Abstract
ObjectiveThe purpose of this study was to evaluate the possible structural changes of the macula in patients with unilateral amblyopia using optical coherence tomography (OCT) image segmentation.Patients and Methods38 consecutive patients (16 male; mean age 32.4±17.6 years; range 6–67 years) with unilateral amblyopia were involved in this study. OCT examinations were performed with a time-domain OCT device, and a custom-built OCT image analysis software (OCTRIMA) was used for OCT image segmentation. The axial length (AL) was measured by a LenStar LS 900 device. Macular layer thickness, AL and manifest spherical equivalent refraction (MRSE) of the amblyopic eye were compared to that of the fellow eye. We studied if the type of amblyopia (strabismus without anisometropia, anisometropia without strabismus, strabismus with anisometropia) had any influence on macular layer thickness values.ResultsThere was significant difference between the amblyopic and fellow eyes in MRSE and AL in all subgroups. Comparing the amblyopic and fellow eyes, we found a statistically significant difference only in the thickness of the outer nuclear layer in the central region using linear mixed model analysis keeping AL and age under control (p = 0.032). There was no significant difference in interocular difference in the thickness of any macular layers between the subgroups with one-way between-groups ANCOVA while statistically controlling for interocular difference in AL and age.ConclusionsAccording to our results there are subtle changes in amblyopic eyes affecting the outer nuclear layer of the fovea suggesting the possible involvement of the photoreceptors. However, further studies are warranted to support this hypothesis.
Highlights
Amblyopia remains an important cause of low visual acuity, affecting 2% to 6% of the general population [1,2,3,4,5]
There was no significant difference in interocular difference in the thickness of any macular layers between the subgroups with one-way between-groups ANCOVA while statistically controlling for interocular difference in axial length (AL) and age
According to our results there are subtle changes in amblyopic eyes affecting the outer nuclear layer of the fovea suggesting the possible involvement of the photoreceptors
Summary
Amblyopia remains an important cause of low visual acuity, affecting 2% to 6% of the general population [1,2,3,4,5]. The neural sites that are influenced by visual deprivation are still under investigation. It has been reported by several studies in humans [7,8] and in animal species [9,10,11,12] that visual deprivation has an effect on the cell growth in the lateral geniculate body that receives input from the amblyopic eye and on the shift in the dominance pattern in the visual cortex [13], Banko et al revealed that latencies of the event-related potential components increased and were more variable in the amblyopic eye compared to the fellow eye [14], the initial neural site of the visual deficit in this condition is still under investigation. Studies using optical coherence tomography (OCT) imaging of the retina have produced discordant results, some investigators have found an increased peripapillary retinal nerve fiber layer (cpRNFL) [20,21,22] or/and macular thickness [20,23,24,25,26] in amblyopic eyes, whereas others have found no significant differences between amblyopic and healthy eyes [27,28,29,30,31,32]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
