Epikeratophakia for high myopia

A cryo-technique for production of corneal epi-lenses has been developed. During the manufacturing procedure the anterior surface of the tissue is moulded and the posterior surface cut with a microtome. After cutting, the epi-lenses are stored for days to weeks in an organ culture medium. Twelve eyes in 10 patients have been treated with epikeratophakia for high myopia (greater than -7 D). In all eyes, epithelialization was complete within one week, and at follow-up 3-18 months after the operation all epi-lenses were clear. The average refractive change in spherical equivalents was 9.7 +/- 4.4 D. All eyes obtained better uncorrected visual acuity, and no eyes lost more than one line of the best corrected visual acuity. At the time of follow-up, the patients' native cornea had regained normal hydration, whereas the epi-lenses did not thin as much as expected.

A clinical comparison of optical and ultrasonic pachometry

Central corneal thickness (CCT) of normal and oedematous corneae was measured in a study comparing a modified Haag-Streit optical pachometer and an ultrasonic pachometer (Teknar Ophthasonic, preset velocity 1630 m/s). Sixty-eight patients were examined before and after cataract extraction with implantation of an anterior chamber lens. Mean values of CCT before operation were 531 +/- 4.9 (SEM) micron by optical pachometry and 524 +/- 4.7 microns when measured by ultrasound (not significantly different). On the first post-operative day the values were 618 +/- 8.4 and 602 +/- 7.6 microns for optical and ultrasonic measurements, respectively (significantly different, 2P less than 0.001). Correlation analysis showed a high dependence between the methods with coefficients of correlation being 0.955 before and 0.958 after the operation. Linear regression analysis revealed small, but significant differences between the techniques. The difference between the two methods increased with increasing corneal hydration, whereas it could not be ascribed to sex, age, or intraocular pressure. It is concluded that for clinical purposes optical and ultrasonic pachometry techniques are comparable.

HLA-DR/RFLP compatible corneal grafts

Fifty-one elective high risk transplantations were matched according to HLA/DR antigens and RFLP-subtypes. The 18 months survival of the grafts are 93% in the matched group compared to 50% in a non-matched compatible historical control group.

Effect of near normoglycemia for 5 years on progression of early diabetic retinopathy and renal involvement

The effect of strict metabolic control for 5 years on renal function and retinal morphology was estimated in 24 insulin-dependent diabetic individuals (age 29 +/- 8 years, diabetes duration 10 +/- 6 years) with albustix negative urine and minimal or no background retinopathy before the study. They were randomized to conventional insulin treatment (CIT) or continuous subcutaneous insulin infusion (CSII) with a portable pump. During CSII treatment the metabolic status was significantly improved. HbA1c fell from 8.9 +/- 2.0 to 7.4 +/- 1.3% (p less than 0.01) whereas HbA1c was unchanged during CIT treatment. The mean value of urinary albumin excretion (UAE) was not statistically significantly changed (from 12 +/- 10 mg/24 h to 13 +/- 5 mg/24 h in CSII patients and from 14 +/- 12 to 11 +/- 6 mg/24 h in CIT patients (p greater than 0.1). On the other hand, the elevated GFR values were significantly reduced in both CSII and CIT patients, 129 +/- 17 to 120 +/- 9 and 129 +/- 18 to 119 +/- 12 ml/min.1,73m2, respectively (p less than 0.05). Both the number of microaneurysms, haemorrhages and exudates tended to increase mor in CIT patients than in CSII patients during the 5 year study period, but the differences did not reach statistically significance (p greater than 0.1). Pump treatment did not induce proliferations or "cotton wool" exudates. We conclude that no statistically significantly differences between GFR values, UAE rates, and progression of background retinopathy was observed between normoalbuminuric IDDM patients treated for 5 years with CIT and CSII, respectively. However, due to the size of the material a type II error must be taken into consideration.

