J. A. Castrén

PATHOGENESES AND TREATMENT OF TERSON-SYNDROME

Subarachnoid hemorrhage is a disease where patients usually have been fallen ill with sudden signs of severe headache, nausea or loss of consciousness. It is also often followed by various kinds of neurologic signs (especially I11 and IV cranial nerve) and visual disturbances. The lumbal puncture always shows blood. Many die already in the first attack: the mortality varies from a few per cent to 50 (Tappura 1962). Various kinds of ocular signs have been described in connection of this disease and it has often been possible to make a diagnosis even prior to the lumbal puncture and angiography or obduction. Paresis of extraocular muscles and exophthalmus are seen sometimes. Changes in the size and reactions of the pupil are common. Rather often it has been seen that the borders of the disc are diffuse or that the disc is moderately choked. Particularly large hemorrhages in the fundus near the disc are common. One case has been described where the main ocular sign was a subconjunctival hemorrhage (Cucco 1951) and one case of hyphema (Walsh). Profuse bleeding into the vitreous in connection with subarachnoid hemorrhage (Tenon-syndrome) is so rare, that in the world literature until now only 16 cases have been described (Paunoff 1962). There is a difference of opinion, whether blood comes into the vitreous per continuitatem from inside of the scull froin the subarachnoid space between the optic nerve and its membranes (e.g. Paton 1924) or from ruptures in the blood vessels in the retina (Riddoch & Goulden 1925, MacDonald 1931 and Ballantyne 1943). During the last years the author has seen in our hospital several cases of vitreous hemorrhages which have come in connection to a subarachnoid hemorrhage. It was decided to study them, particularly because it was possible to see where the blood came from into the vitreous when treating these cases.

CORTICOSTEROID INJECTION OF CHALAZIA

Corticosteroid (triamcinolone acetonide) injection of chalazion intralesionally is an effective, easy and a safe method. Perfect recovery was achieved in 88% of 24 chalazion cases (22 patients). Most of them were cured with a single injection. The steroid therapy is most effective when the chalazion has not been secondarily infected. If this has already happened surgery is the method of choice. If the steroid injections are limited only to common non‐infected chalazia, the results will be excellent in about 100% of the cases. This treatment may be recommended especially for children and persons with allergy to local anaesthetics. It is particularly suitable for chalazia located close to the lacrimal punctum. Because of its simplicity, efficiency and almost non‐existent risks, this method should also be convenient to physicians other than ophthalmologists.

MYOPIA AND SCLERAL RIGIDITY

In a previous investigation (Castrdn and Pohjola 1961) we came to the same conclusion as many other ophthalmologists that the scleral rigidity of the myopic eye is lower than that in an emmetropic or a hypermetropic eye. I t seemed wellgrounded to us to study the relation between scleral rigidity and the degree of myopia, because the opinions about it are somewhat incongruous for the present. Furthermore, in an other previous work (Castrkn and Pohjola 1961) we noticed a tendency to a decrease of scleral rigidity at puberty, which might be associated with the origination of myopia. In 1937 Friedenwald found, that axial myopia of some diopters did not influence noticeable the scleral rigidity. With increasing myopia, however, the rigidity decreased. Friedenwald noticed further that in extreme myopia (more than 20 diopters) the rigidity did not decrease any more on the contrary it rised. He supposed this was due to the sclera having been stretched out to the uttermost. The scleral rigidity became again a question of current interest when Goldmann invented his applanation tonometer. He also found a low rigidity coefficient in myopic eyes. In 1959 Bock and Stepanik arrived at the same conclusion when determining the scleral rigidity coefficient of 57 myopic eyes. In myopia of 6-12 diopters the average of the coefficient was 0.017 and in eyes of 13-16 diopters 0.014. When the degree of myopia was 17-20 diopters the average coefficient was 0.015 and in myopic eyes of 21-25 diopters as high as 0.018. On the other hand, according to Becker and Gay (1959) the rigidity coefficient was lower than normal in myopic eyes of 1-5 diopters, but in myopic eyes of more than 5 diopters the rigidity gradually reached the normal level. In their study the average rigidity coefficient was 0.022, the mean in myopic eyes 0.018 and in eyes with 1-5 diopters myopia 0.015.

Contact lenses in hypoxia

Abstract. Seven women with soft contact lenses were examined during a 4 h period in a decompression chamber. The atmospheric pressure was lowered from the normal value of 1000 millibars (750 mmHg) to 560 millibars (420 mmHg), which corresponds to the altitude of 4000 m above sea level. The humidity, temperature, percentage of carbon acid and illumination were attempted to be kept even. Five test subjects developed subjective, and all the 7 also developed objective eye symptoms. It was concluded that hypoxia itself may cause eye discomfort for aircraft passengers with contact lenses. The most serious objective findings were corneal erosions in 3 and opacities of corneal stroma in 5 test persons. The control group without contact lenses did not develop any symptoms during the test.

