Descrição clínico-cirúrgica de quatro casos de transposição da comissura labial para correção de coloboma palpebral em gatos

Background: Eyelid coloboma or eyelid agenesis is the most common congenital disease in cats. It can affect both the upper and the lower lids and is commonly bilateral. This congenital defect has been reported in several breeds, such as Persian and Domestic Short-Haired Cat. Generally, this defect results in inversion of the colobomatous eyelid, which can cause trichiasis and inflammatory keratitis and corneal ulceration. The only effective treatment is blepharoplasty. This paper describes the clinical and surgical aspects of four patients treated by lip commissure to eyelid transposition for the repair of eyelid coloboma using the technique described in 2010. Results of this procedure have never been reported in Brazil. Cases: Seven eyes of four cats presenting eyelid coloboma affecting up to two thirds of the eyelid were evaluated in this study. Two of the four cats were males and two were females; their average age was 3 years. All patients were admitted at the same institution, and the main issues were purulent discharge and impaired vision. Diagnosis was based on physical and ophthalmic examination. Non-ulcerative keratitis was present in all cases. Corneal ulcer was diagnosed in three patients by the fluorescein dye test. In two cats, a corneo-conjunctival dermoid was found at the temporal-dorsal region of one eye, and measured approximately 0.3 mm; and the other two exhibited microphthalmia in one eye. No abnormalities were seen in the anterior chamber, lens, and vitreous. One of the cats exhibited retinal detachment, and one exhibited testicular agenesis, both of the abnormalities diagnosed by ultrasound. Complete blood count and biochemical tests were performed in all patients before general anesthesia for the corrective procedure. Before surgery, eyes with ulcerative and non-ulcerative keratitis were treated with topical antibiotics and lacrimommimetics. In the 7 eyes, lip commissure to eyelid transposition technique was used for correction of the colobomatous defect. The procedure consisted of a mucocutaneous flap that simulates a natural eyelid. Corneo-conjunctival dermoids were also removed at the same time by superficial keratectomy. In the postoperative period, all patients received oral non-steroidal antiinflammatory drug and an antibiotic, as well as cleansing of the surgical wound. All patients exhibited improvement of corneal abnormalities following one week of the procedure. However, three cats had suture dehiscence on the lip commissure, which healed by secondary intention after a week. Two weeks after surgery, superficial necrosis was observed at the tip of the edge of the transplanted flap, in all cats. In order to promote healing, the necrotic edges were debrided at the time of sutures removal, 10 to 15 days after surgeries; at this time, both lip commissure and eyelid wound had already healed. Facial distortion was present owing to skin overlapping on the site of the flap. All patients had their ability to blink restored, and there was absence of trichiasis on the flap. However, three cats had thichiasis caused by retraction of the pre-existing eyelid at the medial canthus. Discussion: Good functional and esthetic results were achieved, similarly to those previously described, which allows us to consider that this technique is appropriate for eyelid reconstruction in eyelid coloboma or agenesis cases. Nevertheless, this procedure can have some complications, such as suture dehiscence, facial deformity, superficial necrosis of the edges of the flap, and trichiasis of the pre-existing eyelid of the medial canthus. To overcome these issues, authors suggest removal of the skin under the flap to decrease facial distortion, and removal of the whole pre-existing eyelid, in order to avoid trichiasis caused by retraction of this tissue.