To determine the effect of PRK on involuntary eye movements and visual function in myopic patients with infantile nystagmus syndrome (INS).

This prospective interventional case series was conducted on patients with INS and myopia ≥ -1 D. BCVA, contrast sensitivity and video nystagmography were performed for all patients before and 3 months after surgery.

24 eyes of 12 patients with mean age of 23±2 years were enrolled. Spherical equivalent was-2.82 ± 1.65 D and -0.26 ± 0.25D before and after PRK ,respectively; corresponding values for mean spherical error were-2.16±1.36 and -0.10±0.35, and that for astigmatism were -1.33 ± 1.14 and -0.31 ± 0.51(P<0.001 for all comparisons). Monocular VA improved from 0.36±0.21 to 0.27±0.25 LogMAR and binocular VA was improved from 0.33±0.2 to 0.17±0.16 LogMAR(P?0.001). Contrast sensitivity significantly improved at low (P<0.001), intermediate (P<0.001), and high frequencies (P=0.01).The frequency, amplitude and intensity of nystagmus were significantly decreased after PRK (p?0.001). There was no correlation between the degree of myopic correction and improvement in sensory and motor indices of nystagmus(P>0.1, Pearson correlation index).

PRK in patients with INS improved monocular and binocular VA. Also contrast sensitivity and motor indices of nystagmus were significantly improved after surgery.