Topographic characteristics of the optic nerve head measured with scanning laser tomography in normal Japanese subjects.
OBJECTIVE
Few studies have been performed regarding the topographic information obtained with the Heidelberg retina tomograph (HRT) in normal Japanese. In this study, we examined the factors influencing optic disc parameters and hemisphere symmetry obtained with the HRT in normal Japanese subjects.


METHODS
Mean values and the standard deviation range for the main HRT parameters were evaluated in 223 eyes of 223 normal Japanese subjects. The influence of age, sex, and disc size on HRT topographic data was analyzed. The superior and inferior hemisphere topographic parameters were compared.


RESULTS
Disc area showed a significant difference by sex (P = 0.0493). Rim volume (r = -0.208, P = 0.019), height variation contour (r = -0.275, P = 0.001), and mean retinal nerve fiber layer (RNFL) thickness (r = -0.366, P = 0.001) declined with age. All parameters except height variation contour and mean RNFL thickness showed a clinically significant correlation with disc size (-0.159 < r < 0.719, P < 0.01). Cup parameters in the superior hemisphere were significantly greater than those in the inferior hemisphere. In contrast, rim parameters in the superior hemisphere were significantly smaller than those in the inferior hemisphere.


CONCLUSIONS
Some factors, namely, sex, age, and disc size, affected the optic disc parameters in the HRT measurements. Possible parameter asymmetry between the two hemispheres should be considered in normal eyes.
Uchida
Hideya
H
Department of Ophthalmology, Gifu University Graduate School of Medicine, Gifu, Japan. gifhu@aol.com.|Uchida Eye Clinic, Gifu, Japan. gifhu@aol.com.
Yamamoto
Tetsuya
T
Department of Ophthalmology, Gifu University Graduate School of Medicine, Gifu, Japan.
Araie
Makoto
M
Department of Ophthalmology, Tokyo University Graduate School of Medicine, Tokyo, Japan.
Tomita
Goji
G
Department of Ophthalmology, Tokyo University Graduate School of Medicine, Tokyo, Japan.
Shirakashi
Motohiro
M
Division of Ophthalmology and Visual Sciences, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
Yoshikawa
Keiji
K
Yoshikawa Eye Clinic, Tokyo, Japan.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000166:cytology*; D012016:Reference Values; D015203:Reproducibility of Results; D012737:Sex Factors; D041623:Tomography, Optical Coherence / Q000379:methods*