Advanced Midzonal Iris Pigment Epithelial Cyst Managed by Aspiration Deflation.

Background: There are several cysts that can occur in the iris. The midzonal (retroiridic) iris pigment epithelial (IPE) cyst is important because it can simulate melanoma of the ciliary body. However, it is frequently asymptomatic and requires no treatment.

Methods: A 37-year-old asymptomatic woman with visual acuity of 20/20 in each eye was found to have an elevated mass behind the left iris, presumed to be melanoma, and was referred for management. On our examination, there was a typical midzonal IPE cyst in the left eye (OS), requiring observation without intervention. After 4 years, she developed progressive visual loss to 20/40 OS and cyst enlargement was noted, obstructing most of the visual axis and causing partial lens subluxation. Translimbal fine needle aspiration deflation with a 30-G needle was performed.

Results: Immediately at aspiration, the cyst demonstrated collapse, disappearing behind the iris stroma, and the lens subluxation resolved. Visual acuity returned to 20/20 OS and has remained stable without recurrence for 3 years.

Conclusion: Although most midzonal IPE cysts are asymptomatic, this case showed progressive enlargement with visual loss and was managed with translimbal aspiration. Symptomatic midzonal IPE cysts can be deflated with translimbal aspiration rather than more aggressive surgical excision.