Deficits of spatial localization in children with strabismic amblyopia
- 122 Downloads
Besides loss of visual acuity and binocularity, spatial localization deficits (comprising both increased spatial uncertainty and spatial distortions) are an important feature of strabismic amblyopia. Although they have been extensively investigated in adult amblyopes, there are still many open questions concerning their substrate and relationship to clinical parameters. Our aim was to develop a procedure for assessing vertical alignment, which enabled us to find out whether children with strabismic amblyopia had similar spatial localization deficits, and their relation to the children’s clinical condition.
Vertical alignment was assessed in children by comparing the visual direction in space of three loci along the vertical meridian, separated by 5 deg of visual angle. We tested alignment in the amblyopic and dominant eyes of 32 strabismic and in both eyes of 35 control children from 4.5 to 10 years, together with a careful orthoptic examination.
In the amblyopic eyes, increased uncertainty and systematic distortions outside the normal range occurred. Large angles of deviation and pathological fixation patterns were necessary, but not sufficient conditions for gross spatial deficits to occur. The fellow dominant eyes showed spatial localization similar to normal eyes.
Children with strabismic amblyopia exhibited localization deficits and relationship to clinical data similar to those in adult amblyopes. These data are important for further investigations about the substrate, plasticity and the clinical relevance of perceptual distortions.
KeywordsTest Line Control Child Amblyopia Reference Stimulus Vertical Alignment
Author M.F. was supported by grants from the Deutsche Forschungsgemeinschaft (Fr 1312/1-1 and 1-2). Thanks are due to Professors C. Ohrloff and W. Singer for support of this study, to the ophthalmologists and orthoptists who referred patients to our lab and made careful orthoptic examinations (PD Dr. D. Friedrich, Dr. U. Aschoff, M. Theisen, I. Bachert, A. Büttner-Cordey, H. Bartz, B. Herrmann, M. Murtro), and to our patients and their parents for their collaboration. We gratefully acknowledge the secretarial assistance of S. Klekar, help with statistics by Dr. Tews from the Biomathematics Department, and M. Mulvahill for language assistance.
- 9.Flom MC (1991) Contour interaction and the crowding effect. Prob Optom 3:237–275Google Scholar
- 15.Fronius M, Sireteanu R (1995) Distortions of visual space perception in strabismic amblyopia. Strabismus 3:43–45Google Scholar
- 16.Fronius M, Sireteanu R, Fuisting B, Zubcov A (1995) A test for assessing spatial localization in strabismic children. Perception: 24, 53Google Scholar
- 17.Fronius M, Zubcov A, Sireteanu R (1998) Spatial localization changes during occlusion therapy in children with strabismic amblyopia. Perception 27:161Google Scholar
- 18.Fronius M, Zubcov A, Sireteanu R, Büttner A (1999) Dynamics of spatial localization changes during occlusion therapy in children with strabismic amblyopia. Invest Ophthalmol Vis Sci 40 [Suppl]:307Google Scholar
- 20.Fuisting B, Haase W (1989) Gestörte relative Lokalisation bei Amblyopie vor und nach Behandlung. Z Prakt Augenheilkd 10:210–216Google Scholar
- 21.Gingras G, Mitchell DE, Hess RF (1999) The spatial localization deficit in visually deprived kittens. Invest Ophthalmol Vis Sci 40 [Suppl]:287Google Scholar
- 22.Haase W (1989) Amblyopie-Forschung unter klinischen Gesichtspunkten. Hamburger Ärztebl 10:375–382Google Scholar
- 26.Hess RF, Campbell FW, Greenhalgh T (1978) On the nature of the neural abnormality in human amblyopia: neural aberrations and neural sensitivity loss. Pflügers Arch 377:201–207Google Scholar
- 30.Kiorpes L, Movshon JA (2002) Extended developmental time course for global visual functions in primates. J Vision 2(10): 47aGoogle Scholar
- 41.Noorden GK von (1990) Binocular vision and ocular motility. Mosby, St. LouisGoogle Scholar
- 53.Tychsen L, Burkhalter A, Wong A (2002) Paucity of horizontal connections for binocular vision within primary visual cortex of naturally-strabismic macaque. ARVO abstractGoogle Scholar
- 54.vom Hofe K (1930) Untersuchungen über das Sehen in Fällen von Schielamblyopie. Klin Monatsbl Augenheilkd 85:79Google Scholar