Abstract
Abstract: :
Purpose: Accurate measurements are required for appropriate follow-up of patients with macular edema particularly in a research setting. The high axial resolution of optical coherence tomography (OCT) allows for qualitative assessment of the macular area. Quantitative measurements are dependent on appropriate alignment and may be subject to interpolation artifacts. Simultaneous scanning using an SLO (low resolution), and an OCT( high resolution) transversally (C scan mode) may allow reproducible alignment of scanned points (due to pixel to pixel correspondence), providing a more accurate measurement of retinal thickness and retinal structure. Methods: Using a combined simultaneous SLO/OCT scanner, patients with clinically significant macular edema were examined before and after treatment (using laser, triamcinolone, or octreotide). C scans were taken of each patient. Images taken at similar intraretinal depth were compared and analyzed for cyst number, size and area of macular edema. Results: C scans provided qualitative information with regards to cyst size and location. Images revealed a limited complex of large cysts (large cyst area) located in the fovea surrounded by numerous smaller cystic spaces (microcystic area). Response to therapy lead initially to a resolution of the smaller cystic spaces followed only later by a reduction in the area of the larger cysts. Area measurements in a representative patient two weeks following octreotide treatment showed 23,8% reduction of total cystic area, a 33,6% reduction of the microcystic area, and only a 1,1% reduction of the large cyst area. Conclusions: Transversal (C scan) scanning provides both qualitative as well as quantitative information that can be used in the follow-up of patient with macular edema.
Keywords: imaging/image analysis: clinical • macula/fovea • imaging methods (CT, FA, ICG, MRI, OCT, RTA, S