Abstract
Purpose :
We have recently published that meibomian gland probing (MGP) is associated with increased meibomian gland tissue area as indicated by infrared meibography (BJO 2018) but the mechanism of action remains unknown. Confocal microscopy of meibomian gland ducts may help us to understand possible cellular changes in the post probing ductal epithelial cell population which may provide insight as to the underlying mechanism to explain the growth in tissue area.
Methods :
Confocal microscopy images from central third of the lid taken prior to and after MGP on 60 patients and 120 upper lids (average of 3 glands/lid) with obstructive meibomian gland dysfunction (O-MGD) were retrospectively analyzed to identify pre and post probing ducts where surrounding markings confirm identical gland. Of these, confocal images of 8 gland ducts from 8 patients (Mean age (±SD) of 57.3 (±13.7), all female) satisfied this criterion. Images were used with Image J to outline external duct wall and lumen to determine duct wall area in square microns. IBM SPSS version 25 was used to conduct paired non-parametric test (Wilcoxon signed rank test). All probings were done within 6 weeks of pre probing confocal examinations.
Results :
Post probing confocal images demonstrated increased duct wall thickness (p=0.012) ranging from 4 - 39% (mean increase 19%). All cases showed duct wall thickness increased from proliferation of ductal epithelial cells. Post probing confocal microscopy was performed on average of 13.71 months after probing with range from 0.76 to 47.84 months. Post probing confocal images obtained within one year (n=4) of probing indicated a mean growth of 21.24% (±12.0).
Conclusions :
Meibomian gland probing appears to be associated with a proliferative ductal epithelial response and may represent stem cell activation consistent with published study showing increased tissue growth as seen on infrared video meibography.
This is a 2020 ARVO Annual Meeting abstract.