To determine the effect of rigid gas permeable (RGP) contact lenses in improving involuntary eye movements and visual function in hyperopic patients with infantile nystagmus syndrome (INS).

This prospective interventional case series was conducted on patients with congenital nystagmus and hyperopia ≥ +0.5 D and astigmatism ≥-1 D over a two-year period. BCVA, contrast sensitivity and video-nystagmography was performed for all patients before and after RGP fitting and compared.

32 eyes of 16 patients with mean age of 18.6±4.9 years were enrolled. Mean spherical equivalent was +1.5±2.35 (-1 to +6.25) diopters (D); corresponding values for sphere was +2.45±2.44 (+0.5 to +7.5) and for astigmatism was -1.90±0.83 (-1 to -4) D. Monocular visual acuity improved from 0.56±0.23 to 0.51±0.23 Log MAR (P=0.007) and binocular VA improved from 0.54±0.25 to 0.48±0.24 Log MAR (P=0.01). Contrast sensitivity was improved significantly in low (P=0.02) and intermediate (P< 0.001) frequencies but not at high frequencies (P=0.6). The frequency, amplitude and intensity of nystagmus were decreased significantly after RGP use (p< 0.001).

RGP in patients with INS improved monocular and binocular VA and contrast sensitivity. Motor indices of nystagmus (frequency, amplitude and intensity) also were significantly improved after RGP usage