Man presents with intermittent blurry vision for 1 year
A translucent fluid-filled cyst was seen in the anterior chamber of the left eye.
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A 40-year-old man presented to the New England Eye Center with a 1-year history of intermittent blurry vision of the left eye, especially notable in bright lights, as well as difficulty focusing while driving. He also had intermittent double vision and hazy vision in the left eye.
The patient’s complete ocular and systemic review of systems was negative, including eye pain, redness, floaters, neurologic symptoms, eye trauma and prior ophthalmic surgeries. His medical history was notable for hypertension, anxiety and gastroesophageal reflux disease. He stated he had a concussion 4 months before presentation; however, he noted intermittent blurry vision before that injury. He had no known drug allergies and denied the use of alcohol, tobacco or recreational drugs.
Source: Nisha S. Dhawlikar, MD, MPH, and Michael B. Raizman, MD
Examination
Upon examination, the patient’s visual acuity was 20/20 in both eyes. IOPs were within normal limits in each eye. The pupils were symmetric, round and briskly reactive, with no afferent pupillary defect. Motility was full and painless in both eyes. Slit lamp examination revealed white and quiet conjunctivae, clear corneas, and deep and formed anterior chambers in each eye, with no transillumination defects or neovascularization of the iris, and trace nuclear sclerosis in each eye.
Within the anterior chamber of the left eye, there was a translucent fluid-filled cyst measuring 5 mm (horizontal) by 4.5 mm (vertical) by 2 mm (anteroposterior) at its longest axis (Figure 1). The cyst blocked much of the pupil (Figure 2). The anterior chamber was without cell or flare. The cyst appeared to be touching the cornea at the 5 o’clock position in the mid-periphery as well as the cornea centrally; however, the cornea appeared clear (Figure 3). The cyst was translucent, including the walls. There was no pigment on the corneal endothelium. After dilation, the cyst was found to be mobile and not connected to other structures such as the iris or anterior lens capsule.
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Free-floating cyst
Free-floating anterior chamber cysts are uncommon. The differential diagnosis for this patient includes an epithelial cyst, iris stromal cyst, “pearl” tumor of the iris, as well as inflammation such as secondary to iritis, or neoplastic including iris melanocytoma or medulloepithelioma.
Iris stromal cysts are typically found in children and appear as a smooth, round, translucent anterior chamber mass. They originate from the iris stroma and are nonkeratinized, squamous and epithelial-lined on pathology. However, iris stromal cysts have never been described as free-floating, as is the cyst in this case.
As there were no synechiae, keratic precipitates, or anterior chamber cell or flare, an inflammatory etiology, such as iritis, is less likely. Also, much less likely is a neoplastic origin such as an iris melanocytoma as it typically can produce profound pigmentation from necrosis, and the anterior chamber cyst in this patient was non-pigmented. He also had no history of cancer or any systemic signs or symptoms.
Given the translucent nature of the anterior chamber cyst, this case is most likely an epithelial cyst. Due to the mobile nature of the cyst and lack of pigment, it is possible that the cyst originated from the iris and then became free-floating and visually significant. Interestingly, epithelial cysts usually occur after a perforating injury and, in a few cases, after cataract surgery, appearing pearl-like or serous in nature. However, the anterior chamber cyst in this patient seemingly developed in the absence of any ocular trauma or ocular surgery.
Discussion
When an anterior chamber cyst is identified, slit lamp imaging can be useful to monitor for any changes in appearance of the structure. Additionally, anterior segment OCT may be useful in determining how much corneal touch is present. Endothelial cell count can also be obtained and monitored for progression of corneal damage by the cyst.
The patient underwent additional in-office testing including endothelial cell count, which was within normal limits. However, as the cyst appeared to be touching the cornea, there was concern for future endothelial cell loss. Due to this concern, risks and benefits of monitoring of the cyst vs. excision of the cyst were discussed with the patient. To improve vision and prevent further damage to the cornea, the recommendation was made for cyst excision. The possibility of a second surgery was also discussed with the patient if the cyst has damaged the cornea.
Anterior chamber cysts have been described dating back to 1832; however, most cases thus far have been described after a perforating injury and few cases after cataract surgery. Epithelial cysts are thought to be due to implantation of the epithelium in the anterior chamber at the time of an injury or operation. Invasion of epithelium is thought to occur either due to implantation of free conjunctiva or cornea, the inturning of a conjunctival flap, or epithelial ingrowth along a gaping intraocular wound, incarcerated tissue such as lens capsule, vitreous or uveal tissue, or a deeply inserted suture.
The anterior chamber epithelial cysts described in literature are typically not free-floating; however, of those free-floating cysts mentioned, treatment is to closely monitor these patients as long as they are asymptomatic and the cyst is not causing damage to other ocular structures. YAG laser treatment was used to successfully collapse two free-floating iris cysts found in a young boy. Two case reports of free-floating iris pigment epithelium cysts described surgical removal rather than periodic observation, with no recurrence noted during the 6 months of follow-up. Surgery was recommended in these cases due to visual disturbances from cyst movement across the visual axis. One of these cysts also had continuous corneal touch and thus further supported surgical removal due to the risk for further corneal endothelial decompensation.
Similarly, in this case presentation, the patient was symptomatic with intermittent blurry or hazy vision in the left eye. The non-pigmented cyst had corneal touch inferiorly in the mid-periphery, and although endothelial cell count was not compromised, the risk for future corneal endothelial decompensation prompted the recommendation for surgical removal. Surgical removal of the non-pigmented cyst will be performed after pupillary miosis, with the goal being to remove the cyst in its entirety without spreading its contents within the anterior chamber. YAG laser to collapse the cyst was not chosen as the treatment due to the large size of the cyst, as well as the risk for spreading endothelial cells within the anterior chamber, with concern for postoperative IOP rise and possible cyst recurrence. Close follow-up will be observed postoperatively.
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- For more information:
- Nisha S. Dhawlikar, MD, MPH, and Michael B. Raizman, MD, can be reached at New England Eye Center, Tufts University School of Medicine. 800 Washington Street, Box 450, Boston, MA 02111; website: www.neec.com.
- Edited by Alison J. Lauter, MD, and Sarah E. Thornton, MD. They can be reached at the New England Eye Center, Tufts University School of Medicine, 800 Washington St., Box 450, Boston, MA 02111; website: www.neec.com.