Ragnar Törnquist

Chamber Depth in Primary Acute Glaucoma

IT is well known that there is a connexion between a narrow angle of the anterior chamber and primary acute glaucoma. As the chamber angle differs in each individual, it may often be difficult to decide how it should be classified; there is no method of measuring the angle, and it is therefore justifiable to determine a measurement which gives an indirect indication of its size. The axial chamber depth can be measured with great exactitude, and it has been shown that a small chamber depth and acute glaucoma are remarkably often coincident (Rosengren, 1931). It has also been found that the shallow chamber in acute glaucoma probably exists before the onset of the disease (Rosengren, 1931) and is genetically determined (Tornquist, 1953). This particular structure of the eye may thus be considered to be a predisposing factor in the aetiology of the disease. However, little is known of the degree of reduction in cases of acute glaucoma or whether a difference in the predisposition can be related to varying degrees of shallowness of the anterior chamber. The following questions require consideration:

Retinal detachment. A study of a population-based patient material in Sweden 1971-1981. I. Epidemiology.

Abstract A population‐based series of retinal detachments (RD) collected during a 10‐year period (538 patients, 590 ‘cases’, i.e. diseased eyes including new RD after 6 months in the same eye) is reported. The annual incidence was 10.6 per 100 000 population. Bilaterality was observed in 11.2%. In this material preponderance of the right eye was found. In non‐traumatic RD there was a small sex difference, with a higher incidence among females. Older persons were at high risk of sustaining RD, as were myopes. In myopic males the risk increased with the degree of myopia and with increasing age. In myopic females the greatest risk was found in the age group 30–59 years. Myopic eyes are probably also more vulnerable to traumatic RD. Lattice degeneration was more common in middle‐aged than in older patients and was also more common in myopic eyes than in eyes with other phakic RD. High myopia (> –5D) was more frequent in patients with lattice degeneration than in those without. Aphakia was found to be an important predisposing factor for RD. A classification taking into account the above‐mentioned factors is proposed.

ANGLE‐CLOSURE GLAUCOMA IN AN EYE WITH A PLATEAU TYPE OF IRIS

In the type of primary glaucoma, which is characterized by episodes of increased pressure in the eye, as a rule followed by considerable symptoms (blurred vision, haloes, pains and nausea and sometimes vomiting), a closure of the angle of the anterior chamber can often be seen. An important predisposing factor is an originally narrow angle. The cause of the narrowness has only been investigated to a small extent. In general it has been considered as an instance of normal variation of the structure, as no latent pathological process could be seen. It seems likely that a narrow angle is often combined with an anterior chamber, shallow in its entirety, and it has also been shown that a small axial chamber depth is common in this type of glaucoma. The reduction is generally considerable, on an average 30 per cent (Tornquist 1956). The radius of curvature of the cornea is also somewhat reduced, not, however, to the same extent as that of the chamber depth (Tornquist 1957). Presumably there is a disproportion in the structure of the eye, e. g. an increased size of the lens in proportion to the size of the corneoscleral capsule (Priestley Smith 1890). A comparison between the axial chamber depth and the width of the angle shows that, as a rule, there is a considerable correlation. In a few cases, however, the angle may be narrow in eyes with a normal axial depth (Gradle & Sugar 1940). In these surely very rare cases the surface of the iris is flat instead of convex, while the most peripheral part is curved backwards. Thus, the iris has a shape resembling a plateau. Also in eyes of this type acute attacks of glaucoma may occur, probably caused by a closure of the narrow angle. Barkan (1954) and Chandler & Trotter (1955) mentioned the existence of such cases, and Chandler (1956) considered that there are some differences, from a clinical point of view, between them and the ordinary cases of narrow-angle glaucoma. I t is particularly seen in younger persons. Peripheral iridectomy is often not effective enough, and after the operation no widening of the angle is found as in other cases of narrow-angle glaucoma. At the eye-clinic in Gothenburg the following case of acute glaucoma in an eye with plateau-iris has been observed.

Retinal detachment. A study of a population-based patient material in Sweden 1971-1981. III. Surgical results.

Abstract. Surgical results and complications were studied retrospectively in 590 cases of retinal detachment in a population‐based material of 538 patients. Of the 590 cases 96.3% were operated upon, and 22.9% of these underwent one or more re‐operations. The technique used was cryo‐ or photocoagulation (100%) + scleral buckling or an encircling band (96%) + drainage of sub‐retinal fluid (80%). The surgical complications were intraocular bleeding (13%), choroidal detachment (7%), and proliferative vitreo‐retinopathy (5%). All complications were significantly more frequent after re‐operations. Complete re‐attachment was achieved in 78.1%. The re‐attachment rate was significantly lower in aphakic cases (66.7%) than in phakic non‐traumatic cases (80.8%). The visual acuity in re‐attached cases was better than 0.5 in 33.7% and better than 0.1 in 72.2%.

