Surgical Management of Third Eyelid in Dogs

Dogs, in addition to their lower and upper eyelids, have a third eyelid, a nictitating membrane which acts as an additional layer of protection for the dog’s eye cornea. This membrane protects the cornea from debris and foreign substances and the associated gland also produces tears and lubricates the eye surface. This allows dogs to keep their eye lubricated and protected without blinking, something that is useful for predatory animals so they do not miss opportunities to harvest prey animals. This gland of the third eyelid is normally held in place with connective tissue, however, if the connective tissue weakens, or injury occurs, the gland and membrane of the third eyelid prolapses, or protrudes, making it susceptible to irritation from foreign matter and impairing lubrication of the eye surface, which further results in irritation and sometime infection. The resulting condition, called cherry eye, is not uncommon in dogs who then experience a swollen red eye projecting past the third eyelid. Surgical intervention to replace the third eyelid gland and correct prolapse is usually necessary, as even if the condition resolves on its own, it will generally recur without surgical correction. Other structural abnormalities of the cartilage can affect third eyelid functioning. Several surgical procedures are available to correct disorder of the third eyelid and can be performed by an ophthalmic veterinary surgeon under general anesthetic. 

Corticosteroids may be prescribed to reduce inflammation preoperatively, however as they can interfere with healing of tissues post surgery, their use varies depending on your dog's condition and your veterinarian's assessment prior to surgery. Prior to surgery for third eyelid disorder correction, you will be required to fast your dog from food. Anesthetic will be administered by sedating your dog, administering an intravenous anesthetic to put your dog into a deep sleep, and then an intubation tube will be inserted so that anesthetic can be maintained by gas for the ophthalmic procedure. The eyelid will be washed with a solution such as dilute povidone-iodine solution, and rinsed with sterile saline. The eyelids will then be retracted with an eyelid speculum to expose the area for the surgical procedure. Stay sutures or specialized forceps may be used to hold third eyelid structures in place.

A Morgan or pocket technique will involve your surgeon making elliptical incisions on the eyeball side of the third eyelid, both above and below the prolapsed gland, the conjunctiva tissue overlying the gland is excised and invaginated, which means turned back on itself, to form a pouch for the replacement of the gland and membrane. Once the third eyelid gland is replaced. the incision is then sutured.

Alternatively, methods to tack the membrane and gland in place can be used.

If third eyelid cartilage eversion is present, surgery is required to remove the deformed cartridge. In these cases, a vertical incision is made inside the third eyelid, the conjunctiva of the third eyelid cartilage is dissected along with connective tissue, a cut is made above the deformed cartilage. The third eyelid is then sutured across the cornea to the eyeball conjunctiva to prevent the third eyelid from tearing away from the eyeball; these sutures will be removed later, in 10 to 14 days when healing has occurred.

The Morgan or pocket technique allows the third eyelid to move post operatively. Tacking techniques restrict postoperative movement, which may result in decreased protection of the cornea post operatively. Recurrence rates for the Morgan technique are relatively low and complications are minimal.

Recurrence in large dogs after surgery is possible. This can be minimized by oversewing the closure and ensuring cartilage is not deformed. If prolapse occurs again, the pocket procedure can be repeated, and accompanied by tacking procedures. Surgical management of third eyelid in dogs relieves pain and discomfort associated with third eyelid disorders and generally experiences a good success rate.

Ophthalmic antibiotic to be instilled in your dog's eye; three to four times per day for 14 days post-surgery is usually prescribed. Oral anti-inflammatories may also be prescribed in some cases. Topical steroids will be avoided as they may interfere with healing. If your dog interferes with their eye, they may need to use an Elizabethan collar to prevent this after surgery, or bandages can be used on paws to prevent scratching. If procedures using non-absorbable sutures are used, they will need to be removed in 10 to 14 days. Some veterinarians recommend they check the eye 24 hours post-surgery to ensure medication is being administered correctly and to check the condition of the eye. The eye will remain swollen for several days post-surgery, but will usually decrease several days after surgery. Occasionally, swelling persists for several weeks. If you have concerns, address with your veterinarian, however, residual swelling in not uncommon. Your dog should receive regular checkups annually or semi-annually to monitor the condition of their eye throughout their life after replacement of the third eyelid gland.

The cost of surgical third eyelid procedures in dogs ranges from $250 to $2,500 per eye depending on cost of living, accessibility of a specialist, and complexity of your dog’s optical condition.

It is important not to damage the prolapsed gland during surgical management, as it is responsible for a significant amount of your dog’s tear production and damage can cause dry eyes and expose your dog to other medical issues associated with their eyes later on.

Cherry eye may be accompanied with cartilage abnormalities that also need addressing to prevent recurrence of the condition. 

Wound dehiscence, infection, and recurrence of prolapse are complications that may occur with surgery of your dog’s third eyelid and need to be addressed if they occur.

As third eyelid disorders are generally associated with breed predispositions, ensuring that you obtain your dog from a certified breeder, who has addressed reducing the incidence of these conditions in their breeding program, will help reduce incidence of occurrence. Surgical management obtained at an early stage in prolapse development or protrusion before damage to tissues and other complications occur, will increase the success of surgical management and decrease recurrence of the condition.