Abstract
Purpose :
While the clinical applications of choroidal vascularity index (CVI) measures in the diagnosis and monitoring of various ocular diseases are expanding, there is a paucity of data on its topographic variations during physiological aging. This study aimed to examine the regional changes in macular CVI with age in healthy emmetropes.
Methods :
In this retrospective observational study, one eye of 280 healthy subjects including 83 children (5-12 years), 77 adolescents (13-17 years), and 120 adults (18-41 years), was examined using high-resolution enhanced depth imaging optical coherence tomography along the horizontal meridian. All participants were emmetropic with a mean spherical equivalent refraction of +0.39 ± 0.38 D (range -0.50 to +1.00 D) and a minimum visual acuity of 0.00 logMAR. Custom-written software was used for automatic segmentation of the choroid boundaries, along with deep learning methods for choroid binarization to measure the CVI (calculated as the ratio of luminal versus total choroidal area), stromal thickness and luminal thickness across the 5 mm macular region centred on the fovea. Repeated measures ANOVAs were used to examine the regional changes in the CVI, and stromal and luminal thickness associated with age while controlling for gender.
Results :
Mean CVI averaged across the macula reduced significantly from childhood (65 ± 0.5%) and adolescence (63 ± 0.5%) to adulthood (59 ± 0.4%; p<0.05 for all pairwise comparisons). Significant regional variation was observed, with CVI increasing from the temporal (61 ± 0.3%) to the nasal macula (63 ± 0.3%, p<0.001), and from the fovea (61 ± 0.3%) toward the perifovea (64 ± 0.3%, p<0.001). The age-related decrease in CVI was greater in the nasal (-7 ± 0.7%) than the temporal (-5 ± 0.7%) macula (p=0.003) and was associated with a significant age-related stromal thickening in the nasal macula (change in adults vs children, 44 ± 5 µm, p<0.001) and luminal thinning in the temporal macula (-16 ± 6 µm, p=0.03).
Conclusions :
Increasing age was associated with a significant region-dependent decline in CVI in this healthy emmetropic cohort. The age-related decline in CVI was primarily driven by an age-related thickening of the stromal choroid in the nasal macula and thinning of the luminal choroid in the temporal macula. These age-related changes in CVI provide new insights into the morphology of the choroid and its possible role in the pathogenesis of ophthalmic diseases.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.