The lens is the transparent structure within the eye that focuses light on the retina. It is a flattened sphere held in place by tiny ligaments around its circumference.

There are two main conditions affecting the lens, cataract formation and lens luxation.

Lens luxation

In some dogs, particularly the terrier breeds, the support ligaments weaken or break causing the lens to dislocate from its normal position. It can fall backwards into the eye, posterior luxation, where it rarely causes discomfort or can fall forwards, anterior luxation, where it blocks the drainage of fluid from the eye resulting in glaucoma or increased intra-ocular pressure. This is extremely painful and can cause permanent blindness.

Surgical removal of an anteriorly displaced lens is the only treatment. This surgery is usually performed by a veterinary ophthalmologist.

The surgery

Once the eye has been prepared for surgery, the dislocated lens is removed through a tiny incision clearing the cornea. The incision is closed with absorbable sutures that do not need to be removed. Additional sutures may be placed in the corner of the eye (the canthus) depending on your pet’s condition.

Post operative care

Your dog may be hospitalized for a few days after surgery for careful monitoring, treatment and rest. Once home, it is vital that your pet is kept as quiet as possible and not allowed to jump or to run up and down stairs. Short leash walks are the only exercise your pet can have for the first few weeks.

It is important to follow these directions carefully to ensure proper healing and reduce risk of complication. If you have any problems at all it is important that you call us without delay.

Vision

The aim of the surgery is to alleviate pain and restore vision as much as possible. If the lens has been dislocated for any length of time the chance of restoring vision is reduced. With prompt treatment, most cases have good vision post-operatively.

Complications

Complications can occur in some cases. One of the most common complications is persistent glaucoma (increased pressure within the eye). This complication can be difficult to successfully treat.

Another potential complication is retinal detachment. This is a condition where the retina is pulled off the back of the eye when the lens dislocated. These pets often remain blind but they are usually pain free following surgery.

Hereditary lens luxation

Weakness of the lens ligaments is known to be hereditary in the terrier breeds and also the Border Collie. It is important to watch for any signs of discomfort or change in appearance of the eye and call us immediately if you see any changes.

Partial lens luxation

Before the lens completely falls out of position, it can “wobble” as some of the ligaments begin to break. This is known as sub-luxation of the lens. Some veterinary ophthalmologists like to operate before the lens completely dislocates to avoid complications.

We will discuss the best approach to your pet’s condition based on examination and consultation with an ophthalmologist.

Posterior lens luxation

When the lens falls into the back of the eye it causes little or no discomfort. These cases may not require any treatment. The surgery to repair posterior luxation is technically very demanding and the risk of complication greater.

If your dog has a posterior luxation you will be asked to monitor it carefully and seek veterinary attention if there are any signs of discomfort or a change of appearance in the eye. This may indicate that the lens has fallen forward resulting in an anterior luxation. Surgery is often performed at this time.

If you have any questions, please do not hesitate to contact us.