Acta Ophthalmologica

Published by Wiley
Publications
6-Methoxy-1,2,3,4-tetrahydro-beta-carboline (6-MeO-THBC) is a condensation product of 5-methoxytryptamine and formaldehyde. It possesses diverse biochemical and pharmacological properties and has been suggested to act as a neuromodulator. 6-MeO-THBC has been shown to occur in various tissues including the retina in animals and human beings. The present results show that the mouse and rat retina as well as other tissues take up 14C-labelled 6-MeO-THBC injected intravenously or intravitreally. The retinal concentrations show a prompt rise after the injection and significant levels are maintained after 2 days.
 
Macular changes in 60 to 80-year-old people i.e. drusen (DR), pigmentary changes (PC) and exudative changes (EXC) are assessed by fundoscopy in a random and age stratified population with 924 of the participants examined in both maculae (1848 eyes). DR, PC and EXC were found in 18.4%, 12.9% and 2.1% of all eyes with a rising frequency associated with increasing age. A separation was made between changes implying a visual acuity of 6/9 or less as criteria of age-related macular degeneration (AMD) and age related macular changes without visual impairment (AMCW). The occurrence of DR, PC and EXC from eyes with AMD showed an age related rise which was also found for DR, contrary to PC and EXC deriving from eyes with AMCW. The basic forms of AMD, atrophic and exudative, were represented in 78.6% and 21.4% of individuals or 80.9% and 19.1% of eyes with AMD. The predominant findings in AMD eyes were DR + PC in combination represented in 60.7% of atrophic and 66.8% of exudative AMD eyes, while in atrophic AMCW eyes DR as only finding was leading with 59.2%. It is concluded that in eyes with atrophic macular changes, DR, respectively PC as only finding involves no visual deterioration in 80.6%, respectively 72.6%, while DR + PC in combination, as well as the appearance of EXC, are found to be the most likely expression of AMD as long as a visual impairment of 6/9 or worse is included in the definition of AMD.
 
An epidemiological ophthalmic investigation of 1000 individuals aged 60-80 years disclosed age-related macular degeneration (AMD), i.e. macular changes causing visual impairment in at least one eye with a prevalence of 12.2% of 924 individuals with both maculae examined. The prevalence increased with rising age for both sexes: age group 60-64 years: 2.3%, 65-69: 5.9%, 70-74: 12.1% and 75-80: 27.3%. No significant differences in prevalence rates of AMD were demonstrated between males and females in the respective age groups. About one half of the persons with AMD were affected in both eyes. No differences of AMD were found between right and left eyes. Findings of age related macular changes without visual impairment (AMCW) compared to AMD revealed far higher prevalences in the sixties and a smaller rise in the seventies (age group percentage in both sexes: 12.3, 18.0, 17.0 and 17.8%). No systematic prevalence differences were demonstrated between sexes. The collected data of AMD and AMCW might indicate a shift from AMCW to AMD in women, particularly aged 70-74 years and in men, particularly aged 75-80 years. Macular changes in total (AMD + AMCW) was found in 28.5% of the population (age group percentage 14.6, 23.8, 29.0 and 45.0%). No sex differences were found.
 
A prospective study was performed on 46 eyes to compare results of different methods of objective refraction, namely automated refraction with the Nidek AR-1000 autorefractometer and retinoscopy in cycloplegia. We found that automated refraction in cyclopentolate cycloplegia gave results that differed little from results of retinoscopy in atropine cycloplegia both with respect to sphere and cylinder. Axis determination was even better with automated refraction. Dry automated refraction gave inaccurate results for the spheric component presumably because of suboptimal control of accommodation in this group of young patients. We recommend automated refraction in cyclopentolate cycloplegia as an easy, rapid, accurate and convenient method for obtaining an objective refraction where accommodative disorders are suspected.
 
To emphasize the unknown visual impairment of age-related macular degeneration (AMD)-defined as macular changes causing a visual acuity of 6/9 or less-an epidemiological study was designed including 1000 age stratified and randomly selected Danes, 60-80 years of age. Among the 924 individuals in whom both maculae could be examined (1848 eyes) a total number of 173 AMD eyes was found in 112 persons. For all AMD eyes, the composition of visual loss can be described as an iceberg with minor visual impairment of 6/9-6/12 as the predominant base (71.7%), partial impairment of 6/18-6/36 as an interjacent area (15.0%) and major impairment of 6/60 or less (i.e. blindness) as the top (13.3%). By use of a logistric regression model the proportion of exudative macular degeneration among all AMD eyes (atrophic + exudative) was demonstrated to be significantly increasing with decreasing visual acuity but unrelated to age. The prevalence rates of AMD were age related in each of the visual subgroups of minor, partial and major impaired eyes. The prevalence rates of social blindness (6/60 or less in both eyes) due to AMD are estimated to be 4.3 per 1000 persons and of monocular blindness 16.2 per 1000. Further calculations suggest that about 90,000 out of 870,000 Danes. 60-80 years old, have visual impairment of 6/9 or less caused by AMD in one or both eyes.
 
