Perceptual Learning Therapy Improves Vision & Contrast Sensitivity In Amblyopia Related With Post- Cxl Keratoconus & Mf- Iols: Pooled Analysis

To evaluate a computer-based perceptual therapy for improving the best corrected visual acuity (BCVA) and contrast sensitivity function (CSF) in stable crosslinked keratoconic eyes and post-cataract patients with multifocal IOL Implants. 

A pooled analysis of two RCTs carried out at a tertiary eye care center in south India.

Pooled analysis of two RCTs. Post-CXL patients with stable BCVA & keratoconus parameters for over 1 year (AG) and post-cataract with MF-IOL patients (BG) were randomized in a 2:1 ratio comprising 30 eligible subjects in each arm. In each stratified group, 20 patients underwent a novel perceptual visual therapy (AG-1, BG-1) & 10 patients acted as controls (AG-2, BG-2). The three phases were the screening period, therapy period, and follow-up phase. Improvement in BCVA & Contrast Sensitivity Function(CSF) (at different spatial frequencies of 3, 6, 12, and 18 cycles per degree) were analyzed from baseline after 20 & 40 training sessions.

Baseline parameters between control & treatment groups were comparable. Mean BCVA in AG1 were 68.20 (SD- 8.108), 73.30 (SD-7.477) & 79.10 (SD-8.466) characters at baseline, post 20 & 40 sessions respectively. BCVA was 67.40 (SD-7.09) in the control arm (AG2) with no improvements.  Mean BCVA in BG1 were 63.85 (SD- 5.85), 70.65 (SD- 6.25) & 76.20 (SD- 5.69) characters at baseline, post 20 & 40 sessions respectively. Among perceptual learning groups in both strata, repeated measure ANOVA & was significant (p<0.0001). The CSF of control groups against the perceptual learning groups at 3,6,12, & 18 cpd by Friedman's tests showed significant improvements in functional acuity contrast of the perceptual group (AG1 & BG1) but not in control groups. 

With no other alternate therapeutic options available in treating patients suffering from amblyopia associated with post-CXL stable keratoconus and post multifocal IOLs, the Perceptual Learning computer-based therapy improved both BCVA and Contrast Sensitivity Functions (CSF). This approach could be an adjuvant as the "Better Together" concept.