Cataract is the leading cause of blindness, especially in senior dogs. Once a cataract has developed, no eye drops or medication can reverse it. Thankfully, surgery can remove cataracts and help blind dogs see again.
what is a cataract?
The lens is a clear structure inside the eye that focuses light and images on the retina. It is made up of clear protein surrounded by a very thin and elastic capsule. A cataract is an opacity or cloudiness that forms within the lens.
Very small cataracts would not affect vision too much. However, as the cataract progresses, it can cause uveitis (inflammation in the eye), retina damage or glaucoma, leading to permanent blindness. Signs of uveitis include increased eye redness, squinting, excessive tearing and light sensitivity.
WHAT IS NOT A CATARACT?
Senile Nuclear Sclerosis is commonly seen in dogs 7 years and older. Lens fibers are continuously being produced. As older fibers are compressed in the nucleus, the lens take on a bluish-grey hue. No treatment is required as light can pass through a sclerotic lens. The cloudiness does not impair vision.
“We adopted Nala 6 months ago. Because of her cataracts, she knocks into things, especially white walls or chairs, and when she gets excited playing ball.” ~ Rachel Tan
What Causes Cataracts?
When cataracts occur in younger dogs (less than 6 years of age), it is usually hereditary. Cataracts can also develop from:
- diabetes: early detection and surgery is especially important with diabetic cataracts which can progress rapidly
- old age
- nutritional deficiencies
“My mom insisted on Nala having cataract surgery. It is costly. But knowing Nala will regain her vision is more important to my family. My mom, sis and I saved over 6 months for this surgery.”
Preparing The Eye For Cataract Surgery
Under general anaesthesia, the eyeball usually rolls back into the socket, making it inaccessible to the surgeon. An intravenous nerve block is administered which makes the eyeball rotate to the centre.
Staining The Lens Before Phacoemulsification
A small corneal incision is made to gain entry into the eye and a blue dye injected to stain the lens to make it clearly visible. Then a small window is created in the lens capsule through which the cataract is broken apart and removed via a procedure called phacoemulsification.
Inserting The Intraocular Lens (IOL)
Once the cloudy lens material is removed, the capsule is cleaned and polished. An artificial replacement lens is then inserted into the lens capsule. This will improve the vision of the patient tremendously.
Suturing The Corneal Incision
After the corneal incision is closed up with absorbable sutures, the patient is monitored closely as she recovers from anaesthesia. Post-operative eye medications are administered. Intraocular pressure (IOP) is measured at regular intervals to ensure it is within normal range.
how do i Care for my pet after surgery?
Vision usually improves within 24 hours and continues to improve over several weeks. Your pet will require the following:
- oral medication
- medicated eye drops
- an Elizabethan collar to prevent self-trauma to eyes
- re-examination of the eyes within 1 to 5 days, then 1 week after surgery, and again 2 weeks after surgery. Thereafter, the schedule for reviews is determined by the vet and progress of your dog’s recovery.
“When Nala got home last night, she started barking at everyone, probably because she has never seen us & our house before. We comforted her with our voices which she is familiar with. Today, she is much calmer.” ~ Rachel
No matter what our pets are living with, Dr Stanley says it beautifully: “We humans may feel sorry for ourselves. These animals, they just make the best of every situation.” But what a wonderful gift it is, to be able to help the blind see again!
Dr Heng Yee Ling, Mount Pleasant Animal Medical Centre (Farrer), graduated from the University of Edinburgh. During the course of her studies, she realised her interests in soft tissue surgery and in particular, veterinary ophthalmology. In 1997, she completed the Post Graduate Foundation Course in Veterinary Ophthalmology and has been performing cataract surgery for the past 3 years.
Dr Robin Stanley graduated with first class Honours from the University of Melbourne in 1984. He undertook an ophthalmology residency from 1987 to 1989, and in 1990, obtained his Fellowship of the Australian College of Veterinary Scientists in the field of ophthalmology. Dr Stanley is registered as a veterinary eye specialist and works in a dedicated ophthalmology-only practice in Melbourne. He consults and performs eye surgeries at Mount Pleasant Animal Medical Centre (Farrer) every quarter. Contact 6271 1132 for more info.