Characteristics of straylight in normal young myopic eyes and changes before and after LASIK

To investigate the characteristics of straylight and relevant factors in normal young myopic eyes and to assess changes in straylight and possible influencing factors before and after laser in situ keratomileusis (LASIK).

In this prospective nonrandomized study, 105 eyes of 105 patients were included. The level of straylight was measured with a straylight meter, and relationships with some optic parameters were analyzed in normal young myopic eyes. The difference between postoperative and preoperative straylight and the relationship with ablation were studied before and 1, 4, and 10 months after LASIK surgery.

For normal eyes, sphere, astigmatism, keratometric (K) value, corneal central thickness (CCT), and anterior chamber depth (ACD) showed no significant correlation with straylight. However, straylight values showed a statistically significant increase 1 and 4 months after surgery (P < 0.05) but returned to preoperative levels at 10 months after surgery (P > 0.05) in LASIK eyes. No statistically significant relationship was found between straylight values and ablation depth, ablation ratio, residual bed thickness (RBT), or RBT/CCT (P > 0.05) after surgery.

Specific optic parameters (refractive power, K value, CCT, and ACD) have no significant correlation with straylight. Although straylight increased during the early postoperative period, the parameter returned to preoperative levels over time.