Research interests

Kyung-Chul Yoon’s lab is performing research on the topics listed below including pathogenesis of dry eye and development of therapeutics for inflammation of ocular surface, using experimental dry eye animal models.

1. Reasearch on the pathogenesis of dry eye and development of treatment using dry eye animal models

- Dry eye is one of main causes for patients to visit an ophthalmologist. It is an multifactorial ocular surface disease. Dry eye is closely related to inflammation of the cornea and conjunctiva, which is mainly mediated by T cells.

- Using experimentally induces dry eye mouse models, we analyze the tear film, cornea, and conjunctiva to analyze the inflammatory process associated with dry eye and try to develop a new therapeutic approach.

- As well known, not only the acquired immune response but also the innate immune response such as the Nucleotide-binding oligomerization domain (NOD)-like receptor pathway induces an inflammatory response on the ocular surface in dry eyes and induces apoptosis, reducing the tear secretion. We seek to suppress these process as a therapeutic approach to dry eye.

- By studying clinical findings, inflammatory factors (cytokines, T cells, etc.) and apoptosis in the ocular surface and tear film after administrating biological agents that have immunomodulatory and anti-inflammatory effects such as Adiponectin as eye drops, we are developing new types of dry eye treatment.

- We have identified that oxidative stress plays a major role in the pathogenesis of dry eyes, and through this, various types of antioxidant eye drops are being investigated for the treatment of dry eyes.

2. Effects of LED and blu light on the ocular surface

Long-term exposure to smartphone screens (blue light) exacerbats subjective symptoms of the eye and induced tear film instability and oxidative stress. we used a mouse model to investigate the effect of blue light on the ocular surface and observed increased reactive oxygen species, oxidative damage, and apoptosis in the corneal epithelium. Therapeutics that reduce damage to the ocular surface related to blue light by blocking this mechanism are under study.

Blue light can cause dry eyes by inhibiting melatonin, and a treatment for dry eyes using melatonin is under development.

In addition to the acquired immune response, the innate immune response is involved in the ocular damage related to blue light, and the signaling pathway of the NOD receptor has been found to play an important role. We systematically study the expression of cognitive receptors and the role of innate immunity, and we are conducting research on how to block or minimize damage to the ocular surface by inhibiting these receptors.

3. Development of drug-eluting contact lens

Cyclosporine A (CsA) is an anti-inflammatory agent that is being used as a treatment for various diseases related to inflammation of the eye surface, including dry eye. However, CsA eye drops cause eye pain, burning sensation, and redness when instilled, and their bioavailability is low.

We are investigating a method to ensure that drugs are properly delivered to the ocular surface by wearing a contact lens without applying eye drops. In particular, CsA was loaded into a hydrogel contact lens and worn directly on an experimental dry eye rabbit model to enable controlled release and we clinicallt proved it to be effective. Further study developing a contact lens that releases drugs in response to temperature and pH, which only releases drugs in the living environment and does not release drugs in the storage environment is being conducted.

그림1 치료군과 대조군에서의 건성안 쥐 모델 각막 염색

그림2 치료군과 대조군에서의 건성안 쥐 모델 결막의 술잔세포 PAS 염색

그림3 치료군과 대조군에서의 건성안 쥐 모델 각막과 결막의 TUNEL 염색