Editor,—Latanoprost (0.005%) is a prostaglandin F-2α analogue licensed for primary open angle glaucoma. We describe the occurrence of cystoid macular oedema in a pseudophakic patient following its use. A 50 year old pseudophakic myope (−4.50 D) was prescribed latanoprost once daily, because of raised intraocular pressure despite treatment with twice daily betaxolol (1/2%) drops. The right eye was blind from retinal detachment and the left eye had undergone three retinal detachment repairs including one vitrectomy. He had required betaxolol twice daily in the left eye to control the intraocular pressure since then. In January 1994, a left phacoemulsification cataract extraction with posterior lens implant restored the left visual acuity to 6/6. In March 1997, latanoprost was prescribed to control …