Ocular complications to diabetes and their treatment

Ocular complications to diabetes may be described as early or late, the late ones being by far the most important. Early complications are the frequently occuring transitory changes in refraction, and the more serious but rarely occuring diabetes cataract both possibly related to an overloading of the carbohydrate metabolism of the lens with accumulation of sorbitol. Oculomotor palsies (often III-nerve) and optic neuropathy may also occur. The pathogenesis of these lesions are unknown. Late complications comprise diabetic retinopathy (non-proliferative with or without maculopathy and proliferative), vitreous hemorrhage, vitreous membranes, traction detachment of the retina, hemorrhagic secondary glaucoma and a possible accelerating effect on senile cataract, and retinal vascular sclerosis. The treatment of the above mentioned complications is discussed, emphasis particularly being given to the retinopathy.

Corneal transplantation and HLA histocompatibility. A preliminary communication

A series of 222 cases of 7 mm penetrating corneal grafts were analysed with respect to the influence of HLA compatibility. The degree of compatibility was random as no matching was done (HLA types unknown at time of operation). Consequently, most of the cases showed 3 or 4 incompatibilities. The series was divided into seven diagnostic groups (keratoconus, herpetic keratitis, non-herpetic keratitis, stromal dystrophy, endothelial dystrophy, mechanical lesion and corrosion). In all groups there was a tendency towards better results among the compatible transplantation, but only when considering the entire series could statistical significance be demonstrated. The groups of 0--2 incompatibilities showed fewer rejection episodes or opaque grafts than the groups of 3 or 4 incompatibilities (chi 2 = 9.20, P less than 0.005). Comparing only the frequency of opaque grafts among the two groups the correlation was less significant (chi 2 = 3.66, P similar to 0.05).

Early postoperative changes in graft thickness after penetrating keratoplasty. Influence of host corneal disorder on time course

In 172 patients the thickness of the corneal graft was followed with frequent measurements during the first 14 days after operation. Three different graft thickness time courses were observed. Patients with keratitis, stromal dystrophy and corrosion or mechanical lesion showed a secondary rise in graft thickness on the 6th postoperative day, while patients with keratoconus and those treated with tranexamic acid showed no rise on the 6th day. Patients with Fuchs' dystrophy differed from the other groups in not reaching the maximal thickness until the 3rd postoperative day. The possible correlation of these three time courses with changes in the fibrinolytic system is discussed.

Studies on the handling of retinotoxic doses of iodate in rabbits

Accumulation of iodate in eye tissues and fluids as a possible explanation of the retinotoxic effect of iodate has been studied by intravenous injection of NaIO3(30 mg/kg), 125IO-3 and 131I- in rabbits. 125IO-3 was determined in fluids and tissue extracts by precipitation with BaCl2 after addition of KIO3. 125IO-3 was rapidly broken down in blood (T 1/2 = 14 min.). 125IO-3 was not present in aqueous humour, vitreous or extracts from retina, choroid + pigmentary epithelium or liver. Concentrations of 125I were comparable in blood, choroid + pigmentary epithelium and liver tissue while in vitreous and aqueous humour low concentrations of 125I were found which, however, increased gradually during 5 hrs after injection to reach levels comparable with blood levels of 125I. Retina had a low concentration of 125I. The ratio 125I/131I (R) in blood decreases during the first 60 min. after injection followed by a slow rise. R in retina, choroid + pigmentary epithelium and liver was the same as in blood at the same time after injection. During the first 80 min. after injection R was higher in vitreous than in blood while it was lower in aqueous humour than in blood. At longer times after injection R was identical in the three fluids. The investigation has been supplemented with whole body scintigraphy of rabbits injected with NaIO3(30 mg/kg) and 131IO-3 or 131I-. The reduction kinetics of IO-3 to I- by some body fluids, tissues, cystein and glutathione was also studied. It is concluded that the retinotoxic effect of iodate is not due to accumulation of IO-3 in eye tissues, but more likely to damage to biochemical mechanisms involved in the reduction of IO-3 to I-.

Management of late corneal graft problems

Immediately after an operation the corneal graft is taken care of by the surgeon, but after a certain period of time the control lies in the hands of the general ophthalmologist. Examples of the management of different kinds of postoperative complications are presented. Early correct treatment of any graft problem is of decisive importance. Careful slit-lamp examination and measurement of graft thickness is stressed and the prompt use of systemic and subconjunctival steroids is recommended for incipient graft failure. Systemic tranexamic acid may also be useful.

