摘要:

Abstract.A Nordic study group of ophthalmologists, NORDSYN, has compiled data from registers in Denmark, Finland, Iceland and Norway of 2527 visually impaired children. Each record contains the following information: sex, year of birth, year of registration, classification of visual impairment, ocular diagnosis, systemic diagnosis, aetiology and evt. additional impairments. The ocular diagnoses were compiled into groups, and coding systems for aetiology and additional impairment were developed. The sex distribution revealed a dominance of males compared to the general population at the same age. Cases with non‐genetic aetiology showed — though to a lesser extent — the same relative preponderance of males. The diseases in males caused by x‐linked genetic factors do, therefore, not fully explain the sex distribution observed in the study. The national prevalences for registration of childhood blindness (WHO‐definition: best corrected visual acuity in the best eye less than 3/60 or visual field less than 10 degrees around fixation for the ages 0–15 years) are per 100 000 child‐population aged 0–15 years: Denmark 41, Finland 15, Iceland 19 and Norway 15. The differences are primarily presumed to be due to varying efficiency in registration. The proportion of visually impaired children with an additional mobility, hearing or mental impairment is between one‐third and one‐half of the national materials, thus indicating the need for interdisciplinary tracing of and care for the visually impaired child. This study documents the need of uniform routines for data classification of visually impaired children. The quality of the data in the present study calls for caution in the interpretation of the prevalence estimates. Incidence studies are being prepared to obtain information on whether the amount and causes of visual impairment in children with or without multiple impai

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1992.tb04118.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.Careful clinical‐aetiological assessment of visually impaired children is one of the prerequisites for prevention of future, ‘unavoidable’ cases of visual impairment of children in the industrialized part of the world. In a collaborative study (NORDSYN) between four Nordic national registers of visual impairment, we analysed and classified some of the factors considered to be essential components for the development of low vision or blindness in children. We discuss the conceptual basis for aetiological classification of eye disorders and visual impairment. An aetiological classification system, based on the type and debut of an essential causal factor is introduced. We present data on 2527 visually impaired children from the Nordic countries. In accordance with several other reports from the last twenty years it is demonstrated that prenatal factors, including genetic aetiologies, were involved in a large proportion (66%) of the cases. In children without additional impairments the corresponding fraction was 74%. Genetic factors accounted for a little over half of the prenatal cases, and in a substantial number of children (40%) with visual impairments of prenatal origin, the causes were obscure. In 1/5 of the material some peri‐neonatal causal or modifying factor was identified. In 7% only, the presumed aetiological factor was introduced in the infantile‐juvenile period of life. Further prevention of visual impairment among children of the industrialized countries would benefit most from a more comprehensive understanding of prenatal, nongenetic causal factors, further knowledge about regulating mechanisms responsible for gene expression, and additional improvements in perin

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1992.tb04119.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.The aim of this study was a complete survey of all patients in Denmark with a diagnosis of retinitis pigmentosa. The study was performed during the period 1986–1989 and included all persons living in Denmark from 1850 to 1989. We describe the methods of registration from medical and non‐medical sources, based on defined criteria. The inclusion criteria were fulfilled by 1890 persons, 1056 males and 834 females. Evaluation of this ‘Danish Retinitis Pigmentosa Register’ demonstrates an overall completeness of about 80%, increasing from 40% for birth cohorts before 1911 to 90% for patients born since 1981. Concerning diagnostic confidence, 73% of the probands were characterized as certain, 16% as probable, and 11% as possible. Non‐systemic cases comprised 61% of all probands and 31% had systemic disease, the rest being unclassified with respect to systemic involvement. The material is considered very suitable for epi‐demiological treatment and continuous clinical and genetic inv

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1992.tb04120.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.In a nation‐wide study we utilized all available sources to characterize the prevalence rates of retinitis pigmentosa. 1301 persons, 715 males and 586 females, were identified, with a diagnosis of retinitis pigmentosa or some other tapetoretinal dystrophy, and living in Denmark per January 1, 1988. The corresponding completeness corrected prevalence rate of retinitis pigmentosa was 1:3026. All cases were classified as ‘certain’, ‘probable’, or ‘possible’. The age specific prevalence rates increased until 40–50 years, reaching a level of 35–40 male cases per 100 000 and 25–30 female cases per 100 000. Age specific prevalence rates were standardized to the WHO World Standard Population and compared to rates reported from Britain and The United States. World standardized prevalence rate for males was 25.29 per 100 000 and for females 19.31 per 100 000. The preponderance of males was highly statistically si

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1992.tb04121.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.The persistence of a residual flicker electrore‐tinogram 20 Hz response in many cases of retinitis pigmentosa, when the Oscillatory Potentials (OPs) were no longer recordable, led the authors to an investigation by Fourier analysis. The study was carried out in 33 patients affected by different hereditary forms of retinitis pigmentosa revealing recordable 20 Hz flash ERG responses. We applied the Fourier analysis to this ERG response and compared the weight percentage of the first two components to the OP added amplitude. The analysis showed that the 20 Hz flash ERG response contains only the first harmonic in patients with no recordable OPs and both harmonics in patients with recordable OPs. This relationship between OPs and 20 Hz second component, that is possibly related to the activity of inner retina as well as the OPs, can demonstrate an alteration of the inner retina which evolves with distinct electrophysio‐logical features from the ERG photoreceptor impairm

