Visual Rehabilitation Using Gabor Patches Improves Functional Ability In Neuro-Adaptation Failures After Multifocal Implants: A Randomized Controlled Trial

Photic phenomena and neuro-adaptation failures are major concerns after MFIOLs. This study evaluated patient-specific, perceptual visual therapy(VPL) regime using Gabor patches (grey level gratings, specific for receptive visual fields) in improving vision & contrast sensitivity function(CSF) in patients not satisfied after MF-IOL implantations

A Prospective, controlled-randomized study.

A  Prospective, controlled-randomized study. Adults (50-70 yrs) with uneventful MF IOLs, over 24 weeks post-surgery, BCVA worse than 20/40 with sub-optimal Contrast(CSF), complaining about vision quality, were randomized in a 2:1 ratio into Treatment(G1), in which computer-based perceptual therapy using Gabor patches amidst co-linear flankers was employed & Control(G2) arms. The study had 2 phases (screening + therapy). Mid-training (Post 20 sessions), 40 training sessions, and post-therapy follow-up at 6 months were evaluated for improvements in BCVA distance & near (ETDRS) & CSF at spatial frequencies of 3, 6, 12, & 18 CPD with FACT sine-wave gratings, using Friedman tests for repeated measures

30 cases were randomized into the treatment and control arms in a 2:1 ratio. Subgroup consisted of 16 Trifocals (PanOptix) and 14 Bifocals (Tecnis). The average improvement after VPL therapy is 2.5 lines in LogMar in the Treatment arm (p<0.0001), whereas no significant improvements were observed among the controls. Tests for repeated measures showed 83% improvement in Contrast Sensitivity (CSF at spatial freq. of 3,6,12 & 18 CPD) in the Treatment Group(G1, all p<0.0001), whereas no significant improvements were observed amongst the controls. The improved functional vision and CSF remained stable 6 months post-training with perceptual therapy.

Sequential, post-operative, patient-specific, visual perceptual training employing Gabor patches improved vision & CSF in patients with dissatisfied Multi Focal-IOL subjects & acts as proof of concept of improving neural connections at cortical levels.

The key to optimizing vision following MF-IOLs lies in training the brain to improve neuroadaptation processes.