Long-term visual results in eyes cured for retinoblastoma by radiation

Twenty-four eyes from 18 patients cured for retinoblastoma by radiation on an average 12 years previously, were re-examined with respect to visual performance. The macular functions, i.e. visual acuity, colour vision and contrast sensitivity demonstrated performances predictable from tumour localization and radiation dose to the macula. The rod functions, i.e. visual field and dark adaptation were found to be relatively resistant to the radiation treatment. A special problem encountered in two-eyed patients was the unavoidable amblyopia due to unequal handicaps in the two eyes at the vulnerable age.

Some metabolic changes during human corneal organ culture

In order to evaluate the changes in medium composition during closed system corneal organ culture at 30 degrees C, pH, pO2, glucose and lactate was measured 1 to 7, 14 and 28 days after incubation of a total of 49 human corneas. During organ culture pO2 decreased from 17.3 kPa to 8.8 kPa at day 28. The average oxygen consumption was initially 0.16 mumole/h/cm2, but decreased rapidly to an average of 0.04 mumole/h/cm2 during the first weeks of incubation. The glucose concentration fell from 5.1 mM to 0.25 mM after 28 days, and the lactate concentration rose from 2.5 mM to 11 mM. The concentration changes were for both substances highest during the first 14 days of organ culture. The pH fell from 7.36 to 6.64 after 28 days. These findings indicate that the cultured human cornea predominantly metabolizes glucose anaerobically, and that the metabolic activity decreases during incubation. The limiting metabolic factors for prolonging the culture period seem to be development of severe acidosis and glucose depletion in the medium.

Exogenous, ocular, and systemic factors associated with keratitic ulceration

Information on type and frequency of empirically observed exogenous, ocular, and systemic predisposing factors for keratitic ulceration is important for clinical identification of groups at risk and may form a basis for planning experimental studies on the pathogenesis of ulceration. Therefore a retrospective study comprising 104 patients with 25 herpetic and 79 non-herpetic corneal ulcerations was performed. Patients with herpetic ulcerations were mainly males and were younger than patients with non-herpetic corneal ulceration. Keratoplasty and steroid treatment was found as frequent co-existing predisposing factors in the herpetic group. In the non-herpetic group an exogenous factor was found in 56%, an ocular factor in 56%, and a systemic predisposing factor in 46% of the patients. In only 2.5% of these patients was there found no predisposing factor. Pathogenetic mechanisms of predisposing factors for non-herpetic corneal ulceration is discussed.

Evaluation of keratoplasty in cases of post-inflammatory corneal opacity with vascularization

Penetrating keratoplasty was performed in 106 cases of post-inflammatory corneal opacity with vascularization. Donor material obtained post mortem was preserved in a moist chamber, MK-medium at 4 degrees C or in culture medium at room temperature. 55.7% of patients gained a useful vision after keratoplasty. The post-operative spherical error of refraction was found to be -1.4 +/- 3.6 D and the astigmatic error of refraction -3.3 +/- 2.0 D. The post-operative visual acuity was found to be 0.2 +/- 0.2. The ocular pathology associated with keratoplasty is discussed.

Evaluation of penetrating keratoplasty in keratoconus. Nine years follow-up

Penetrating keratoplasty was done in 104 cases with keratoconus. The donor material were preserved either as a whole eye in moist chamber at 4 degrees C, or as a corneoscleral segment in MK-medium at 4 degrees C, or in a tissue culture. The post-operative observation time varied between 6 months and 9 years. The visual acuity was found to be better than before surgery in 96%, unchanged in 3%, and worse in 1% of the cases. The average visual acuity was found to be after 6 months 0.25 +/- SD 0.2 and after 7 years 0.65 +/- SD 0.23. The post-operative spherical error of refraction was found to be -3.26 +/- SD 3.5 D, and the post-surgical astigmatism -2.6 +/- SD 1.9 D.

