Differences in contact lens-induced responses in the corneas of Asian and non-Asian subjects.
OBJECTIVE
To investigate ethnic differences in corneal endothelia bleb formation and corneal swelling during contact lens wear under closed-eye conditions, with the use of lenses of varying oxygen transmissibilities (Dk/L) in Asian and non-Asian subjects


METHODS
Asian and non-Asian contact-lens naive subjects were fitted with one of four different types of contact lenses at each 20-minute session. During lens wear, the eyelid was closed Endothelial bleb formation was determined by specular microscopy or confocal microscopy immediately on eye opening. Some Asian contact-lens naive subjects were asked to wear one of two types of lenses (Dk/L values of 24 and 175) on each eye for 1 hour Corneal swelling was determined immediately after opening of the eyes.


RESULTS
Asian subjects had a significantly higher degree of endothelial bleb formation than the non-Asian population for all closed eye conditions, p=0.0001. There was no significant difference in endothelial bleb formation between closed eves with or without lenses in the non-Asian population. There was a significantly higher degree of bleb formation with low Dk/L lenses, < or = 40, compared to high Dk/L lenses, > or = 110, in Asian subjects, p=0.0001.


CONCLUSIONS
There is a significant difference between Asian and non-Asian subjects in the corneal response to stress. Under a closed eyelid only contact lenses with very high levels of Dk/L do not cause cornea stress in Asian patients.
Hamano
Hikaru
H
Hamano Eye Clinic, Osaka, Japan.
Jacob
Jean T
JT
Senft
Carl J
CJ
Hamano
Tamotsu
T
Hamano
Takashi
T
Mitsunaga
Sachiko
S
Kotani
Setsuko
S
Kaufman
Herbert E
HE
D001741:Black or African American; D044466:Asian People; D044383:Black People; D001768:Blister / Q000208:ethnology / Q000209:etiology / Q000473:pathology; D003261:Contact Lenses / Q000009:adverse effects*; D003316:Corneal Diseases / Q000208:ethnology* / Q000209:etiology* / Q000473:pathology; D015715:Corneal Edema / Q000208:ethnology / Q000209:etiology / Q000473:pathology; D005006:Ethnicity; D006801:Humans; D008853:Microscopy; D018613:Microscopy, Confocal; D044465:White People