Abstract
Purpose:
To measure circumpapillary and macular choroidal thickness (CT) in perimetrically affected eyes using swept source OCT (SS-OCT) and to determine the relationship between CT and visual filed sensitivity.
Methods:
Circumpapillary and macular and SS-OCT scans were obtained with the Topcon DRIOCT-1 on 32 perimetrically affected eyes of 26 patients. The observer used manual segmentation to outline the choroidal vasculature as the structure between the retinal pigment epithelium and the sclerochoroidal interface. Circumpapillary CT were measured at 1, 2, and 3 mm from the optic nerve head border at the superior, inferior, nasal, temporal, superonasal, inferotemporal, superotemporal, and inferonasal positions. Macular CT were measured at 1, 2, and 3 mm from the fovea at the superior, inferior, nasal, and temporal positions. Statistical analysis was conducted to compare the CT at each measurement point and to correlate CT with mean visual field sensitivity of the superior and inferior hemispheres.
Results:
The average circumpapillary CT varied around the disc at all distances (1, 2, and 3 mm, repeated-measures ANOVA, all P<0.001). The thinnest position was inferior at all distances (P<0.001). CT was thinnest near the disc and increased in thickness towards the periphery. The average macular CT varied around the macula, at all distances except for 1 mm (2 mm, P<0.001; 3 mm, P<0.001, 1mm, P=0.287). The CT nasal to the fovea was the thinnest (p<0.001). There was moderate agreement between the hemifield with worse damage and the macular region where the choroid was thinnest (kappa=0.37, P=0.03). There was a significant linear relationship between the macular CT and the corresponding mean VF sensitivity (based on hemifields, R-squared=0.12, P=0.003), whereas the relationship between circumpapillary CT and VF sensitivity was not significant (P=0.25).
Conclusions:
Circumpapillary CT is thinnest inferiorly and the macular CT is thinnest nasally. Regions with more significant CT thinning correspond to the hemifield with the greater glaucomatous damage and there is a significant relationship between CT and VF sensitivity. However, the temporal relationship between CT thinning and VF loss cannot be inferred based on the present findings.
Keywords: 436 blood supply •
452 choroid •
758 visual fields