[An in vivo OCT study of human natural accommodation in a 19-year-old albino]. / Etude in vivo de l'accommodation naturelle chez un sujet albinos.

Modifications of the anterior segment during accommodation of the eye under examination cannot be studied in a simple and direct way with anterior segment imaging techniques such as Scheimpflug photography, A Scan, B Scan, and UBM. With this equipment, it is necessary to stimulate the fellow eye in order to observe the variations of the analyzed eye. The techniques using ultrasound equipment can only be used with contact systems or with water baths that will modify the anatomical dimensions or the pressure of the anterior segment. With the Scheimpflug photographic technique, geometrical reconstructions are necessary and cannot be used in certain axes. Optical coherence tomography provides the advantage of producing non-contact images of the anterior segment in static and dynamic conditions that are then easy to use. The target of the optical system can be focused and unfocused with negative or positive lenses, thus reproducing the conditions of natural accommodation. With a normal subject, the morphological modifications of the crystalline lens behind the iris screen cannot be studied because the infrared light source used is blocked by the pigment epithelium. The absence of this pigment in an albino subject allowed us to study the modifications of the crystalline lens and the ciliary body during accommodation. In this study, we were able to definitely confirm all the modifications of the anterior segment as described by von Helmholtz in 1855, who, at the time, used very rudimentary optical procedures based on the reflections of a flame on the surface of the crystalline lens.

[Analysis of the eye's anterior segment with optical coherence tomography. Static and dynamic study]. / Analyse du segment antérieur de l'oeil avec un tomographe à cohérence optique. Etude statique et dynamique.

PURPOSE: To study the biometric modifications of the anterior segment depending on accommodation and age. To try and define their possible applications in certain fields of anterior segment surgery, in particular in refractive implants. MATERIAL AND METHOD: Anterior chamber biometry can be very easily studied with 1310-nm wavelength optical coherence tomography. The equipment has a fixation target that can be focused and defocused with negative lenses in order to stimulate natural accommodation. The human anterior chamber was therefore studied during accommodation. We studied 104 eyes of 56 patients aged between 7 and 82 years. Refraction was between +5D and - 5D. A single operator carried out all the measurements. The anterior chamber's horizontal diameter, the anterior chamber's depth, the horizontal pupil diameter and the horizontal radius of curvature of the crystalline lens' anterior pole were measured unaccommodated or after stimulating accommodation. RESULTS: The different static or dynamic measurements were compared to ametropia, age and accommodation. At rest, the average AC diameter was 12.33 mm, the average AC depth was 3.11 mm and the average pupil diameter was 4.26 mm. On average, for 1 D of accommodation, the crystalline lens anterior pole moved forward by 30 microm. There was a 0.3-mm reduction in its radius of curvature and a 0.15-mm reduction in pupil diameter. Several other measurements are illustrated on graphs. CONCLUSIONS: The AC OCT is a user-friendly instrument to evaluate the anterior segment and explore the anterior chamber (cornea, iris, crystalline lens, irido-corneal angle). The 1310-nm light wavelength is blocked by pigments preventing exploration behind the iris. However, the AC OCT is capable of providing good-quality images and a better visualization of the anatomical relationships of the anterior segment, even behind an opaque cornea.

[Refractive phakic IOLs: three different models and contact with the crystalline lens. An AC-OCT study]. / Contact entre le cristallin naturel et différents modèles d'implants réfractifs phakes. Etude avec l'OCT de chambre antérieure.

Three patients received three different models of phakic implants. With the usual slit-lamp examination method, we were not able to establish whether there was contact between the implants and the natural crystalline lens. Using the anterior chamber optical coherence tomography scanner (AC-OCT), we were able to demonstrate that there was direct contact between the natural crystalline lens and the three different phakic implants. A dynamic study of these contacts was carried out during accommodation. These observations show that examination of the anterior segment with the optical coherence tomography scanner is essential in refractive surgery.

[Evaluation of capsular block syndrome with an anterior segment OCT]. / Evaluation d'un syndrome de blocage capsulaire tardif avec l'OCT de segment antérieur.

A year after routine phacoemulsification and insertion of a soft posterior chamber IOL, a 59-year-old woman developed progressive moderate myopia. A syndrome of late capsular block was diagnosed following biomicroscopic examination, which was treated by Nd YAG laser posterior capsulotomy. The myopia disappeared immediately. This observation was illustrated with optical coherence tomography (OCT) developed for the anterior segment. After capsulotomy, the IOL moved backwards by 448 microm, which corresponds exactly to a--1D induced myopia.

Possible involvement of Von Willebrand factor in pancreatic graft thrombosis after kidney-pancreas transplantation: a retrospective study.

Early postoperative graft thrombosis remains the second cause of failure in pancreas transplantation. Thus, the aim of this study was to compare retrospectively coagulation and fibrinolysis in type I diabetic recipients of simultaneous kidney pancreas transplants having or not experienced thrombosis of their pancreatic graft. From December 1990 to August 1996, 30 simultaneous kidney pancreas transplants were performed in 30 uremic type I diabetic patients. Acute thrombosis of the pancreatic graft was observed among 6 patients (group A), whereas 24 did not develop thrombosis (group B) although 4 died from other causes. The control groups were composed of kidney transplant (group C) or haemodialysed (group D) non-diabetic patients, type I diabetics with HbA1C < 8% (group E) or > or = 8% (group F) who were not in end-stage renal failure and kidney transplant type I diabetic patients (group G). Beginning at least 6 months after transplantation, we analysed hemostatic factors (fibrinogen, thrombin, and prothrombin times), coagulation inhibitors (proteins C and S), fibrinolysis (plasminogen activator inhibitor) and endothelial cell abnormalities (Von Willebrand factor: VWf). Micro and macrovascular complications were evaluated on a score ranging from 0 to 12. Hemostatic factors, coagulation inhibitors and fibrinolysis were similar in groups A and B whereas VWf differed significantly in group A (3.49 +/- 0.93 IU/ml) as compared to group B (2.04 +/- 0.92 IU/ml) (p < 0.05). VWf was also significantly increased in group A relative to the control groups C, D, E, F, and G. The score of vascular complications was increased in groups A and B and significantly higher in group A (9 +/- 0.81 vs. 6.07 +/- 1.75) (p < 0.01), while a correlation (r = 0.812, p > 0.05) was observed between VWf levels and the severity of vascular complications. These results point out the possible involvement of VWf in the pathogenesis of pancreatic vein thrombosis in kidney-pancreas transplantation.

[Experience in hepatic transplantation. Report of 118 cases]. / Expérience en transplantation hépatique. A propos de 118 cas.

From February 1978 to November 1989, 118 orthotopic liver transplantations were performed in 106 patients, including 100 adults and 6 children; 11 of these grafts were performed before 1984. The study of this series emphasizes the casuistical peculiarities, with high incidence of alcoholic cirrhosis, 24/106 (22.6%) and of fulminating hepatitis, 17/106 (16%). The study of the results yields a real survival rate of 61% in the total series, 78% for the recent period including the past 3 years, and 86% if excluding the emergent cases. The comments also deal with the changes in the procedure and in postoperative complications, with some immunological issues and with the peculiar features connected with the insertion of this operation into a combined medical and surgical program of multi-organ transplantation.