Abstract
Purpose :
Myopic axial elongation is associated with choroidal thinning in general. We examined whether the thickness of the choriocapillaris decreases in relationship to axial length.
Methods :
Sagittal histological sections of human globes enucleated due to malignant choroidal melanomas or secondary angle-closure glaucoma were histomorphometrically examined.
Results :
The study included 62 globes with a mean age of 62.0 ±18.8 years (range: 24-88 years). The choriocapillaris was significantly (P=0.002) thickest at the fovea (7.8±7.0µm (median: 5.0µm; range:0.00-30.0µm) followed by the midpoint between fovea and equator (5.4±4.1µm;median:4.8µm;range:0-15.0µm), where it was tendentially thicker (P=0.08) than at the equator (4.5±3.7µm;median:3.8µm;range:0-19.5µm) with no significant (P=0.30) difference from there to the ora serrata (4.9±4.0µm;median:4.8µm; range:0-19.5µm). At all measurement points, the choriocapillaris thickness was not significantly associated with axial length (fovea: P=0.82; midpoint fovea/equator: P=0.49; equator: P=0.47; ora serrata: P=0.08) or with the diagnosis of glaucoma (fovea: P=0.86; midpoint fovea/equator: P=0.29; equator: P=0.96; ora serrata: P=0.81). As a corollary, the sequence of the ocular regions in choriocapillaris thickness was independent of axial length (all P>0.05) and glaucoma (all P>0.05).
Conclusions :
In human eyes, the thickness of the choriocapillaris in the subfoveal region or any other ocular region was not significantly related to axial length. The findings are helpful to explain the clinical finding of a full best-corrected visual acuity in myopic eyes without myopic macular Bruchs membrane defects.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.