Surgical correction of aberrant conjunctival overgrowth in a rabbit: a case report
© Kim et al.; licensee BioMed Central Ltd. 2013
Received: 27 February 2013
Accepted: 1 October 2013
Published: 5 October 2013
A dwarf rabbit presented with unilateral aberrant conjunctival growth. Allgoewer’s U-suture therapy was initially used to correct the overgrowth. Centrifugal incisions extending up to the limbus were made on the hypertrophic conjunctiva. Transpalpebral limbal fixation was performed next. When the symptoms recurred 3 weeks later, a second operation was performed using the Lembert suture method instead. The overgrowing membrane was excised radically just posterior to the limbus. The conjunctiva was then sutured using the Lembert pattern. The rabbit recovered with no further complications.
Aberrant conjunctival overgrowth (stricture) is a unique and unusual eye disease [1, 2] and has only been observed in dwarf rabbits. It appears as a pink, double-layered, vascular membrane that overlies the full 360 degrees of the corneal rim and extends centrally. This condition is poorly understood and appears to be unique to the rabbit . The pink tissue is a conjunctival fold, which grows centripetally from the bulbar conjunctiva at the limbus and obscures the cornea to varying degrees . It remains attached at the limbus, but the central fold of tissue moves freely over the corneal surface [3, 4] without adhesions [1, 4]. In cases of aberrant conjunctival overgrowth, only loose-to-moderately firm focal adhesions at the peripheral cornea have been reported . Generally, eyes with overgrowth do not have symptoms of conjunctivitis, but in some cases, mild inflammation can occur. Corneal oedema may present at the central conjunctival opening. Aberrant conjunctival overgrowth differs from human pterygium [1, 4] and from feline symblepharon. In these two conditions, conjunctival overgrowth is intimately attached to the cornea, and the conjunctiva replaces the corneal epithelium .
Aberrant conjunctival stricture generally occurs in adult animals [1, 2]. Neither topical nor systemic medication is effective for membrane regression or for prevention of further growth . Only surgical intervention can remove the membrane, but simple resection of the membrane back to the limbus is not sufficient, because the membrane regrows rapidly . Therefore, after membrane removal, the cut edge is sutured to the bulbar conjunctiva and sclera just behind the limbus . Allgoewer et al.  reported surgical success in 10 eyes of 6 dwarf rabbits operated using Stades’ U-suture therapy for aberrant conjunctival stricture and overgrowth. Another method is the Lembert suture method for aberrant conjunctival overgrowth. Although steroid and cyclosporine treatments are ineffective, topical cyclosporine ointment is generally used after surgical correction to reduce the risk of regrowth.
Here, we report the clinical presentation of aberrant conjunctival stricture and overgrowth and report the therapeutic efficacy of the U-suture and Lembert suture methods.
History and ophthalmic findings
Surgical treatments and postoperative care
The conjunctival overgrowth was treated surgically using a modification of Stades’ U-suture technique as introduced by Allgoewer in . After induction of anaesthesia by using propofol (10 mg/kg, Provive Inj 1%, Myungmoon Pharm. Co., LTD, Seoul, Korea), the patient was intubated. Maintenance was followed with isoflurane (Ifran, Hana Pharm. Co., LTD, Kyonggi-Do, Korea). After preparing the eyes with 0.2% povidone-iodine, the conjunctival fold was incised from the central rim up to its attachment at the limbus in 6 equally sized segments. All segments were then relocated to the normal position in the fornix and fixed into place with mattress sutures (Prolene 6–0) that passed through the skin .
In the current case, we used Allgoewer’s method for the first operation. Moderate eyelid inflammation appeared postoperatively and persisted for 1 week. Three weeks after surgery, the conjunctival fold re-grew from the limbus. Within a week, the membrane had extended to cover most of the cornea. Despite the use of Maxitrol® eye drops, the eyelid and conjunctiva continued to exhibit signs of inflammation (Figure 5). To treat the recurrence, we used a different surgical method. The entire membrane was removed, and the cut edge was folded into the limbus, similar to the method introduced by Turner . Eight simple Lembert sutures were created, followed by the placement of a continuous Lembert suture. With this method, the cut edge of the membrane is folded more securely under at the limbus.
When using Allgoewer’s method, the third eyelid caused some difficulty in suturing the tissue at the medial canthus. Furthermore, it was not easy to surgically handle six radial pieces of the membrane, which shrank after they were cut. After the first surgery, a certain degree of eyelid inflammation persisted, even with the use of steroid eye drops. This inflammation was not observed after the second surgery and may have occurred during the first surgery because the suture material (Prolene) can irritate the eyelid. Allgoewer et al.  did not report the same inflammation in their research.
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