So far, no epidemiological studies have dealt with the relationship between dark and light pigmented Caucasians and the risk of developing age-related macular degeneration (AMD). Based upon hospital referred eye patients, dark ocular pigmentation has previously been suggested as a protective factor. The present study reviews macular degeneration, defined as macular changes implicating a vision of 6/9 or less, in prevalence rates in relation to ocular pigmentation and hair colour in an ethnic homogeneous and random population of 1000 Danes, 60-80 years of age. The population was predominantly light pigmented. Brown iris colour was only present in 15.9%, dark pigmented fundi in 19.0% and a black juvenile hair colour supposed in 6.5%. The prevalence rates of AMD ranged from 16.0 to 10.5% for brown respectively blue iris colour, and from 13.3% to 9.0% for dark respectively light pigmented fundi. The presented data indicate that no significant differences in prevalence rates of AMD seem to exist between dark and light ocular pigmented Danes. An additional comparison between 100 AMD patients referred to hospital and the epidemiological sample did not reveal a difference in pigmentation. The prevalence analysis also showed that neither is juvenile hair colour of prognostic value in terms of later occurrence of AMD nor seems greyness of hair to be an independent indicator of AMD, but related to age as is AMD, when simultaneously entered into a logistic regression model.
 
The relationship between age-related macular degeneration and cardiovascular risk factors and certain life-style factors, collected in the Copenhagen City Heart Study (1981-83), was studied by multiple logistic regression analysis. The ophthalmological study sample comprised 1000 randomly selected persons aged 60 to 80 years. Separate analyses were made for the atrophic and the exudative forms of age-related macular degeneration. Among all the possible risk factors analysed, only three factors were significantly associated with macular degeneration. Age was associated with both atrophic and exudative macular degeneration (P less than 0.01). Among smokers who inhaled, the risk of atrophic maculopathy was 2.5 times higher than among non-smokers (P less than 0.01), whereas the use of hypnotics increased the risk of exudative maculopathy by 3.4 times (P less than 0.01).
 
A report on 105 cases of ocular trauma hospitalized in St. Joseph's Hospital in Reykjavik during a 12-year period is presented. Of these patients 94 were males and 11 females. Thirty-nine patients were children, and only six patients were older than 50 years. Most common were occupational accidents (43 cases) and of these 29 were connected to industry. Other main causes were traffic accidents, sport and dangerous play by children. Of the total 105 cases, 70 had perforation of the bulb. All but nine underwent some kind of operation, and enucleation was performed in 10 patients. Nearly two thirds of the patients were hospitalized within six hours of the accident and 84% within 24 h.
 
A 44-year-old man presented with an exophytic papillomatous growth in the tarsal conjunctiva of his right eye. The tumour was excised and subjected to histological examination. On light microscopy, a squamous cell papilloma without signs of dysplasia was disclosed, because the entire tissue block was cut into sections, the performance of a conventional in situ hybridization for detection of human papillomavirus (HPV) DNA was not possible. An alternative approach was used to demonstrate the presence of HPV 11 DNA in the papilloma. The cover slip was removed. The individual van Gieson-stained sections on the (routine, uncoated) slides were cut apart by glass knife, and mounted (still attached on the original slide) separately on new microscopy slides. These slides were subjected to in situ DNA hybridization with biotin-labelled DNA probes of HPV 6, 11, 16, and 18, under conditions of high stringency (Tm-17 degrees C). Special caution was taken to prevent the detachment of sections. The papilloma displayed positive hybridization with the HPV-II probe, the intense signals being localized on the nuclei of koilocytotic cells. Infection with HPV-6 (or the closely related HPV-11) appears to be responsible for the majority of the conjunctival papillomas of children and young adults reported so far. The presence of genital tract HPV types 6/11 in these lesions suggests that some of the infections might have been acquired during the passage through an infected birth canal. The presence of HPV 6/11 in adult conjunctival papillomas might reflect a) an activation of a latent infection acquired as above, or b) a new infection transmitted from other mucosal sites, the genital tract included. The role of HPV in conjunctival dysplasias and malignant transformation is not clear as yet.
 
