- Thickening of the fovea of at least 300 microns (thickness of the central point in OCT) with a standard deviation of the center point <10% and signal strength of ≥ 5 OCT ILM and borders (internal limiting membrane) and RPE (retinal pigment epithelium) properly identified. Also, the initial OCT must be confirmed by repeated measurements on the same day, with the thickness of the central point being within 10% between measurements. In cases where the OCT imaging program can not properly define the limits of ILM and RPE, if the investigator can obtain an estimate of the thickness of the manual by OCT central point of at least 300 microns, the patient will be considered eligible.