Characterization of an In Vivo Model for the Study of Eyelash Biology and Trichomegaly: Mouse Eyelash Morphology, Development, Growth Cycle, and Anagen Prolongation by Bimatoprost

The study established a mouse model using female C57BL/6J mice to investigate eyelash biology and the effects of hypertrichosis agents, specifically bimatoprost. The researchers found that mouse eyelashes have a synchronized growth cycle that is shorter than that of pelage hairs, with a strictly regulated exogen phase occurring in every cycle. Morphologically, mouse eyelashes were similar to pelage hairs. When treated with bimatoprost, a known eyelash growth-stimulant in humans, the mice exhibited a significant extension of the anagen (growth) phase, resulting in increased number and length of eyelashes without evidence of new follicle formation. This study demonstrated that mouse eyelashes are a suitable in vivo model for analyzing eyelash morphology, development, growth cycle, and the pharmacological impact on these factors, which could aid in understanding the molecular mechanisms of eyelash growth and developing treatments for eyelash disorders.