Meibomian Gland Alterations in Keratoconus Patients After Corneal Cross-Linking

The objective of the study was to evaluate the changes in the meibomian glands (MGs) and ocular surface parameters after corneal cross-linking (CXL) in keratoconus patients.

Forty-eight eyes of 48 keratoconus patients that underwent epi-off CXL were included in this prospective study. Upper and lower lid MGs were assessed with non-contact meibography at preoperatively, 1^st, 3^rd, 6^th, and 12^th month after CXL. Uncorrected distance visual acuity (UCVA), corrected distance visual acuity (BCVA), spherical equivalent (SE), and corneal tomography findings (K1, K2, Kmean, and 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 (NI-TBUT) were evaluated at preoperatively and 12 months after CXL.

K1, K2, Kmean, and Kmax were decreased at post-operative 12^th month compared to baseline (p=0.004, p<0.001, p<0.001, and p<0.001, respectively). UCVA, BCVA, and SE did not change between preoperatively and post-operative 12 months (p=0.142, p=0.306, and p=1.000, respectively). NI-TBUT showed similarity between pre-operative 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 pre-operative values at any of the follow-up visits (p=0.121 and p=0.117, respectively).

CXL treatment did not significantly affect the NI-TBUT and MGs morphology, while improving ocular symptoms.