Abstract
Purpose :
To explore whether combined perceptual learning (PL) and non-invasive brain stimulation (NIBS) can enhance near visual acuity (VA) in individuals with presbyopia.
Methods :
Thirty participants (mean age 50.1; 15 males, 15 females) completed two weeks of perceptual learning of a contrast detection task in combination with either transcranial magnetic stimulation (TMS), transcranial random noise stimulation (tRNS), or sham transcranial direct current stimulation (tDCS) (n=10 in each group). The primary outcome measure was binocular distance corrected near visual acuity (DCNVA; Good-Lite® near VA chart at 40cm). Contrast sensitivity (custom code implemented in Psychopy), and functional reading ability (MNREAD app Ver. 1.17, iPad Pro) were also assessed. Inclusion criteria included age between 40-55, diagnosis of presbyopia (near addition of ≥ +0.75 diopter at 40cm), distance VA of ≤ 0.10 logMAR in each eye, and a maximum interocular difference of 1-logMAR line. Exclusion criteria included ocular and neurological pathologies affecting vision and visual function, history of ocular surgery (except refractive correction), and contraindications to non-invasive brain stimulation. Paired t-tests were conducted to compare pre- and post-intervention, as well as pre- and post-1-month-intervention, within each group, in order to assess treatment efficacy and retention of effects.
Results :
The tRNS group (t = 2.371, p = 0.04) and the TMS group (t = 1.902, p = 0.09) demonstrated improvements in DCNVA exceeding 1-logMAR line, while the sham group improved by less than 1-logMAR line (t = 2.140, p = 0.06). Sustained improvements were observed at the 1-month follow-up for both the tRNS group (t = 4.033, p = 0.003) and the TMS group (t = 2.817, p = 0.02).
Conclusions :
Interventions combining NIBS and PL shows promise in enhancing unaided near vision in individuals with presbyopia. Further studies are warranted to explore the potential of non-optical approaches in managing this condition, as indicated by results of this pilot investigation.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.