Amino acid transport in human ciliary epithelium

A statistical study of the co-variation of the concentrations of 19 amino acids and related compounds from 21 persons was performed as a factor analysis of Caq/Cpl and of Caq. Six factors explained about 83% of the observed variation. Factor 1 showed a correlation to alpha-amino-N-butyric acid, valine, methionine, isoleucine, leucine, tyrosine and phenylalanine, factor 2 to lysine, histidine, arginine and glutamine (containing serine), factor 3 to taurine and proline, factor 4 to glycine and cystine, factor 5 to urea and factor 6 to glutamic acid. Only alanine and threonine showed a correlation to different factors in the Caq/Cpl- and the Caq-matrix. This correlation of groups of substances to different and independent factors is considered to be an argument in favour of the existence of six transport systems in the ciliary epithelium for the investigated substances.

Free light chains in serum during short course immunosuppression after corneal transplantation

The effect of low doses of prednisone on the serum concentration oflight chains, IgG, IgA and IgM in nineteen corneal transplanted patients was investigated. Prednisone in doses of 30 mg daily for 6 days had an instantaneous effect on the concentration of light chains resulting in a mean decrease of 16.5% in relationship to the pre-treatment values. Decrease in the prednisone dose to 15 mg daily was followed by normalization of the light chain concentration. The effect of prednisone on the IgG concentration was less pronounced and more delayed. A mean decrease for IgG of 9.0% of the pre-treatment values was found. Minimum IgG concentration was found 3 weeks later than the minimum for light chains. Differences in the metabolization rate of light chains and IgG is suggested as an explanation for this. The concentration of IgA and IgM was unchanged during treatment. Correlation between corneal rejection and changes in the level of light chains or IgG was not found.

Central thickness in corneal disorders

In the single individual the central corneal thickness (CCT) shows only small variations. Therefore CCT has been studied in a number of corneal diseases in order to investigate if this dimension might contribute to the diagnosis or to the understanding of the pathogenesis. Normal CCT was found in hereditary dystrophies with the exception of the macular dystrophy of Groenouw (type II), which showed a significantly reduced thickness. Reduced CCT was found in chronic degenerations of leutic, tuberculous or indefinite nature. Marginal degenerations of Fuchs-Terrien type also showed reduced CCT. The possible role of abiotrophic processes in this corneal thinning is dicussed. Endothelial dysfunction is indicated by increased CCT. This occurs in bullous keratopathy and in many acute disorders. Vascularisation of the cornea does not preclude the occurrence of normal or even reduced thickness.

A double-blind study of the influence of tranexamic acid on the central corneal thickness after cataract extraction

A double-blind study of the influence of systemic tranexamic acid on the central corneal thickness after cataract extraction was performed in 17 pairs of patients. Apart from the cataract, no were present. A sequential statistics was used to show that the increase in central corneal thickness after operation was significantly less in the tranexamic acid treated group than in the placebo group. There was no significant difference in intraocular pressure between the tranexamic acid and the placebo treated group. The possible influence of tranexamic acid on the thickness controlling mechanism of the cornea is discussed, and studies concerning the fibrinolytic system, the complement system and the aqueous humour amino acid treated patients are mentioned.

Clinical copper metabolism parameters in patients with retinitis pigmentosa and other tapeto-retinal degenerations

Reports have appeared of abnormal copper metabolism in retinitis pigmentosa, and of a family with vitelliform retinal degeneration in which other members suffered from hepatolenticular degeneration. In the present study 15 patients with retinitis pigmentosa, 4 with various other retinal degenerations, and 1 with a family disposition to retinitis pigmentosa were examined. The copper concentration in serum and the coeruloplasmin concentration in plasma were found to be within normal limits. In 9 of the patients with retinitis pigmentosa the urinary excretion of copper per 24 hours was determined and was found to be normal. The results of the present study lend no support to the hypothesis of abnormal copper metabolism in retinitis pigmentosa.

Bullous keratopathy (Fuchs' endothelial dystrophy) treated systemically with 4-trans-amino-cyclohexano-carboxylic acid

Twenty patients with bullous keratopathy (Fuchs' endothelial dystrophy) were treated systemically with the antifibrinolytic drug tranexamic acid. The effect was evaluated by slit-lamp biomicroscopy, measurement of central corneal thickness and determination of visual acuity. The patients subjective complaints were also registered. The duration of the treatment varied from 3 to 16 months. In most cases the treatment was given over several periods with intervening free intervals. In all cases the central corneal thickness decreased and slit-lamp biomicroscopy revealed an improvement. The visual acuity improved and all patients became free of pain. A possible mechanism involving the complement system is discussed and preliminary studies on the composition of the aqueous humour in cases of bullous keratopathy are mentioned.

Central corneal thickness in newborns and children

Central corneal thickness was measured optically in premature and full-term babies and in children. The thickness was found to decrease from the values found in premature and full-term babies to those found in small children aged between 2-4 years. The thickness of the adult cornea is reached at the age of about 3 years. These findings are discussed with respect to the possible role of corneal thickness as a biometric parameter, to intraocular pressure measurement, and to corneal thickness steady state regulation.

