Reduction of retinal blood flow in high myopia.
OBJECTIVE
To investigate changes in retinal vessel diameter and blood velocity in high myopia using laser Doppler velocimetry.


METHODS
Thirty-nine subjects (39 eyes) were enrolled in the study. The subjects were divided into three groups according to their refractive status; 15 eyes (15 patients) with emmetropia (within +/-3.0 diopters), 14 eyes (14 patients) with mild myopia (between -3.0 and -8.0 diopters), and 10 eyes (10 patients) with high myopia (>-8.0 diopters). Patient age was matched between groups. Blood velocity and vessel diameter of the upper or lower temporal retinal artery were measured using laser Doppler velocimetry with an eye-tracking system, and measurements were compared between groups.


RESULTS
The average retinal blood flow and vessel diameter in highly myopic eyes were significantly decreased compared with emmetropic eyes or mild myopic eyes (Mann-Whitney U test, p<0.05). Also, there was significant difference regarding retinal blood flow and vessel diameter between eyes with mild myopia and the other groups. In addition, there was no significant difference in blood velocity between the three groups.


CONCLUSIONS
Retinal blood flow was decreased in high myopia, mainly due to the narrowing of the retinal vessel diameter. Impaired retinal blood flow might have a role in the development of chorioretinal atrophy in high myopia.
Shimada
Noriaki
N
Department of Ophthalmology and Visual Science, Tokyo Medical and Dental University, 1-5-45 Yushima, 113, Bunkyo-ku, Tokyo, Japan.
Ohno-Matsui
Kyoko
K
Harino
Seiyo
S
Yoshida
Takeshi
T
Yasuzumi
Kenjiro
K
Kojima
Ariko
A
Kobayashi
Kanako
K
Futagami
Soh
S
Tokoro
Takashi
T
Mochizuki
Manabu
M
D000328:Adult; D001783:Blood Flow Velocity; D005260:Female; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D009216:Myopia / Q000503:physiopathology*; D012161:Retinal Artery / Q000503:physiopathology*