A malignant melanoma of the choroid was observed in an 11-month-old fair-skinned Danish boy — one of the youngest cases ever published. There was no evidence of pre-existing melanosis of eyes or skin. The tumour showed histopathologically a typical “adult” pattern and was classified as a mixed tumour. The melanin content was marked. In some earlier reports on uveal tumours within the first year of life, pigmentation was sparse or lacking; a hypothesis has therefore previously been advanced: That melanomas are unable to produce melanin so early in life. The present case renders proof against this hypothesis.
 
A family with pterygium affecting 11 members of 3 generations was reported. Although the disease is not necessarily hereditary in most of the patients, the mode of transmission in this particular family was autosomal dominant. The relationship between individual predisposition and the external factors in pterygium formation is briefly discussed.
 
An epidemiological and genetic study in Denmark of granular corneal dystrophy Groenouw type I is described. Ninety-one living patients were found. The disease is inherited as an autosomal dominant trait with a 100% penetrance of the gene. The 91 cases could be traced back to 6 different mutations. The mutation rate was estimated to be about 0.3/1,000,000; the possible sources of error of this estimate are discussed. The age distribution of the patients is shown to be similar to that of the Danish population in general.
 
Nineteen patients with malignant uveal melanomas were treated with I-125 applicators. There were 10 males and 9 females with a median age of 61 years (range 42-76). The tumour was located in the choroid in 12 eyes and in the choroid and ciliary body in 7 eyes. The size of the tumours was 7-18 mm in maximal basal diameter (median 12), 5-16 mm in minimal basal diameter (median 10), and 5.5-15 mm in thickness (median 8.5). The volume of the tumours was 123-1890 mm3 (median 540). All tumours were classified as large (T3). For the irradiation, a computer program, which calculates three-dimensional dose distribution of I-125 seeds in gold plaques, was developed. By modifying the seed positions, activity and the orientation, patients can be treated individually. Iodine-125 emits low energy photons, ideal for intraocular tumour therapy and tissue. Extra-ocular tissue located behind the applicator can be completely shielded by a 0.5 mm gold layer. The dose at the apex of the tumour ranged from 30 to 120 Gy (median 93). The treatment time ranged from 44 to 600 h (median 235). Preliminary results are good. After a median follow-up of 6 months, the tumour growth has been arrested in all eyes and in 10 eyes the tumour has decreased in size.
 
We compared corneal penetration of idoxuridine (IDU) to liposome-encapsulated IDU. Liposomes of phosphatidic acid, phosphatidyl choline, and alpha-tocopherol in a molar ratio 1:8:1 were prepared using the reverse phase evaporation method. New Zealand albino rabbits received either 0.1% solution of I125-labelled aqueous IDU or liposome-encapsulated IDU topically every 2 min for 6 min. Corneal, aqueous, and vitreous samples were assayed for I125 radioactivity at 15 min and at 1, 2, 3, and 6 h following drug application. Our results indicated that corneal penetration of liposomal IDU was significantly increased over the regular form of the drug for a time interval of 6 h.
 
A hospital material considered refractively unselected is made up by adult patients referred for general eye examination from other (non-ophthalmic) departments (n = 1416; 2832 eyes). Thirty per cent of all eyes had negative refractive value. The highest myopia prevalence, about 40%, was seen in the age group 26-45 years. Glass-demanding myopia (of at least -0.75 D) occurred in 14% of the elderly (66 years +) against 27-28% in younger adults. Up to the age of 45, more females were myopic than males. The present prevalences are considerably higher than expected from previous Danish studies. It is discussed to what extent this increase is real. The diabetes of the sample (representing 762 eyes) show a shift towards negative refractive values (37.9% with myopia) as compared to non-diabetics (27.5%). The diabetic surplus is due to low degree myopia cases. The association between myopia and (well-controlled) diabetes seems to be a new observation.
 
A follow-up was planned of 1076 subjects with ocular normotension, with an observation period ranging from 15.8 to 18.3 years. Initially, they were included in a glaucoma screening on the island of Falster comprising 2031 volunteer blood donors. In the primary screening all 1976 persons had an applanation pressure below 20 mmHg in both eyes. The 55 with intraocular hypertension have been followed up in other studies, already published. It was possible to trace only 408 subjects (20.6%), now aged 37-78. Fourteen subjects (24 eyes) had developed ocular tensions equal to or higher than 20 mmHg. One of these, a 56-year-old man had a glaucomatous visual field defect in the right eye and a cup/disc ratio of 0.6 in both eyes. A glaucoma risk of 0.25% can thus be given.
 
