Unidirectional delivery of heat to the eyelid by GoldInLens - Meibomian gland dysfunction (MGD) is the leading cause of the dry eye disease which affects 6 to 7 million people in the United States. The Meibomian glands in MGD dry eye patients are unable to secrete oily lipids resulting in loss of the lipid layer on the surface of tears, leading to an increase in tear evaporation. Current treatments for patients with MGD include warming of the glands to temperature higher than melting point of the meibomian in MGD patients to increase secretion of the lipids, which will increase tear volume and reduce dry eyes symptoms. Most commercial therapies for the warming- treatment heat eyelids from the outside even though the glands are located close to the inner surface of the eyelids in contact with tears. Warming from outside requires heat to be applied at about 45 oC which can cause discomfort and burns. Additionally, heat supplied to the eyelids can reach the cornea which can also damage the cornea, particularly in conjunction with applied massage. We are proposing a novel approach for warming the eyelids from inside by designing gold nanoparticle loaded contact lenses (GoldInLens) which can be warmed by exposure to a low intensity light source due to the absorption of light by gold nanoparticles due to surface plasmon resonance (SPR) effect. To use the GoldInLens treatment, patients will insert the lens, and then keep their eyes open while the lens is exposed to the light source for about 10 s to increase lens temperature to the targeted 40 oC. The patients will then close the eyes to warm the Meibomian glands. The lens will cool during this phase and so after certain time, which will be determined in this study, the patients will open eyes for subsequent exposure to the light source to warm the lens. This cycle of warming of lens during open eyes followed by warming of the glands during closed eyes will be repeated for 10 min. To eliminate the potential for cornea damage, we will design a piggyback system by placing the GoldInLens on top of a low thermal conductivity polymethyl methacrylate contact lens which will act as an insulator to minimize exposure of the cornea to the elevated temperatures. Additionally, gradient lenses with gold nanoparticles located only near the front surface will be prepared to produce the benefits of the piggyback design but with a simpler manufacturing process. Lenses will be tested extensively in vitro for transparency, warming, and proof-of-concept in vivo studies will be conducted in rabbits to explore feasibility. The overall hypothesis of this study is that gradient or piggyback lenses of gold nanoparticles will warm the inner eyelid preferentially, relative to the ocular surface. The hypothesis will be tested in the following two aims. 1) To design gradient and piggyback lenses for unidirectional delivery of heat to the eyelids. 2) To test directional delivery of heat in vivo in the rabbit. Successful completion of this research will lead to the development of a novel platform for providing affordable, at-home warming therapy for treating MGD. In future, we will expand the platform to include directional release of anti-inflammatory drugs to the eyelid while minimizing corneal toxicity. 2
