|Year : 2021 | Volume
| Issue : 2 | Page : 193-195
Diagnosis and management of post - traumatic pearl iris cyst
KS Siddharthan, Shraddha Shah, Jagdeesh Kumar Reddy
Department of Cornea, Sankara Eye Hospital, Coimbatore, Tamil Nadu, India
|Date of Submission||10-Dec-2020|
|Date of Acceptance||13-Jan-2021|
|Date of Web Publication||24-Jun-2021|
K S Siddharthan
Sankara Eye Hospital, Coimbatore, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Epithelial iris cysts still comprise a mystery with regard to pathogenesis, modes of presentation, and response to treatment. Here, we report an 8-year-old boy who presented with a pearly white iris cyst, 2-year postcorneal tear repair. After Anterior segment optical coherence tomography confirmation, an en block resection of the cyst was done. Eleven months later the patient presented with recurrence of the iris cyst. This recurrence was due to incomplete removal of the epithelial tissue lining the pearly cyst. Ultrasound bio-microscopy (UBM) was done to delineated the posterior extent of the cyst, and a sector iridectomy with a 4 mm margin around the cyst was done. Our case reinforces the fact that delineating the extent of these iris cysts posteriorly with UBM is mandatory in all cases, and it provides a basis for surgical resection for favorable visual outcomes.
Keywords: Iris cyst, pearl type, secondary, sector iridectomy, ultrasound bio-microscopy
|How to cite this article:|
Siddharthan K S, Shah S, Reddy JK. Diagnosis and management of post - traumatic pearl iris cyst. TNOA J Ophthalmic Sci Res 2021;59:193-5
| Introduction|| |
Epithelial iris cysts may be primary or secondary and are a relatively rare occurrence. Primary iris cyst include posterior pigment epithelial cyst, iris stromal cyst, and free-floating cyst. Secondary iris cysts are seen after a penetrating injury or postsurgery. Post-traumatic implantation iris cysts are more commonly encountered and have a varied presentation ranging from a serous cyst to a rather rare pearl cyst, whose diagnosis and treatment pose a great challenge to the clinician. With the advent of ultrasound bio-microscopy (UBM), the diagnosis of these cysts has become rather simplified and thus help the clinician in determining the treatment modality. The purpose of this paper is to highlight the importance of identifying and delineating the cyst at an early stage and the need to aggressively approach it, to achieve favorable outcomes.
| Case Report|| |
Eight-year-old boy presented with complaints of pain, redness, and watering for the past 3 weeks. He had a history of a penetrating ocular injury to the same eye and underwent a full-thickness corneal tear repair at our hospital 2 years back. Visual acuity was 6/36 in the left eye (LE) and intraocular pressure was 14 mmHg. Anterior segment examination of the LE showed a 4 mm healed linear nebula-macular corneal scar. The anterior chamber showed 1+ cells with flare. A whitish pearly oval cystic lesion measuring 4 mm × 2 mm was noted at 2o clock position embedded in the iris without touching the corneal endothelium [Figure 1]a. Fundus examination was normal.
Anterior segment optical coherence tomography (AS-OCT) was done to confirm the diagnosis of an iris epithelial cyst [Figure 1]b. Under topical steroid cover, the cyst was removed completely along with a 1 mm margin of normal iris. UBM was not done at that instant. Postoperatively, the eye was quiet, and the patient was followed up at frequent intervals. However, 11 months later, the patient again presented with a similar round cystic lesion adjacent to the area of excision measuring 2 mm × 2 mm with mild iris pigments at the base [Figure 2]a. UBM was carried out this time to assess the extent of the cyst [Figure 2]b. UBM showed a mass in the superior quadrant of the iris with medium reflectivity not involving the ciliary body [Figure 2]c. We went ahead with a sector iridectomy with a 4 mm margin around the cyst, to avoid further recurrence of the cyst [Figure 3]. The excised tissue was sent for histopathological examination, and the microscopic section showed iris tissue with a cyst wall lined by stratified squamous epithelium containing a granular layer suggestive of an epidermal cyst [Figure 4]. Postoperatively, the visual acuity was maintained at 6/36 and the eye remained quiet till the last follow-up at 18 months.
