Human cornea corneal epithelium

In humans, cases of dermatitis have been described after contact with DHBs. Combined exposure to hydroquinone and quinone airborne concentrations causes eye irritation, sensitivity to light, injury of the corneal epithelium, and visual disturbances (126). Cases with an appreciable loss of vision have occurred (127). Long-term exposure causes staining due to irritation or allergy of the conjunctiva and cornea and also opacities. Resorcinol and catechol are also irritants for eyes. 

Keywords Transcorneal drug absorption Corneal epithelium Corneal cell lines Primary culture of rabbit corneal epithelium Cornea equivalents Human cornea construct... 

When methyl 2-cyanoacrylate was applied as an adhesive to rabbit or human eyes, some reports described corneal haze and inflammation other reports with highly purified material indicated less toxicity. Mistaken use in the eyes as eyedrops has caused immediate brief smarting and firm gluing of the eyelids together. Acetone on a swab can be used to unglue the lids and remove the glue from the cornea with minimal, if any, injury to the corneal epithelium. ... 

Accidental installation in a human eye of one drop of a 50% zinc chloride solution caused immediate and severe pain, which persisted despite immediate irrigation with water. The corneal epithelium was burned, and corneal vascularization followed. After many weeks, areas of opacification and vascularization remained in the cornea. Zinc chloride has caused ulceration of the fingers, hands, and forearms of workers who used it as flux in soldering. ... 

The synchronized movement of the eyelids spreads the precorneal tearfilm across the cornea and pushes it toward the nasolacrimal duct. Precorneal drainage is quite efficient. An aqueous instilled dose leaves the precorneal area within 5 min of instillation in humans. Most of the drug absorbed by transcorneal penetration, without retention modification, is spread across the cornea by the eyelids in the first minutes postdosing. In the precorneal space transcorneal penetration is limited by solution drainage, lacrimation and tear dilution, tear turnover, conjunctival absorption, and the corneal epithelium. Slowing down tear film turnover has well-established benefits to topical ocular drug delivery. 

Benzalkonium chloride is used in eye-drops in concentrations of 0.033 or 0.025%. At a dilution of 1 1000 (0.1%), a drop applied to the human cornea causes mild discomfort that persists for 2 or 3 hours. Slit-lamp examination within 90 seconds shows fine grey clots (epithehal keratitis) in the corneal epithelium. Within 10 minutes, a grey haze can be seen on the comeal surface superficial desquamation of the conjunctival epithehum can follow. The superficial irritation and disturbances disappear in a day or less. 

The eye is an important site relevant to the glaucoma associated with loss of activity alleles (Sect. 7.3.7, vide infra). In the eye (human), P450 IB 1 mRNA is present at a high level in the iris and ciliary body and at lower levels in the cornea, retinal pigment epithelium, and retina [127, 339]. P450 IBl protein is absent in the trabecular network but present in nonpigmented ciliary epithelium, corneal epithelium and keratocytes, both layers of the iris pigmented epithelium, and retina [127, 339]. 

The EpiOcular corneal model involves culturing normal, human-derived epidermal keratinocytes to form a stratified, squamous epithelium similar to that found in the cornea. The epidermal cells, which are cultured on specially prepared cell-culture inserts using serum-free medium, differentiate to form a multi-layered structure that closely parallels the corneal epithelium. EpiOcular is mitotically and metabolically active and releases many of the pro-inflammatory agents (cytokines) known to be important in ocular irritation and... 

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