Pathology and pathomechanisms of epithelial microcystic and basement membrane abnormalities of the cornea

Four patients with 'microcystic epithelial abnormality' were studied. Photographs demonstrated biomicroscopically visible alterations taking place over months. The histopathology comprising intraepithelial basement membrane abnormalities and intraepithelial cysts is described at the light and electron microscopical level. The biomicroscopically grey-white microcysts correspond in size to the basement membrane abnormalities. The histopathologically described cysts are much smaller. The pathogenetic mechanisms are discussed and it is suggested that breaks in the normal basement membrane are a more likely initial event than a speculative 'primary cellular dystrophy or degeneration'. Cells grow beneath the basement membrane and lift it up into the epithelium. A subsequent intraepithelial synthesis of basement membrane material may account for part of the ultrastructural appearance. The epithelial cysts were found exclusively beneath the basement membrane. They are thought to reflect the cellular maturation which is altered by the inserted membrane. It is suggested that the cysts pass through stages of maturation, which account for the observed difference in appearance.

The influence of donor age and post mortem time on corneal graft survival and thickness when employing banked donor material (A five-year follow-up)

Sixty-three consecutive corneal transplantations employing banked donor material were grouped according to donor age and post mortem time, respectively, and followed at regular controls for 5 years. Twenty-six cases (38% belonging to a risk group i.e. had earlier had corneal transplantation(s) and/or vascularized corneas) with a mean donor age of 55.8 years were compared with 37 cases (35% at risk) with a mean donor age of 75.7 years. The five-year graft survival was 72.0% in the first group and 86.3% in the second group, however, the difference was statistically insignificant. In 27 cases (26% at risk) with a mean post mortem time of 17.4 h a five-year graft survival of 81.0% was found compared with 80.3% for 36 cases (44% at risk) with a mean post mortem time of 40.5 hours. No difference in graft thickness was demonstrated between any of the groups, and in all cases with surviving grafts normal values for corneal thickness were achieved. It is concluded that neither donor age nor post mortem time are limiting factors when selecting donor material for organ culture and corneal grafting.

Predictive value of flow cytometric DNA-analysis on fresh retinoblastoma tissue

The cellular DNA content and the distribution of tumour cells in different phases of the cell cycles has been analysed in 8 consecutive enucleated eyes with retinoblastoma. All tumours had abnormal ploidy levels. The analysis did not reveal any specific pattern in 2 tumours which had metastasized compared to 6 local tumours. The flow cytometric analysis alone or in combination with histopathology appeared not to improve the classification of large retinoblastomas.

Histopathological changes in an intraocular retinoblastoma-like tumour following photodynamic therapy

The histopathological effect of photodynamic therapy (PDT) was investigated in an intraocular retinoblastoma-like tumour in vivo. Eighty-two tumours were studied by light microscopy and 8 by electron microscopy. Damage of the vascular endothelium with dilation of the organelles was evident 1 h after treatment, followed by leakage of the blood vessels, tissue hemorrhages, and vascular collapse. Histopathological examination showed an overall pattern of shrinkage of the cytoplasm and pycnosis of the nuclei in most of the tumour cells 3-5 days after treatment. The tumour recurrence often developed from the periphery of the tumours and in a few cases from small islets of viable tissue. Use of high doses of Photofrin II or light energy was associated with damage in the light irradiated area both to the conjunctiva or cornea in the form of leucocyte infiltration or ulcers, and to the retina, which often developed edema and appeared severely disorganized, with damage of the photoreceptors.

Radial keratotomy for pseudophakic myopia

Cataract extraction with implantation of a standard power IOL occasionally gives rise to considerable post-operative myopia. When operation of the second eye is indicated, the question may arise whether the patient should be made strongly myopic in both eyes, be made anisometropic, or have the already implanted IOL exchanged for a weaker one. We report here on 3 patients made isometropic and low-grade myopic after radial keratotomy in the myopic pseudophakic eye followed by cataract extraction and implantation of an IOL of predicted power in the second eye.

