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Biomedical subjects

T Olsen

Publications and source records attributed to T Olsen.

At least 91 records · Page 5Linked to original sources
PubMed1985

Diabetic retinopathy after one year of improved metabolic control obtained by continuous subcutaneous insulin infusion (CSII).

Twenty-four insulin dependent juvenile diabetics, with no or minimal background retinopathy, were randomly allocated to conventional insulin therapy (CIT) or continuous subcutaneous insulin infusion (CSII) administrated by means of a portable pump. The metabolic control was significantly improved in the CSII group as compared to the CIT group. After one year, a progression of diabetic retinopathy (criterion: development of more than 2 microaneurysms) was observed in 3 of 12 patients in the CSII group and in 4 of 12 patients in the CIT group (P greater than 0.05). A tendency to more severe progression was observed in the CIT group. None developed soft exudates or retinal proliferations. Although no significant beneficial effect of pump treatment could be demonstrated, it seems safe to conclude that pump treatment does not accelerate progression of diabetic retinopathy in patients with no or minimal background retinopathy.

Adolescent↗
PubMed1984

Is there an association between Fuchs' endothelial dystrophy and cardiovascular disease?

In order to investigate whether there is a clinical association between Fuchs' endothelial dystrophy of the cornea and atherosclerosis, the prevalence of cardiovascular disease was studied retrospectively in 27 patients with Fuchs' dystrophy and in 27 age- and sex-matched controls. The presence of cardiovascular disease was judged from a patient history of myocardial infarction, angina pectoris or heart insufficiency treated by medicaments and was found in 44% of the group with Fuchs' dystrophy and in 11% of the control group (P less than 0.05). The hypothesis is advanced that there may exist a common endothelial factor of possible significance for the development of corneal endothelial dystrophy, as well as the development of atherosclerotic lesions.

Adult↗
PubMed1984

Abnormal pupillary function in third nerve regeneration (the pseudo-Argyll robertson pupil). A case report.

A case of congenital oculomotor paralysis demonstrating retraction of the upper lid and constriction of the pupil in response to eye movements is described. The pupil was found to be unresponsive to light, but to contract promptly on attempted ocular movements which involved motor neurons of the third nerve. As demonstrated by infrared pupillography, the duration of the constriction phase was found to be remarkably long. Also, very little hippus was noted during constriction. The findings are explained on basis of the 'misdirection' hypothesis according to which regenerating nerve fibres find a wrong path in the peripheral part of the damaged nerve.

Adolescent↗
PubMed1984

Long term results of corneal grafting in Fuchs' endothelial dystrophy.

The long term results of grafting for Fuchs' endothelial dystrophy are reported in 25 patients with 33 penetrating keratoplasties, with a mean observation period of 50 months, 33% of the cases showed a visual acuity of 0.5 or better, while 42% had a visual acuity less than 0.1. The cause of visual acuity less than 0.1 was largely permanent corneal oedema, which was observed to develop in 39% of the cases. Some of the causes of oedema were accounted for by graft rejection, glaucoma and other obvious causes, but in a significant number of cases (12% of all cases), the oedema developed as a quiet, slowly progressive oedema without any obvious aetiology. It is tentatively suggested that the recurrence of oedema might be associated with the primary disease in patients with Fuchs' endothelial dystrophy.

Aged↗
PubMed1984

The thickness of the human cornea as determined by a specular method.

The thickness of the human cornea was measured by a simple accurate method which entails measurement of the distance between the anterior and the posterior corneal reflections when the cornea is illuminated at an angle. As compared to methods measuring the width of the optical section, the advantage of this method is that the end-points of measurement are clearly defined, providing a better basis for an exact estimation of the corneal thickness. The optical principle of this specular method is presented in a general form. The influence of physiological variation in corneal curvature and index of refraction is analysed and shown to cause an insignificant error on the standard thickness estimate. Using this method, the corneal thickness was measured in a random population sample of 115 normal subjects, aged 10-90 years. The corneal thickness was found to approximate a normal distribution with a mean value (+/- SD) of 0.515 mm (+/- 0.033). A significant decrease in corneal thickness with age of 0.0045 mm per decade was found.

