What are the treatment options for an iris cyst?

Treatment Options for Iris Cysts

For most iris cysts, observation without intervention is the appropriate initial management, as the majority remain asymptomatic and stable over time; however, symptomatic cysts causing visual obstruction, corneal decompensation, secondary glaucoma, or uveitis should be managed with a stepwise conservative approach starting with fine-needle aspiration, reserving surgical excision only for refractory cases. 1

Initial Management Strategy

Asymptomatic iris cysts require only observation with regular monitoring. 1, 2 The vast majority of iris cysts remain stable and do not require any intervention, with less than 1% requiring surgical treatment. 2

• Annual follow-up is appropriate for stable, asymptomatic cysts, with patients advised to return immediately if they develop pain or visual symptoms. 3
• Ultrasound biomicroscopy (UBM) is the gold standard imaging modality for iris cysts, providing excellent resolution with sufficient tissue penetration to characterize the lesion and monitor for changes. 1
• Anterior segment optical coherence tomography (AS-OCT) can also be used to document and follow cyst characteristics. 2

Indications for Intervention

Treatment becomes necessary when iris cysts cause specific complications:

• Visual axis obstruction with documented visual acuity decline 4
• Corneal decompensation from direct contact or endothelial compromise 1
• Secondary glaucoma from angle closure or trabecular meshwork obstruction 1
• Secondary uveitis from inflammatory response 1
• Lens subluxation from mass effect 4

Stepwise Treatment Algorithm

First-Line: Fine-Needle Aspiration

When intervention is required, translimbal fine-needle aspiration is the preferred initial approach. 1, 4

• Perform aspiration using a 30-gauge needle through a translimbal approach. 4
• The cyst typically collapses immediately upon aspiration, disappearing behind the iris stroma. 4
• This technique has demonstrated sustained success with visual acuity restoration and no recurrence at 3-year follow-up in documented cases. 4
• Intracystic injection of absolute alcohol or antimitotic agents can be combined with aspiration to reduce recurrence risk, though this increases the invasiveness of the procedure. 1

Second-Line: Laser Treatment

If aspiration fails or is not feasible:

• Argon or Nd:YAG laser photocoagulation can be attempted for cyst wall disruption. 1, 5
• Laser treatment carries variable success rates and may require multiple sessions. 1

Third-Line: Surgical Cystotomy

For cysts that fail needle aspiration, surgical cystotomy using microsurgical instruments is an effective alternative. 5

• This technique creates a surgical opening in the cyst wall using microinstrumentation. 5
• Visual symptoms typically resolve within 1 week postoperatively. 5
• No recurrence has been documented at 14-month follow-up in reported cases. 5

Last Resort: Surgical Excision

Complete surgical excision via iridectomy or iridocyclectomy should be reserved only for refractory cases, as this approach carries higher complication rates and is no longer favored as first-line treatment. 1

• The historical approach of radical surgical intervention has been abandoned due to high recurrence rates. 1
• Surgical excision may be necessary for cysts associated with underlying iris or ciliary body melanoma (found in <1% of cases). 2

Critical Pitfalls to Avoid

• Do not confuse midzonal iris pigment epithelial cysts with ciliary body melanoma. These cysts can simulate melanoma but have characteristic features on UBM showing thin walls and no internal reflectivity. 4, 3
• Avoid aggressive surgical intervention as initial treatment. The current evidence strongly favors conservative stepwise management given high recurrence rates with radical excision. 1
• Do not overlook associated pathology. Although rare (<1%), iris cysts can be associated with iris nevus, iris melanoma, or ciliary body melanoma requiring different management. 2
• Screen for systemic disease in patients with pupillary margin cysts (iris flocculi). These can be markers for dissecting thoracic aortic aneurysm related to smooth muscle genetic mutations. 2

Special Considerations by Cyst Type

Free-floating iris cysts (dislodged pigment epithelial cysts) typically remain stable and require only observation unless complications develop. 3, 2

Peripheral iris cysts are the most common type (63% of cases) and most often affect young adults aged 21-40 years. 2 These rarely require intervention.

Midzonal cysts account for 28% of cases and characteristically appear as fusiform brown lesions behind the iris. 2 When symptomatic with progressive enlargement, aspiration deflation is highly effective. 4