Abstract
Purpose :
To investigate choroidal thickness changes in response to monocular defocus in 1000 lux and 10 lux conditions in Chinese young adults.
Methods :
Choroidal thickness was measured in 19 young adults aged 20 to 30 years old (24.4±2.12) before and after 30 minutes of exposure to +5D of monocular defocus on the right eye on two different days while watching movies at 5 meters distance in 1000lux and 10lux room illuminance. Choroidal thickness of both eyes was measured by SD-OCT (Heidelberg Spectralis OCT; Heidelberg Engineering, Heidelberg, Germany). The left eye was wearing its usual spherocylindrical correction and was measured after the right eye for biometric changes.
Results :
After 30 minutes of exposure to monocular defocus on the right eye in 1000 lux conditions, choroidal thickness of the right eye (change value = 1.59±15.05, t=0.823, p=0.414) and left eye (change value = -2.90±15.36, t=1.463, p=0.149) exhibited no significant change. After 30 minutes of exposure to monocular defocus on the right eye in 10 lux conditions, choroidal thickness of the right eye showed a significant increase (change value = 7.75±19.46, t=3.007, p=0.04) while the left eye exhibited no significant change (change value = 4.09±21.90, t=1.411, p=0.164).
Conclusions :
A significant increase in choroidal thickness was observed after 30 minutes of monocular +5D defocus in 10 lux low light, but not in 1000 lux bright light conditions. Increase of depth of focus due to pupil diameter decrease in bright light may affect choroidal response to defocus.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.