Posterior lamella substitutes in full-thickness eyelid reconstruction: a narrative review

Background and Objective: Severe full -thickness eyelid defects seriously endanger the health and beauty of the ocular surface. It is the most challenging field of oculoplastic and reconstructive surgery to reconstruct eyelid's natural appearance and function, in which the posterior eyelid lamella plays an essential role. Without enough substitute support in eyelids suffered sizeable posterior lamella defects, various complications may occur, e.g., entropion, ectropion, incomplete eyelid closure, corneal irritation, keratitis, corneal ulcers, and even vision loss, leading to failure of eyelid reconstruction. This manuscript aimed to summarize recent advances in posterior eyelid lamella substitutes and summarize the types, advantages, and disadvantages of the present posterior lamella substitutes in full -thickness eyelid reconstruction. Methods: A literature search was conducted in the PubMed database to identify relevant publications using the search algorithm "eyelid reconstruction". The full -text publication reports about posterior substitutes from January 2016 to April 2021 in English were selected and reviewed. We also screened relevant research missed in this search algorithm from the reference lists of specific full -text papers. Key Content and Findings: A variety of autologous or allogeneic tissues have been reported as promising techniques for replacing the posterior eyelid lamella in full -thickness and more than 50% length eyelid defects, e.g., the auricular cartilage, hard palate mucosa, buccal mucosa, nasal septum, and periosteal flaps, among others. However, various disadvantages have to be considered, i.e., limited sources, surgical complexity, increased complications, poor mechanical properties, inflammatory immune response, and the spread of potential infectious diseases. Besides, it provides a novel perspective for posterior lamella reconstruction to develop new biomaterials with excellent biocompatibility and more physiological properties, as well as tissue -engineered tarsal and conjunctival tissues with appropriate structure, biomechanical properties, and specific secretory function similar to the human tarsus. Conclusions: In summary, our findings suggest that autologous and allogeneic tarsal substitutes are practical reconstructive technique in current condition, but in the future, in-depth study of new biomaterials and tissue engineering may provide a novel perspective for the research of tarsal substitutes in oculoplastic and reconstructive surgery.