Choroidal Thickness in Open-Angle Glaucoma Measured by Spectral-Domain Scanning Laser Ophthalmoscopy/Optical Coherence Tomography

<b><i>Aims:</i></b> To measure macular choroidal thickness in healthy and glaucomatous eyes using spectral-domain scanning laser ophthalmoscopy/optical coherence tomography. <b><i>Methods:</i></b> Choroidal thickness was measured in 21 healthy eyes and 16 glaucomatous eyes. Choroidal thickness was measured under the fovea and at 500-µm intervals from the foveal center to 4 mm in the nasal and temporal directions. Vessels were counted in a macular area of 8,000 µm². Only choroidal vessels with a horizontal diameter of at least 155 µm and a vertical diameter of at least 50 µm were considered. <b><i>Results:</i></b> The mean choroidal thickness was greatest below the fovea, i.e. 343.8 µm (SD ±29.06) in controls and 411.56 µm (SD ±33.60; p < 0.001) in the glaucomatous group. The mean vertical diameter was significantly greater (p = 0.008) in glaucomatous eyes (112.18 ± 37.64 µm) than in healthy eyes (103.98 ± 25.67 µm), whereas the luminal area of vessels was significantly larger (p = 0.3) in glaucomatous eyes (39,157.34 ± 21,657.23 µm²) than in healthy eyes (43,779.84 ± 22,874.87 µm²). <b><i>Conclusions:</i></b> We show that choroidal thickness is increased in glaucomatous eyes due to an increase in both the vertical diameter and the luminal area of the vessels. This seems to implicate the choroid in the pathogenesis of open-angle glaucoma.