Refraction and scleral rigidity.

The scleral rigidity is low in myopic eyes (Friedenwald 1937 and Goldmann 1955). According to Goldmann & Schmidt (1957), the rigidity coefficient of niyopic eyes varied between 0.0060 and 0.0136. They reported a mean coefficient value of 0.0203, whereas Friedenwalds tables are based on the rigidity coefficient of 0.0215. Lavergne ,pC Weekers & Prijot (1957) found in their investigation, that the rigidity coefficient of myopic eyes was 0.0150-0.0214. Heinzen & Luder & Miiller (1958) reported an average value of 0.0233 in hyperopic eyes, in emmetropic eyes 0.0220. In myopic eyes the coefficient varied between 0.0192 and 0.021 I. The results of Draeger (1959) are to a great extent similar: in hyperopic eyes 0.021 1-0.0220, in emmetropic 0.0199, and in myopic eyes 0.0144-0.0165. In a previous publication we reported a low rigidity coefficient at puberty, a period when myopia often develops or increases (Castrtn 8. Pohjola 1961). The present paper sets out first to study the rigidity coefficient by different refraction groups and second, to reveal if the rigidity coefficient in myopic eyes at puberty would be particularly low.

A CLINICAL EVALUATION OF MEPIVACAINE (CARBOCAIN) IN OCULAR SURGERY

Ekenstam, Egnkr and Pettersson synthetized mepivacaine in the year 1956 in the AB Bofors Nobelkrut laboratories in Sweden. The substance is d,l-methylpipecolic acid 2,6 dimethylanilide hydrochloride, and is available on the name Carbocain. It is a crystal powder which being a hydrochloride is easily soluble in water. It is boilfast and can be boiled up to several hours. In several both experimental and clinical studies it has been shown that Carbocain is a very useful local anesthetic in various kinds of surgery. Special attention has been paid to the long effect of Carbocain anesthesia compared e. g. to lidocaine (Alfthan 1962) and also to the superiority of Carbocair, compared to procaine or lidocaine when it is question of determining the side effect dose (Ulfendahl 1957 and Henn 1960). Out of the ophthalmological publications should be mentioned the study of Boberg-Ans (1958). In this study it was demonstrated that in five test persons the effect of the anesthetic upon the sensitivity of the cornea after a retrobulbar injection lasted two times as long as when lidocaine was used. Also, in the recent study of Vey, Finlay and Everett in 1962 where in 70 cases carbocaine and in 100 cases monocaine was given retrobulbarly, it was shown that the effect of carbocaine lasted about 2 times as long as the effect of monocaine. Carbocain was also found to produce an excellent duration of akinesia with no tissue irritation when used for retrobulbar injection in the Rhe*sus monkey (Everett & Vey & Finlay 1961). In our hospital the use of Carbocain was started in the year 1962. Soon afterwards some of our surgeons started to question the suitability of this substance in eye surgery. For this reason it was decided to study especially the side effects of Carbocain and to compare them to the side effects of lidocaine.

SGLERAL RIGIDITY AT PUBERTY

It is a well-known fact today that the intraocuIar pressure values obtained by the Schi~tz tonometer may differ notably from the true values, by more than 12.5 mm H g even. This is due more frequently to abnormal rigidity of the sclera than e. g. to the curvature of the cornea (Schmidt 1961). The use of a special rigidity coefficient by means of which the real intraocular pressure could be established was proposed by Friedenwald (1 937). Only since the appearance of Goldmann’s applanation tonometer, however, has it been possible to determine intraocular pressure and consequently scleral rigidity with considerably greater reliability than earlier. It was found that the deviation of a single rigidity estimate with the method of paired Schic?tz readings was twice as great as that obtained with applanation and Schietz tonometer (CastrCn and Pohjola 1961). Scleral rigidity and intraocular pressure are different at different ages according to Draeger (1959), with the rigidity coefficient decreasing and intraocular pressure increasing with age. His series, however, included only 14 eyes from persons under 20 and the rigidity value obtained from them was not statistically reliable. His total material consisted of 175 eyes. Rigidity seemed to decrease with age also in Ytteborg’s (1960) material of 166 eyes (the age of the persons examined was 12-92 years). The differences, however, were not significant. He, too, observed an increase in intraocular pressure with age though the difference was no more than 0.1 mm Hg between subjects aged 12-19 and 25-45. Twenty five of the eyes belonged to persons aged 12-19. On the other hand, Goodside (1959) for instance reported that the rigidity coefficient increases with age. His material was large, 852 eyes, but the measurements were made by the so-called paired weights method and not with an applanation tonometer.