Occurrence of lymphocytotoxic lymphocytes and antibodies after corneal transplantation

Twentyfive recipients of penetrating corneal grafts were investigated for the presence in the peripheral blood of cytotoxic lymphocytes by the Direct Cell Mediated Lympholysis (Direct CML) test as well as for lymphocytotoxic antibodies. Eight patients presented a positive Direct CML. Six of these patients have shown clinical signs of graft rejection, while two patients had a clinically uncomplicated course. Only one of the 25 patients had lymphocytotoxic antibodies. This patient showed a negative Direct CML, and a clinically uncomplicated course.. The findings seem to imply that recipients of corneal grafts can be immunized by their grafts and that cytotoxic lymphocytes in peripheral blood appear frequently in those patients showing graft rejection.

Central cloudy corneal dystrophy of François

A family is reported with central cloudy dystrophy of the cornea, as described by François in 1956. The lesion consists of a grey zone deep in the stroma, made up of polygonal or rounded areas with indistinct margins, separated by apparently clear, normal stroma. No deposits are visible in the slit lamp. The anterior and posterior boundary layers appear normal. The corneal thickness is normal. Open angle glaucoma was present in the family. The pathogenesis of the dystrophy is unknown, and histopathological examination has not been described. The differential diagnosis is briefly discussed. The family tree is suggestive of a dominant mode of transmission.

Visual functions after perinatal macular haemorrhage

Perinatal macular haemorrhage has been suggested as being a cause of amblyopia and strabismus. 39 of 48 children with macular haemorrhage after birth were examined at the age of 5 years. The study comprised visual acuity with E-test types and cycloplegic refraction. Binocular function was evaluated by cover test, and 4d-prism test. Fixation was studied by an ophthalmoscope with a central dark star. Sensory function was estimated by Schober test and Worth 4-dot-test. The observations gave no support to the existence of organic amblyopia or strabismus following perinatal macular haemmorrhage.

Demonstration of the hemiopic border in the normal person

The hemiopic border is the vertical line in the visual field separating the two halves which represent each cerebral hemisphere. This border, which becomes clinically manifest in the hemiopias, may be demonstrated in the normal person either (1) by covering an eye with the palm of the hand while facing the sun with the eyes closed, or (2) by fixing a near point and observing the background while the two eyes are dissociated by red and green glasses, or (3) by two-object perimetry, in which an inhibition may be observed along the vertical median through the fixation point.

Radiation treatment of retinoblastoma

In a series of 45 children with retinoblastoma, from the period 1953-1973, comprising 27 bilateral cases, 32 eyes were treated by irradiation. The different techniques of radiation are reviewed. In the present series small tumours were irradiated by local application of Stallard discs or Rosengren balls, while advanced cases were treated by external radiation. The results are discussed, and it is emphasized that the major factor of importance for the success of the treatment is the size of the tumour. Small tumours are cured, large ones are not. Future efforts must be directed towards early diagnosis. The treatment should be centralized in order to secure sufficient experience for the ophthalmologist and radiotherapist, as evaluation of the post- radiation fundus findings may present difficulties.

Remarks on the aqueous humor/plasma ratios for amino acids and related compounds in patients with various chronic ocular disorders

The concentration of 19 amino acids and related compounds was simultaneuosly determined by means of ion exchange chromatography in the aqueous humour (Caq) and blood plasma (Cpl) of 40 patients with various chronic ocular disorders. The physiological aspects will be published elsewhere. It is of interest to note that very few significant differences have been found between the Caq/Cpl ratios for the groups into which the material could be clinically divided. This enables the conclusion to be drawn that determination of Caq/Cpl for amino acids and related compounds are not of diagnostic importance in the chronic ocular disorders which were studied.

Biometric correlations of corneal thickness

Central corneal thickness, depth of anterior chamber, thickness of lens, length of vitreous, axial length, applanation (Goldmann) and indentation (Schiotz) tension and rigidity (Friedenwald) were determined in three groups of patients; (1) 16 patients with glaucoma simplex, (2) 25 patients with ocular hypertension, and (3) 26 patients with fibrillopathia epitheliocapsularis (so-called pseudoexfoliation of the lens). Average data and computed correlations between the parameters are given in tabular form. Corneal thickness was normal in glaucoma simplex, but significantly increased in ocular hypertension. Corneal thickness was positively correlated to applanation tension but not to indentation tension, nor to any other of the studied parameters. It is suggested that corneal thickness can be considered as a biometric parameter which yields new information about the eye not covered by the conventional parameters.

Quadrant sparing of the macula

Macular sparing is an indisputable clinical finding in cases of hemianopia. Several explanations have been given, some of which are not mutually exclusive. Eight cases, encountered in a study of more than 100 hemianopias, are presented, in which the sparing has the form of a quadrant, either upper or lower. The explanation in these cases seems to be the double vascular supply to the tip of the occipital pole. It is stressed, however, that macular sparing may have a different explanation in other cases.