Man presents with 3-month gradual decline in vision

A large iris cyst, filled with white cells, was seen on examination of the right eye.

Issue: August 10, 2016

ByKenneth R. Kenyon, MD

ByJames Constans, MD

A 33-year-old man with a history of penetrating ocular trauma in the right eye during childhood presented to the New England Eye Center with a gradual decline in vision in the right eye over a 3-month period. At the time of presentation, he described a thick white haze overlying his visual field in its entirety on the affected side. There were no flashes, floaters, curtaining or absence of vision. He further reported no accompanying pain, irritation, redness or foreign body sensation.

Examination

At presentation, the patient’s best corrected visual acuity was 20/70 in the right eye with improvement to 20/40 after refraction. There was no afferent pupillary defect, although the right pupil was 6 mm in diameter and demonstrated minimal reactivity to light. Extraocular motility was normal. IOP was within normal limits in both eyes.

There was trace diffuse conjunctival injection with a small well-healed scar noted at the 9 o’clock position adjacent to the corneal limbus. A small 1-mm pterygium was noted temporally, and the cornea was otherwise grossly clear. A large iris cyst originating temporally from the 7 to 11 o’clock position was present with balloon-like medial extension overlying 95% of the pupil (Figure 1). A dependent collection of white cells was noted inferiorly within the cyst, and the entire anterior face of the cyst was in contact with the overlying corneal endothelium. A transillumination defect was noted posteriorly. The anterior chamber was otherwise deep and quiet without hypopyon. A UBM was obtained at initial consultation, revealing the cyst to be 6.8 mm × 3.3 mm (Figure 2).

Figure 1. Slit lamp photo discloses opalescent anterior chamber cyst extending centrally from temporal traumatic incision to nearly occlude the pupil.

Figure 2. Ultrasonic biomicroscopy confirms presence and dimensions of cyst with lucent contents apposed to the iris surface and the corneal endothelium.

What is your diagnosis?

Iris cyst

The patient’s previous trauma occurred at the age of 2 years when a dinner plate shattered and penetrated the right globe along the temporal limbus. The rapid emergence and growth of this cyst after 30+ years of quiescence was suspicious for epithelial ingrowth along the previous wound tract. This was supported by the cyst’s overall clinical appearance, seeming extension from the site of initial trauma, and by the presence of a dependent collection of white cells found within.

Management of epithelial iris cysts

Epithelial ingrowth into the anterior chamber is an infrequent complication of penetrating trauma or intraocular surgical intervention, although it may also be found congenitally. Multiple patterns of ingrowth have been observed, ranging from the advancement of a sheet-like extension of epithelial cells across structures within the anterior chamber to the formation of a focal cyst. These cysts can be of varying size and are often dynamic, as seen by the rapid growth demonstrated by our patient. While small stable-appearing cysts may be observed, their larger counterparts have the potential to cause further complications including pupillary obstruction, secondary glaucoma, iridocyclitis, corneal decompensation, loss of vision and intractable pain. The gravity of these sequelae necessitates close observation of visibly enlarging cysts with timely surgical intervention when indicated. Various techniques and approaches can be found throughout the literature, including en bloc excision, partial excision with regional ablation via cryotherapy or photocoagulation, aspiration and use of sclerosing agents, electrolysis, and direct photocoagulation of the cyst without surgical intervention.

Forster described the presentation of epithelial ingrowth occurring after cataract surgery in three patients, with two associated with fistulae and conjunctival blebs. Block excision with corneoscleral graft was performed in each of these cases with no demonstrable recurrence at 26 months, 23 months and 7 months, respectively. The histopathology of each specimen demonstrated that the epithelial ingrowth had occurred via migration through the previous clear corneal incisions. Similarly, Ganesh and colleagues advocated for en bloc excision with corneoscleral graft (syngeneic auricular cartilage) in their series of two children whom developed cystic epithelial downgrowth following penetrating eye injuries.

