Regional Changes in Choroidal Thickness Associated With Accommodation

Abstract

PURPOSE.To characterize the changes occurring in choroidal thickness (ChT) across the posterior pole during accommodation using enhanced-depth imaging optical coherence tomography (OCT).METHODS. Forty participants (mean age 21 6 2 years) had measures of ChT and ocular biometry taken during accommodation to 0, 3, and 6 diopter (D) stimuli, with the Spectralis OCT and Lenstar biometer. A Badal optometer and cold mirror system was mounted on both instruments, allowing measurement collection while subjects viewed an external fixation target at varying accommodative demands.RESULTS. The choroid exhibited significant thinning during accommodation to the 6 D stimulus in both subfoveal (mean change, À5 6 7 lm) and parafoveal regions (P < 0.001). The magnitude of these changes varied by parafoveal meridian, with the largest changes seen in the temporal (À9 6 12 lm) and inferotemporal (À8 6 8 lm) meridians (P < 0.001). Axial length increased with accommodation (mean change, þ5 6 11 lm at 3 D, þ14 6 13 lm at 6 D), and these changes were weakly negatively associated with the choroidal changes (r 2 ¼ 0.114, P < 0.05). CONCLUSIONS.A small, but significant thinning of the choroid was observed at the 6 D accommodation demand, which was greatest in the temporal and inferotemporal parafoveal choroid, and increased with increasing eccentricity from the fovea. The regional variation in the parafoveal thinning corresponds to the distribution of the nonvascular smooth muscle within the uvea, which may implicate these cells as the potential mechanism by which the choroid thins during accommodation.

Validation of Macular Choroidal Thickness Measurements from Automated SD-OCT Image Segmentation

“…59 Their findings across multiple studies, showed that choroid thickness in the macula was greater among myopic children, thickest near the fovea, and thinner in the periphery (with inferior-nasal thickness less than superior-temporal). 59-61 Their findings agree with what Gupta has reported (i.e. that the choroid peripheral (temporal) to the fovea (208 μm) is thinner than at the fovea (242 μm).…”

Effect of amblyopia treatment on choroidal thickness in hypermetropic anisometropic amblyopia using swept-source optical coherence tomography

“…Based on these findings, we assume that there are some structural changes that do occur in the choroid of hypermetropic anisometropic amblyopic eyes. In normal human eyes, it has been reported that SFCT decreases during accommodation [22]. Also, Chakraborty et al reported that the presence or absence of hyperopic defocus affects the amplitude of the diurnal change in CT [23].…”

Correlation of choroidal thickness and ametropiain young adolescence

“…Studies on chicken eyes showed that the thickness of choroid increased and move the retina forward to compensate the myopic defocus, or decreased and move the retina backward in the case of hyperopic defocus [1, 6]. In the research on human eyes, the thickness of choroid decreased during the hyperopic accommodation [20]. On the other hand, choroid might also modulate the sclera growth by passing through the molecular signals [21].…”