Abstract
Patients exhibiting uniocular cataract often report an improvement in vision on closing their cataractous eye. Such qualitative evidence suggests the presence of binocular inhibition—the converse of binocular summation (that is the normal superiority of binocular over monocular vision). To quantify the extent of inhibition in cataract, binocular and monocular visual acuity and contrast sensitivity were measured in 28 patients. Twelve patients showed binocular inhibition for visual acuity whilst 11 showed inhibition for contrast sensitivity measured at four cycles per degree (c.deg-1). Contrast sensitivity for 8 c.deg-1 targets was further recorded in a subset of 14 patients in whom seven showed inhibition. In patients who demonstrated inhibition, the mean decrement in performance for visual acuity was 13%. For contrast sensitivity at 4 and 8 c.deg-1 the mean decrement was 25% and 32% respectively. The clinical significance of these findings is discussed with respect to the assessment of visual function and management of the cataract patient.
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Jones RK and Lee DN : Why two eyes are better than one : the two views of binocular vision. J Exp Psychol 1981, 7: 30–40.
Blake R and Fox R : The psychophysical inquiry into binocular summation. Percept Psychophys 1973, 14: 431–6.
Frisén L and Lindblom B : Binocular summation in humans: evidence for a hierarchic model. J Physiol 1988, 402: 773–82.
Gilchrist J and Pardhan S : Binocular contrast detection with unequal monocular illuminance. Ophthal Physiol Opt 1987, 7: 373–7.
Pardhan S and Gilchrist J : The effect of monocular defocus on binocular contrast sensitivity. Ophthal Physiol Opt 1990, 10: 33–5.
Pardhan S and Gilchrist J : Binocular contrast sensitivity with monocular glare disability. Ophthal Physiol Opt 1990, 10: 37–9.
Pardhan S and Gilchrist J : The importance of measuring binocular contrast sensitivity in unilateral cataract. Eye 1991, 5: 31–5.
Bailey IL and Lovie JE : New design principles for visual acuity letter charts. Am J Optom Physiol Opt 1976, 53: 745–53.
Rubin GS : Assessment of visual function in eyes with visual loss. In Fuller DG and Birch DG eds. Assessment of visual function for the clinician: Ophthalmology Clinics of North America: 1989, 2(3): 357–67.
Kitchin JE and Bailey IL : Task complexity and visual acuity in senile macular degeneration. Aust J Optom 1981, 64: 235–42.
Wilkins AJ, Delia Sala S, Somazzi L, Nimmo-Smith I : Age-related norms for the Cambridge Low Contrast Gratings including details concerning their design and use. Clin Vision Sci 1987, 2: 210–12.
Sparrow JM, Bron AJ, Brown NAP, Ayliffe W, Hill AR : The Oxford Clinical Cataract Classification and Grading System. Int Ophthalmol 1986, 9: 207–25.
Heravian JS, Jenkins TCA, Douthwaite WA : Binocular summation in visually evoked responses and visual acuity. Ophthal Physiol Opt 1990, 10: 257–61.
Campbell F and Green D : Monocular versus binocular visual acuity. Nature (Lond) 1965, 208: 191–2.
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Taylor, R., Misson, G. & Moseley, M. Visual acuity and contrast sensitivity in cataract: Summation and inhibition of visual performance. Eye 5, 704–707 (1991). https://doi.org/10.1038/eye.1991.129
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DOI: https://doi.org/10.1038/eye.1991.129
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