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1992.tb04122.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.The postnatal development of the oscillatory potentials (OP) of the rat's electroretinogram (ERG) was studied during relatively mesopic adaptational conditions. The behaviour of the OPs induced at an inter‐stimulus interval (ISI) of 30 sec entailed photopic qualities at an individual level, but when summated conformed to a scotopic course of postnatal maturation. An ISI of 1 min elicited OPs with individual scotopic characteristics. The total oscillatory activity culminated at 17 days of age at both ISIs, similar to more scotopically induced oscillations. These results show that relatively mesopic states of adaptation do not promote any earlier appearance of the OPs, and that the immature mesopi‐cally induced OPs seem to contain both scotopic and photopic qualities reflecting a postnatal change of balance between these components. Furthermore, photopic mechanisms seem to govern the oscillatory activity in the mature rat retina. We suggest that the differences in relation to adaptational conditions between the immature and mature OPs may reflect the postnatal status of the dopamine and its synthetizing enzyme, tyrosine‐hydro

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1992.tb04123.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.We used the laser flare‐cell meter to measure aqueous flare and aqueous ‘cells’ in 38 eyes of 38 patients with pseudoexfoliation, in 36 normal control eyes of 36 subjects, and in 19 eyes of 19 patients with chronic open‐angle glaucoma unrelated to pseudoexfoliation. In pseudoexfoliation eyes, both aqueous flare (0.61 ± 0.55 mg/ml human albumin equivalent) and aqueous ‘cells’ (mean 10.70, range 0–50.6 cells/0.075 mm3) were significantly higher than in the normal control group (flare 0.15 ± 0.06 mg/ml, ‘cells’ 0.43, range 0–2,P<0.0001) and in the glaucoma group without pseudoexfoliation (flare 0.19 ± 0.08 mg/ml, ‘cells’ 0.80, range 0–2.4,P<0.0001 andP0.4). Our findings indicate that the blood‐aqueous barrier is impaired in eyes with pseudoexfoliation, and that the laser flare‐cell meter may be a useful tool to quantify these changes. These alterations of the blood‐aqueous barrier need to be considered in med

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1992.tb04124.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.In this study we evaluated the frequency of pseudoexfoliation syndrome, the percentages of glaucoma and senile cataract in patients with and without pseudoexfoliation syndrome, and the percentages of pseudoexfoliation syndrome in patients with glaucoma and senile cataract in the Eastern Mediterranean area of Turkey. We examined 1356 persons over 40 years of age. Frequency of pseudoexfoliation syndrome in the ≥50 years old age band was 7.2%, and there was a statistically significant difference between the sexes. Over 60 years of age, the frequency of pseudoexfoliation syndrome was 11.2%, the percentage of glaucoma in patients with pseudoexfoliation syndrome was 34.3%, the percentage of pseudoexfoliation syndrome in patients with glaucoma was 46.9%, the percentage of cataract in persons with pseudoexfoliation syndrome was 88.1%, and the percentage of pseudoexfoliation syndrome in persons with cataract was 17.7%. The differences between the percentage of glaucoma and cataract in patients with and without pseudoexfoliation syndrome, were both statistically significant (p<0.001

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1992.tb04125.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.Clinical features of capsular glaucoma during a recent 15‐year period were compared with those of primary open‐angle glaucoma (POAG). Out of 1623 new glaucoma patients, 263 patients (16.2%) were capsular glaucoma and 268 (16.5%) were POAG. The patients with capsular glaucoma were older than the patients with POAG. The former had higher intraocular pressure, lower visual acuity, more advanced visual field change and heavier trabecular pigmentation than POAG patients at the time of initial examination. These findings suggest that capsular glaucoma is more difficult to manage than POAG and that the prognosis is poorer than for POAG. Pseudoexfoliative material was found on the pupillary border in 98.3%, on the central lens surface in 46.1%, and on the peripheral lens surface in 72.3%. Though 190 of 263 patients with capsular glaucoma (73.9%) were unilateral cases, 38.9% of the fellow eyes had some abnormalities related to glaucoma. Phakodonesis was found in 10% of patients with capsular glaucoma. This finding suggests that the presence of capsular glaucoma might be a risk factor in cataract surg

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1992.tb04126.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.Fourteen eyes (12 with open‐angle glaucoma and 2 with secondary glaucoma) of 14 patients were operated by trabeculectomy at the inferior limbus. The surgical technique is described and results of 6–12 months follow‐up are reported. Complication rate was reasonably low. Early postoperative IOP higher than 30 mmHg occurred in one eye where a blood clot and sodium hyalu‐ronate obstructed filtration of aqueous. Postoperative mean IOP was 16.3 mmHg (6–29 mmHg) in 13 eyes at 3 months, 17.1 mmHg (13–26 mmHg) in 12 eyes at 6 months and 20.1 mmHg (11–31 mmHg) in 12 eyes at 12–16 months. Three eyes had follow‐up of 19–21 months and corresponding IOPs were 14, 15 and 22 mmHg. IOP was<22 mmHg in 10/12 eyes at 6 months and in 8/12 eyes at 12–16 months. 6/12 eyes managed without medication at 6 months and 2/12 eyes at 12–16 months. Trabeculectomy at inferior limbus is a safe procedure and it is recommended as a surgical procedure in eyes after pr

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1992.tb04127.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY