Functional importance of central retinal artery anastomoses in the anterior part of the optic nerve

A three-dimensional study showed the existence of three vascular networks in the optic nerve: a peripheral, a periaxial and an axial one. The axial network, which was seen in 30% of the specimens, was formed by ramifying collateral branches from the pia mater of the optic nerve, but in the anterior part of the optic nerve there was an axial system which entirely depended on branches of the central retinal artery. This artery had important anastomoses with branches originating from the pia mater of the optic nerve and other collateral branches originating from the ophthalmic artery and its branches (the ciliary system).

[The sclerocorneal trabeculum following cortisone treatment and perfusion of the anterior chamber with hyaluronidase (author's transl)]

Following perfusion of the anterior chamber with hyaluronidase, a great reduction in the basic substance of the sclero corneal trabeculum as well as increased activity of the goniocytes were observed with the electron microscope. The opening of the trabecular meshes thus produced constitutes a kind of chemical trabeculectomy, attributable to the depolymerization of the hyaluronates of the basic substance by the hyaluronidase of the goniocytes.

[Tissue cultures of normal and pathological corneal epithelia (author's transl)]

The changes of the cornea epithelium in the case of macular dystrophy are secondary. Those in lattice dystrophy are primary, the epithelial cells exhibiting the characteristics of cancer cells as well as hypertrophy of the lysosomal system and vacuolisation with autolysis.

[Genetic counseling for parents of children with impaired vision]

What is the empirical risk of children being born with a disease or malformation? In healthy families, the parents being normal, the probability is 2 to 4%; when the parents are first cousins, although healthy, it is 5%. Of course, the risk if greater in affected families. When the mother or father is affected and there is no consanguinity, the risk if 20%, but when the parents are first cousins, it is 32.5%. When both parents are affected it is 100%. When the parents are normal but one child is affected, the risk for the other children is 25%. When the mother or father is affected and there is already one child affected, the risk for the other children is 50%. When a grandparent is affected, the risk for the grandchildren is 10%. When an aunt or an uncle is affected, the risk for the nephews and nieces is 7%. With regard to genetic counseling, the parents must understand that no physician can guarantee that a child will be normal. They must also understand that the mendelian risks are the same for each pregnancy. Finally, they must know that for each child there is a 2 to 4% risk of a major congenital anomaly. From the human and psychological point of view, the physician must convince the parents that they are not responsible and that both the husband and the wife may carry pathologic genes, as every individual carries 2 to 10 pathologically recessive genes. Finally, it is not the geneticist's responsibility to impose a decision. Only the parents can decide whether they want more children or not.

[Metabolic disorders and corneal changes (author's transl)]

The following inborn errors of metabolism may show corneal changes: A. Inborn errors of metabolism affecting the corneal epithelium: (1) familial dysautonomia, (2) tyrosinaemia type II, (3) Fabry's glycolipidosis. B. Inborn errors of metabolism affecting the corneal stroma: I. Localized amyloidosis (lattice dystrophy of the cornea), II. Defects in carbohydrate metabolism: (1) localized mucopolysaccharidosis (macular dystrophy of the cornea), (2) systemic mucopolysaccharides, (3) glycogen storage disease. III. Defects in lipid metabolism: (1) localized from (Schnyder's crystalline dystrophy), (2) systemic forms (hyperlipoproteinaemia, hypolipoproteinaemia, Lecithin-cholesterol acyl transferase deficiency, Wolman's disease, Gaucher's disease). IV. Combined defects in lipid and carbohydrate metabolism (mucolipidoses). V. Other inherited metabolic disorders: (1) aminoacidopathies (cystinosis, Wilson's disease, ochronosis, Chediak-Higashi syndrome), (2) hemochromatosis.

[Genetic counseling of parents of children with eye diseases]

What is the empirical risk for children to be born with a disease or a malformation? In healthy families, the parents being normal, the probability is 2 to 4% and when the parents are first cousins, although healthy, it is 5%. Of course, the risk is greater in affected families. When the mother or the father is affected and when there is no consanguinity, the risk is 20%, but when the parents are first cousins, it is 32,5%. When the two parents are affected, it is 100%. When the parents are normal, but when already one child is affected, the risk for the other children is 25%. When the mother or the father is affected and when there is already one child affected, the risk for the other children is 50%. When a grand parent is affected, the risk for the grand children is 10%. When an aunt or an uncle is affected, the risk for the nephews and nieces is 7%. In the case of genetic counseling, the parents must understand that no physician can guarantee that a child will be normal. On the other side, they must understand that the mendelian risks are the same for each pregnancy. Finally, they must know that at each birth there is a risk of 2 to 4% of having a major congenital anomaly. On the human and psychological point of view, the physician must convince the parents that they are not responsible and that, if a woman may be a gene carrier, the husband may also carry pathological genes, as each individual carries 2 to 10 pathological recessive genes. Finally, it is not the geneticist who has to impose a procreative decision. Only the parents have to decide if they want or do not want other children.