Haller and colleagues discussed a single surgeon’s experience in the management of seven cysts: four related to trauma, one following penetrating keratoplasty, one congenital and one related to corneal perforation in a patient with Terrien’s marginal degeneration. Three of the patients with traumatic etiologies underwent vitrectomy, excision of the cyst and adjacent iris, and local cryotherapy of surrounding tissue under thermal insulation via fluid-air exchange. The other four cases were managed via simple cyst excision or aspiration followed by endolaser ablation of the remaining cyst wall or base. The conservative approach taken with the latter four cases produced more favorable visual outcomes, with BCVA ranging from 20/20 to 20/40 compared with the count fingers-hand motion vision attained in the former three. It should be mentioned, however, that the varied presentations of each case might preclude them from true comparison. The more significant extent of disease at presentation in the former cases necessitated a more aggressive treatment and may have carried a poorer visual prognosis all along.

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Behrouzi and colleague reported on a series of 99 eyes with epithelial iris cysts that were managed via aspiration and ethanol sclerosis. In each case, the cysts were gently drained via a 27-gauge needle followed by intracystic exposure to 100% ethanol for 60 seconds. The ethanol was then aspirated, and the patients were treated with topical atropine and dexamethasone. All steps of the intervention were performed via the same needle/positioning without other violation of the anterior chamber or its contents. They reported that 93 of 99 cases (93.9%) resolved after a single irrigation, three cases (3%) and two cases (2%) required second and third irrigations, respectively, and a single case did not respond altogether. Anterior chamber reaction was seen on postoperative day 1 in two cases presumed to be due to ethanol leakage and in nine cases without evidence of leakage. Furthermore, of the 21 cases (21.2%) noted to have IOP greater than 20 mm Hg at presentation, 11 (52.4%) demonstrated normalization of IOP following irrigation.

Reports of less invasive approaches have also been described. Okun and colleague advocated for the use of xenon arc photocoagulation without surgical intervention in their series of three patients who developed iris cysts 5 to 6 months after intracapsular cataract extraction. In each instance, patients required four to six treatments over a 7- to 13-month period of time before complete collapse of the cyst was observed. Repeated follow-up thereafter demonstrated no recurrence of the iris cysts. Remnants were visible in the angle on gonioscopy in two of the three cases, with IOP remaining within normal to high-normal limits. Visual acuities of 20/60 (amblyopic), 20/20 and 20/25 were obtained, respectively.

Follow-up

Given the size, growth and visual implications of the patient’s cyst, the decision was made to pursue surgical intervention. After discussion of the risks, benefits and alternatives, he elected to proceed, and surgical planning and coordination are currently underway.

The literature suggests less invasive approaches may provide the best visual outcomes, and while en bloc resection was discussed, there is concern that the ensuing iris defect would likely lead to significant visual symptoms and would not be amenable to a suture iridoplasty. Additionally, we feel that the amount of debris within the cyst necessitates aspiration and further pathologic classification. While there is low suspicion for a neoplastic process at this time, special care will be employed not to rupture the cyst or seed the remaining portion of the anterior chamber. The approach taken by Behrouzi and colleague would best facilitate safe and effective removal of the cystic contents as well as definitive destruction of the cyst wall, preventing future recurrence; this will likely be the approach taken for this case.

References:
Behrouzi Z, et al. Ophthalmology. 2003;doi:10.1016/S0161-6420(03)00543-8.
Forster RK. Trans Am Ophthalmol Soc. 1995;doi:10.1016/S0002-9394(14)70550-1.
Ganesh A, et al. Eye (Lond). 2005;doi:10.1038/sj.eye.6701483.
Haller JA, et al. Trans Am Ophthalmol Soc. 2002;100:79-84.
Kennedy PJ. AMA Arch Ophthalmol. 1956;doi:10.1001/archopht.1956.00930030526011.
Okun E, et al. Trans Am Ophthalmol Soc. 1974;72;170-183.

For more information:
James Constans, MD, and Kenneth R. Kenyon, MD, can be reached at New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111; website: www.neec.com.
Edited by Kristen E. Dunbar, MD, and Kendra Klein, MD. They can be reached at New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston MA 02111; website: www.neec.com.