Purchase this article with an account.
Fatema Firoz Ghasia, Charles Gallagher; Visual Sensory Deficits in Amblyopic Children with and without Latent Nystagmus. Invest. Ophthalmol. Vis. Sci. 2018;59(9):5957.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Amblyopic patients are known to have a host of visual sensory function abnormalities. It is possible that patients with disruption of binocularity in early infancy would have greater visual function deficits than those who have some binocular experience early in life. None of the studies to date have assessed monocular and binocular visual functions in conjunction with oculomotor functions in children. The purpose of our study was to identify the extent of visual dysfunction in amblyopic children with and without binocular decorrelation in early infancy.
We used a pediatric friendly battery of tests to measure contrast sensitivity, vernier, grating and optotype acuities, stereopsis and eye movements during visual fixation. We looked for the presence of fusion maldevelopment nystagmus (FMN) as a marker of disruption of binocularity in early infancy. We recorded 16 amblyopic patients [5 mixed (2 mild, 1 moderate, 2 severe) 8 anisometropic (4 mild, 2 moderate, 2 severe), and 3 strabismic (2 mild, 1 moderate), and 5 of them had FMN] and 11 healthy subjects.
We found abnormal contrast, visual, grating and vernier acuities in the amblyopic eye of patients with and without FMN as expected. Patients with FMN had greater impairment of vernier, grating and contrast sensitivities for given level of optotype acuity. We also found subtle abnormalities in the visual sensory functions of the fellow eye that were more pronounced in patients with FMN compared to normals. Stereopsis was worse in patients with mixed/strabismic amblyopia compared to anisometropic amblyopia (mean: 4169 ± 3323 versus 1162 ± 2381 arc seconds respectively, Mann- Whitney P <0.05). 54% of pure anisometropic subjects had poor binocular function (stereopsis worse than 140 sec of arc) with no correlation with the optotype acuity in the amblyopic eye (Chi-square test p>0.05). Patients with FMN had worse stereopsis compared to those without FMN irrespective of the type of amblyopia.
In addition to the expected abnormalities of the amblyopic eye, we observed minute deficits in the visual sensory functions of the fellow eye. These observations were more pronounced in amblyopes with fusion maldevelopment nystagmus (FMN). Amblyopia is not a simple monocular visual afferent system problem but is a binocular disorder affecting visual afferent and efferent system with impairments of both the amblyopic and fellow eye.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
This PDF is available to Subscribers Only