Patients with amblyopia, particularly older children who had not benefited from at least 2 years of prolonged patching, experienced clinically meaningful improvements in visual acuity and stereoacuity following perceptual learning therapy with RevitalVision, according to a prospective interventional study published in Clinical Ophthalmology.

Researchers enrolled 73 patients (mean age, 14.6 years; 67% male), including 60 patients aged 18 years or younger who had undergone at least 2 years of unsuccessful patching because of poor compliance or lack of response. All participants completed a minimum of 40 RevitalVision sessions, with 41 patients completing 80 sessions. Amblyopia subtypes included anisometropic (34 patients), strabismic (20), isometropic (6), deprivational (4), and other causes (9). Best-corrected visual acuity and stereoacuity were evaluated at baseline, after 40 and 80 sessions, and at 3, 6, and 12 months. Multivariable regression was performed to identify predictors of outcome.

Visual Outcomes Varied by Amblyopia Subtype

After 40 treatment sessions, visual acuity improved across several amblyopia subtypes, with the most consistent gains observed among patients who had anisometropic amblyopia. Mean visual acuity improved from 0.50 to 0.32 logMAR, and 40% of these patients achieved visual acuity of 20/40 or better. Patients who had strabismic amblyopia showed slower recovery (0.54 to 0.38 logMAR) and greater variability. Patients who had deprivational amblyopia showed a limited response. At 12 months, mean stereoacuity had improved from 175 to 67 arcseconds among patients who had anisometropic amblyopia and from 214 to 48 arcseconds among those who had strabismic amblyopia. Patients who had isometropic amblyopia also demonstrated stable improvements in visual acuity and stereoacuity, although the subgroup was small.

Baseline Visual Acuity Predicted Response

Multivariable regression identified pretreatment visual acuity as the strongest independent predictor of the visual outcome after 40 sessions. Amblyopia subtype and age were not independently associated with the outcome after adjustment. The time required to complete the initial 40 sessions also did not affect visual acuity outcomes, with patients completing treatment more slowly achieving results comparable to those who finished within the recommended timeframe.

Patients completing 80 sessions achieved only marginally greater visual acuity gains than those completing 40 sessions, although the difference was not significant after adjustment for baseline visual acuity. However, stereoacuity improvement was significantly greater in the extended-treatment group, suggesting that prolonged exposure may preferentially benefit binocular visual function.

Durability Findings and Study Limitations

The researchers observed a subtle but consistent "waning effect" during the 6- to 12-month follow-up period across the 3 main amblyopia subtypes, reflected in marginal regressions in both visual acuity and stereoacuity. While these regressions were small and occurred in limited subsets, the researchers said the findings may indicate a need for sustained engagement or booster therapy to consolidate long-term outcomes in eyes with failed prolonged patching.

The researchers noted several limitations, including the modest sample size, particularly among patients who had isometropic and deprivational amblyopia, the absence of a randomized control group, and attrition during long-term follow-up that may have affected assessment of treatment durability and regression trends. They also highlighted the study's real-world clinical design, inclusion of a refractory cohort with prolonged failed patching, stratified analysis by amblyopia etiology, and longitudinal assessment of both visual acuity and stereoacuity, as strengths.

The researchers concluded that baseline visual acuity emerged as the strongest predictor of outcome, underscoring the importance of disease severity in determining both the magnitude and durability of response. They wrote, “Although extending therapy beyond 40 sessions conferred limited additional benefit in visual acuity, improvements in stereoacuity suggest a role for longer or staged treatment in selected patients. These findings support the use of perceptual learning therapy as a valuable adjunct in resistant amblyopia and highlight the need for future studies to individualize treatment duration based on baseline characteristics to optimize long-term outcomes.”