Abstract: The tear film covers the anterior eye and the precise balance of its various constituting components is critical for maintaining ocular health. The composition of the tear film amphiphilic lipid sublayer, in particular, has largely remained a matter of contention. The limiting concentrations of lipid amphiphiles in tears have also posed considerable challenges to their detection and accurate quantitation. Using systematic and sensitive lipidomic approaches, we reported the most comprehensive human tear lipidome to date; and conferred novel insights to the compositional details of the existent tear film model, in particular the disputable amphiphilic lipid sublayer constituents, by demonstrating the presence of cholesteryl sulfate, O-acyl-ω-hydroxy fatty acids, and various sphingolipids and phospholipids in tears. Lipidomic analysis of human tear fluid from patients with various subtypes of dry eye syndrome (DES) revealed structure-specific lipid alterations in DES, which could potentially serve as unifying indicators of disease symptoms and signs.

The meibomian glands constitute the predominant source of lipid supply to the human tear fluid. Meibomian gland dysfunction (MGD) is a leading cause of evaporative dry eye and ocular discomfort, characterized by an unstable tear film principally attributed to afflicted delivery of lipids to the ocular surface. We investigated the longitudinal tear lipid alterations associated with disease alleviation and symptom improvement in a cohort of MGD patients undergoing eyelid-warming treatment for 12 weeks. Our preliminary data indicated that excess ocular surface phospholipase activity detrimental to tear film stability could be alleviated by eyelid warming alone without application of steroids and identify tear OAHFAs as suitable markers to monitor treatment response in MGD.

Abstract: Eyelid surgery is widely and extensively used in facial plastic and reconstructive surgeries. There are many categories of eyelid surgeries, the most common of which include blepharoplasty, ptosis surgery, and eyelid reconstruction. In many cases, these procedures are combined, and there are many different techniques for each type of operation. Upper eyelid blepharoplasty usually includes the excision of skin, preseptal orbicularis oculi muscle, and orbital fat. Common methods of lower eyelid blepharoplasty are the skin-muscle flap, the skin flap, and the transconjunctival. Ptosis surgery is mainly divided into three types: transcutaneous, transconjunctival, and sling surgery. Surgeons often used the Hughes or Cutler-Beard Bridge Flaps in eyelid reconstruction. Different types and methods of surgery have their own advantages and disadvantages, and postoperative complications may occur. Therefore, postoperative complications of eyelid surgeries, such as dry eye symptoms, should be taken into serious consideration. Relevant literature involving these complaints can be found in PubMed by searching the terms “dry eye”, “eyelid”, “surgery”, and other related keywords. Moreover, various ocular surface and tear film alterations may be detected using the Ocular Surface Disease Index (OSDI), tear film breakup time, Schirmer test, fluorescein staining, and lissamine green staining after various eyelid surgeries. As dry eye disease is prevalent in the general population, it is more urgent to figure out what we can learn from these complaints. Further exploration in this field may help surgeons to choose a better surgical method and give an accurate evaluation of the postoperative effect.