In a population-based cross-sectional study of insulin-dependent diabetes mellitus, 42 children--with a median age of 11 years (range 7-15 years) and a median duration of diabetes of 4 years (range 1-12 years)--underwent an ophthalmological and a biochemical examination (HbA1c). None of the children had visual loss due to diabetes, and only 4.8% had mild, non-proliferative retinopathy. Using cycloplegic refractioning, we found low degree myopia (less than -2D) in 12% of the patients, whereas non-mydriatic measurements increased the frequency of myopia to 29%. We therefore recommend the use of cycloplegia in refractive evaluations of diabetic children.
 
Seventeen organ cultured cryopreserved corneas were grafted in 1978-79. When published in 1982, 12 of the grafts (71%) were clear with an average thickness of 0.51 mm and an endothelial density of 1028 cells/mm2. A re-examination of these patients after 13 years is presented. Seven grafts (58%) were clear. Average CCT was 0.51 mm and endothelial cell density was 988 cells/mm2. Visual acuity was 0.4 or better. The morphology resembled that seen after 1 year with large, multinucleated cells. It is concluded that cryopreserved grafts show a fair long-term survival. Cryopreservation may still present a possibility in the establishment of a corneal bank with the perspective of supplying histocompatible donor material.
 
Re-examination of corrected visual acuity was done in 137 18-year-old Danes, who were originally examined at the age of 10 years, as part of a study of sequels to low birth weight (LBW) (Fledelius 1976). Median values indicate that most adolescents are able visually to discriminate considerably above the customary 6/6 limit. As compared with low-birth-weighters (n=70), full-terms (n=67) show a significantly higher cumulated visual acuity score. Similarly, binocular median visual acuities are 1.2 (LBW) and 1.4 (in FT). The difference is neither explained by the ex-prematures' higher frequency of heterotropia, nor by their (minor) share of eyes with subnormal vision. The latter occurred especially in the subgroup of 'myopia of prematurity'. The exceptional cases with RLF-blindness were discarded from follow-up. Concerning visual acuity, the previously reported lagging behind of ex-prematures in childhood has proven to be not only a temporary delay, but a permanent (adult) feature.
 
The authors assessed a fluorophotometry follow-up study of 18 months in 24 juvenile insulin-dependent diabetic patients with no retinopathy. The initial duration of diabetes was 5.96 +/- 3.44 years and the glycosylated hemoglobin (HbA1c) was 10.12 +/- 2.27%. The baseline Vitreous Penetration Ratio transmittance value (VPRt) was 4.13 +/- 1.31 x 10-6 min-1 and after 18 months was 5.36 +/- 1.85 x 10-6 min-1, yielding a statistically significant difference (p < 0.01). The average HbA1c during the follow-up term was 9.80 +/- 1.72%. VPRt values were significantly correlated with the duration of diabetes and HbA1c. During the follow-up 3 patients developed foveal background diabetic retinopathy with respect to a high initial VPRt value (6.22 +/- 0.27 x 10-6 min-1), nevertheless, the other 7 patients with high baseline VPRt did not do so. We suggest that vitreous fluorophotometry could be a beneficial procedure in the management of insulin-dependent diabetic patients; however, there is not a cut-off value for VPRt values to help distinguish patients prone to develop retinopathy.
 
A serological study was carried out by ELIFA (Enzyme Linked Immuno-Filtration Assay) for 50 children with congenital toxoplasmosis diagnosed by several parasitological and serological methods showing that the fetus had been infected by the parasite and had developed it's own specific immune response. At birth, anti-Toxoplasma gondii IgE antibodies were detected in the sera of 66% of the 18 children who had retinochoroiditis and in 32% of the 32 children without this complication. During the 4 months before or at the time of diagnosis of retinochoroiditis, specific IgE antibodies were detected in 70% of the 20 cases (2 children with 2 successive lesions); but during the 4 months following the discovery of ocular lesions, anti-Toxoplasma IgE antibodies were only detected in 30% of the 20 cases. Among all the 50 children, the prolonged detection of specific IgM + IgE association (for at least 4 months) was followed in 46% of cases by the appearance of chorioretinitis (predictive value).
 
