120 patients will be enrolled from both the clinic and OR, with the latter patients undergoing surgery for proliferative diabetic retinopathy, rhegmatogenous retinal detachment with PVR, rhegmatogenous retinal detachment without PVR, macular pucker, or macular hole. Clinic patients must be receiving an intraocular injection of a steroid as part of standard of care for macular edema or progressive fibrosis.