Abstract
Purpose :
Patients complaining of dry eye symptoms commonly exhibit signs of MGD that are identified by in vivo transillumination meibography as meibomian gland dropout. While mouse models of dry eye have been developed, studies evaluating the role of the meibomian glands in these models have been hampered by an inability to document changes in the meibomian gland due to the lack of an in vivo meibography system for mice. In this project, we developed a new transillumination meibography system for mice and compared the morphology of meibomian glands between young and old mice.
Methods :
The mouse meibography system was comprised of a 3 mm wide right angle prism attached to broad spectrum light source by an optical fiber (Figure A). Eyelids of anesthetized mice were then pulled over the prism using double teeth forceps (Polack) and transilluminated light imaged using a Leica stereo microscope (no filter) with a low light level camera. Meibomian glands from the upper and lower eyelid of BALB/c mice (four young (< 3 month) and four old (> 18 month) male mice) were then imaged and analyzed using ImageJ to measure average gland area for each eyelid.
Results :
In upper eyelids of young mice, mouse meibography documented the presence of 7-8 meibomian glands appearing as black and distinct eyelid structures containing circular acini (Figure B). In lower eyelids, the length of meibomian glands were shorter with wider gaps between glands compared to that of upper eyelids. In eyelids of old mice, drop-out of meibomian glands was detected along with smaller and more irregularly shaped acini. The mean area of a lower eyelid meibomian gland in young mice was 0.101 mm2 compared to 0.087 mm2 (p<0.05) in the lower eyelids of old mice.
Conclusions :
In conclusion, we could take distinct in vivo photographs of meibomian glands in mice using a new transillumination meibography system. Furthermore, analysis of in vivo images showed distinct and significant age-related changes that were consistent with earlier reports using volume reconstruction of excised, fixed and processed tissue. Future use of mouse meibography may prove valuable in detecting changes in the meibomian gland structure and function in dry eye mouse models.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.