Iridal posterior pigment epithelial detachment induced by pilocarpine: a case report

Background Pilocarpine is a commonly used miotic agent in clinical ophthalmology and a first-line medication for glaucoma treatment. In recent years, it has also been gradually applied in the field of presbyopia treatment. The drug has good clinical safety with rare adverse reactions. Known adverse reactions include anterior chamber flare, headache, decreased visual acuity, and rare drug-induced malignant glaucoma. This article reports a case of severe binocular anterior chamber flare accompanied by posterior iris pigment epithelium detachment and secondary glaucoma after miotic eye drops, aiming to provide a reference for clinical safe medication. Case Presentation A 39-year-old female patient presented to another hospital with "bilateral eye redness and photophobia for 3 days after staying up late and overworking". Ocular examinations showed normal visual acuity and intraocular pressure (IOP) in both eyes, conjunctival hyperemia, negative Tyndall sign in the anterior chamber, pupil diameter of approximately 4.5 mm, and absent light reflex. She was prescribed diclofenac sodium eye drops and tobramycin dexamethasone eye drops. Three days later, re-examination showed normal visual acuity and IOP, resolved conjunctival hyperemia, pupil diameter still around 4.5 mm, and absent light reflex. Since the patient's pupils were larger than normal, 1% pilocarpine eye drops were added to both eyes to relieve photophobia. After a single instillation of pilocarpine eye drops, the patient developed severe bilateral eye pain, increased IOP, and posterior iris pigment epithelial detachment. During this period, pilocarpine eye drops were continued, along with ocular IOP-lowering treatments, but IOP was not well controlled. Systemic IOP-lowering treatments and anterior chamber paracentesis were added, and IOP improved but was still not well controlled. Medication was adjusted: pilocarpine eye drops were discontinued, and local IOP-lowering treatments were continued. Subsequent re-examinations showed that bilateral IOP and anterior chamber flare gradually stabilized, and the pupil margin iris cyst significantly regressed before medication was stopped. The patient remained stable during a 2-year follow-up and is currently under continuous observation. Conclusions Pilocarpine eye drops are widely used in clinical practice with good medication safety, and reports of adverse reactions are rare. There are no previous reports of severe binocular anterior chamber flare accompanied by posterior iris pigment epithelium detachment and secondary glaucoma after pilocarpine eye drops. Therefore, we report this case to alert clinicians to pay attention to the adverse reactions of miotic drugs and provide a reference for clinical safe medication.