Choroidal thickness decreases with age and during accommodation, researchers found in a study published in Experimental Eye Research. This change may play a role in presbyopia development and have implications for glaucoma.
The primary objective of the study was to determine the accommodative movements of the choroid in the optic nerve region and any association they may have with changes in lens dimensions that occur with aging.
Investigators enrolled 12 adults in the study and stratified them according to age: young (n=6, age range 18-23 years), middle aged (n=2, age 29 years), and older aged (n=4, age range 46-51 years). They obtained fundus and choroid imaging in the optic nerve region with optical coherence tomography (OCT) and measured choroidal thickness. The team also performed ultrasound biomicroscopy (UBM) in the region of the lens/capsule and ciliary body.
Researchers determined that unaccommodated choroidal thickness was inversely associated with age (r=0.73; P =.0073). They also determined negative associations between choroidal thickness and lens thickness in both accommodated (P =.01) and unaccommodated (P =.005) states.
Older adults, but not younger or middle-aged adults, experienced significant choroid thinning during accommodation (17.2±4.7 µm difference; P =.036) and researchers determined that choroidal thickness was associated with age in the resting eye and in the accommodated state. It was also associated with lens thickness in the resting eye.
The team noted significantly significant choroid movements around the optic nerve during accommodation. These movements did not decline significantly with age and were not associated with amplitude of accommodation.
“The findings suggest that glaucoma and presbyopia may be literally linked to each other, via the choroid and the ‘cistern’-like vitreous structure, and that damage to the optic nerve may be inflicted by age-related changes in accommodative intraocular pressure and choroidal tension ‘spikes’ and the dysfunction of the accommodative apparatus,” according to the researchers. They also acknowledged that “age-related changes in scleral contour or rigidity may also play a factor.”
Study limitations include a small sample size and a disproportionate representation of patients who were of White ethnicity.
Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Croft MA, Peterson J, Smith C, et al. Accommodative movements of the choroid in the optic nerve head region of human eyes, and their relationship to the lens. ExpEye Res. Published online June 7, 2022. doi:10.1016/j.exer.2022.109124