Comparison of in vivo efficacy of different ocular lubricants in dry eye animal models.
OBJECTIVE
To compare the efficacy of three types of ocular lubricants in protecting corneal epithelial cells in dry eye animal models.


METHODS
Ocular lubricants containing 0.1% or 0.3% sodium hyaluronate (SH), carboxymethylcellulose (CMC), or hydroxypropyl methylcellulose (HPMC) were tested. First, ocular lubricant containing 0.002% fluorescein was dropped onto the rabbit corneas. The fluorescein intensity as an index of retention was measured. Second, a rabbit dry eye model was made by holding the eye open with a speculum, and 50 μL of each ocular lubricant was dropped onto the cornea. After 3 hours, the corneas were stained with 1% methylene blue (MB), and the absorbance of MB was measured. Third, a rat dry eye model was treated with the ocular lubricants for 4 weeks, and the corneal fluorescein staining was scored. Eyes treated with physiological saline were used as controls. Finally, immunohistochemistry was used to analyze occludin, an epithelial barrier protein, in cultured human corneal epithelial cells pretreated with ocular lubricants and desiccated for 20 or 60 minutes.


RESULTS
Our results showed that 0.3% SH had a significantly longer retention time than the other lubricants (all P < 0.01). The absorbance of MB was significantly lower in the 0.3% SH group. The corneas of rats exposed to 0.3% SH had significantly lower fluorescein staining scores. A significantly higher number of occludin-positive cells were found after exposure to 0.3% SH than other lubricants.


CONCLUSIONS
Ocular lubricant containing 0.3% SH would be preferable to treat patients with dry eye syndrome.
Department of Ophthalmology, Ehime University School of Medicine, Toon City, Ehime, Japan.
Xiaodong
X
Zheng
Department of Ophthalmology, Ehime University School of Medicine, Toon City, Ehime, Japan.
Tomoko
T
Goto
Department of Ophthalmology, Ehime University School of Medicine, Toon City, Ehime, Japan.
Yuichi
Y
Ohashi
D000818:Animals; D002266:Carboxymethylcellulose Sodium / Q000008:administration & dosage*; D003315:Cornea / Q000187:drug effects*; D004195:Disease Models, Animal; D015352:Dry Eye Syndromes / Q000188:drug therapy*; D006820:Hyaluronic Acid / Q000008:administration & dosage*; D065347:Hypromellose Derivatives; D008297:Male; D008747:Methylcellulose / Q000008:administration & dosage / Q000031:analogs & derivatives*; D009883:Ophthalmic Solutions / Q000008:administration & dosage; D011817:Rabbits; D051381:Rats; D016896:Treatment Outcome; D055675:Viscosupplements / Q000008:administration & dosage
D009883:Ophthalmic Solutions; D055675:Viscosupplements; D065347:Hypromellose Derivatives; D006820:Hyaluronic Acid; D008747:Methylcellulose; D002266:Carboxymethylcellulose Sodium
animal model; cornea; dry eye syndrome; ocular lubricant