Adolescent↗
PubMed1983

Long term results of corneal grafting in keratoconus.

Fifty-four corneal grafts in 45 keratoconus patients have been followed for 3 to 12 years (average 5.8 years). The corneal clarity, visual acuity, incidence of immune rejections, relation to HLA compatibility, corneal thickness and endothelial cell density are reported. At the follow-up 98% (53 out of 54) of the grafts were clear. Visual acuity was greater than or equal to 0.67 in 72% of the cases. Suboptimal vision was due to cataract or large astigmatism. Rejection had occurred in 5 cases (10%). The graft thickness was found to decrease steadily, reaching subnormal values about 1/2 year after the operation. Six years after grafting, however, the thickness did not differ from that of normal corneas. The endothelial cell density in uncomplicated cases ranged from 450 to 3000 cells/mm2, decreasing with length of post-operative period. The HLA compatibility could not be shown to influence the endothelial cell density.

Adult↗
PubMed1982

Post-operative thickness and endothelial cell density in cultivated, cryopreserved human corneal grafts.

Seventeen corneas obtained 2-72 h post mortem, from donors aged 17-78 years, were cultivated for 24 h, cryopreserved, thawed, cultivated for another 24 h and grafted. One year post-operatively 12 of the 17 grafts were clear. In 10 of these 12 cases the visual acuity was greater than or equal to 0.33. One primary graft failure occurred, while 4 primarily clear grafts became cloudy due to glaucoma (2), phthisis bulbi (1) and herpetic reinfection (1). One year after the transplantations the central thickness of the clear grafts was 0.51 mm, and the endothelial cell density was 1028 cells/mm2, corresponding to 32% of the cell density before cryopreservation. This endothelial cell loss was not correlated to donor age or to the time between the death of the donor and the primary cultivation.

Adolescent↗
PubMed1982

Light scattering from the human cornea.

A clinical method of measuring angular scatter from the human cornea is described. The method entails the use of a slit-lamp photometer with a pin-light attachment to control the angle of measurement. Corneal scatter and corneal thickness were measured in 93 normal subjects and 56 patients recently operated on for cataract. In the latter group, the surgically induced increase in corneal thickness was found to increase corneal scatter markedly, demonstrating the well-known dependence of scatter on corneal hydration. For the normal cornea, thickness and scatter were only insignificantly correlated. This finding was interpreted as evidence that the normal variation in corneal thickness is caused by a variation in mass content rather than in water content of the cornea. An increase in corneal scatter with age was demonstrated. Because this was seen at a constant corneal thickness, the mechanism was presumably that of age-related alterations in the latticelike organization of the collagen fibrils. These results suggest that clinical measurements of scatter may be used as a means to study hydration and ultrastructural characteristics of the human cornea in vivo.

Adolescent↗
PubMed1982

Corneal edema as a result of ischemic endothelial damage: a case report.

In a 79-year-old woman with temporal arteritis, an attack of corneal edema coincided with an ischemic attack of the anterior eye segment. Specular microscopy 17 months after the acute attack demonstrated a 72% endothelial cell loss on the side with previous edema as compared to the other side without corneal involvement. The development of endothelial damage is assumed to be caused by ischemia of the endothelial cells during the acute phase, which, in turn, caused the corneal edema.

Aged↗
PubMed1981

The endothelial cell density after cataract surgery in young patients.

The central corneal endothelium was photographed with a specular microscope in 14 patients in the age range 7 to 31 years, who, at the age of 3 to 22 years, had been cataract operated due to a congenital cataract. Mean endothelial cell density (+/- SD) of operated (n = 20) and unoperated (n = 8) eyes was 2479 (+/- 490) and 3140 (+/- 188) cells/mm(2), respectively (P less than 0.01). It is concluded that, like in older patients, healing of the endothelial layer in young patients does not involve cell proliferation to the extent of complete restoration of the cell density. The significance of these findings is discussed.

Adolescent↗
PubMed1981

Transient changes in specular appearance of the corneal endothelium and in corneal thickness during anterior uveitis.

