Abstract
Purpose: :
To analyze the peripapillary choroidal thickness in eyes with open angle glaucoma utilizing spectral domain optical coherence tomography (SD OCT) and to compare it to the peripapillary choroidal thickness in normal eyes.
Methods: :
Twenty-six eyes of 26 patients with open angle glaucoma and 36 eyes of 36 normal subjects evaluated at the New England Eye Center were included in this study. All patients underwent high-definition scanning with the Cirrus HD-OCT. A horizontal and a vertical raster scan, both centered at the optic nerve were obtained for each eye. Two independent graders then independently measured the choroidal thickness in each of the raster scans, defined as the distance from the posterior edge of the retinal pigment epithelium to the choroid-scleral junction at 500 µm intervals away from the optic nerve in the superior, inferior, nasal and temporal quadrants. Analysis of variance testing was conducted to compare the choroidal thicknesses between each quadrant in glaucomatous eyes and between each quadrant in normal eyes, and also between corresponding quadrants in normal versus glaucomatous eyes.
Results: :
In glaucomatous eyes, the average peripapillary choroidal thickness in the inferior quadrant was significantly less than in the superior (p< 0.05), nasal (p< 0.001) and temporal (p< 0.01) quadrants. The inferior quadrant peripapillary choroidal thickness in the normal eyes was also significantly less than in the superior (p< 0.001), nasal (p< 0.001) and temporal (p= 0.001) quadrants. The peripapillary choroidal thickness in the glaucomatous eyes was significantly less in all quadrants when compared to the corresponding quadrant in the normal eyes (superior: p<0.01; inferior: p< 0.05; nasal: p< 0.01; temporal: p< 0.01).
Conclusions: :
In both normal and glaucomatous eyes, the inferior peripapillary choroidal thickness was significantly less than in all other quadrants. Additionally, in eyes with glaucoma, peripapillary choroidal thickness in each quadrant was significantly less than the corresponding quadrant in normal eyes. These findings suggest that the choroidal vascular changes in glaucoma may occur globally in all peripapillary quadrants. However, given that the normal thickness of peripapillary choroid is least inferiorly, clinical manifestation of glaucoma may become evident earliest in the inferior quadrant. Alternatively, the finding of a thin peripapillary choroid in glaucomatous eyes relative to normal eyes may instead be a baseline finding and a potential risk factor for the development of glaucoma.
Keywords: imaging/image analysis: clinical • choroid