The impact of artificial tears containing hydroxypropyl guar on mucous layer.
OBJECTIVE
The aim of this study was to investigate the effect of lubricant eyedrops containing propylene glycol 400 (PEG) and polyethylene glycol (PG) with hydroxypropyl guar (HP-guar) as a gelling agent on the precorneal mucous layer in vivo.


METHODS
Sixteen New Zealand white rabbits were randomly assigned to 1 of 4 groups. All rabbits received PEG/PG/HP-guar tear products in the right eye. PEG/PG/HP-guar with Polyquad, 0.1% hyaluronate sodium, 0.5% carboxymethylcellulose, or phosphate-buffered saline was placed in the left eyes of animals in each group. All eyedrops were used 4 times a day for 7 days. An additional 8 rabbits were randomly assigned to 1 of 2 groups. One group received PEG/PG/HP-guar products 4 times a day for 7 days (long-term exposure group), and the other group received PEG/PG/HP-guar products 3 times at 5-minute intervals (short-term exposure group). Fifteen minutes after the last drop was administered, each cornea was immediately excised and mucous layer thickness measured by transmission electron microscopy.


RESULTS
Mucous layer thickness was significantly greater in eyes treated with PEG/PG/HP-guar products compared with those treated with 0.1% hyaluronate sodium, 0.5% carboxymethylcellulose, or phosphate-buffered saline (all P values < 0.001). There were no significant differences in mucous layer thickness between PEG/PG/HP-guar products and PEG/PG/HP-guar with Polyquad or in the long- and short-term exposure animals.


CONCLUSIONS
This study demonstrates that even a short exposure to PEG/PG/HP-guar tear product increased precorneal mucous layer thickness.
Moon
Sang-Woong
SW
Deparment of Ophthalmology, East-west Neo Medical Center, Kyung Hee University College of Medicine, Seoul, Republic of Korea.
Hwang
Je-Hyung
JH
Chung
So-Hyang
SH
Nam
Kee-Hyun
KH
D000818:Animals; D002266:Carboxymethylcellulose Sodium / Q000633:toxicity; D003315:Cornea / Q000187:drug effects* / Q000648:ultrastructure; D004338:Drug Combinations; D006820:Hyaluronic Acid / Q000633:toxicity; D008297:Male; D046529:Microscopy, Electron, Transmission; D009092:Mucous Membrane / Q000187:drug effects / Q000648:ultrastructure; D009883:Ophthalmic Solutions / Q000633:toxicity*; D011092:Polyethylene Glycols / Q000633:toxicity*; D011134:Polysaccharides / Q000633:toxicity*; D011817:Rabbits
D004338:Drug Combinations; D009883:Ophthalmic Solutions; D011134:Polysaccharides; C519976:hydroxypropyl guar; D011092:Polyethylene Glycols; D006820:Hyaluronic Acid; D002266:Carboxymethylcellulose Sodium