The present report on vitreous and axial length completes an analysis of changes in eye size during adolescence. The sample is divided into 70 with low birth weight (less than 2000 g) and 67 full-term controls (FT). 1) Contrary to classical statements regarding early arrest of eye growth, a basic 'pubertal' axial growth of about 0.4-0.5 mm is found in refractively static eyes. Eyes with progressive myopia elongate even more, due mainly to vitreous elongation. 2) The previously reported 10-year LBW ocular size deficit remains an adult feature, even in seemingly normal eyes. There is a parallel permanent lack of catching-up also regarding height, head circumference, and some other anthropometric parameters. 3) Two classical rules of thumb are discussed: a) 1 mm axial length change coincides with 3 D refractive change, and b) that of 24 mm as the emmetropic eye length. Although tenacious, bot statements have to be modified--according to biological variation and the weak correlation between most refractive parameters.
 
Anterior eye segment features were investigated longitudinally by ultrasound and keratometry in 70 low-birth-weight subjects (LBW less than 2000 g) and 67 full-term controls, at the ages of 10 and 18 years. Concerning the changes during adolescence, a slight significant deepening of anterior chamber and lens position is found (about 0.1 mm), while lens thickness, corneal curvature radius and corneal astigmatism have remained stable. Differences between BW-groups indicate a permanent influence of LBW on ocular development, as evident from a presumed early environmental (LBW) arrest of corneal growth, given by a significantly lower value of corneal curvature radius, just as zonular slackness due to a smaller suspension ring may explain a thicker lens. Further a LBW disturbance of correlation between refraction and anterior eye segment parameters is suggested. Besides the documented occasional posterior eye segment damage of LBW (retinopathy of prematurity), the present study indicates a more general restraining influence also on anterior eye segment development.
 
A report is given on refractive changes (delta R) from age of 10 to 18 years. The 1979 follow-up comprises 137 persons who had earlier (around 1970) participated in a larger investigation into ophthalmic sequels to a low birth weight (n = 539). In general (127 out of 137), there is a shift towards lower dioptric values (increase in refraction). Seven remained static while three showed a slight decrease in refraction (0.25-0.5 D). Adult emme- and hypermetropia show a median delta R about 0.7 D (increase) during adolescence, against median values of 1.7 and 2.5 D in juvenile myopia, of ex-prematures and full-terms respectively. With a median delta R of 1.2 D, 'myopia of prematurity' occupies an intermediate position (21 eyes of 13 subjects). Except for this subgroups, there is no evidence that low birth weight has influenced refractive distribution. With a (planned) skewing towards myopia, the 1979-sample cannot be considered epidemiologically representative, as was the original 1970-material. Concerning the latter, the 18-year incidence of myopia is given as 17.6% for ex-prematures and 13.1% for fullterms (minimum figures, based on school medical records).
 
Five subjects wearing soft contact lenses were placed in a low pressure chamber where the atmospheric pressure was reduced to 50%. Subjective and objective criteria were used to determine corneal distress. After four hours at 1/2 atmosphere all 10 eyes showed objective changes and four out of five subjects claimed subjective changes indicating corneal distress. None of the subjects showed subjective or objective signs of similar changes, when the study was repeated at normal atmospheric pressure.
 
Thirty-five repeated 50-spot/180 degree argon laser trabeculoplasties (ALT) are prospectively compared to as many first ALT's. The distribution of the treatment variables possibly affecting the results was almost identical between the two groups. The postoperative intraocular pressure decrease was statistically significant in both groups but it was significantly smaller in the re-ALT group as compared with the pressure reduction taking place in the group receiving their first ALT.
 
Primary LTP was performed in 20 eyes with 50 spots in 180 degrees and in 26 eyes with 100 spots in 360 degrees of the trabecular meshwork. These eyes had received no earlier glaucoma medication. They were followed prospectively for 12 months. Prelaser IOP was 36.3 +/- 8.0 mmHg in the 50 spot group and 35.9 +/- 6.6 mmHg in the 100 spot group. Treatment was considered successful if IOP was less than or equal to 22 mmHg with no medication and no further disk damage or loss of visual field. The success rate 12 months after LTP was 15% in the 50 spot group and 69% in the 100 spot group.
 
Top-cited authors
Niels Ehlers
Ahti Tarkkanen
  • Helsinki University Central Hospital
Hans C Fledelius
  • University of Copenhagen
Amund Ringvold
  • University of Oslo
Thomas Olsen
  • Aarhus University