Iris colour and the influence of local anaesthetics on pre-corneal tear film stability.
Using non-invasive methods we report here that the stability of the pre-corneal tear film is lower in the brown eye than in the blue eye. The average stability in the blue eye is 15.8 sec (SD +/- 5.8) and in the brown eye it is 12.3 sec (SD +/- 2.9). On average, instillation of topical anaesthetics, benoxinate hydrochloride (0.4%) or amethacaine hydrochloride (0.5%), depress the stability of the pre-corneal tear film in blue eyes but not in brown eyes.
Patel
S
S
Department of Optometry & Vision Science, Glasgow Polytechnic, Scotland, UK.
Laidlaw
S
S
Mathewson
L
L
McCallum
L
L
Nicholson
C
C
D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D000779:Anesthetics, Local / Q000494:pharmacology*; D005127:Eye Color / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D011343:Procaine / Q000031:analogs & derivatives* / Q000494:pharmacology; D013666:Tears / Q000378:metabolism*; D013748:Tetracaine / Q000494:pharmacology*
D000779:Anesthetics, Local; D013748:Tetracaine; D011343:Procaine; C005298:benoxinate