Complications in 1,000 consecutive intracapsular cataract extractions

In a series of 1,000 consecutive intracapsular cataract extractions, the most important peroperative complications were rupture of the capsule in 6.5% of the cases and vitreous loss in 3.0%. The most important immediate postoperative complications were delay in wound closure in 2.7% of the cases, iritis in 2.9%, ocular hypertension in 3.4%, and some other complications. The late complications were an Irvine-Gass syndrome in 2.8% of the cases, an epithelial downgrowth in the anterior chamber in 0.6%, and a retinal detachment in 2%. alpha-Chymotrypsin often causes a temporary ocular hypertension (in at least 25.2% of the cases). The functional results are very good, when there is no pre-existing ocular pathology: in 90% of the cases the vision was 7/10 or more.

Late extraocular tumours in retinoblastoma survivors

Radiogenic or non-radiogenic osteosarcomas were found in approximately 15% of the observed bilateral retinoblastoma cases, and only exceptionally in the unilateral cases. Such osteosarcomas are also seen in subjects without retinoblastoma, but belonging to affected families. Late second malignant extraocular tumours were only observed when we were dealing with a germinal mutation, that is in hereditary retinoblastoma. They are due to a pleiotropic effect of a single gene situated on the chromosome D13 (q14), or to two different but very close genes.

Congenital glaucoma and its inheritance

Congenital glaucoma may be associated, secondary or primary. Primary congenital glaucoma is due to the persistance in the anterior chamber angle of embryonic mesodermal tissue. Its inheritance is autosomal-recessive, sex-controlled and variable in penetrance. The treatment is surgical, goniotomy being as good as trabeculotomy.

Morphometric study of the hydration capacity of the scleral trabeculum after hyaluronidase action

The non-depolymerised mucopolysaccharides of the anterior chamber angle can become hydrated. This biological oedema can obstruct the trabeculae, but the physiological liberation of catabolic enzymes from the lysosomes depolymerises the mucopolysaccharides and prevents this obstruction. This is, on the contrary, facilitated by the corticosteroids, which reinforce the lysosomal membranes and impede the liberation of the catabolic enzymes. There are clones of goniocytes which are corticosensitive and others which are not. Depending upon the predominance of one or the other, the cortisone test will be positive or negative. The outflow facility of the aqueous humour is determined by the hydration state of the trabeculae. This state depends upon the polymerisation of the mucopolysaccharides of the trabecular skeleton.

Melanocytoma of the optic disc

On the occasion of the observation of 4 cases of melanocytoma of the optic disc, the authors stress the relative rarity of this pigmented tumor, its benignity and its frequent association with a choroidalnevus. The melanocytoma is mostly stationary and produces no functional symptoms. It is generally diagnosed after the age of 30, and its pathogenesis is unknown.

[Juvenile macula degeneration]

Among the various forms of juvenile macular degeneration, one can distinguish those that primarily involve: 1. The neuro-epithelium: Stargardt's disease; dominant juvenile degeneration; central or pericentral pigmentary retinopathy, progressive dystrophy of the cones and cystoid macular oedema. 2. The pigment epithelium: vitelliform degeneration of the macula, fundus flavimaculatus, Sjögren's reticulated pigmentary dystrophy, butterfly shaped pigment dystrophy of the macula and grouped pigmentation of the macular region. 3. Bruch's membrane: the hyaline dystrophies or drusen of the lamina vitrea and dominant progressive foveal dystrophy. 4. The choroid: central areolar atrophy of the choroid and Sorsby's pseudo-inflammatory dystrophy. -- All these macular heredo-degenerations are characterized by the fact that they are bilateral and symmetrical. For diagnosis and differential diagnosis not only the ophthalmoscopic appearance is important, but also the examination of the visual functions, which must include an electroretinographic and electro-oculographic examination, as well as the genetic study of the affected families.

[Toxic retinopathies]

Among the drugs, which are topically administered, only epinephrine may produce retinal changes (macular oedema) in aphakic patients. Among the drugs, which are systemically administered, some immunodepressors, ethambutol, indomethacine, digitalis, but particularly chlorpromazine, thioridazine, quinine and chloroquine may produce toxic retinopathies. Concerning the intraocular metallic foreign bodies, siderosis is much more toxic for the retina than chalcosis.

[Importance of heredity in ophthalmology (author's transl)]

On the basis of his studies on Fabry's disease, the dyscephalic syndrome of François, the ligneous conjunctivitis and the macular dystrophy of the cornea the author stresses the importance of heredity in ophthalmology.

Histoenzymologic study of hyalocytes in tissue culture

The mitochondrias of the hyalocytes contain lactic dehydrogenase but no glucose-6-phosphate dehydrogenase, so that only aerobic respiration is possible. Among the lysosomal enzymes, acid phosphatases and beta-glucuronidase are found, the latter facilitating the turnover of the hyaluronic acid. There is no galactosidase, as the hyaluronic acid of the vitreous does not contain galactose.

