Abstract
Abstract: :
Purpose: To present software algorithms for measuring retinal thickness with the SLO, including methods for artifact detection and management. Methods: The backscattered light intensity profiles, along the z axis, of the SLO image stack carry an abundance of information about the layers that lay between the internal limiting membrane (ILM) and the retinal pigment epithelium (RPE). By using simple, realistic, knowledge based algorithms based on the optics of the eye, it is possible to determine if the profiles result from normal assumptions of the anatomical structure, or if they are likely the result from specific adversities. Such adversities include extensive cystoid edema and macular holes. Results: Example results are shown with images that contain cystoid edema, macular holes and other adversities. It is shown that, for most diffuse and focal edema that is not cystoid, it is possible to reliably and repeatably measure the thickness of the retina. Conclusions: For situations where the reflectance of the ILM is compromised, it is difficult presently to provide an absolute thickness measurement. However, in such cases it is still straightforward to determine that an anomaly is present, so there is still diagnostic value in the software's output.
Keywords: retina • macula/fovea • image processing