Fovea thinning in macula off rhegmatogenous retinal detachment. Preoperative OCT of a patient with a macula off rhegmatogenous retinal detachment was suggestive of cystic swelling of the perifoveal outer plexiform layer, discontinuation of the outer foveal layers and fovea thinning. Fovea thickness was measured 132μm with the OCT caliper software (markedly reduced compared to the average fovea thickness of 240μm).