation of the tissue and an oedematous appearance of the endothelium around the nylon suture was the result. At first a kind of collagen network, often mixed with inflammatory cells, was deposited on the nylon material before fibroblast cells could grow in. Covering of the stainless steel started quite soon after implantation, without preliminary deposition of collagen material. The reason for this phenomenon must be sought in the high free surface energy of the stainless steel, which attracts cells, in contrast to nylon which has a very low free surface energy.

Animals↗
PubMed1989

Comparison of the reaction of the cornea to nylon and stainless steel sutures: an animal study.

In 11 rabbits a comparison was made between the reactions of the cornea to nylon and to stainless steel sutures, macroscopically and by means of scanning electron-microscopy (SEM). Macroscopically, the wounds sutured with steel thread showed much less reaction than the wounds sutured with nylon. Vascularization was never encountered in the wounds sutured with steel thread. SEM examination also showed clear differences, which became noticeable within a short time. Both on the suture and round the opening in the cornea extensive deposits of material are seen within a short time (1 week) in the case of nylon, in the case of stainless steel this reaction is much less marked. A few weeks later deposits also appear on the steel thread, but these have a different composition and contain no material suggestive of an inflammatory reaction.

Alloys↗
PubMed1979

Squint in monozygotic twins.

In a group of monozygotic twins, in which at least one of the pair squinted, strabismus was observed in both twins in only about half of the cases. Within the concordant group there was variation in the way in which the anomaly became manifest.

Adolescent↗
PubMed1979

Lacrimal sweating in a patient with Reader's syndrome.

A patient is described with a right-sided Reader's syndrome and extensive sweating in the frontal area above the right eye. This pathological sweating can be explained by sprouting of lacrimal parasympathetic fibres in the previous denervated sympathetic sudomotor pathways to that area.

Adult↗
PubMed1977

Vertical motor fusion.

An analysis is given of the eye movements which take place in vertical fusion. These movements are compared with the movements that occur in horizontal fusion. The differences and similarities that can lead to a model are stressed.

Eye Movements↗