[Hyalocytes transplantation after pars plana vitrectomy (author's transl)]

The transplantation of cultivated hyalocytes after vitrectomy gave favourable functional results in 64% of the cases and appears to be a method of preventing atrophy of the globe and ocular hypotony after vitrectomy. We have nevertheless still to demonstrate that the results are better than these after injections of physiological saline.

Acquired macroaneurysms of the retinal arteries

Acquired macroaneurysms of the retinal arteries are rather frequent. Four new cases are reported. Aetiology, clinical features, fluorescein angiographic aspects, complications, prognosis, pathogenesis, differential diagnosis and treatment by photocoagulation are discussed.

[Hereditary demyelinating diseases - the leukodystrophies]

Schilder's disease and Greenfield's metachromatic leucodystrophy are hereditary demyelinating diseases, which are probably metabolic and lysosomal, although the responsible enzyme is not yet known for all.

Corneal infections by Rhodotorula

Rhodotorula, isolated from a human keratitis, was experimentally and microscopically found inactive, so that the question arises if micro-organisms found in a given eye lesion are always pathogenic. The answer is probably no.

[Keratomycoses]

(1) In the presence of a torpid corneal ulcer, resistant to antibiotics and accompanied by dirty exudates and a hypopion, one must always think of a keratomycosis. (2) A mycotic examination with direct microscopic examination, culture and sensitivity test should immediately be made. (3) At the present time the best antimycotics are miconasol and econasol.

Considerations on the importance of genetics in ophthalmology

On the basis of his studies on Fabry's disease, the dyscephalic syndrome of François, ligneous conjunctivitis and macular dystrophy of the cornea, the author stresses the importance of heredity in ophthalmology.

Neonatal or juvenile leucocoria

The differential diagnosis between the diseases which cause leucocoria is discussed. Among them congenital cataract, persistence of the primary vitreous, retrolental fibroplasia, retinoblastoma, Coats' disease, von Hippel's disease, inflammatory pseudoglioma, Norrie's disease, and organized intraocular haemorrhage are mentioned.

Excretion of vanilmandelic acid in the urine of retinoblastoma patients

The idea of determining the urinary excretion of vanilmandelic acid (VMA) in children with retinoblastoma derives from the fact that elevated amounts of VMA were found in children with neurogenic tumours and especially neuroblastoma. The method of VMA analysis and the results are discussed. In view of the fact that in only 5 out of our 12 patients an elevated urinary VMA excretion was found, we cannot recommend this determination as a routine diagnostic procedure. However, further research in this direction is necessary.

Scleral pockets and lyophilized sclera in retinal detachments

For our buckling operations in retinal detachment, we prefer lyophilized sclera because it is well tolerated without tissue reaction, and very easy to handle. Its inertness is demonstrated by histopathological examination of sclera fragments taken during reoperations.

Gyrate atrophy of the choroid and retina

A case of gyrate atrophy of choroid and retina is presented. The serum level of ornithine was 788 mumol/l. The clinical features, the error of metabolism, the inheritance and the treatment of the disease are discussed.

Albinism

There are seven forms of oculo-cutaneous albinism, which are all autosomal recessive: three are tyrosinase-negative (complete oculo-cutaneous albinism, Amish albinism, Hermansky-Pudlak syndrome) and four are tyrosinase-positive (incomplete oculo-cutaneous albinism, Chediak-Higashi syndrome, Cross syndrome, Bergsma's albinism). There are three forms of sex-linked albinism: ocular albinism, which is intermediary sex-linked, François-De Rouck syndrome and Ziprkowski syndrome, which show a generalized albinism and are recessive sex-linked. There are two principal forms of cutaneous albinism, one without deafness and the other with deafness (Waardenburg-Klein syndrome).

Relationship between the drainage of the subretinal fluid in retinal detachment surgery and the appearance of macular pucker

In a series of 470 rhegmatogenous retinal detachments, the relation between the incidence of macular pucker and puncture of the subretinal fluid was studied. We found macular pucker in 7.1% of the cases where a drainage was performed and only in 3.2% of the cases where it was not. In 85% of these cases, the macular region was preoperatively detached.

Differential diagnosis of leukokoria in children

The differential diagnosis between the diseases, which cause leukokoria, is discussed. Among them congenital cataract, persistence of the primary vitreous, retrolental fibroplasia, retinoblastoma, Coats' disease, von Hippel's disease, inflammatory pseudoglima, Norrie's disease, and organized intraocular hemorrhage are mentioned.

[Control of the viability of the endothelium of the graft in keratoplasty (author's transl)]

Since we use a very strict control of the viability of the endothelium of the graft, we have no more failures in corneal grafting, even not in cases with bad prognosis, such as Fuch's endothelial dystrophy. On the contrary, in corneal grafting without this control, we had a failure in 20% of the cases.