|Year : 2011 | Volume
| Issue : 4 | Page : 331-332
Surgical treatment and histopathology of a symptomatic free-floating primary pigment epithelial iris cyst in the anterior vitreous
Eman Al-Kahtani, Hind M Alkatan
Department of Ophthalmology, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
|Date of Web Publication||23-Nov-2011|
Vitreoretinal Division, King Khaled Eye Specialist Hospital, PO Box 7191, Riyadh 11462
Source of Support: None, Conflict of Interest: None
| Abstract|| |
We report the surgical removal of an iris pigment epithelial cyst that was floating freely in the posterior chamber of an 18-month-old child. The reason for surgical removal was disturbance in near vision secondary to the movement of the cyst across the visual axis. Visual disturbance secondary to a unilateral anterior vitreous iris cyst at this age is a rare presentation and, to the best of our knowledge, has not been reported previously as an indication for surgery. We performed histopathological study of the cyst aspirate to determine its contents and its possible origin.
Keywords: Iris Cyst, Pars Plana Vitrectomy, Pigment Epithelial, Vitreous
|How to cite this article:|
Al-Kahtani E, Alkatan HM. Surgical treatment and histopathology of a symptomatic free-floating primary pigment epithelial iris cyst in the anterior vitreous. Middle East Afr J Ophthalmol 2011;18:331-2
|How to cite this URL:|
Al-Kahtani E, Alkatan HM. Surgical treatment and histopathology of a symptomatic free-floating primary pigment epithelial iris cyst in the anterior vitreous. Middle East Afr J Ophthalmol [serial online] 2011 [cited 2022 Aug 16];18:331-2. Available from: http://www.meajo.org/text.asp?2011/18/4/331/90141
| Introduction|| |
Iris cysts in children are uncommon and little is known regarding the different types, histology, and management. Generally, cysts are symptomatic and found on routine examination of the anterior segment or, rarely, posterior segment. Iris cysts are classified as primary or secondary, with the primary cysts being further divided into pigment epithelial or stromal.  Most primary iris cysts in children arise from the iris stroma.  It can be solitary but is more characteristically seen as multiple cysts occurring bilaterally. 
A solitary free-floating pigmented iris cyst in the anterior vitreous is rare in infancy and usually does not warrant any intervention other than periodic observation. Here, we report a unique case of vitreous cyst and its surgical management.
| Case Report|| |
An 18-month-old male child presented to the retina service at the King Khaled Eye Specialist Hospital for examination under sedation as a case of a mass in the anterior vitreous, which had been found on routine eye examination by the referring ophthalmologist. The patient had originally undergone evaluation for abnormal head movement. The parents gave history of abnormal head movement each time the child's attention was drawn to any object on which he had to fixate. On examination by the child was able to fixate and follow. The intraocular pressure was normal, as also the eyelids and adnexa. Examination under sedation revealed unremarkable anterior segments bilaterally. Examination of the posterior segment revealed a dark brown, pigmented round cyst float freely in the anterior vitreous unconnected to the iris and located immediately behind the lens in the right eye. The cystmoved freely with changes in head position. In the primary position, the cyst was large enough to obscure the macula and obstruct the visual axis [Figure 1] and [Figure 2]. It was difficult to properly evaluate the child's abnormal head movement. The child was considered to be visually symptomatic because of the above findings and the history of abnormal head movement. To avoid the risk of secondary amblyopia the patient was taken to the operating room for pars plana vitrectomy and aspiration of the iris cyst. The technique selected was intended to free the cyst from the vitreous, with aspiration of the cyst wall and contents to achieve complete removal. Examination of the periphery and the anterior chamber angle revealed no other cyst or any other abnormality.
|Figure 1: Clinical picture of the affected eye in primary position showing the critical location of the cyst, obscuring the macula|
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|Figure 2: The cyst moves when the gaze is shifted to the right or left, allowing visualization of the macula|
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The histopathology smears revealed dispersed pigment and several pigmented epithelial cells, suggestive of a primary iris cyst [Figure 3].
|Figure 3: The histologic smear showing pigmented epithelial cells (H and E, ×400)|
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At the first postoperative visit 2 weeks after surgery, the parents reported marked improvement of the abnormal head movement further improvement of approximately 100% perceived by the second postoperative visit.
| Discussion|| |
Iris cysts have been proposed to be of congenital origin because pigmented cysts are not normally present in the vitreous. These cysts represent a choristoma of the primary hyaloid system. It has also been suggested that an iris cyst floating in the vitreous may actually originate from displacement of the pigmented ciliary epithelium at the region of the pars plana, possibly as a result of blunt trauma. , In the absence of definite history of trauma, the origin of the vitreous located iris cyst in the current case was most probably congenital.
Visually symptomatic iris cysts need to be surgically removed. Disrupting the cyst by argon laser photocystotomy may seem a simple and safe method, but it may not relieve the symptoms  and, moreover, may expose the patient to the risk of secondary inflammation and epiretinal membrane formation from rupture of the cyst and possible dispersion of pigmented cells.
Surgical aspiration of the cyst after releasing the vitreous adhesions to the cyst surface via a pars plana approach allows the cyst to collapse and to be safely and easily aspirated and overcome the risk of late complications secondary to dispersed pigmented cells.
Dispersed pigmented cells of the ruptured cyst can cause a severe inflammatory reaction and lead to the formation of an epithelial membrane on the surface of the retina (epiretinal membrane).
Although the cyst was unilateral in the present case, its critical location may explain the abnormal head movements of the child and defines this cyst as a symptomatic cyst. This is supported by the improvement in the abnormal head movements postoperatively.
| References|| |
|1.||Shields JA, Shields CL, Lois N, Mercado G. Iris cysts in children: Classification, incidence, and management. The 1998 Torrence A Makley Jr Lecture; Br J Ophthalmol 1999;83:334-8. |
|2.||Nork TM, Millecchia LL. Treatment and histopathology of a congenital vitreous cyst. Ophthalmology 1998;105:825-30. |
[Figure 1], [Figure 2], [Figure 3]