Good morning, animal friends. My name is Len S. Lux, and I am the spokesdog for the Animal Lens Luxation Association (ALLA). Unfortunately, the spokespony could not be here today because he was a little hoarse, so I will do my best to cover his portion of the presentation.
Lens anatomy 101
First, what does a normal lens look like? Many of you may have seen something called a trampoline in your human’s backyard. Imagine that the solid part they jump on is the lens (i.e., the clear disc inside the eye that focuses light), and the springs that attach the circle of fabric to the frame are the zonules (i.e., fibers holding the lens in place). What happens if the springs break? The fabric circle is no longer attached to the trampoline frame. Similarly in the eye—when the zonules break, the lens partially slips out of place (i.e., lens subluxation) or falls out of place completely (i.e., lens luxation). If the lens lands in front of the iris, it’s an anterior lens luxation, and if it falls behind the iris, it’s a posterior lens luxation.
Demographics and causes of pets’ lens luxations
By now you may be thinking, “This doesn’t sound good. Could this happen to me?” Let’s take a closer look at why lens luxations occur and who is at risk.
- Primary lens luxation — In dogs such as myself—a terrific terrier—this type of lens luxation occurs because of a genetic weakness in the zonules, and is most common in 3- to 9-year-old terriers, Shar-peis, border collies, and German shepherd dogs. Typically, affected dogs will have lens luxations in both eyes, which may or may not happen at the same time. Cats, other than the occasional Siamese, rarely have primary lens luxations, and they have not been reported in horses.
- Secondary lens luxations — Eye trauma, hypermature cataracts, chronic glaucoma (i.e., high inner eye pressure), certain cancers, and ongoing eye inflammation (i.e., anterior uveitis) can all lead to zonule damage and eventual lens luxation in dogs. Horses are more likely to have lens luxations from equine recurrent uveitis and cats from anterior uveitis, but both can also be affected by the same causes as dogs.
Recognizing pet lens luxations
Remember that earlier we talked about the different kinds of lens luxations? Depending on where the lens lands, the only sign may be slight farsightedness, as with a posterior lens luxation, or you may have these more troublesome anterior lens luxation signs:
- Eye pain
- Squinting, or a desire to keep the eye closed
- Redness to the eye and conjunctiva
- Blue hazy appearance to the cornea
- Difficulting seeing, or blindness
- Excessive tearing
- Solid white structure visible in front of the iris
If you have any of these signs, alert your owner right away, and have them take you to Veterinary Vision Center. Anterior lens luxations are an emergency, and can lead to glaucoma and blindness, if not treated quickly and correctly.
Diagnosing pets’ lens luxations
Our Dr. Pierce will examine your eye with a handheld microscope to see if your lens is still in place and, if not, where it landed in your eye. To check for glaucoma, he will measure your eye pressure by putting some numbing drops in your eye, and then touching it with a little instrument. Sometimes he will do other tests to check your retina or other eye parts. The veterinary technicians will give you cuddles or scratches and do their best to make the exam as pleasant as possible, so you do not need to worry.
Treating lens luxations in pets
Lens luxations can be treated several different ways. If you have an anterior lens luxation and can still see, Dr. Pierce can surgically remove the rogue lens. This leaves you farsighted and sometimes carries a risk of glaucoma, anterior uveitis, or retinal detachment post-op, but is still the best option in many situations. He has done this to both of my eyes, and so far they are doing great. Permanently blind eyes with lens luxations are usually removed, because they are at risk for painful glaucoma and no longer useful. The good news is that you may become blind in one or both eyes, but many resources are available to help you navigate, so you can still have a great quality of life. Sometimes Dr. Pierce can turn an anterior into a posterior lens luxation by gently maneuvering the lens into the back of the eye, and then using medications to reduce inflammation, manage eye pressures, and keep the lens in the back of the eye. Unfortunately this maneuver, and posterior lens luxations in general, may carry the same risks as lens removal. Nonetheless, Dr. Pierce can be trusted to find the best plan for you.
Thank you for your kind attention, ladies and gentledogs. Remember to tell your owners to contact Veterinary Vision Center for all your vision needs, and feel free to ask me, your ALLA spokesdog, any questions. I am happy to share more about my lens luxation journey, and want to ensure you have the support you need.