ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1983.tb03925.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

A summary of the visual pathways in the brain is presented as a basis for considering abnormalities in this system. The role of the cortical associative regions in visual function is briefly delineated. A short summary of experiments describing plastic properties of the visual pathways at early age is also presented, and experiments describing neural and behavioural changes after binocular deprivation are reviewed. It is concluded that early visual deprivation leads to a profound alteration of the associative systems of the brain and that in monkeys and humans these changes are difficult to remedy later. Therefore early detection and correction of visual abnormalities is very important as well as early compensation using other forms of sensory communication.

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1983.tb03926.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

The forced‐choice preferential looking method (FPL) shows the development of acuity during the first year of life, and is applicable to clinical assessment. A tracking test using a narrow strip of grating yields a more sensitive measure for the later part of this age range, however. The development of acuity is dominated by neural rather than optical or accommodative factors. By age 3 years resolution acuity is very close to adult performance, but at 5 years ‘crowding’ effects may still impair performance on practical acuity tasks more than for the

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1983.tb03927.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Binocular function in infancy can be assessed by means of the visual evoked potential (VEP) induced by a dynamic random dot pattern which alternates between a binocularly correlated and an anticorrelated state. A VEP timelocked to the alternation can only be produced by binocular interaction in the cortex. This interaction becomes detectable at around three months of age. Optokinetic nystagmus (OKN) in monocular viewing becomes symmetrical in nasal and temporal directions around the same age. Animal analogues and clinical cases suggest that this may also be an indicator of cortical binocularity. These techniques may be applicable to clinical assessment of binocular function in young infants.

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1983.tb03928.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Isotropic photorefraction is a technique which makes possible the rapid, economic, large scale screening of infants and young children for refractive errors. The relative size of blur circles reflected from the fundus in 3 flash photographs with different camera settings allows the size and direction of refractive errors to be estimated. The method has been validated against retinoscopic measures on a large group of infants. Findings of a high incidence of astigmatism in the first year are confirmed. Detection of hypermetropia in early infancy by this screening procedure may allow preventive treatment for accommodative strabismus.

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1983.tb03929.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

A simple photorefraction method using simultaneous photography of corneal and fundus reflexes have been used to screen 239 children aged 10 to 15 months for significant refraction errors. The photorefraction results were calibrated to those of cycloplegic retinoscopy. A good agreement was found between the 2 sets of values. The frequency distribution of refraction errors were similar to those presented by Ingram (1979). The aim to detect hyperopia ≥+2 or myopia ≥‐4 diopters together with significant anisometropia or astigmatism was fullfilled with high reliability. Low degrees of hyperopia, myopia and astigmatism might be missed. Photorefraction therefore is considered to be a reliable, simple and cheap tool with high sensitivity and specificity in screening small children for significant refraction e

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1983.tb03930.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

In children with a visual handicap, colour vision testing may provide additional cues to diagnosis. Some information is given by pseudo‐isochromatic plates. More informative are the arrangement tests, especially the Panel D‐15. These tests can be used also in cases with severely reduced visual acuity. In suspected achromatopsia, the scotopic spectral sensitivity can be revealed by the D‐15 test, the anomaloscope, or measuring the spectral sensit

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1983.tb03931.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Spatial contrast sensitivity may decrease differently at different spatial frequencies when vision is impaired. Patients with central scotoma may have normal or decreased sensitivity at low spatial frequencies, their Snellen acuity often is lower than grating acuity estimated on the basis of contrast sensitivity values. In retinitis pigmentosa contrast sensitivity may decrease at the low spatial frequencies already in the early teens. Because the ability to discern low contrasts is important in daily living, spatial contrast sensitivity measurements should become a part of clinical evaluation of vision.

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1983.tb03932.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

We report our experience with 2 new methods of assessing visual functions in children: grating acuity determination by means of preferential looking technique and contrast sensitivity measurements. Acuity determinations with preferential looking proved useful for evaluation of the effects of amblyopia treatment in young children (0–3 years) with esotropia and for monitoring visual development in children operated early for congenital cataract. We have also used these methods successfully for diagnostic acuity determinations in very young children or in older but mentally retarded children with suspected visual impairment. In 4‐year‐old children contrast thresholds were determined for sine wave gratings of different spatial frequencies displayed on an oscilloscope screen. The results were less reproducable than those obtained earlier in somewhat older children, and did not correlate as well as the results of other visual tests as in the older chi

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1983.tb03933.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

ISSN:1755-375X    

DOI:10.1111/j.1755-3768.1983.tb03934.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY