Lens Luxation In Dogs

Dislocation or luxation of the lens is the movement of the lens of the eye from its normal position into the posterior or anterior chamber.

In some dogs, the suspensory ligaments and zonules of the lens break or weaken causing the lens to dislocate from its normal position. It can fall forwards into the eye, in front of the iris called an anterior luxation, where it blocks the drainage of fluid from the eye resulting in increased intraocular pressure (IOP) or glaucoma. The lens may also fall backward into the eye known as a posterior luxation, it rarely causes discomfort.

This is extremely painful, blinding, and affects both eyes, although not necessarily at the same time. Lens luxation is often secondary to other conditions such as glaucoma, uveitis, cancer of the eye, trauma, or in rare cases, the improper use of medications, such as atropine.

• Sudden change in shape and size of the pupil
• Pain while squinting or holding the eyes closed
• Increased tears
• Inflammation of the eyes, redness
• Cloudiness or haziness to the cornea
• Reluctance to exercise
• Visual impairment or loss

Lens luxation treatment is determined by the degree of luxation of the lens inside the eyes. The objective is to lower the pressure inside the eyes, to also see if glaucoma is present, and evaluate the restoration of vision after surgery.

Lens luxation that caused irreversible loss of vision is not suitable for lens removal.

Anterior lens luxation: Medical management alone is ineffective at controlling high eye pressures. Without the removal of the lens, the eyes will irreversibly lose their vision blind, and extremely painful.

If surgery cannot be carried out, the pupil can be widened medically and the lens is pushed into the back of the eye or removal of the eye (enucleation) to provide relief from pain will be the options

Posterior lens luxation: Long-termmedications such as eye drops may be prescribed to help prevent the lens from shifting forward.

Subluxated lenses:These can be removed through large incision surgery (just like fully luxated lenses) or through a procedure called ‘phacoemulsification’ (similar way as cataracts are removed)

• Gently washing the eyelids using baby shampoo and/or applying warm compresses to the eyes can help discharge the oil in the tear glands.
• After surgery, most pets will take a little time to adapt to the new vision (they can cope very well without a lens). Remember, dogs without lenses can still able to steer well through barriers, and most of them can still chase a ball.
• The initial healing period in dogs following lens surgery is approximately 2 weeks. All through that period, make your dog wear a cone or other protection and have their movement limited to leash walks only.

In cases of primary lens luxation, prevention is possible.  When the earliest signs of subluxation are detected, the lens may be surgically removed before the first eye is completely affected.

Unstable lens management or removal provides the best possibility of long-term success.

Moreover, it may be possible to perform the surgery in these cases using specialized equipment for operating through a smaller incision; this, in turn, gives a better prognosis.

Terrier Dog Breeds, Brittany Spaniel, Parson Russell Terrier, Jack Russell Terrier, Miniature Bull Terrier, Bull Terrier, Patterdale Terrier, Sealyham Terrier, Fox Terrier, Toy Fox Terrier, Rat Terrier

Causes:

Hereditary or primary lens luxation:

• Inherited weakness or degeneration of the lens zonules
• Most commonly occurs in terrier breeds of dogs
• Typically affects between 3-6 years of age.
• Both eyes are at risk for luxation of the lens.

Acquired or secondary lens luxation:

• This happens when an underlying disease process inside the eye damages the zonules.
• Glaucoma, cataracts, intraocular tumor, trauma, and chronic inflammation inside the eye (uveitis)

Morbidity:

This is awfully painful and can cause permanent blindness.

Mortality:

There is no documented mortality due to this condition

Diagnosis:

• Tonometer
• Corneal stain to eliminate corneal ulcer
• Ocular ultrasound
• ERG or Electroretinogram to check the dog’s vision

Prognosis:

The surgical removal of luxated lenses offers a good prognosis provided the eye is monitored closely for proper healing.

After lens removal, vision in the eyes will be hyperopia (farsighted). They will have a good up-close vision but sometimes blurred (similar to humans, for them, it is corrected by using glasses to read a book). Typically, hyperopia is not a hindrance in everyday activities in dogs.

The two most common potential, vision-threatening complications after surgery are retinal detachment and glaucoma.

Intraocular pressures should be monitored carefully in every vet checkup, as the susceptible breeds of dogs with congenital (primary) lens luxation are also prone to primary glaucoma.

The periodic examination is important for eyes with lens subluxation (movable yet still attached lenses). Watch out for signs of lens shifting in your periodic visits.

Contact your vet right away, if you notice any of the following:

• If your dog blinks excessively or the eyes look painful and red continuously
• Sudden change in shape and size of the pupil

The diet should be included foods containing vitamins A, C, omega-3 fatty acids, anthocyanins, carotenoids, beta-carotene, lycopene, glutathione, phytonutrients—and the special partnership of zeaxanthin and lutein( sunscreen for eyes)

• Pick seafood over the usual beef and chicken.
• Omega-3 oily fishes such as salmon, tuna, cod, etc.
• Leafy greens such as spinach, kale, watercress etc
• Nonmeat/plant protein sources such as nuts, Lentils, Beans, Eggs, etc.
• Citrus fruits or juices.
• Sweet potatoes, tomatoes, pumpkin
• Pork, tuna, Oysters.
• Blueberries, Broccoli, cabbage, carrots

The chance of a successful prognosis depends in part on the existence of the duration of the underlying problem prior to the presentation of symptoms. Unfortunately, post-surgery blinding complications do occur depending upon the duration of the problem and the condition of the eye at the time of surgery.

After the initial treatment, monthly checkups are recommended and intraocular pressure has to be closely monitored. Eye medications have to be administered according to the vet’s instructions.