Specular microscopic investigations on the corneal endothelium and optical measurements of the corneal thickness were carried out before and at intervals during treatment in 15 patients with acute anterior uveitis. The inflammatory induced changes in the specular appearance of the endothelium included a range of specular defects of which 4 types were distinguished: 1) large defects caused by large precipitates on the back of the cornea, 2) smaller defects also ascribed to precipitates, 3) gutta-like defects which were not associated with typical precipitates, and 4) defects smaller than one cell's width, the non-specular correlate of which was uncertain. The fractional area occupied by the specular defects in the acute phase was found to correlate significantly to the observed increase in corneal thickness. With a few exceptions, the endothelial changes disappeared completely in parallel with the other signs of acute inflammation. No cell loss was demonstrated in patients where a control count could be obtained. The maximum increase in corneal thickness ranged from 0.015 to 0.200 mm. During recovery the thickness showed a peculiar tendency to reach slightly subnormal values as a transient phenomenon. The clinical significance of these findings is discussed.

Acute Disease↗
PubMed1981

Corneal graft rejection probably mediated by antibodies.

A clinical and laboratory analysis of a rejection episode is presented. A clear graft in a non-vascularized cornea from 1975 was rejected when the contralateral eye was grafted in 1979. Clinically this case was unique by showing no endothelial rejection line and no precipitates and, as seen after successful treatment, no endothelial cell loss. A test for direct cell mediated lympholysis (DCML) was negative while antibody dependent cell mediated cytotoxicity (ADCC) was positive at time of rejection, and negative three months later. This case suggests that humoral factors may be involved in corneal graft rejection.

ABO Blood-Group System↗
PubMed1981

Fresh and cultured corneal grafts compared by post-operative thickness and endothelial cell density.

Thirty-nine corneas were removed within 6 h post mortem and stored in a moist chamber at 4 degrees C before grafting. The mean donor age was 33 years and the average time between death and grafting was 11 h. Thirty cadaver corneas were selected after trypane blue staining and cultured at 31 degrees C for 24 h before grafting. The mean donor age was 61 years and the mean time between death and culture was 18 h. During the first 10 postoperative days fresh grafts were thinner than cultured grafts. One year after the transplantation the two groups did not differ significantly in regard to the clinical result, corneal thickness, or endothelial cell loss. This indicates that corneas from old donors with extended post mortem time can be used for transplantation after individual evaluation and corneal culture.

Adult↗
PubMed1981

Clinical observations on the corneal thickness and the corneal endothelium in diabetes mellitus.

The corneal thickness was measured by pachometry and the corneal endothelium was photographed by specular microscopy in 81 insulin-dependent juvenile diabetic outpatients. The corneal thickness of a normal group, diabetics without and with proliferative retinopathy was (mean +/- SD): 0.527 +/- 0.028, 0.544 +/- 0.028, and 0.566 +/- 0.027 mm, respectively (2p less than 0.01). As revealed in the specular photomicrographs, minute folds in the endothelial layer were found in 13 of the diabetics versus 1 of the normal group (2p less than 0.01). The cell density and the occurrence of dystrophic changes in the endothelium did not differ from those in normal persons. The augmented corneal thickness in the diabetic subjects is tentatively interpreted as minimal corneal swelling. It seemed to be present very early in the disease and may thus be one of the earliest clinically detectable changes off the diabetic eye.

Adolescent↗
PubMed1981

Corneal thickness in eyes with diabetic and nondiabetic neovascularisation.

The corneal thickness was measured in 20 patients with ocular neovascularisation of diabetic and nondiabetic aetiology. Mean corneal thickness (+/- SD) was 0.561 mm (+/- 0.027) and 0.499 mm (+/- 0.029) in the diabetic (n = 11) and the nondiabetic groups (n = 9), respectively (2p less than 0.001). The increased corneal thickness in the diabetic group is comparable to that previously reported in diabetics with proliferative retinopathy. These results indicate that the increased corneal thickness found in diabetics is peculiar to the diabetic eye and not secondary to the process of ocular neovascularisation as such.

Adult↗