INTRODUCTION
Corneal injury is a common disease which is accounting for approximately 3% of emergency department visits. [1] Cornea can be injured from numerous causes including oculopathy, mechanical trauma, infection, inflammation, chemicals, and radiation. [2] Corneal injury is important because it may be vision-threatening. However, there are no absolute medical therapies for it.
Corneal healing consists of a complex process involving cell death, migration, proliferation, differentiation, and extracellular matrix remodeling. [3] In addition, limbal stem cells and basement membrane remodeling have key roles in corneal healing. [4] Numerous cytokines, chemokines, and growth factors are involved in corneal healing.
Epidermal growth factor (EGF) is one of the growth factors which is secreted from lacrimal gland. [5] EGF involves corneal healing; it regenerates limbal stem cells and regulates migration of corneal cells thus accelerating corneal healing. [6, 7] In addition, previous studies showed that tear EGF concentration was significantly decreased in dry eye syndrome which is the one of common causes of corneal injury. [8] Therefore, EGF has been thought a treatment option for corneal injury.
For the treatment of corneal injury, the topical eye administration of EGF has been used through cord blood serum, autologous serum, amniotic membrane extract, and amniotic membrane transplantation. [9-12] However, the currently implemented treatment options may not be wildly used because these mass produce for treatment options is difficult, not only infection risk is relatively high. Therefore, human recombinant EGF (rhEGF) eyedrops can be an appropriate treatment option to solve the above problems.
Some studies showed the effect of rhEGF eyedrops in vitro study and animal study. [7, 13] However, there are no published human data about rhEGF eyedrops. The purpose of this study was to evaluate the safety/tolerability, and pharmacokinetics (PKs) of EGF in serum and tear after topical administration of a single and multiple doses of rhEGF eyedrops in healthy subjects.