[Studying VSX1 gene mutations in patients with keratoconus of chaharmahal and Bakhtiari Province, Iran]

Background and Aims: Keratoconus [KC] is an eye disorder in which the cornea is swollen, thinned and deformed. Despite extensive studies, the pathophysiological processes and genetic etiology of KC is unknown. The disease incidence is approximately 1 in 2000 and is the most common cause of corneal transplantation in the US. Many genes are involved in the disease, but evidence suggests a major role for VSX1 in the etiology of KC. This study aimed to determine the frequency of mutations in exons 2, 4 of the VSX1 gene in Chaharmahal and Bakhtiari province, Iran

Methods: In this experimental study, mutations in two exons including exons 2 and 4 of VSX1 were investigated in 50 patients with KC. DNA was extracted using a standard phenol-chloroform method. PCRSSCP/HA was performed, followed by DNA sequencing to confirm the identified motility shift

Results: H244R mutation was identified in exon 4 of only one patient

Conclusion: Our investigation showed that the KC-related VSX1 mutations are found in very small samples in the study subjects from Iran. Further investigations on other genes are needed to clarify their roles in KC pathogenesis

[Stereoacuity after LASIK]

To evaluate the effect of laser in situ keratomileusis [LASIK] on stereoacuity [SA]. In this prospective study, 200 patients scheduled for LASIK were evaluated for SA preoperatively and one week and one and three months postoperatively by Random Dot test. Patients with preoperative SA worse than 480 sec/arc were excluded. Patients included 138 female [69%] and 62 male [31%] subjects. Spherical equivalent was between -0.5 and -12.0 D. Mean preoperative SA was 124.80 +/- 124.64 [range 480-15] sec/arc which deteriorated to 138.30 +/- 126.48 sec/arc one week after surgery [P= 0.158] and improved to 111.30 +/- 112.15 sec/arc [P=0.002] one month and 103.65+112.20 sec/arc [P=0.001] three months postoperatively. Patients with anisometropia had lower SA. Eventually, SA increased in 5 nonamblyopic anisometropic patients. Overall, stereoacuity decreased in 9.5%, increased in 32.5% and remained unchanged in 58% of patients [P=0.007]. Despite the overall improvement in mean SA after LASIK, a considerable number of patients experienced decreased SA. It seems that anisometropic patients without amblyopia have a higher chance for improvement in SA