ISSN:1395-3907    

DOI:10.1111/j.1600-0420.1995.tb00645.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACTVisual acuity and the prevalence and causes of impaired vision were studied in an epidemiological cross‐sectional population study of inhabitants aged 70 years or older in three communities in the county of Oulu, Finland. 500 of the 560 eligible persons (89.3%) were examined. Information on visual acuity was obtaned for 476 co‐operative persons (85.0%). 59.0% had a visual acuity of 0.3–0.6 in the better eye. 10.1% (48 persons) had low vision and 1.9% (9 persons) were blind as categorized according to the classification of visual impairment by the World Health Organization. Experienced visual capacity did not, however, always correspond to objective tests. Age‐related maculopathy and cataract were the leading causes of visual deterioration. Age‐related maculopathy was the main cause of low vision and blindness in 4.6% of the population. In 1.3% the etiology was cataract, and in 2.1% both early age‐related maculopathy and cataract were present without obvious dominance. Cataract was often associated with other conditions. Glaucoma was considered the main cause of visual deterioration in 1.5%, diabetic maculopathy in 0.6% and macula pucker in 0.4%. In 1.5% the visual deterioration was due to o

ISSN:1395-3907    

DOI:10.1111/j.1600-0420.1995.tb00646.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACTIn a population based study on 500 persons aged 70 years and older, photographic and/or ophthalmoscopic evaluation of the macula at least in one eye was possible for 478 persons (96%). No macular pathology in either eye was observed in 46%, signs of age‐related maculopathy in one eye or both eyes occurred in 41% and other pathology in 16%. Early age‐related maculopathy was diagnosed in 32%, geographic atrophy in 4.4% and disciform degeneration in 3.8%. Geographic atrophy was most common in persons aged 90 years and older (36%), and the highest prevalence of disciform degeneration was found in the age group of 85–89 years (17%). Of the 155 eyes with low vision or blindness and visible fundus, early age‐related maculopathy was found in 35%, geographic atrophy occurred in 14% and disciform degeneration in 14%. Age‐related maculopathy was considered the main cause for low vision and blindness in 4.7% of the 468 persons in whom visual acuity and information on fundus could be obtained, and in 3.6% it was one of the causes, usually together with cataract. The other macular disorders caused 1.5% of low vision and

ISSN:1395-3907    

DOI:10.1111/j.1600-0420.1995.tb00647.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACTThe visual acuity of the better eye in the elderly inhabitants of three communities (476 persons, aged 70 years or more) ranged from 0 to 1.4 (mean 0.7), and 12% saw less than 0.3. The logarithm of binocular contrast senstivity ranged from 1.0 to 2.75 (n = 412, mean 2.19) in the Cambridge test and from 0.15 to 1.95 (n = 468, mean 1.48) in the Pelli‐Robson test. The 72 subjects with healthy eyes had a mean visual acuity of 1.03 (range 0.5–1.4) in the better eye, and the two contrast sensitivity tests gave mean values of 2.45 and 1.69, respectively. Cortical, nuclear and mixed cataracts and macular pathology impaired both contrast sensitivity and visual acuity. The correlation between the three tests was good in the whole sample and in the different subgroups of cataract and macular changes. Individually, however, a few contradictory results were obtained. According to these results measurement of contrast sensitivity does not add much to the general information obtained in the elderly by visual acuity measurement alone, but in selected cases it may give valuable informat

ISSN:1395-3907    

DOI:10.1111/j.1600-0420.1995.tb00648.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACTPattern‐reversal visual evoked potentials elicited by patterns of 60′ and 20′ checks and 33 Hz steady‐state flash visual evoked potentials were recorded in low‐vision children (visual acuity less than 20/120) with optic atrophy (18 eyes), amblyopia (18 eyes), macular degeneration (7 eyes) and controls (24 eyes). Steady‐state visual evoked potentials were non‐recordable in 17 out of 18 eyes of optic atrophy patients and normal in other children. Abnormalities of pattern‐reversal visual evoked potentials were similar in all groups of patients. 33 Hz steady‐state flash visual evoked potentials are recommended for differential diangosis of optic atrophy with other causes of low v

ISSN:1395-3907    

DOI:10.1111/j.1600-0420.1995.tb00649.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACTRetinal vessel diameters of 45 diabetic children and adolescents with diabetes were measured on black‐and‐white fundus photographs (negatives) using digital image analyses technique and microdensitometry as well as with direct micrometry. The changes in vessel diameters in two sets of photographs taken at an interval of 2.4 ± 0.3 years were compared with glycated haemoglobin level, retinopathy status and various other parameters. During the follow‐up period both arterial and venous diameters increased significantly (p = 0.0436 and p = 0.0001, respectively), but the changes in individual vessels and between patients differed markedly. The superior temporal vein dilated more than the inferior temporal vein. The average increase in venous calibre was related to the glycated haemoglobin level on the date of the second examination (p = 0.0492). Signs of early retinopathy developed more often in the eyes with venous dilation (6 of 18 eyes) than in those without (3 of 24 eyes), but the difference did not reach statistical significance. The results indicate that retinal vasodilation is associated with chronically elevated blood glucose level in diabetic children, and may precede development of other signs of retin

