Abstract
Purpose :
This study describes the histopathological findings of different morphologies of human meibomian glands (MG) seen on infrared imaging.
Methods :
Tarsal plates dissected from 7 cadaveric upper eyelids were imaged using infrared meibography and then studied histopathologically using hematoxylin-eosin and peroxisome proliferator-activated receptor-gamma (PPARγ) antibody (for meibocyte differentiation) staining. The different morphological characteristics of MG (varying size and shape) on meibography were correlated with histopathology using image analysis software.
Results :
Of the total 127 glands, the observed morphological variants on meibography based on size were: normal (n=62), short (n=18), severely short (n=6), and dropout (n=12) glands, and on shape were hooked (n=2), tortuous (n=5), overlapping (n=1), thick (n=15) and fluffy (n=6) glands. Short, hooked, tortuous, overlapping glands had similar histological structure as seen in normal glands whereas thick, and fluffy glands had increased acinar diameter. In normal glands, the ductal epithelium was 2-3 layers thick of nucleated non-keratinized squamous cells and more multilayered in thick and fluffy glands. The areas where acini were emptying their contents into the lumen had multilayered ductal epithelium, whereas areas with no actively secreting acini had a single cell layer ductal epithelium. The mean thickness of the periacinar acellular matrix zone in normal glands was 4.21.2 microns, whereas it was 6.70.98 microns in severely shortened glands. The glands with morphology other than severely short type demonstrated strong nuclear, and weak cytoplasmic PPARγ expression limited to the basal acinar cells similar to normal glands, whereas severely short glands showed atrophic acini with weak cytoplasmic expression of PPARγ. Gland dropout areas showed no evidence of any glandular tissue and had normal tarsal architecture on histology.
Conclusions :
Hooked, tortuous, short glands have similar acinar histology as normal glands, whereas severely short glands show atrophic acini with decreased PPARγ expression. A larger study is warranted to validate the findings in a clinical setting with various pathologic conditions.
This is a 2021 ARVO Annual Meeting abstract.