The Effect of Glaucoma Medication on Choroidal Thickness Measured with Enhanced Depth-Imaging Optical Coherence Tomography

The aim of this study was to examine the effect of the glaucoma medication on Choroidal Thickness (CT) in those with Primary Open-Angle Glaucoma (POAG) and normal cases. This prospective study included 27 patients with newly diagnosed POAG (group 1; 49 eyes), undergoing glaucoma treatment, and 30 patients, whose treatment was terminated due to misdiagnosis (group 2; 57 eyes). Choroidal thickness was measured using Enhanced Depth Imaging (EDI) with Spectral Domain Optical Coherence Tomography (SD-OCT) at the first visit and almost one month later. In group 1, the mean Sub-Foveal CT (SFCT) was 301 ± 91 µm, the mean CT was 264 ± 87 µm at the nasal point, 1 mm to the fovea, and 271 ± 84 µm at the temporal point, 1 mm to the fovea. The second measurements were obtained as 39 ± 8.5 days after treatment began; the SFCT was 319 ± 85 µm (P = 0.0017), the nasal 1 mm CT was 275 ± 88 µm (P = 0.162), and the temporal 1mm CT was 291 ± 80 µm (P = 0.007). In group 2, the mean SFCT was 292 ± 100 µm, the nasal 1 mm CT was 254 ± 97 µm, and the temporal 1 mm CT was 261 ± 97 µm. The second measurements were obtained 37.5 ± 5.5 days after the treatment ended; the SFCT was 295 ± 107 µm (P = 0.212), the nasal 1 mm CT was 262 ± 104 µm (P = 0.709), and the temporal 1 mm CT was 266 ± 104 µm (P = 0.792). Glaucoma medication affects the CT as a marker for choroidal blood flow in patients with glaucoma. Further studies with larger sample sizes are required to examine each glaucoma medication subgroup.