Home-based perceptual learning augments high-frequency contrast sensitivity and stereopsis after esotropia surgery: A...

Despite successful surgical realignment, children with esotropia often retain deficits in medium and high spatial frequency (SF) contrast sensitivity (CS) and stereopsis due to persistent cortical suppression. While perceptual learning (PL) improves binocular outcomes in exotropia and amblyopia, its efficacy in esotropia remains unexplored.

This retrospective study analyzed 44 pediatric esotropia patients (mean age: 4.34 ± 1.68 years) who underwent strabismus surgery followed by ≥3 months of home-based computerized PL. CS was assessed at five SFs (1.5-18 cycles per degree [cpd]) using the Optec 6500 system, and stereoacuity was graded via Randot Preschool/Titmus Fly tests. Outcomes were evaluated preoperatively, postoperatively (baseline), after 3 months of PL, and at final follow-up (mean: 172.15 ± 86.03 days).

Post-PL, significant improvements emerged at medium SF: logCS increased from 2.02 ± 0.45 to 2.15 ± 0.37 at 6 cpd (P < 0.0001), and high SFs: logCS increased from 1.66 ± 0.53 to 1.89 ± 0.41 at 12 cpd (P < 0.0001) and from 1.18 ± 0.53 to 1.52 ± 0.41 at 18 cpd (P < 0.0001). Low SFs (1.5-3 cpd) showed no significant changes. Stereoacuity improved markedly, with 47.73% achieving good stereopsis (≤100 arcseconds) versus 13.64% post-surgery (P = 0.0003).

This study demonstrates, for the first time, that home-based PL selectively enhances medium-to-high-SF contrast sensitivity and promotes stereopsis recovery in pediatric esotropia after surgical alignment. These gains, likely mediated by cortical plasticity, address deficits unmitigated by surgery alone. PL represents a scalable adjuvant therapy to optimize functional vision, advocating for its integration into post-surgical rehabilitation protocols.