Corneal radius in primary acute glaucoma.

EXCEPT in hydrophthalmos very little is known about the size and shape of the cornea in glaucoma. About 100 years ago von Helmholtz (1855) and von Graefe (1857) supposed that the corneal radius increased when the intraocular pressure was rising. They thought that the shallow anterior chamber found in acute congestive glaucoma could be explained in this way. However, when measurements were made, no increase or only insignificant increases of the radius could be demonstrated. The shallow anterior chamber is probably the result of genetic factors creating a structure of the eye predisposing to acute glaucoma but not produced by the acute attacks themselves (Rosengren, 1930, 1931; T6rnquist, 1953, 1956a, b). No systematic investigations concerning the radius of curvature of the cornea in glaucomatous eyes as compared to normal eyes have been made. The transverse corneal diameter was measured by Smith (1890), who found that it was, on an average, about 0 5 mm. smaller in glaucomatous eyes than in normal eyes. The small cornea was thought to be combined with a small eyeball, and a disproportion in size between the corneo-scleral capsule and the lens was considered to be a predisposing factor in glaucoma. In the present paper a comparison is presented between the radius of curvature of the cornea in a series of cases of acute glaucoma and that in a series of normal eyes. The purpose is to elucidate the problems of the specific structure of the eye in this disease.

Retinal detachment: A study of a population-based patient material in Sweden 1971-1981. II. Pre-operative findings

Abstract In a population‐based material of patients with retinal detachment (RD), the pre‐operative findings in different subgroups were studied. In traumatic cases flap tears and round holes were found in at least as high a frequency as oral dialysis, or even higher. In aphakic cases subtotal or total RD was often observed on admission for surgery. A high proportion of aphakic eyes without lattice degeneration exhibited no breaks. RD in myopic eyes was usually large, and round holes were frequently found. Full‐thickness fixed retinal folds were more seldom seen pre‐operatively en myopic than in non‐myopic eyes. Lattice degeneration was usually observed in myopic RD patients of ages less than 30 years, but mainly in hyperopic or emmetropic eyes in patients over 60. In RD with lattice, multiple breaks were frequently found. A comparatively large group of RD cases without lattice were non‐traumatic, phakic and non‐myopic (40%). Most of these patients were 60 years and older. Flap tears were often seen, and the detachment was seldom large in this group.

Retinal detachment in aphakia.

In a prospective study five hundred consecutive cases of cataract operations were followed during ten years. Nine cases of retinal detachment were observed.

Bowen's disease of the cornea and conjunctiva.

In 1912 Bowen described a skin lesion which he called precancerous dermatosis. It has since borne his name. The concept precancerous had been coined as early as 1896 by the French dermatologist Dubreuilh and implies that the lesion more or less regularly becomes carcinomatous. Jessner (1921) reported the first cases of Bowen’s disease of mucous membrane (glans penis) and McGavic (1942) the first ones involving the cornea and conjunctiva. In the same year Ash & Wilder reviewed 93 cases of epithelial tumours at the limbus, 4 of them being classified as Bowen’s disease. Changes at the corneal limbus resembling Bowen’s disease have, however, previously been reported by German workers (cf. Contino, 1901; Heilbrun, 1910), i. e. before Bowen described his precancerous dermatosis. A type of diffuse papilloma at the limbus which Weymann (1932) reported was likened to Bowen’s disease of the skin.

Retinal detachment. A study of a population-based patient material in Sweden 1971-1981. IV. Prediction of surgical outcome.

Abstract. The association between the outcome of 531 surgically treated retinal detachments (RD) and preoperative findings was studied by logistic univariate and multivariate analysis. The following factors were significantly, and negatively associated with the surgical results: 1) previous RD in the same eye, 2) pre‐operative visual acuity less than 2/60, 3) cloudy ocular media and/or a poorly dilated pupil, 4) an RD area of more than three quadrants, and 5) no retinal breaks detected. In the multivariate analysis no significant association was found for 9 factors: open angle glaucoma, interval of more than 2 months between symptoms and surgery, aphakia, pre‐operative hypotony, absence of demarcation lines, posterior retinal breaks, pre‐operative proliferative vitreo‐retinopathy, sex and age. The significant factors combined with aphakia were studied in all conceivable combinations. The estimated probability of failure varied between 4 and 93%, indicating that the most important factors were observed.

DIAGNOSTIC AND PROGNOSTIC PROBLEMS OF RETINOSCHISIS.

During recent years increasing attention has been paid in retinal surgery to a condition which is usually known as retinoschisis. It is characterised by confluent intraretinal cyst formation leading to splitting of the retina whereby the layer of rods and cones with their nuclei remain in contact with the pigment epithelium, while the inner layers of the retina are elevated and gradually atrophy. Tlhe cause oi the disease is not established but it is presumed to be degenerative in nature.