Treatment of central corneal ulcers by à chaud transplantation of organ culture preserved donor tissue

In the period 1979-83 a total of 232 penetrating corneal transplantations were performed with organ culture preserved donor material. Forty-two operations were made à chaud for central corneal ulcerations. The results of these interventions are reported and discussed. The surgery presented no serious problems and on first post-operative day the anterior chamber was reformed in all cases, and pain was relieved. Patients were confined to bed only for 1 day. Graft deswelling was slightly retarded compared to planned surgery, but all functioning grafts obtained normal thickness. The overall graft survival rates after 6, 12 and 18 months were 66, 53 and 48%, respectively. For herpetic ulcers the survival after 18 months was 49% and for non-herpetic ulcers 47%. The grafts failed in all cases where it had been necessary to employ grafts of more than 10 mm. This latter group was comprised of the non-herpetic cases; were they excluded, the graft survival rate would increase to 60%. Among cases with a clear graft the median visual acuity after 18 months was 0.33 (range less than 0.1-0.67). Excluding cases with a non-corneal cause of visual reduction, the median visual acuity was 0.4 (range 0.33-0.67). It is concluded that grafting can be successfully employed in the treatment of central ulcers, as it not only restitutes tissue integrity, but also preserves useful vision.

Post mortem HLA-DR typing of donor corneas using DNA-hybridization technique

With donor material kept under banking conditions, corneal grafting is today an elective routine surgical procedure. Increasing evidence suggests that the clinical results may be improved by HLA matching. However, serological tests require that a blood sample be taken while the donor is still alive or shortly post mortem. We report HLA-DR donor typing with a DNA hybridization technique using DNA isolated from the donor eye more than 24 h post mortem. The practical implications of this procedure are briefly discussed.

Corneal transplantation using 4-week banked donor material. Long-term results

Thirty-six corneal transplantations employing banked donor material maintained during prolonged storage (mean: 29.5 days) in organ culture at 31 degrees C were followed for 5 years. The overall graft survival was 80% , and graft failures were almost exclusively found in a pre-operatively defined risk group where the survival rate was 49.6% compared with 95.5% in the non-risk group. Five years after transplantation the mean central thickness of surviving grafts was 0.52 mm and the mean endothelial cell density 862 cells/mm2. All grafts were optically clear judged by slit-lamp appearance even though a higher degree of light-scatter was demonstrated compared with controls. The functional results were satisfactory with an over-all mean visual acuity of 0.67 cc. Excluding cases where low visual performance had non-corneal causes, 88% of patients obtained 0.5 cc or better. The median spherical equivalent of corneal curvature was 8.23 mm and the median astigmatism 4 diopters. Intraocular pressure was normal, and all grafts had obtained some degree of sensibility, although reduced compared with controls. The study demonstrates that banked donor material can be successfully employed for corneal transplantation achieving favourable long-term results.

Diabetic retinopathy after 3 years' treatment with 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 sc insulin infusion (CSII) administrated by a portable pump. At the present 3 year follow-up, there was one drop-out in the CSII group. Although the metabolic control was significantly better in the CSII patients, both groups improved significantly in metabolic control during the observation period. After 3 years, the HbA lc level was 7.4% +/- 1.2 (+/- SD) in the CSII patients and 8.6% +/- 1.6 in the CIT patients (P less than 0.01). As compared to the status at the beginning of the study, a progression of diabetic retinopathy (criteria: development of more than 2 microaneurysms) was observed in 4 of 11 in the CSII group and in 5 of 12 in the CIT group (P greater than 0.05). None of the patients were seen to develop soft exudates or neovascularisations. This study confirms the impression gained from a previous one-year follow-up of similar progression of retinopathy in patients on CSII and CIT.

No additive effect of tranexamic acid and naproxen on corneal deswelling. A study on oedema after uncomplicated intracapsular cataract extraction with anterior chamber lens implantation

The influence of systemic antifibrinolytic and antiprostaglandin medication on post-operative central corneal thickness was studied. Thirty patients underwent uncomplicated intracapsular cataract extraction with implantation of anterior chamber lens. The patients received either tranexamic acid, naproxen or both. The post-operative oedema did not differ significantly between the three groups studied. Models for studying changes in central corneal thickness are discussed. A review of the influence of drugs on corneal thickness is presented.

