Complex sentence: Another group of patients at risk are patients who have a retinal condition or who underwent retinal surgery; for example, with an epiretinal membrane (macular pucker) or after a retinal detachment surgery.
Split into simpler sentences: Another group of patients at risk are patients who have a retinal condition or who underwent retinal surgery. For example with an epiretinal membrane (macular pucker) or after a retinal detachment surgery.