[The effect of long-term contact lens wear on the morphology of meibomian glands].

Objective To evaluate the effect of long-term contact lens (CL) wear on the morphology of meibomian glands (MGs) using meiboscore and digital analysis. Methods Retrospective study. Sixty right eyes of sixty patients were involved in this study, and the data were analyzed retrospectively. According to the duration of CL wear, all patients were divided into three groups, nonwear group (n=21), short-term group (duration of CL wear ≤3 years, n=19) and long-term group (duration of CL wear>3 years, n=20). Digital images of MGs obtained by meibography were analyzed using Image J software, providing the area percentage of MGs loss. The meiboscores were also examined, and the data were analyzed using one-way ANOVA and Kruskal-Wallis test. Results Ten out of 21 nonwearers were scored 0 point, and 11 were scored 1 point in the upper lid meiboscores, while 7 were scored 0 point, 9 were scored 1 point, and 5 were scored 2 points in the total meiboscores. Seven out of 19 short-term wearers were scored 0 point, 10 were scored 1 point, and 2 were scored 2 points in the upper lid meiboscores, while 5 were scored 0 point, 6 were scored 1 point, 6 were scored 2 points, and 2 were scored 3 points in the total meiboscores. Four out of 20 long-term wearers were scored 0 point, 7 were scored 1 point, and 9 were scored 2 points in the upper lid meiboscores, while 3 were scored 0 point, 4 were scored 1 point, 4 were scored 2 points, 4 were scored 3 points, 4 were scored 4 points, and 1 was scored 5 points in the total meiboscores. The meiboscores of the upper eyelid and total meiboscores among the three groups were significantly different (Hc=9.967, P=0.007; Hc=9.725, P=0.008). The meiboscores of the upper eyelid and total meiboscores were significantly higher in the long-term group compared to the nonwear group (Z=102.500, P=0.003, Z=100.500, P=0.003) and the short-term group (Z=120.500, P=0.050, Z=117.500, P=0.041). No significant difference was found between the short-term group and the nonwear group. The median of the MGs loss area percentage in the upper eyelid of the nonwear, short-term and long-term groups was 9.2%, 13.3% and 16.7%, respectively. The median of the total MGs loss area percentage in the nonwear, short-term and long-term groups were 6.6%, 8.8% and 13.0%, respectively. The above medians were significantly different among the three groups (Hc=6.390, P=0.041; Hc=7.019, P=0.030). They were significantly larger in the long-term wearers than the nonwearers (Z=120.500, P=0.019, Z=120.500, P=0.009). No significant difference was found between the short-term group and the nonwear group, or between the short-term group and the long-term group. No significant differences in the meiboscores or MGs loss area percentage in the lower eyelid were noticed among the three groups. The area under the curve of total area percentage of MGs loss in receiver operating characteristic analysis was 0.981 (P<0.001). Conclusions Long-term (more than 3 years) CL wear can cause MGs loss. Digital analysis is helpful in the morphologic evaluation of MGs. (Chin J Ophthalmol, 2016, 52: 604-609) Key words: Contact lenses; Meibomian glands; Infrared rays; Diagnostic techniques, ophthalmological; Image processing, computer-assisted; Software