Corneal transplantation using long-term cultured donor material

Twenty-seven corneal transplantations with a mean duration of donor incubation of 14.3 days (group 1) and 36 transplantations with a mean duration of incubation of 29.8 days (group 2) were followed for 18 months. No significant difference was found in graft survival between the two groups (81 versus 80%). Almost all graft failures were found among pre-operatively defined high-risk cases, i.e. previously transplanted and/or vascularized recipient cornea. The profile of the corneal thickness curve was almost identical in the two groups, and normal values were reached in both. Visual acuity was 0.5 or better in 23% of the cases in group 1, and 35% in group 2. These figures were highly influenced by co-existing and complicating eye disease i.e. amblyopia, cataract, macular degeneration and glaucoma. The results show that 2 weeks and 4 weeks cultured cornea do not differ with respect to graft survival and thickness. The over all results indicate that long-term cultured donor material is suitable for corneal transplantation and fully comparable to material stored by other methods.

Effect of insulin pump treatment for one year on renal function and retinal morphology in patients with IDDM

The effect of strict metabolic control for 1 yr on renal function and retinal morphology was estimated in 24 insulin-dependent diabetic individuals (age 29 +/- 8 yr, diabetes duration 10 +/- 6 yr) with Albustix negative urine and minimal or no background retinopathy before the study. They were randomized to conventional insulin treatment (CIT) or continuous subcutaneous insulin infusion (CSII) with a portable pump. During CSII treatment the metabolic status was significantly improved and glomerular filtration rates (GFR) were found to decline (from 130 +/- 18 to 116 +/- 15 ml/min/1.73 m2, P less than 0.01). The mean value of urinary albumin excretion (UAE) was not statistically significantly reduced (from 15.3 +/- 24.1 to 6.8 +/- 1.5 mg/24 h, P greater than 0.1). In the CIT group both GFR and UAE values were unchanged. In all subjects before treatment we found a positive correlation between the metabolic status, estimated by the HbA1c values, and GFR as well as UAE values, respectively (r = 0.64, P less than 0.01 and r = 0.42, P less than 0.05). We conclude that elevated GFR values can be reduced toward normal level by insulin pump treatment for 1 yr. Retinal morphology was found to deteriorate in four of 12 CIT subjects and in three of 12 CSII subjects. However, the progression was mild and in most individuals only due to a slight increase in the number of microaneurysms. Pump treatment did not induce proliferation and "cotton-wool" exudates were not detectable in any pump subject after 1 yr of treatment. We conclude that CSII treatment for 1 yr was unable to stop the progression of retinopathy in individuals with minimal or no retinopathy on entering the study. On the other hand, pump treatment did not induce cotton-wool exudates or proliferation in these subjects as previously reported in subjects with more severe retinopathy before CSII treatment.

Early treatment of granular dystrophy (Groenouw type I)

Eight patients with dystrophia corneae (Groenouw type I) were studied. Fifteen eyes in 8 patients were treated with epithelial abrasion, and 5 eyes in 3 patients obtained improvement of visual acuity. In the remaining 10 eyes, the elements were localized so deep in the stroma that they were not altered by the abrasion. Five patients had been treated by corneal grafting. Evident recurrence along the suture lines was observed in 3 eyes and suspected in 2 eyes. It may be concluded that Groenouw type I changes are affected by epithelial abrasion. Early stages obtain visual improvement. Repeated therapeutic epithelial abrasions would seem to be a treatment possibility for patients with incipient changes.

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.

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.

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.

The combined effect of haematoporphyrin derivative and light on the normal mouse retina

Combined treatment with haematoporphyrin derivative (Hpd) and light irradiation has been reported to be an effective method of killing cancer cells. This would be a very suitable treatment of intraocular tumours because the light can be controlled by the refractive media of the eye. Light and electron microscopy of Hpd and light treated normal mouse retina showed that only the irradiated area was damaged. Tissue destruction increased with greater concentrations of Hpd and longer light exposure. The outer layers of the retina were most sensitive. Hpd was retained in the tissue for 6 days.

Importance of age in management of retinoblastoma of the first eye

The possible treatments of retinoblastoma are briefly discussed, and the different situations when one or two eyes are affected is stressed. The age at onset is an important factor in distinguishing between uni and bilateral cases. By an analysis of 59 cases it is shown that below the age of 12 months, the risk of bilaterality is above 90 per cent whereas above the age of 18 months the risk is almost zero. It is recommended that in retinoblastoma, uni- as well as bilateral cases, the possibility of a conservative treatment is seriously considered. Radiation is today the basic modality of treatment. The acute management by the mutilating enucleation is a procedure of the past.

