effect of the photorefractive keratectomy on improvement of involuntary eye movements and visual function in myopic patients with congenital nystagmus

purpose: to determine the effect of photorefractive keratectomy (prk) on improvement of involuntary eye movements and visual functions in myopic patients with congenital nystagmus. methods: this prospective interventional case series included patients with congenital nystagmus and myopia ≥ -1 d who underwent prk over a 2-year period. complete ophthalmological examinations including visual acuity, contrast sensitivity and video-nystagmography were performed and compared before and 3 months after prk. results: a total of 24 eyes of 12 patients with a mean age of 23±2 years were enrolled in the study. spherical equivalent was -2.82 ± 1.65 preoperatively and -0.26 ± 0.25 postoperatively (p<0.001). pre- and postoperative mean sphere was -2.16±1.36 and -0.10±0.35 and astigmatism was -1.33 ± 1.14 and -0.31 ± 0.51, respectively (p<0.001 for both comparisons). mono-ocular visual acuity was improved from 0.36±0.21 in logmar preoperatively to 0.27±0.25 logmar postoperatively (p<0.001). binocular visual acuity was significantly improved from 0.33±0.2 logmar to 0.17±0.16 logmar (p<0.001). a significant increase in contrast sensitivity was observed in low (p<0.001), intermediate (p<0.001) and high (p=0.01) spatial frequencies. frequency, amplitude and intensity of nystagmus were significantly decreased after prk (p<0.001). there was no correlation between degree of myopic correction and improvement in sensory and motor indices of nystagmus (p>0.1 for all correlations). conclusion: prk in patients with congenital nystagmus increased mono-ocular and binocular vision. additionally, contrast sensitivity and motor indices of nystagmus (frequency, amplitude and intensity) were significantly improved postoperatively.