부산대학교 도서관

Purpose: To investigate the occurrence of myofibroblasts (MFBs) in the normal conjunctival surface and to evaluate any anatomical and time-related variations. Methods:  MFBs were screened among healthy individuals (35 eyes) by collecting impression cytology (IC) samples from the bulbar conjunctiva. A cohort of volunteers (12 eyes) was followed for 1 year by taking two to five imprints every month. MFBs were identified by immunohistochemical localization of the MFB marker α-smooth-muscle actin (α-SMA). Results: Using a filter imprint technique, MFBs were found consistently in 94% of samples from the conjunctival surface of participating individuals. The overall MFB levels, expressed as percentage of all cells on the filter, were highest in March–May [mean 4.1%, standard deviation (SD) ± 1.5] and lowest in December–February (mean 1.2%, SD ± 0.5). The difference was statistically significant [p < 0.0005, Friedman test, one-way repeated measures analysis of variance (anova)]. Moreover, there was a clear divergence of MFB density between the nasal, temporal, superior and inferior bulbar conjunctiva (mean 1.7%, 1.9%, 22% and 9.7%, respectively). Conclusion: MFBs, known as a cellular constituent of granulation tissue in wound healing, occur in the normal conjunctival surface, which is a novel finding. Our results also show that MFB level follows a seasonal variation pattern in a temperate climate, increasing in April–September and decreasing in October–March. This variation might reflect a degree of a transient or ongoing state of tissue repair after conjunctival trauma or stress caused by exposure to environmental factors. [ABSTRACT FROM AUTHOR]