This study was performed at the Clinic of Surgery and Ophthalmology of the Faculty of Veterinary Sciences between years of 1998 and 2001.
Deep melting and uncomplicated corneal ulcers are common in dogs. Only medical treatment is not effective in the therapy. There are numerous methods for the surgical management of corneal ulcers. We wanted to answer the next questions:
1. If the free island graft method effective enough in the healing of deep ulcers?
2. If the free graft remains vital after transplantation?
3. Is the graft able to integrate into the tissue of the cornea?
4. If the vision is affected after the complete healing?
Fifty canine eyes (of 49 dogs; 42 pure breed dogs, 7 mixed) with deep corneal ulcers were operated with the free conjunctival graft transplantation method during the examination period. Detailed physical eye examination were performed regularly in each dogs prior and after to surgery with slit lamp biomicroscope, applanation tonometer and indirect binocular ophthalmoscope. Propofol-isoflurane general anesthesia was created. Surgery was performed with help of an operating microscope and standard microsurgical instruments. The graft was freely dissected from the ventral palpebral conjunctiva and was sutured to the edge of the deep corneal ulcer with 8/0 Vicryl suture material. The eye was covered by a third eyelid flap for two weeks. Postoperative management was achieved with topical antibiotics and atropine and systemic nonsteroids.
49 of the 50 eyes (98%) could be restored, and only one was enucleated after a longer period of time of surgery. In 48 eyes (96%) the free island conjunctival graft has been vascularized completely at the time of the suture removal of the third eyelid flap. Two grafts has rejected and were no vascularization observed. In 42 of the 50 eyes (84%) there already were blood vessels in the cornea at the time of the surgery. The visual function was restored in 26 eyes of the 50 eyes (52%). There were no severe discharge or pain after surgery in any cases. The graft finally has completely integrated in the tissue of the cornea in 48 eyes (96%)and formed a pigmented opacity with ghost vessels at the site of the operation.
Free island conjunctival graft transplantation in the therapy of deep corneal ulcers is a highly effective method in dogs. Vascularization of the grafts is almost obligate (96%) and this is the fundamentals of this procedure. The preexisting blood vessels in the cornea help the vascularization of the transplanted grafts: in all of such eyes (42 of 42 eyes, 100 %) exhibited a complete and vital vascularization of the grafts. However, 6 eyes of the remaining 8 eyes without preexisting blood vessels in the cornea also exhibited a good vascularization of the transplanted grafts. Two eyes with graft rejection belonged to this group, so there were no vessels in the cornea prior to surgery in these two dogs.
We stated and answered the next:
1. The method is effective in the surgical management of every types of deep corneal ulcers
2. Free grafts remain vital and will be vascularized after surgery; the chance of the vascularization is better if there already are blood vessels in the cornea at the time of the surgery
3. The grafts are able to integrate completely into the tissue of the cornea in 6-18 months after surgery
4. The vision will be slightly impaired on the operated eyes, but it rather depends on the preexisting visual capability and other ocular conditions.