Long-term results of surgical excision of conjunctival retention cyst using trypan blue with methylcellulose.

PURPOSE: Conjunctival retention cysts may recur if not completely removed. However, the cyst wall often ruptures during surgical excision, making complete removal difficult. In order to ensure complete cyst excision, we used a method of staining the inner cyst wall using trypan blue augmented by Methyl cellulose. OBSERVATION: Interventional study. Staining was performed by injecting trypan blue using an insulin needle. Then the needle was kept in place and methyl cellulose was injected to make the cyst content viscous to avoid its collapse after removing the needle. By using this technique, it was possible to excise the lesion as a whole. Three patients were included (unilateral). Two patients had cysts that were secondary to trachoma and were followed for up to 2 years without recurrence. A third patient had a conjunctival cyst following strabismus surgery was not successfully removed.
CONCLUSION: This method is simple and effective for complete excision of conjunctival retention cysts exception for cysts post strabismus surgery.

Introduction

Conjunctival epithelial retention (inclusion) cysts are common, with one or more small cysts often seen in the inferior fornices of healthy people. 1These cysts resemble epidermal cysts of the eyelids, and can be congenital (primary) or acquired (secondary). Histopathologically, small cysts may form by apposition of conjunctival folds while large, solitary cysts are considered as implantation cysts in which the surface epithelium was implanted into the substantia propria by trauma, surgery, or inflammation. Clinically, conjunctival epithelial retention cysts are thin-walled, containing clear or occasionally turbid fluid, and most commonly occur in either the bulbar conjunctiva or the conjunctival fornix. These cysts are most commonly asymptomatic and therefore may be simply observed; there may be a mild cosmetic blemish. Treatment is indicated only if cysts cause bothersome symptoms. Since the inner epithelial lining of the cyst is secretory, it usually recurs after aspiration of its fluid. Marsupialization or complete excision is necessary to prevent recurrence.

Surgical excision of conjunctival retention cysts is fraught with recurrence due to incomplete removal. During surgical dissection, healthy conjunctiva may be sacrificed, creating a problem of closure and the need for graft in the case of a large defect. Incomplete excision is not uncommon due to the thin cyst wall, and clear contents and this predisposes to recurrence. New techniques have been devised to achieve complete removal, such as staining of the cyst wall using Indocyanine green (ICG) and trypan blue (TB) combined with the use of ophthalmic viscosurgical devices (OVDs)., In this study, we introduced a modified surgical technique to ensure complete removal and to preserve as much as possible healthy conjunctiva.

Finding

Three patients were studied from 3/2013 to 3/2015. The study was approved by the Menoufia University Institutional Review Board and ethical committee.

Patient 1: A 20 - year old male had an inferior temporal forniceal cyst of his left eye due to old trachoma (Fig. 1). There were post trachomatous concretions.

Fig. 1

Patient 1: Inferior temporal forniceal cyst of the left eye, post trachoma; Pre-operative photo showing the cyst (A), Intraoperative photo illustrating staining of the cyst wall after injection of trypan blue and stabilization of the cyst with methylcellulose (B), postoperative (C).

Patient 2: A 50 - year old male had an upper nasal forniceal cyst of the left eye, loculated into two parts with localized symblepharon due to old trachoma (Fig. 2). There were post trachomatous concretions and a localized fornix symblepharon. The cyst was cosmetically disfiguring.

Fig. 2

Patient 2: Upper nasal forniceal cyst of the left eye, post-trachoma; pre-operative (A), intraoperative (B), postoperative (C).

Patient 3: 3- year-old girl developed a conjunctival retention cyst shortly following medial rectus muscle resection for exotropia (Fig. 3).

Fig. 3

Patient 3: Cyst post strabismus surgery; pre-operative (A), intraoperative(b), recurrence of the cyst following unsuccessful excision (C).

Informed consent was obtained for all patients, who then underwent surgical excision using the following technique. The first two patients had surgery under subtenons anesthesia using lidocaine 2% injected into the lower quadrant opposite the site of the retention cyst, while the third girl had general anesthesia. Traction sutures were applied to improve exposure which varied according to the position of the cyst. A silk 6-0 traction suture in the same quadrant at the limbus to ensure good the exposure. Injection of trypan blue ophthalmic solution 0.6 mg/ml using insulin syringe (27-gauge needle) into the cyst, its amount guided by the size of the cyst, the least amount that results in staining was injected. The needle was kept in place and the syringe replaced by an ampoule containing methyl cellulose (2%). Then, incision of conjunctiva anterior to anterior limit of the cyst with subconjunctival blunt dissection, trying to identify the plane of cleavage between the undersurface of the conjunctiva and the outer wall of the cyst. After complete dissection, an artery clamp was applied to the base of the cyst, then cut with scissors and cauterized to the edge. Finally, the conjunctival defect was closed by inverted interrupted sutures 8-0 Virgin silk. Postoperative topical steroid and antibiotic eye drops three times a day and ointment at bed time for three weeks were prescribed.

As the cyst wall was very thin, small leaking perforation at the site of initial puncture to the cyst was easily encountered. It happened in first two patients yet despite this, complete removal was achieved due to staining of the inside wall of the conjunctival cyst and viscosity of the injected methylcellulose. In the third patient, staining by trypan blue spread along the muscle sheath prevented complete cyst removal resulting in recurrence that mandated another surgery to remove the cyst without staining. There was no cyst recurrence in the first two patients up to 2 years. No other complications like symblepharon, granuloma or infection were encountered in the three patients.

Discussion

Secondary conjunctival cysts are usually acquired due to conjunctival inflammation such as trachoma and vernal keratoconjunctivitis, or trauma. Cysts can result from conjunctival surgery such as for pterygium, strabismus, scleral buckling, and pars plana vitrectomy. Conjunctival inclusion cysts can be solitary as in the first and the third patient or multiple as in the second patient who had a bipartite cyst).

Conjunctival cysts, particularly if large, can result in irritation, foreign body sensation, corneal astigmatism or cosmetic blemish. In case of inflammation, the first step is to control inflammation and monitor cyst size. Once inflammation is controlled, cyst removal may be required. While the best curative treatment is removal of the cyst without leaving any remnants, treatment with Nd-YAG laser has been reported.

The safety of vital stains and intraocular OVD suggest its safety in extraocular tissue such as conjunctiva. The use of trypan blue stain is not new in intraocular surgery. It has been used for staining of the epithelial lining capsule in cataract surgery and vitreoretinal surgery. Other vital stains such as Indocyanine green (ICG) have been used by Kobayashi et al. These authors used ICG alone in one patient with idiopathic conjunctival cyst; and in 2005, they stained with Healon V combined with 0.06%TB for removal of a conjunctival cyst without recurrence. Use of stain helps visualize the cyst wall and achieve total removal, however, adding viscous material like sodium hyaluronate hinders its collapse during excision. Chan et al. had used a similar method of combination of a stain (Indocyanine green) and viscosurgical device (1%sodium hyaluronate).

Methyl cellulose is a viscodispersive and less expensive than Healon yet can function like Healon to fill the cyst and achieve the same function. However, we did not compare methyl cellulose to Healon. On the other hand, dispersive agents maintain less space than Healon. We found that staining can help in removing the conjunctival retention cysts even after rupture due to their thin walls. However, as seen in the third patient, staining can also make removal more difficult.

Patient consent

Patient consent had been taken from the first two patients and from the mother of the third patient in an Arabic written form.

Conflicts of interest

The following authors have no financial disclosures: GR and JD.

Authorship

All authors attest that they meet the current ICMJE criteria for Authorship.

Funding

No funding or grant support.