Hereditary bilateral retinoblastoma, pinealoma and normal chromosomes. A case report

We report a boy with bilateral, familial retinoblastoma recognized at the age of 3 months. At the age of 2 1/2 years the patient developed a tumour in the pineal region. Both tumours were successfully treated by radiation. The chromosomes were normal when examined by the prophase technique, in particular there was no deletion of band q14 of chromosome 13. We consider the simultaneous occurrence of retinoblastoma and pinealoma as more then a pure coincidence, probably a consequence of a generally increased susceptibility to cancer and of the histogenetic similarities of retina and pineal body.

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.

Cataract extraction in the 'nineties'

A total of 55 cataract extractions were performed on 53 patients aged 90 years or more in the period 1972 to 1982. Assessment of the outcome was based on data from hospital records and on questionnaires to the patient's ophthalmologist and general practitioner. Cataract surgery had improved visual acuity in 42 patients. Only 25 patients (47%) could, however, utilize the improved visual acuity, and obtain some practical benefit from the cataract extraction. Thus, the benefits of cataract surgery seem to be reduced in this age group. The reasons appear to be a high frequency of severe macula degeneration, some degree of senility hindering the adaptation to aphakic spectacles, and a somewhat higher frequency of per- and post-operative complications. This suggests that indications for cataract surgery in very old patients should be limited, at least if rehabilitation with aphakic spectacles is planned. An earlier surgical intervention would probably have been advantageous in the majority of these patients.

Ultrastructure of cryopreserved, functioning human corneal endothelium

The endothelium was studied by light- and electronmicroscopy in a cryopreserved cornea transplanted to a woman with herpetic keratitis and removed after 18 months because of wound dehiscence and epithelialization of the anterior chamber. The graft was perfectly transparent and of normal thickness. Light microscopy revealed the existence of a continuous layer of endothelial cells, showing pronounced pleomorphism when examined in flat preparation, with large multinuclear cells between smaller more normal looking mononuclear cells. The heterogeneous cell pattern resembled that observable in vitro after freezing and 24 h of culture. The cells therefore are not considered to be in a steady state. The ultrastructure of the majority of the cells was similar to that of non-cryopreserved endothelium. Cell cohesion took place by tight junctions, the intercellular spaces were of normal width. Ultrastructurally there was, however, a cellular heterogeneity, due to the occurrence of light cells with few organelles, but always with intact cell membranes. These cells probably represent slow death of endothelial cells, demonstrated by falling cell density during the 18 months between grafting and examination. We conclude from this study that cells surviving the freezing can maintain a clinically normal endothelial function for 18 months by forming a continuous quasistatic monolayer of tightly bound living cells.

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.

Juxtapapillary retinal hemangioblastoma (angiomatosis retinae) in an infant: light microscopical and ultrastructural examination

A retinal tumor in an 8-month-old boy clinically resembled a retinoblastoma. Light microscopic and ultrastructural examination revealed a hemangioblastoma (von Hippel's disease). It was mainly composed of large, light, lipid-containing cells (so-called stroma cells) lying between numerous vessels, which ultra-structurally were seen to be surrounded by several layers of pericytes separated by abundant basement membrane material. The origin of the stromal cells is discussed in particular. Ultrastructural examination of this tumor has not previously been performed in such an early case, but 2 adult cases have been recorded. Based on their findings the authors favor a vascular origin but conclude that the derivation of the stroma cell is still unresolved.

