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

Abstract 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 ۲۷ patients with newly diagnosed POAG (group ۱; ۴۹ eyes), undergoing glaucoma treatment, and ۳۰ patients, whose treatment was terminated due to misdiagnosis (group ۲; ۵۷ 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 ۱, the mean Sub-Foveal CT (SFCT) was ۳۰۱ ± ۹۱ µm, the mean CT was ۲۶۴ ± ۸۷ µm at the nasal point, ۱ mm to the fovea, and ۲۷۱ ± ۸۴ µm at the temporal point, ۱ mm to the fovea. The second measurements were obtained as ۳۹ ± ۸.۵ days after treatment began; the SFCT was ۳۱۹ ± ۸۵ µm (P = ۰.۰۰۱۷), the nasal ۱ mm CT was ۲۷۵ ± ۸۸ µm (P = ۰.۱۶۲), and the temporal ۱mm CT was ۲۹۱ ± ۸۰ µm (P = ۰.۰۰۷). In group ۲, the mean SFCT was ۲۹۲ ± ۱۰۰ µm, the nasal ۱ mm CT was ۲۵۴ ± ۹۷ µm, and the temporal ۱ mm CT was ۲۶۱ ± ۹۷ µm. The second measurements were obtained ۳۷.۵ ± ۵.۵ days after the treatment ended; the SFCT was ۲۹۵ ± ۱۰۷ µm (P = ۰.۲۱۲), the nasal ۱ mm CT was ۲۶۲ ± ۱۰۴ µm (P = ۰.۷۰۹), and the temporal ۱ mm CT was ۲۶۶ ± ۱۰۴ µm (P = ۰.۷۹۲). 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.