Amaurosis fugax. A unselected material.

Forty-four unselected patients with amaurosis fugax (AF) have been followed for 4.6 years (mean 2.6). Thirty per cent had atheromatous lesions, 20% had miscellaneous diagnoses (temporal arteritis 5, transitory ocular hypertension 2, glaucomatous iritis 1, benign intracraniel hypertension 1), 50% consisted of young, mainly women, in whom no cause was found. Prior to AF 2 had hemiplegia, 4 TCI, one optic atrophy and suspicion in 3. None died, one developed hemiparesis and one macular degeneration. An individual conservative attitude to AF seems justified in this material.

The colour of the optic disc variation with location of illumination.

The variation of the colour of the optic disc was examined with a slit lamp and contact lens in 200 normal subjects simply by moving the image of the slit across the optic disc. This event was photographed in 15 subjects and colour densitometry was performed. The temporal part of the pale central excavation changes colour to red, when illuminated nasally and vice versa. The colour change could not be provoked in subjects with normal discs with flattening of the temporal disc sector. The whole neurorim reddens the whole way round when the slit hits the optic disc border, and dependent on fundus pigmentation slight redness was produced even when the slit was placed outside the disc in the neighbourhood of the border.

Retinal fluorescein angiography and hemoglobin A1C in borderline diabetes.

In a controlled study fluorescein angiography of the retina and measurements of hemoglobin A1C were carried out in subjects with slightly abnormal two-hour glucose tolerance and controls with normal glucose tolerance. Fluorescent dots were present in 50 per cent of the series with a reduced glucose tolerance. Leakage from retinal vessels was noted in 20 per cent. In the control group fluorescent dots were present in 25 per cent, of whom none showed leakage. In neither of the series did any subject display ophthalmoscopically visible signs of diabetic retinopathy. In the subjects with abnormal glucose tolerance the mean concentration of hemoglobin A1C was 5.88% +/- 1.15 (SD) and in the control group 5.11% +/- 0.85 (SD) (P less than 0.05) . No correlation was demonstrable between the number of fluorescent dots, hemoglobin A1C and age in the group with abnormal glucose tolerance, but a relationship was noticed between a hereditary disposition to diabetes mellitus and presence of fluorescent dots. Smoking appeared not to have any influence. The result of the present study indicates that incipient retinal microvascular changes and evidence of an early breakdown of the blood-retinal barrier may be present in subjects before diabetes becomes manifest.

Ocular hypertension. A 15-year follow-up.

A group of 55 subjects with ocular hypertension were followed-up after 15 years. They were detected at a glaucoma screening on the island of Falster between 2031 volunteer blood donors, and they had an applanation pressure of greater than or equal to 20 mmHg in one or both eyes. All the subjects were traced. Nine have died, all from general causes, and one of the deceased subjects was treated for simple glaucoma. Of the remaining 46 living subjects, 3 developed glaucomatous visual field defects despite treatment. In another 4 subjects anti-glaucoma treatment was felt to be indicated. Of the non-treated 39 living subjects, 20 had a decreased applanation pressure, well below 20 mmHg, and 19 had an unaltered applanation pressure. We found that neither the common blood groups nor a water provocative test performed in 1962 were of any help in predicting glaucomatous visual field defects. Central corneal thickness measurements performed in 1977 could not allocate the subjects to the groups simple glaucoma, applanation pressure greater than 20 mmHg or less than or equal to 20 mmHg.

Choroidal absorption angiography with patent blue V.

The vital dye patent blue V is used as a negative contrast dye in order to obtain information about the vascular filling events of the choroid in relation to the retinal circulation and the papilla employing intravenous injection and serial photography. Patent blue is bound to plasma proteins to a limited degree and the angiograms therefore do not only picture the choroidal vessels but also reveal the filling of the choriocapillaris and the transcapillary exchange. It is demonstrated by microdensitometry that the patent blue leakage and subsequent reabsorption is rapid, and that the choroidal dilution curve almost parallels that of the retinal vessels. Our measurements might indicate a diffusion of patent blue from the choroid to the papillary tissue.

Transitory blindness during ethanol and phenethylbiguanide induced lactic acidosis in a subject with diabetes mellitus. A case report.

Transitory blindness is described in a diabetic patient with typical ethanol- and phenethylbiguanide induced lactic acidosis. The blindness developed in the course of 8 hours, but the vision returned during treatment with iv bicarbonate, insulin and glucose. The condition is discussed in relation to a presumed inhibition of the oxidative metabolism in the retina.

The effect of magnesium sulfate on the absorption of acetylsalicylic acid and lithium carbonate from the human intestine.

Magnesium sulfate given orally in a hypertonic or isotonic solution did not alter the absorption of therapeutic doses of acetylsalicylic acid or lithium carbonate, despite a purgative effect in 10 volunteers. The concentration of magnesium in serum remained unchanged during the experiments.

The noncontact tonometer. Clinical evaluation on normal and diseased eyes.

The measurement of intraocular pressure with a noncontact tonometer was correlated to a Goldmann tonometer in 20 normal persons, 20 glaucomatous patients, and 8 patients suffering from corneal diseases. In normal persons the error in measurement for the noncontact tonometer was related to their skill in fixation, and in eye patients to height of pressure and corneal state. Acceptable correlation was found between noncontact tonometry and Goldmann applanation tonometry when the cornea was normal and the pressure below 35 mmHg (Goldmann), otherwise noncontact tonometry was only a guide, and in the presence of corneal disease, unreliable. Good fixation reduced the method error. The standard deviation was 1.09 mmHg at poor fixation and 0.60 mmHg at good fixation. Repeated measurements on the same eye with noncontact tonometry did not alter the intraocular tension.