No increase in arteriolosclerotic retinopathy or activity in tests for circulating immune complexes 5 years after vasectomy

On the basis of studies in monkeys, the hypothesis has been proposed that vasectomy induces the formation of circulating immune complexes (CICs), which--via activation of the complement system--may result in immune injury of the endothelium and thereby exacerbate atherosclerosis; the same mechanism has been suggested to cause retinal arteriolar changes in vasectomized men. We compared 46 men, 5 years after vasectomy, with 46 age-matched control subjects and found no difference in the distribution of arteriolosclerotic retinopathy gradings evaluated by ophthalmoscopy and fundus photography. Blood samples from the two groups were collected and handled identically, and no significant difference in activity was found in four different tests for CICs and two tests for split products of complement factor C3. Thus, the results do not support the hypothesis that changes mediated by CICs occur in vessels after human vasectomy.

A-beta-lipoproteinaemia. Ocular involvement in a Danish case

A-beta-lipoproteinaemia in a Danish woman is reported. The ocular involvement comprised pigmentary retinopathy, anisocoria and reduced corneal sensibility. Serum concentrations of vitamin A and retinol-binding protein (RBP) were low, but were normalized after vitamin treatment. Serum concentration of carotene was low, and not altered by treatment. The retinopathy progressed over a 2 1/2 year period in spite of controlled serum vitamin A and RBP concentrations. The possible role of vitamin A in the development of retinopathy is discussed.

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.

Aqueous humour and plasma amino acids in tapeto-retinal degenerations

The concentration of 18 amino acids and related compounds has been determined in plasma and aqueous humour in 17 patients with tapeto-retinal degenerations, among them 10 patients with retinitis pigmentosa. When compared with a previously obtained reference series of 40 patients abnormal aqueous concentrations (Caq) were found for taurine, glutamine, glutamic acid, proline, glycine, alpha-ANBA and cystine. As regards the plasma concentrations (Cpl) only glutamic acid and alpha-ANBA showed abnormal values. Several of the substances showing abnormal concentrations are possible neurotransmittors or inhibitors. The results suggest that aqueous humour analysis will be a useful way of studying retinal degenerations.

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.

On the optical measurement of corneal thickness. II. The measuring conditions and sources of error

The optical measurement of corneal thickness based on oblique viewing of the optical section of the cornea is complicated by the finite width of the incident slit beam. In this report the theoretical and practical aspects of the effect of the slit width on the thickness reading are analysed. In practice, it was not possible to make slit-width independent thickness readings which were reproducible from one observer to another. In addition, the observed slit-width error was found to vary from one patient to another. The lack of reproducible estimate of the corneal thickness is attributed to difficulties associated with an exact definition of the edges of the visible bands of the optical section, which are determined by biological properties of the cornea as well as perceptive properties of the observer. Although inter-observer errors up to 0.02 mm were found, the intra-observer error amounted to only 0.005-0.006 mm (SD) between consecutive readings. Presumably this high intra-observer reproducibility is the result of the auxiliary pin-lights used. Changes in corneal thickness, measured by the same observer, can therefore be determined with great accuracy.

On the optical measurement of a corneal thickness. I. Optical principle and sources of error

The optical principle for the estimation of corneal thickness with a commonly employed method is considered. The theoretical relationship between the apparent and true corneal thickness is described in a simple manner. Based on the theoretical results it could be confirmed that physiological variations in refractive index and radius of the cornea induce an insignificant error in the corneal thickness estimate. The theoretical relationship between apparent and true corneal thickness was compared to the performance of two commercially available pachometers (Haag-Streit and Zeiss). The actual reading of the pachometers was found to be lower than the theoretical reading by a non-linear error amounting to about 0.010 and 0.100 mm at a true corneal thickness of 0.50 and 1.00 mm, respectively.

Influence of tranexamic acid and acetylsalicylic acid on the thickness of the normal cornea

In a masked cross-over study ten normal subjects were treated with tranexamic acid and acetylsalicylic acid one g three times daily for seven days. The central corneal thickness. was found to increase in response to acetylsalicylic acid and to decrease in response to tranexamic acid. This finding provides evidence for the involvement of the fibrinolytic system in the regulation of the normal corneal thickness. The endothelial morphology, as seen with the specular microscope, was unchanged during treatment with either drug.

Enucleation in children

In adults enucleation is usually considered a rather simple operation. By contrast the removal of an eye of a child is often a difficult task. We describe an effective technique which makes this surgical intervention a safe and trouble-free procedure.