spectral domain optical coherence tomography, SD-OCT, (Heidelberg Engineering, Heidelberg, Germany) is a widely used commercial device in ophthalmology field. For a long time, retinal nerve fiber layer (RNFL) thickness was measured with OCT to detect and follow up glaucoma patients. Bruch's membrane opening - minimum rim width (BMO-MRW) is relatively new parameter which measures the minimum distance between Bruch's membrane opening to internal limiting membrane (ILM). BMO-MRW,a new parameter, is known to have better diagnostic performance than RNFL thickness and recently, many researches has been performed on this new parameter. SD-OCT can measure RNFL thickness and BMO-MRW at the same time. The test procedure is not different from RNFL thickness measurement but only software implemented in OCT device calculates BMO-MRW as well as RNFL thickness. The investigators are going to compare these two parameters and find out the relationship between two parameters.