|Figure 1: (a) Pearly white pedunculated iris cyst of 4 mm × 2 mm size seen superotemporally at 2° clock position with a healed 4 mm linear corneal scar. (b) Anterior segment optical coherence tomography image showing a homogenous reflective oval cyst seen arising from the iris epithelium. Healed and thinned out cornea in the area of repair (arrow)|
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|Figure 2: (a) Recurrent pearly white round cyst of 2 mm × 2 mm size, 11 months postcyst removal. (b) Ultrasound bio-microscopy showing the extent of the iris cyst (arrow). (c) Ultrasound bio-microscopy showing no involvement of the root of the iris (arrow)|
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|Figure 3: Superior sectoral iridectomy from 11° to 1° clock hours postcomplete excision of the cyst|
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|Figure 4: Microscopic section showing iris tissue with a cyst wall lined by stratified squamous epithelium containing a granular layer suggestive of an epidermal cyst|
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| Discussion|| |
The pathogenesis of an implantation cyst is said to be due to invasion of a double continuous layer of epithelium from the surrounding cornea or conjunctiva into the anterior chamber through a traumatically created defect. The implanted epithelium, due to the exuberant vascularity of the iris, proliferates into a sheet or forms a cyst. The spread of the epithelial cells can occur over the iris into the angles anteriorly and into the ciliary body posteriorly and beyond. Delayed wound closure due to lens debris and incarceration of iris, wound dehiscence, and ocular hypotony are all risk factors for iris cyst formation.
Based on the proliferation of the epithelium, posttraumatic cysts take the form of three distinct varieties such as serous cyst, pearl cyst, or an epithelial downgrowth., This prolific behavior of the epithelial cells is responsible for the high rate of recurrences and complications seen with secondary cysts. The pearl cyst or epidermoid cyst, which is the least common of the three, is a solid-looking cyst formed by entry of cilia into the anterior chamber. The epithelial cells of the root sheath get implanted near or at the iris and begin to proliferate, resulting in cyst formation. It is lined by stratified squamous or cuboidal epithelium, resembling that of cornea or conjunctiva, having concentric lamellar layers, and clear cystic spaces in the center.,
UBM, a noninvasive diagnostic tool, helps in assessing the posterior extent of the cyst, differentiating it from uveal tumors and delineating the surrounding structures. The UBM features of a pearl cyst are seen in three layers, as a moderately reflective thicker epithelial cyst wall, an intermediate layer with lower reflectivity, and a central hyperechoic core filled with keratinous debris. It is superior to AS-OCT due to its higher tissue penetration of up to 4 mm. However, noninvolvement of ciliary body on UBM does not rule out recurrences in future as the epithelial cells migrate and may present with pars plana cysts which needs to be monitored long term. Histopathological studies on iris cysts help to complement clinical and UBM findings to differentiate iris amelanotic tumors from pearly cysts. The intermediate layer of low reflectivity of a pearl cyst as seen on UBM corresponds to the presence of degenerated epithelium and inflammatory debris confirmed on histopathology.
Different treatment modalities for the management of iris cysts have been explained in literature. Conservative approach includes the use of intracystic injection of sclerosing agents such as saline, iodine, phenol, 50% dextrose, and ethanol or anti-mitotic agents such as mitomycin-C and 5-flurouracil, to permanently damage the epithelial and goblet cells that secrete the cyst fluid, thus helping in cyst regression. These procedures can be augmented with cautery, electrolysis, diathermy, and cryotherapy particularly at the base of the iris to prevent recurrences. Newer advances include the use of neodymium-yttrium-aluminum-garnet and argon laser photocoagulation causing rupture and shrinkage of the cyst, respectively. Even though conservative approach maintains the surrounding intraocular structures, in a setting of high recurrence and severe complications, a need for surgical excision is warranted. Surgical options include en bloc resection of all the layers, sector iridectomy, excision plus posterior corneal lamellar resection, iridectomy plus cryotherapy of the residual epithelial cells, iridocyclectomy with or without vitrectomy and lensectomy.,
In our patient, the pearl iris cyst appeared 2 years post-trauma. After initial resection of the cyst with surrounding 1 mm margin of normal iris, the second cyst appeared adjacent to the area of excision indicating that already the epithelial cysts had disseminated into the surrounding iris stroma, even before excision. This highlights the need for a wider resection of iris tissue and the importance of histopathological confirmation after resection to see for an infiltration-free iris margin. That was why we performed a 4 mm wider excision of the iris and also confirmed it with histopathological examination to avoid further chance of spread.
In conclusion, our case reinforces the fact that there is no scope for conservative management in these pearly iris cysts, and delineating the extent of these cysts posteriorly is critical. UBM is mandatory in all these cases as it clearly demarcates the extent and provides a basis for surgical resection for favorable visual outcomes.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]