WHAT IS THE LENS?
The lens is a highly transparent structure in the eye that focuses light rays entering the eye onto the retina to create an image. It lies immediately behind the pupil and is held in place by zonular fibers.
WHAT IS LUXATION OR SUBLUXATION OF THE LENS?
Rupture of the zonular fibers results in partial (subluxation) or complete (luxation) dislocation of the lens. The lens can then be positioned in the front part of the eye (anterior chamber) or in the back part of the eye (posterior segment).
WHAT ARE THE CLINICAL SIGNS AND HOW IS IT DIAGNOSED?
You will notice discomfort in the affected eye.Â Signs of discomfort are: squinting, tearing, rubbing or pawing at the eye. A veterinary ophthalmologist can determine the exact position of the lens using a slitlamp.
WHAT CAUSES A LENS LUXATION OR SUBLUXATION?
Lens luxation can be primary, due to an inherited weakness in the zonular fibers. Terrier breeds are especially predisposed. Spontaneous luxation of the lens in these cases occurs in early adulthood and often affects both eyes, although not necessarily at the same time. Lens luxation can also occur secondary to other diseases of the eye, such as inflammation, glaucoma, cataracts, neoplasia, or trauma.
WHAT IS THE TREATMENT OF A LENS LUXATION?
This condition is usually very painful and can lead to secondary problems within the eye, such as glaucoma. Glaucoma can lead to permanent blindness. In cases of anterior lens luxation a surgery is recommended to remove the lens in order to prevent further problems. A general anesthesia is necessary. If no secondary problems occur, your pet will have far-sighted vision in the affected eye. Posterior luxations may be treated with medications to constrict the pupil, trapping the lens in the back of the eye where it is less likely to cause a problem. If the eye is already suffering from severe inflammation or glaucoma, eye removal or a procedure to place a prosthetic eye may be recommended to provide comfort.