Long-Term Evaluation of Ocular Surface and Meibomian Gland Function after Laser Assisted in Situ Keratomileusis surgery.

Introduction: Laser-assisted in Situ Keratomileusis (LASIK) is a common refractive surgery. But it may lead to temporary dry eye due to reversible damage to the corneal sub-basal nerve plexus. However, chronic ocular surface changes are unclear. This study reports the ocular surface changes, partial blinking rate, and meibomian gland status in eyes that underwent LASIK for at least 48 months.

Methods: Cross-sectional, matched case-control comparison study, including 48 post-LASIK patients and 48 sex-, age-, smoking-, and axial length-matched healthy controls, recruited from a community eye screening program. Outcome measures include anterior segment clinical findings, keratographic and meibographic imagings.

Results: Totally 48 right eyes of 48 post-LASIK Chinese patients (39 females, 2 smokers) were analyzed with 48 right eyes of 48 matched healthy controls. The age on ocular surface examination was 50±11 years, and the axial length 26±1mm. Post-LASIK eyes had a lower quality of meibum (P=0.008) compared to healthy controls. Post-LASIK eyes were associated with a shorter Schimer test (P=0.03). The ocular surface disease index (OSDI) score was higher in post-LASIK patients (P=0.00001). Other anterior segment examination parameters, partial blinking rate, meibomian gland dropout, lipid layer thickness, non-invasive tear break-up time, and tear meniscus height were comparable between the 2 groups.

Conclusions: Up to 75% of post-LASIK patients complained of chronic dry eye symptoms. Post-LASIK eyes were associated with a reduced aqueous tear production. Post-LASIK patients with chronic dry eye symptoms should have comprehensive ocular surface evaluation. Treatment should be commenced in patients with poor tear film stability.