ISSN:1395-3907    

DOI:10.1111/j.1600-0420.1995.tb00650.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACTThe effects of diabetes on retinal function before the onset of clinically detectable retinopathy have been investigated with several methods. Our aim is to evaluate the usefulness of computerized perimetry in early diagnosis of retinal sensitivity impairment in lack of fluorescein angiographic signs of diabetic retinopathy. Seventy diabetic children and adolescents, 39 normoalbuminuric and 31 microalbuminuric patients, and 70 normal subjects were investigated with static computerized perimetry. Normoalbuminuric patients showed functional parameters similar to those of controls, while microalbuminuric patients had a significant reduction of mid‐peripheral light sensitivity in comparison with both normoalbuminuric children and controls. Our data suggest that an impaired light sensitivity, in mid‐periphery of the visual field, is present in diabetic patients with persistent microalbuminu

ISSN:1395-3907    

DOI:10.1111/j.1600-0420.1995.tb00651.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACTIn a population of 212 mentally retarded, retinoscopy could be performed in 342 eyes in 182 patients. Of these, 334 eyes were phakic. Hypermetropia of +5 or more was encountered in 20 eyes (6.0%), while 26 (7.8%) had a myopia of ‐5 or more. The most striking finding was a high number of severe astigmatism, cylindrical power of ‐3.25 or more being present in 29 eyes (8.7%). Glasses were initially prescribed to 88 patients. Six months after the prescription, 59.1% used their glasses regularly. Aspects of glass prescription to mentally retarded are discussed in the pa

ISSN:1395-3907    

DOI:10.1111/j.1600-0420.1995.tb00652.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACTIn this study we describe certain aspects of normal variability of oscillatory potentials, with particular reference to interaction between pupil size and stimulus intensity. The mean latencies of the earlier oscillatory potentials, O1 and O2, were significantly shorter when adopting the dilated pupil condition than when stimulating with a normal pupil. This occurred at various light intensities, although the difference was more significant at the highest intensity. O1 and O2 latencies became significantly longer as the stimulus intensity was progressively reduced. The latencies of the later components O3 and O4 were unaffected. The O1 and O2 amplitudes were not influenced by pupil size, but a significant reduction occurred with the progressive decrease in stimulus intensity. The later components O3 and O4 are greatly reduced in amplitude after pupil dilatation using higher stimulus intensities; the O4 potential may even disappear in 10% of the cases. These data provide further support for the existence of two distinct behavior patterns for earlier and later oscillatory potentials. Although light adaptation may affect oscillatory potentials, we suggest that in our experimental conditions, oscillatory potential changes may occur as a result of the activity of the neural modulating system, not only as a result of photoreceptor interaction.

ISSN:1395-3907    

DOI:10.1111/j.1600-0420.1995.tb00653.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACTHydrogel contact lenses require a settling period before lens fit stabilizes, but the process underlying the initial reduction in lens mobility is poorly understood. Explanations for this phenomenon include base curve steeping with dehydration, expulsion of postlens tear fluid, and osmotic flow of hypotonic tears into the cornea. We conducted two randomized, single‐masked interocular comparisons for ten subjects wearing HEMA lenses for 1 h. We investigated potential mechanisms of dehydration‐dependent lens tightening, by limiting dehydration in one eye using a high humidity environment (experiment 1), and of a hypotonic lacrimation‐dependent decrease in lens movement, by presoaking lenses in isotonic (0.9%) or hypertonic (1.5%) saline (experiment 2). Lens mobility profiles were not significantly affected by modification of environment; lenses in both normal and high humidity environments displayed a significant reduction in lens movement during the first 15 min of wear (ANOVA, p = 0.0001), and no change in lens mobility thereafter. Lens mobility profiles were identical for lenses presoaked in isotonic and hypertonic saline, with initial lens movement being significantly greater than for subsequent measurements (ANOVA, p<0.05). These studies find no evidence to support dehydration‐dependent steepening of base curve, or osmotic‐dependent binding from hypotonic lacrimation as mechanisms for the initial postinsertion decrease in lens

ISSN:1395-3907    

DOI:10.1111/j.1600-0420.1995.tb00654.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY