Kristen Arnesen

Ocular encephalitozoonosis (nosematosis) in blue foxes. Polyarteritis nodosa and cataract.

In young blue foxes an association has previously been established between the protozoon Encephalitozoon (Nosema) cuniculi and generalized arterial lesions of the polyarteritis nodosa type. The same vascular changes are found in the posterior ciliary arteries and their intraocular branches of these foxes. Most of the eyes which are thus affected, have a severe cataract. The parasite can easily be demonstrated both in the arteries and the lenses. It is thought that the Encephalitozoon is the cause of the vascular lesions and the cataract, and that possibly an autoimmune reaction is involved.

HISTOCHEMICAL STUDIES OF THE DEPOSITS OF BUSACCA IN EYES WITH GLAUCOMA SIMPLEX AND SO‐CALLED SENILE EXFOLIATION OF THE ANTERIOR LENS CAPSULE

The condition designated as the ,senile exfoliation of the anterior lens capsule<< was first described by Mulling (1923). This term implies the finding of an opacity or a grey film on the anterior surface of the lens. Malling even observed flakes attached to the zonula Zinni and the hyaloid membrane. The so-called exfoliation syndrome is seen with varying frequency in glaucoma simplex. The incidence is high in Norway, Greece, Egypt, Italy, and Russia, but low in England and Denmark. (For full references, see Sunde, 1956). There have been two different theories to explain this condition: (1) The ,>material of exfoliation<< consists of deposits on the surface of the lens and other structures in the anterior part of the eye (Malling, 1923, Busacca, 1928). (2) The process is interpreted as a degeneration of the lens capsule with shedding off (,exfoliation<<) of material from this structure (Vogt, 1931). Dvorak-Theobdd (1954) distinguished between >>true exfoliation<< and ,pseudo-exfoliation<<, and correlated the latter only with the deposits which had been described by Bzisacca (1928). She mentioned in her paper that Dr. George Gomori had found the deposits to be ,,moderately positive with periodic acid and to the Schiff and Millon tests<<, so that it >,may be assumed that mucopolysaccharides and tyrosine a re presents. In this presentation we shall not,

Malignant melanoma of the choroid as related to coexistent benign nevus.

Ninety‐five cases of malignant choroidal melanoma collected during a 15‐year period have been studied with special emphasis on histological type, coexistence of benign nevus, and prognosis. Elements of benign nevus were found in 78% of the cases. The data tend to support the hypothesis that most cases of malignant choroidal melanoma have their origin in a preexisting benign nevus, and that the tumours undergo a gradual change from a differentiated to a less differentiated type.

Plasmacytoma of the uvea in a case of multiple myeloma

Abstract A case of plasmacytoma in the uvea, both clinically and grossly anatomically mimicking a malignant melanoma, is described in a 63‐year‐old man who died from multiple myeloma. This is an extremely rare condition in the eye. Only one report of a similar tumour has been found in the literature.

MALIGNANT LYMPHOMA OF THE EYE AND BRAIN Report of a case

A case of malignant lymphoma (reticulosarcoma) of the eye and brain is reported in a 66‐year‐old man presenting clinically as bilateral uveitis. In the brain, the tumor was confined to the perivascular spaces and in the retina, tumor tissue was found round the retinal vessels, diffusely in the retina, in the subretinal space and to a very limited extent round choroidal vessels. It is postulated that originally the eye tumor was located in the perivascular spaces of the retina with secondary breaks into the other localizations.

REACTIVE CHANGES IN THE HUMAN RETINAL PIGMENT EPITHELIUM IN VITRO

Explants from the retinal pigment epithelium and the underlying choroid and sclera were dissected from human eyes and transfered to culture wells. The mechanical trauma caused by the dissection and removal of the explants, and the changes in biological milieu caused by transfer of the tissue to an in vitro system causes injury, necrosis and detachment of cells from Bruchs membrane. In the retinal pigment epithelium, cells adjacent to damaged, spherical and detaching cells and smaller cell free zones form rosettes. At the periphery of big defects, the cells spread out to cover the denuded areas of Bruchs membrane. The present work has shown that cell injury in the human retinal pigment epithelium is followed by reactive cellular changes in vitro. The result of these reactive changes are increased variation in cellular form and magnitude and in pigment concentration per unit area.

The neural crest origin of uveal melanomas.

On the basis of two cases the relation between ‘neurogenic’ tumours (neurinomas, neurilemmomas, Schwannomas, neurofibromas) and malignant melanomas of the uvea is discussed with emphasis on the close association of both groups of neoplasms with the ciliary nerves. The great histopathological diversity between different cases of melanoma as well as within individual cases is also pointed out. On histological and cytological criteria it may be difficult to differentiate between the ‘neurogenic’ tumours and the highly differentiated, spindle cell variants of the melanomas. Since all these tumours are derived from the neural crest, they might be grouped under one common heading. It is postulated that ‘neurogenic’ tumours have been overdiagnosed to the disadvantage of the highly differentiated spindle cell melanomas.

Orbitography with a new non-ionizing water-soluble contrast medium.

Metrizamide is a non‐ionic water‐soluble contrast medium which is isotonic with human blood and tissue fluid at a concentration of 170 mg I/ml. Ketrobulbar injection of 3 ml isotonic metrizamide in the muscular conus of rabbits causes slight and inconstant cellulitis, but a similar reaction can also be found after injection of the same amount of saline. It seems probable that the introduction of fluid sufficient to cause an increase in the retrobulbar pressure can cause inflammatory changes in the orbital tissue, and that this is not always caused by the contrast medium itself. Four patients were examined by orbitography with injection of 4 ml isotonic metrizamide. There were no side effects, and the orbitograms showed contrast of good quality. Metrizamide is therefore considered very suitable for orbitography, especially in hospitals where computer‐tomography is not yet available.

LATE RECURRENCE OF RETINOBLASTOMA

A case is presented with recurrence of retinoblastoma in a 14‐year‐old girl 12 years after irradiation treatment. The first eye had been enucleated for the same diagnosis at the age of 12 months. In the differential diagnosis between an inflammatory and a neoplastic condition in the eye, cytologic examination of material aspirated from the anterior chamber appeared useful.