Abstract:

Objective To investigate the clinical features of ocular surface of patients with demodex infection after laser-assisted in situ keratomileusis (LASIK). Design Retrospective case series. Participants 56 patients with demodex blepharitis who were admitted to Beijing Tongren Hospital from September 2017 to May 2018. They were divided into LASIK group (n=9) and control group (n=47). Methods The ocular surface examination was performed on two groups of patients using Keratograph5M ocular surface comprehensive analyzer and tear secretion test, including cornea fluorescence staining (FL), tear film break-up time (TBUT), and red eye analysis (conjunctival hyperemia index, CHI), meibomian gland photography and tear secretion test (Schirmer I test, SIt). Main Outcome Measure Corneal FL score, non-invasive TBUT, CHI, meibomian gland score and basic tear secretion. Results The FL value of the LASIK group (1.3±1.0) was significantly higher than that of the control group (0.38±0.15) (P<0.01). TBUT (10.55±5.8) s, CHI (1.7±0.5), SIt (16.4±3.8)mm, and meibomian gland score (1.42±1.0) in LASIK group were no significant difference with the TBUT (9.93±5.3) s, CHI (1.74±0.67), SIt (14.0±11.2)mm, and meibomian gland score (1.45±1.03) in controls (all P>0.05). Conclusion Demodex blepharitis in patients after LASIK is more likely to secondary to corneal epithelial punctate lesions and aggravate ocular surface damage.

Key words: demodex, meibomian gland dysfunction, demodex blepharitis, LASIK