Involvement of Inward Upper Eyelid Push on the Lower Eyelid during Eyelid Closure in Development of Involutional Lower Eyelid Entropion

Purpose To examine whether an inward upper eyelid push on the lower eyelid margin during eyelid closure is involved in involutional lower eyelid entropion. Methods This prospective observational study included 34 sides from 27 patients with involutional lower eyelid entropion. The positional relationship between the upper and the affected lower eyelid margins during eyelid closure were examined before and after posterior layer advancement of the lower eyelid retractors. In addition, we preoperatively examined whether the affected lower eyelid turned in during a voluntary maximum force eyelid closure from the normal position. We then held the upper eyelid away from the lower eyelid during a voluntary maximum force eyelid closure to eliminate the influence of an inward upper eyelid push on the lower eyelid margin. At the time, we investigated whether the affected lower eyelid turned in. All these examinations were performed from the normal lower eyelid position. Results Although the upper eyelid margin was on the lower eyelid margin before surgery, this was corrected after surgery in all patients. All affected lower eyelids turned in after voluntary maximum force eyelid closure. However, the lower eyelid margin did not show an inward rotation with holding of the upper eyelid away from the lower eyelid. Conclusions These results indicate that an inward upper eyelid push on the lower eyelid is involved in development of an involutional lower eyelid entropion.