Perceptual learning may offer sustained visual acuity improvements in keratoconus patients, according to a study published in the American Journal of Ophthalmology.

"Overall, the results of this randomized clinical trial suggest that perceptual learning is a promising visual therapy for keratoconus patients, and could provide steady improvements in visual function," the study authors wrote.

In a randomized, double-blind clinical trial, researchers randomly assigned 35 nonprogressive keratoconus patients aged 9 years and older to a perceptual learning group or a placebo group. After 3 months of performing the practice, each group was monitored for an additional 3 months without additional training.

At the 3-month visit, participants in the perceptual learning group had significantly improved spectacle-corrected distance visual acuity (CDVA) compared with the placebo group, with 47.06% of perceptual learning participants gaining a 2-line or better CDVA, and none of the placebo group achieving that level of improvement. At 6 months, these improvements persisted.

Perceptual learning participants also demonstrated sustained changes in visual acuity parameters, including uncorrected distance visual acuity, presenting distance visual acuity, uncorrected near visual acuity, corrected near visual acuity and presenting near visual acuity.

"[Perceptual learning (PL)] provides a potential therapeutic choice for keratoconus patients who are contact lens intolerant and have visual difficulties despite using spectacles," the authors wrote. "Further studies in a larger population are needed to evaluate the long-term use of PL and to explore its internal mechanism."