A 72-year-old man diagnosed with primary open angle glaucoma and underwent trabeculectomy of both eyes in February 2001 with good blood pressure control. One year later, the patient underwent cataract surgery by phacoemulsification plus posterior chamber intraocular lens implantation, which took place without complications, preserving the posterior capsule intact and achieving a visual acuity (VA) of 0.6 in the OD and 0.5 in the OI. Two years after the filtering surgery, the visual field showed progression in the OD and an intraocular pressure of 23 mmHg, so treatment was started with travoprost 0.004% (Travatan®, Alcon, Fort Worth, Texas). One month after starting treatment, the patient reported a decrease in VA in his OD, and the examination was compatible with the development of cystic macular oedema that had reduced VA to 0.2. The diagnosis was confirmed by OCT (OCT 3000, Humphrey Zeiss Instruments, Dublin, CA) which revealed the existence in the retinal thickness of low intensity spaces corresponding to cystic spaces, and an accumulation of underlying subretinal fluid, reaching a thickness at the foveal level of 437 SD 21 microns. Travoprost was discontinued and treatment with oral acetazolamide (edemox®, Chiesi wassermann, Madrid, Spain) 125 mg every 6 hours, ketorolac (acular®, Allergan, Madrid, Spain) 1 drop every 6 hours and timolol maleate 0.5% (timoftol 0.5%®, Madrid, Spain) twice daily. At two weeks, VA had improved to 0.6, and OCT showed normal macular thickness (213 OD 9 microns), with disappearance of the cysts and recovery of the foveal depression.