Iris cyst: a rare postoperative complication

Abstract

Introduction. For the first time iris cyst was diagnosed by Mackenzie in 1830. It was a post traumatic iris cyst located in the eyeball's anterior chamber (AC). Cysts can form in different parts of the iris and ciliary body. They are not common and can be a challenge for clinicians in terms of diagnosis and treatment. Case presentation. The 45-year-old patient was diagnosed with a secondary endothelial cyst. Comorbidities: insulin-dependent diabetes for over 18 years. Clinical diagnosis: OD-Iris cyst, RDP, Avitria, Artiphakia, OS- RDP, Panretinial photocoagulation. In 2018, the patient underwent 2 surgeries: a Pars Plana Vitrectomy and a Cataract extraction with IOL. During a routine check-up in December 2021 (3 years after surgery), an AC cyst was found located at OD in the temporal quadrant of the iris. During the 3 months, we observed the growth of the cyst. AV OD=0.2bc0.5. PIO OD=26 mmHg(Maklakov). BiomicroscopyOD sac-like pocket of membranous tissue that contains transparent fluid and corneal adhesion in the temporal area of the iris with the extension from the chamber angle up to 1mm from the pupillary edge. The UBM exam (gold standard) showed an ovoid volume formation measuring 0.36x0.15mm, growing in the AC with transparent contents and uniform walls. The increase in the volume of the cyst and the increase in ocular pressure were indications for surgical treatment-Excision of the cyst. We performed a paracentesis of the AC with the subsequent detachment of the cyst from the cornea with viscoelastic and excision of the cyst from the iris with intraocular scissors. Postoperative period without complications. The patient needs to follow up for a long time. Discussion. An iris cyst is an epithelial-lined space that involves a layer of the iris. The etiology of secondary iris cysts is surgical or ocular trauma. They can be implantation cysts, drug-induced, uveitic, tumour-induced, parasitic, or associated with systemic disorders. The diagnosis is based on the slit-lamp exam and UBM or AS-OCT. The differential diagnosis includes iris nevus, Lisch nodules, melanoma, iris pigment epithelium adenoma, metastatic iris lesions, and intraocular tumours. Complications can include obstruction of the visual axis, mechanical corneal decompensation, glaucoma, recurrent iritis, cataract, vitreous hemorrhage, scleral cyst formation. Treatment is performed for secondary glaucoma or pupil blocked. Treatment options are available from simple observation to fine-needle aspiration (±intracystic injection of alcohol), laser (argon, Nd: YAG) or surgical excision. After treatment, 40% of patients can relapse. Conclusion. UBM investigation helps to differentiate the types of eye neoformations and to put together a clinical diagnosis. The progress in the volume of the cyst and the increase in ocular pressure were indications for surgical treatment. Because of the high risk of relapse, it’s important to monitor the patient's dynamic.