Dry eye syndrome after laser in situ keratomileusis [LASIK] for correction of myopia

ABSTRACT

To evaluate the incidence of dry eye syndrome after laser in situ keratomileusis [LASIK] and to determine the pattern of tears recovery. In a prospective, non comparative case study, 33 eyes [20] patients underwent laser in situ keratomileusis to correct myopia ranging from -0.75 to -14.00D. Each eye was followed for mean period of 12 months [10 - 14 months]. Patients were followed at 2 weeks and 2 days preoperatively and 1 day, 1 and 2 weeks, 1, 3, 6, 9 and 12 months postoperatively, measuring the Snellen visual acuity, corneal sensitivity, corneal fluorescein staining, tear break-up time, basic aqueous tear production by the Anaesthetized Schirmer test, and corneal Surface Regularity Index [SFU]. Patients were divided according to the depth of ablation into group A [ablation depth < 100 microm and group B [ablation depth >100 microm] dry eye syndrome after laser in situ keratomileusis was evident at the ablated zone during the first 3 months after surgery and only at the 6th months it returned to its preoperative values. Recovery was more rapid at the hinge than the other points. The degree of sensation loss appears to correlate with the ablation depth and degree of dry eye symptoms. The results suggest that lamellar cutting of the cornea during LASIK impairs corneal sensitivity and modifies tear production and the depth of the corneal ablation affects the extent of dryness and recovery