What is Lens Luxation?

The lens is a clear structure inside the eye. It helps focus light so your pet can see. Lens luxation means the lens has moved out of its normal place. This happens when the tiny fibers that hold the lens in place become weak or break. This is a serious eye problem because it can cause pain, inflammation, high eye pressure, and vision loss.

Why Does it Happen?

Lens luxation can happen for two main reasons.

Primary lens luxation: This means the pet was born with weak lens-support fibers. This is often inherited. Although it can happen in any dog, it is most common in certain dog breeds.

• Jack Russell Terrier
• Rat Terrier
• Bull Terrier
• Tibetan Terrier
• Chinese Crested
• Toy Fox Terrier
• Border Collie
• Australian Cattle Dog
• Welsh Terrier 

Secondary lens luxation: This means another eye problem damaged the lens supports. 

• Glaucoma
• Cataracts
• Long-term eye inflammation
• Eye trauma
• Cancer inside the eye
• Any advanced eye disease

What Makes Lens Luxation Dangerous?

If the lens slips forward, it can block fluid from draining out of the eye. This can cause glaucoma, which means the pressure inside the eye becomes too high. Glaucoma is painful and can cause blindness quickly. If the lens slips backward, it may be less urgent, but it still needs monitoring. It can still cause inflammation, pain, or future glaucoma.

Signs you may observe:

• Squinting
• Red eye
• Cloudy or blue-looking eye
• Tearing
• Rubbing or pawing at the eye
• Sudden vision trouble
• A pupil that looks odd or uneven
• A “shimmer” or “wobble” in the eye
• A large, firm, or bulging eye

Some pets hide eye pain well. They may still eat and act normally even when the eye hurts.

Diagnosis

Your veterinarian will examine the eye closely and may measure intraocular pressure, stain the eye to look for scratches or ulcers, or examine the inside of the eye with a special light.
Referral to an eye specialist is often recommended, especially if the eye still has vision.

Short-term Treatment

The first goal is to control pain, inflammation, and eye pressure, and may include:

• Eye pressure medication
• Anti-inflammatory eye drops
• Pain medication
• Medication to change pupil size, depending on where the lens is
• Emergency referral if the lens has moved forward. 

If the lens is forward and the eye can still see, this may be an eye emergency. Early surgery may offer the best chance of preserving vision.

Long-term Treatment

Long-term treatment depends on whether the eye can still see and whether the eye is comfortable, and may include:

• Regular eye pressure checks
• Long-term eye drops
• Monitoring the other eye, especially in breeds at risk
• Surgery to remove the lens
• Surgery to remove the eye if it is blind and painful

If one eye has primary lens luxation, the other eye may also be at risk. Your veterinarian or eye specialist may recommend preventive medication or regular exams for the other eye.

What if the Eye Is Already Blind?

If the eye is blind and painful, the kindest treatment may be the removal of the eye. This sounds scary, but pets usually do very well after eye removal. Most pets feel much better once the painful eye is gone.

What Should You Watch For at Home?

Call your veterinarian or an emergency clinic right away if you notice:

• Sudden squinting
• A red or cloudy eye
• Sudden vision loss
• A large or bulging eye
• Pawing or rubbing at the eye
• Your pet is acting quiet, painful, or not eating

Do not wait several days with a painful or cloudy eye. Eye problems can worsen quickly.

Prognosis 

The outlook depends on where the lens is, how long it has been out of place, whether glaucoma is present, and whether the eye can still see. If treated quickly, some pets can keep useful vision. If pressure stays high too long, vision may be lost. Even when vision cannot be saved, treatment can usually keep the pet comfortable.