INTRAMUSCULARLY ADMINISTERED ATROPINE AND THE EYE

I t is a common procedure to give operative patients also other than eye patients as premedication among other drugs intramuscularly administered atropine primarily to reduce secretion and to prevent the vagotropic reflexes. There seems to be a considerable amount of uncertainty about what effect the atropine injection may have on the eyes of a patient with glaucoma. Leopold and Comroe (1948) showed, using 8 persons with normai eyes as subjects, that intramuscularly administered atropine caused clearly less dilation of the pupil and weakening of the accommodation than scopolamine when used in equivalent doses. Schwartz and al. (1957) had a niaterial of 14 glaucoma simplexpatients. In lhis material the intramuscularly administered atropint: (0.4-1.0 ma.) caused a slight increase in the intraocular tension in only five eyes. On the other hand the pupil was dilated in 11 of 15 eyes. However the diameter of the pupil did not in a single case increase more than one mm. The treatment of the glaucoma had been interrupted 48 hours before the experiment in these patients. De Torres (1947) used moderately large intravenous doses of atrupine and notified in a material of 62 glaucoma patients that the intraocular tension was lowered in 38 and increased in as many a s 51 per cent. In only three patients the pupil did not dilate in all others i t did. When BQrBny (1962) studied the mechanism of the pilocarpine effect in the eye he injected atropine in apes both intravenously and also directly into the anterior chamber after administration of pilocarpine We refer to these studies in the discussion.

THE RESORPTION SPEED OF INTRAVITREALLY INJECTED TRACED PROTEINS

The chemical composition of the vitreous of a rabbi,t eye has been illustrated by e. g. Pirie 8c van Heyninger (1956), Long et al. (1961), Skmonin (1961), Cristiansson (1958) and CastrCn & Laamanen (1963). The resorption speeds of intravitreally injected implants have been studied by Widder (1962). He used precious gases (A, Kr and Rn), sodium chloride solution and hyaluronic acid solution in his experiments. He fixes considerably accurately the time of the variations in concentrations of these substances in experimental conditions. He observes resorption speed in correlation to molecule size by comparing the transfer of glucose amine solution and hyaluronic acid. The authors of this study think that Rinderknecht (1962) has presented a very suitable modification to the Novels method to trace the proteins fluorescent which in the biological milieu regularly are dissolved. This gave us reason to study the resorption speed of thus traced substances out of the rabbit vitreous. According to Pirie e. g. the total protein concentration of a cow vitreous would be 46 mg./100 ml.; 31.7 mg. of these globulins and 14.3 mg. albumin. Thus the above mentioned traced proteins would be characteristic and suitable for this purpose.

On vitreous implants.

Many kinds of experiments have been tried to substitute a losed quantity of the vitreous or to clarify a clouded vitreous. E. g., conservative therapy is still in use, but if it not has relieved the situation, more radical methods have been tried. Normal saline solution, cerebrospinal liquor and vitreous from an animal, another person, or from the one eye of the same patient have been injected in the other eye. In animal experiments also hyperand hypotonic saline solutions have been used, but with unsatisfactory results (Elschnig 1912). The intrabulbar injections of air and normal saline solution are well known in operations of retinal detachments. Romer proposed in year 1903 after animal experiments, that intrabulbar injections of hemolytic serum prepared with human blood corpuscles could be used in cases of vitreous hemorrhages. Elschnig, however, demonstrated, that this method cannot be adopted into use. H e recommended the utilization of normal saline solution. Levin and Knapp, both have with good results filled an eye with saline solution, when the eye had losed its vitreous to a great extent in a cataract operation. Elschnig had once a patient with traumatic scleral perforation, total retinal detachment, and a large loss of vitreous in the same eye. Elschnig sutured the perforation and injected normal saline solution in the eye: the retinal detachment disappeared and the vision became good. Many investigators have tried to eliminate vitreous opacities by removing vitreous from the eye in some way or other (Ford, Rosenstein, Komoto, Erlander, Blatt, Blaisch, Hamburg, Zirm, Bufili and zur Nedden). Usually about 0,5-2,0 cc clouded vitreous has been aspirated in a syringe and then substituted with clear vitreous, cerebrospinal fluid, or saline solution. Already at the end of the 19th century Weber and Deutschmann experimented with vitreous implants in cases of retinal detachment. W e do not know,