Effects of Perceptual Learning on Deprivation Amblyopia in Children with Limbal Dermoid: A Randomized Controlled Trial

Abstract

Limbal dermoid (LD) is a congenital ocular tumor that causes amblyopia and damages visual acuity (VA) and visual function. This study evaluated the therapeutic efficacy of perceptual learning (PL) toward improving contrast sensitivity function (CSF) and VA. A total of 25 children with LD and 25 normal children were compared in terms of CSF and VA. The LD group was further randomly allocated into two arms: nine underwent PL combined with patching and eight underwent patching only; eight patients quit the amblyopia treatment. The primary outcome was the area under log CSF (AULCSF), and the secondary outcome was the best corrected VA (BCVA). The CSF was obviously reduced in the LD group compared with that in the normal group. Moreover, the difference in the changes in the AULCSF between the PL and patching groups after 6 months of training was 0.59 (95% CI: 0.32, 0.86, p < 0.001), and the between-group difference in VA at 6 months was −0.30 (95% CI: −0.46, −0.14, p < 0.001). Children suffering from LD with amblyopia exhibited CSF deficits and VA loss simultaneously. PL could improve CSF and VA in the amblyopic eye better than patching.

Current Developments in the Management of Amblyopia with the Use of Perceptual Learning Techniques

“…One branch of the amblyopic patients underwent a combined treatment of PL and subsequent patching in each session. Results showed an improvement in both VA and CS after a long-term treatment period (6 months) [5].…”

“…Finally, a small sample randomized control study with deprivation amblyopia participants versus healthy subjects evaluated the effectiveness of an online PL training program with adjustable low-contrast Gabor stimuli hidden between high-contrast Gabors, performed in both office and home sessions [5]. One branch of the amblyopic patients underwent a combined treatment of PL and subsequent patching in each session.…”

“…It is the most common vision impairment in children, affecting up to 3.9% of the world population [1,2,4]. The main amblyogenic factors are: (a) Refractive errors, presented as anisometropia, which refers to a significant difference in refractive error between the two eyes, or as high ametropia, which refers to a high refractive error existing in both eyes; (b) strabismus, which is the misalignment of both eyes; and (c) deprivation of visual input, usually due to congenital cataract, eyelid ptosis, corneal opacities, limbal dermoids, or other ocular conditions preventing light from reaching the normal retina [2,5,6]. According to these causes, amblyopia is classified as refractive, strabismic, or deprivation amblyopia.…”

Refractive Characteristics and Related Factors of Amblyopia after Lamellar Keratoscleroplasty in Children with Limbal Dermoids

“…As surgery cannot change the high refractive abnormality, especially the astigmatism, we should seek ways to reduce the astigmatism of patients, including adjusting the tightness of sutures and removal of intermittent stitches, as well as postoperative optical correction methods (i.e., wearing RGP lenses) and active amblyopia treatment methods (i.e., perceptual learning) [ 17 ].…”

Treatment of corneal dermoid with lenticules from small incision lenticule extraction surgery: a surgery assisted by fibrin glue

“…They most commonly occur in the inferotemporal quadrant of the bulbar, straddling the limbus and often having a keratinized surface with hair follicles on its surface [1][2] . They may grow into cornea slowly or maintain stationary, but can result in astigmatism, amblyopia, and even monocular blindness if pupil is covered [3][4] . Corneal dermoid shows abnormal ocular appearance.…”