Ophtalmologie : organe de la Societe francaise d'ophtalmologie最新文献

After the theoretical analysis, the authors describe the experimental results of hydrogel intracorneal lenses in the rabbit stroma.

The Sonocare system CST 100 provides high-intensity focused ultrasound to lower the intraocular pressure by three different mechanisms: partial destruction of the ciliary epithelium, scleral thinning allowing transcleral outflow of aqueous humor, and mainly the ciliary body separation from the sclera. Initially it was used to treat blind eyes with painful elevated intraocular pressure; now the indications are gradually extended to eyes with good vision. This technique takes place between laser trabeculoplasty and filtering surgery. The first 395 cases which were treated with ultrasound these two last years in the Quinze-Vingts Hospital, are displayed in this report.

A drainage of aqueous humor from the anterior chamber to the subtenonian space using a tube and a scleral implant was performed in 22 eyes, previously unsuccessfully operated on for glaucoma. The results after a follow up of 12 to 36 months were good, specially in cases with undissectable conjunctiva (a 73% rate of success). The small incidence of serious complications incites us to use this technique earlier in the surgical treatment of uncontrolled ocular hypertension.

A randomized double-blind study of aqueous humor flow and intraocular pressure measurements before and four hours after instillation of placebo and beta-blocker eyedrops, was carried out in 40 hypertensive patients. The treated and non-treated patients either did or didn't show an optic disc excavation and a visual field defect. Hypertensive patients with a previous tension treatment will stop therapy on a 3-week period up to an increase of their own ocular tension value greater than or equal to 3 mmHg. The intraocular pressure statistically decreased of 20.8% four hours after topical placebo, the aqueous humor flow remaining unchanged. In this study, timolol eyedrops induced a greater decrease of the aqueous humor flow (39%), followed equally by betaxolol (23.8%) and carteolol (20.42%). Timolol and betaxolol eyedrops equally induced a significant decrease of the intraocular pressure. There was no effect of carteolol on the intraocular pressure. The outflow facility was independent of the instilled beta-blocker eyedrop.

The involvement of the retina in the inflammation being one important factor in severe uveitis, the authors have tested the "ganzfeld" electroretinogram (ERG) in various forms of uveitis, especially in cases having opaque media. In Fuchs' syndrome and chronic anterior uveitis, the ERG is normal or only slightly altered, while important reduction of the potentials can occur even in case of good vision in intermediate uveitis, probably indicating concomitant retinal vasculitis. In Behçet's disease, ERG is mostly useful in testing the efficacy of therapy. ERG can be rather deceiving in idiopathic vasculitis, where the potentials are not always as reduced as expected. On the contrary, this test seems to allow differential diagnosis between Harada's disease and acute multifocal placoid pigment epitheliopathy. However, one must bear in mind that concurrent steroid treatment can elevate the amplitude of the potentials, a phenomenon which has to be taken into account when interpreting ERG results.

Assessment of visual resolution with Teller Acuity Cards is now routine procedure in infant visual check-up. A grating is printed on one end of a card on an homogeneous background of the same mean luminance. A series of spatial frequencies at an interval of one half octave covers the range of infant acuity. Binocular and monocular acuities have been measured on 517 infants between 100 and 399 days of age. The cards can be used from a few weeks of age up to 18 months at least. Then it gets more chancy to keep the child attentive. Binocular and two monocular tests take 6 minutes with a normal child. Binocular grating acuity normally reaches 6.5 cycles/degree at 4 months of age, and 12 c/deg at 12 months. Monocular acuity is one half octave lower. From the level of acuity obtained and observation of the behaviour, amblyopia can be detected and low vision can be estimated easily in infants.

Aqueous flare and cells can be quantified by a new system, the laser flare-cell meter (KOWA FC 1000). Mydriasis does not influence the results, that can positively be compared to fluorophotometry. It is possible to precisely measure the surgical trauma, and inflammatory diseases of the eye.

This statistical study follows the one already made in 1987 on a series of 200 patients, 150 of them have been properly analysed after 24 months. It shows that after this delay the ECCE gives an efficient protection against complications especially in regard of central and peripheral retina.

Focused high-intensity ultra-sound is used to treat glaucoma. Histopathologic examinations of rabbit and pig eyes following therapeutic ultrasound demonstrated highly localized lesions including destruction of the ciliary epithelium and thinning of the sclera. The bond between the sclera and the ciliary epithelium is weakened. The conjunctiva remains intact. The histologic findings in human eye enucleated after ultra-sound therapy are identical. Three mechanisms for pressure reduction are proposed: transscleral outflow of aqueous humor can occur under the overlying conjunctiva; focal destruction of the ciliary epithelium can reduce aqueous production; scleral scarring produces the potential for separation of the ciliary body and the sclera.

3D vision assessment depends on monocular and binocular factors. In ophthalmology, it is clinically evaluated through the optometric examination which is not exhaustive according to the monocular elements and doesn't take on the visual stimulus quantification. The video and electro-optic displays can meet all these exigencies. The basic principles they share are exposed and then an illustration is given of their performance and their adaptation to the physiologic mechanisms. So is presented a study on the fusion area of heterophoric subjects depending on the stimulus spatial frequencies (the synthetic precisely quantified images shown were circular DOGs). This area is greatly modified following the variety of subject's heterophoria.