[Electro-ophthalmological responses in inflammations of various sections of the orbital visual pathways (author's transl)]

In a study of electro-ophthalmological responses of the EOG, the photopic and scotopic ERG, the OP and the VECP, in combination with fluorescein angiography and computerized perimetry, in 34 patients suffering from uveitis, chorioretinitis (lesions near the macula and at the periphery), papillitis or retrobulbar neuritis, the following results were obtained: Uveitis and chorioretinitis with lesions either near the macula or at the retinal periphery produce different responses; generally, pathologic responses of the EOG and ERG and normal VECP are obtained in cases of uveitis. Peripheral chorioretinal lesions lead to a diminution of the scotopic ERG, OP and EOG, in contrast to lesions near the macula, in which pathologically diminished amplitudes of the photopic ERG and VECP are found. In papillitis and retrobulbar neuritis, however, the most important peculiarity is the increase in latency and the decrease in amplitudes of the VECP, especially in retrobulbar neuritis.

Lysophosphatidyl choline in the aqueous humour during ocular inflammation

Phospholipase A and lysophosphatidyl choline (LPC) have been shown to induce significant changes in the lens permeability in vitro to cations and soluble proteins. During uveal inflammation, in various experimental models and in man as well, the levels of LPC in the aqueous humour have been shown to reach values which are harmful to the lens in vitro. In addition, a phospholipase is thought to be activated during the antigen + antibody + complement sequence. The possible significance of these findings is discussed in relation to the pathogenesis of complicated cataracts in uveitis and the possible role of the lens as a source of autoantigens in recurrent uveitis.

The role of prostaglandins in experimental ocular inflammations

Intraocular inflammations (uveitis) were produced in rabbits by intravitreal injection of killed and dried Mycobacterium butyricum or E. coli endotoxin, or paracentesis of the anterior chamber. The increase in permeability of the blood-aqueous barrier and the leucocyte migration into the aqueous humor were observed after these stimuli, although the leucocyte did not migrate after paracentesis. Topically applied indomethacin reduced these inflammatory parameters in the latter two models. However, ththacin, though the leucocyte was not affected by indomethacin, though the leucocyte migration was reduced. On the other hand, prostaglandin-like substances in thces of these substances were detected in the former model. These results indicated that, unlike the increase in the permeability of the blood-aqueous barrier after endotoxin injection andparacentesis, the response after M. butyricum injection is not mediated by prostaglandins. The role of prostaglandins in the leucocyte migration in these ocular inflammations was also discussed.

Chemotactic activity and cellular infiltration of aqueous humor in experimental herpes simplex uveitis

The degree of chemotactic activity of the aqueous humor for a specific type of inflammatory cell is in direct proportion to the extent of such cells infiltrating the aqueous humor of rabbits with either primary or secondary experimental herpes simplex uveitis. Chemotaxis may thus be a contributing factor in the pathogenesis of herpetic uveitis.

The structural basis of altered vascular permeability following intraocular inflammation

An immunogenic uveitis was produced in rabbits by the intravitreal injection of bovine gamma-globulin. Four to six months later, an alteration in vascular permeability was determined by greater accumulation of iodinated I 125 serum albumin in the previously inflamed eye than in the normal eye. An altered vascular permeability was found only in eyes with profound structural changes. Possible sites of extravascular protein leakage were: (1) proliferated blood vessels in the posterior chamber and vitreous; and (2) leakage through the disrupted and scarred ciliary epithelium. In eyes without evidence of altered vascular permeability, a persistent chronic inflammation was observed, and gliosis and chorioretinal scarring was prominent.

Serum obstruction of aqueous outflow in enucleated eyes

We perfused enucleated human eyes via the anterior chamber by the constant pressure technique. Infusion of human serum into the anterior chamber of enucleated human eyes for 30 minutes at 23 mm Hg pressure induced a 42% decrease in facility of outflow, which was not relieved by irrigation of the anterior chamber with balanced salt solution or alpha-chymotrypsin. Diluted serum also reduced the facility of outflow. Measured in a glass viscometer, diluted serum had less viscosity than undiluted, but interfered with outflow from the eye more than anticipated on the basis of viscosity alone. When we used lens depression to induce tension on the iridocorneal angle to simulate the effects of contraction of the ciliary muscle, outflow facility increased in control eyes that had not been exposed to serum and in serum-perfused eyes. However, the partial obstruction to outflow that had been induced by serum persisted. Normal serum components may become adsorbed or entrapped in the aqueous outflow system so as to obstruct outflow, and this may result in secondary glaucoma in eyes with chronic uveitis.

[ERG in Behçet's disease (author's transl)]

Rod- and cone-system electroretinograms from 16 patients suffering of recurrent posterior uveitis and one or more symptoms of Behçet's disease were studied. On the basis of an evaluation of the clinical picture and of the progression three stages of the disease were distinguished. These stages were compared to the changes in amplitude of the b-waves of the ERGs (Fig 1). The findings in this group of patients were also compared to those from 11 patients with "simple" posterior uveitis (Fig. 2). The electroretinographic results in both these groups were highly similar: in all patients progression of the ocular disease was accompanied by parallel reduction in amplitude of the b-wave of the ERG. All ERG responses were affected in a similar way: the rod-system was in general more severly affected than the cone-system in both groups of patients. On the basis of these data it appears that the ERG indicates the stage of retinal damage in posterior uveitis. However, we could not detect ERG changes characteristic for the Behçet type of uveitis.

Measurement of capillary function in eye diseases

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