Meibomian Gland Alterations in Keratoconus Patients After Corneal Cross-Linking

OBJECTIVES: To evaluate the changes in the meibomian glands (MGs) and ocular surface parameters after corneal cross-linking (CXL) in keratoconus patients.
METHODS: Forty-eight eyes of 48 keratoconus patients that underwent epi-off CXL were included in this prospective study. Upper and lower lid MGs were assesed with non-contact meibography at preoperatively, 1st, 3rd, 6th and 12 month after CXL. Uncorrected distance visual acuity (UCVA), corrected distance visual acuity (BCVA), spherical equivalent (SE) and corneal tomography findings (K1, K2, Kmean, Kmax) were recorded at each visit. Ocular surface staining score (Oxford grade), ocular surface disease index (OSDI) questionnaire and non-invasive tear break-up time (NITBUT) were evaluated at preoperatively and 12 month after CXL.
RESULTS: K1, K2, Kmean, and Kmax were decreased at postoperative 12th month compared to baseline (p=0.004, p<0.001, p<0.001, p<0.001, respectively). UCVA, BCVA and SE did not change between preoperatively and postoperative 12 month (p=0.142, p=0.306, p=1.000, respectively). NI-TBUT showed similarty between preoperative and 12 months values (p=0.180), while OSDI scores significantly decreased (p<0.001). MG loss in the upper and lower lids did not show significant difference compared to preoperative values at any of the follow-up visits (p=0.121, p=0.117, respectively).
DISCUSSION AND CONCLUSION: CXL treatment did not significantly affect the NI-TBUT and MGs morphology, while improving ocular symptoms.