Posterior Lens Luxation (PLL)
The lens is the clear structure inside the eye that allows the eye to focus. When the lens becomes unhealthy, it is called a cataract and looks white. The lens normally sits behind the iris (the coloured part of the eye). When the lens falls backward behind the iris, it is called a posterior lens luxation (PLL).
Consequences of PLL
Fluid that normally keeps the eye round is produced and drained at the same rate. When the lens falls backward, this fluid is allowed to filter out normally and pressure is usually maintained in the normal range. If the lens suddenly comes forward, it can blocks the fluid from leaving the eye, and the eye pressure quickly goes up. This is called glaucoma and can result in substantial pain and vision loss.
Clinical signs of PLL
Subtle and difficult to determine, may include:
Breed predisposition
Breeds that commonly develop PLL are Jack Russell Terriers, Australian Cattle Dogs, Fox Terriers and Bull Terriers. Many more breeds can develop anterior lens luxation.
Treatment for PLL
Long term medical management with a drop called a miotic (shrinks the size of the pupil) can help keep the lens behind the iris. Twice daily treatment is usually required. If the pupil is allowed to dilate the lens may come forward, resulting in anterior lens luxation and secondary glaucoma. This treatment will not work if the pupil is not physically capable of miosis (becoming small) for example due to age-related degeneration of the iris sphincter muscle.
Complications of PLL
Even with long term treatment, complications do occur and include:
Vision with PLL
Without a lens in place, dogs can still manage to navigate but close up focus (less than 75 cm) is poor. With a small pupil due to the drops, vision can also be reduced, especially in dim light.
Should you have any questions or concerns please contact us on 03 9545 0103.
The lens is the clear structure inside the eye that allows the eye to focus. When the lens becomes unhealthy, it is called a cataract and looks white. The lens normally sits behind the iris (the coloured part of the eye). When the lens falls backward behind the iris, it is called a posterior lens luxation (PLL).
Consequences of PLL
Fluid that normally keeps the eye round is produced and drained at the same rate. When the lens falls backward, this fluid is allowed to filter out normally and pressure is usually maintained in the normal range. If the lens suddenly comes forward, it can blocks the fluid from leaving the eye, and the eye pressure quickly goes up. This is called glaucoma and can result in substantial pain and vision loss.
Clinical signs of PLL
Subtle and difficult to determine, may include:
- Iris wobble
- Deeper anterior chamber
Breed predisposition
Breeds that commonly develop PLL are Jack Russell Terriers, Australian Cattle Dogs, Fox Terriers and Bull Terriers. Many more breeds can develop anterior lens luxation.
Treatment for PLL
Long term medical management with a drop called a miotic (shrinks the size of the pupil) can help keep the lens behind the iris. Twice daily treatment is usually required. If the pupil is allowed to dilate the lens may come forward, resulting in anterior lens luxation and secondary glaucoma. This treatment will not work if the pupil is not physically capable of miosis (becoming small) for example due to age-related degeneration of the iris sphincter muscle.
Complications of PLL
Even with long term treatment, complications do occur and include:
- Glaucoma (Elevated eye pressure)
- Uveitis (Inflammation in the eye)
- Hyphaema (Blood inside the eye)
- Retinal Detachment (Blindness)
- Corneal oedema (Cloudiness of the cornea)
Vision with PLL
Without a lens in place, dogs can still manage to navigate but close up focus (less than 75 cm) is poor. With a small pupil due to the drops, vision can also be reduced, especially in dim light.
Should you have any questions or concerns please contact us on 03 9545 0103.
