Cataract
Cataract means opacification of the natural intraocular lens. Cataract is observed in most of the animal species as well as companion birds; but Dogs are the most prone to cataract formation.
There are many reasons for cataract formation in animals:
Inherited juvenile cataracts
which are seen mainly in young animals and both eyes have cataracts (Age: 1-6yrs).
Senile cataracts
Unlike people, old age cataracts are not normal phenomena in dogs but it does happen in occasional patients (Age: more than 12yrs).
Traumatic cataracts
are caused due to penetrating or blunt injury.
Inflammatory cataracts
Long term intraocular inflammation can lead to cataract formation.
Toxic cataracts
These types of cataracts are observed when the dying retina (progressive retinal atrophy) releases toxins which lead to cataract formation.
Nutritional cataracts
Nutritional deficiency in the early stages of life can cause cataracts.
Diabetic cataracts
Dogs are prone to developing cataracts because of Diabetes Mellitus. Such cataracts can develop overnight and are caused due to sugar seeping into the natural lens which attracts water. This type of cataract tends to cause the lens to swell up and can even rupture if the capsule of the lens is stretched too much. If the lens material leaks out, it leads to severe intraocular inflammation and can even lead to loss of the eye. Such cataracts need urgent surgical correction. Success rate is very good in these cases if the surgery is done early enough.
which are seen mainly in young animals and both eyes have cataracts (Age: 1-6yrs).
Unlike people, old age cataracts are not normal phenomena in dogs but it does happen in occasional patients (Age: more than 12yrs).
are caused due to penetrating or blunt injury.
Dogs are prone to developing cataracts because of Diabetes Mellitus. Such cataracts can develop overnight and are caused due to sugar seeping into the natural lens which attracts water. This type of cataract tends to cause the lens to swell up and can even rupture if the capsule of the lens is stretched too much. If the lens material leaks out, it leads to severe intraocular inflammation and can even lead to loss of the eye. Such cataracts need urgent surgical correction. Success rate is very good in these cases if the surgery is done early enough.
Long term intraocular inflammation can lead to cataract formation.
These types of cataracts are observed when the dying retina (progressive retinal atrophy) releases toxins which lead to cataract formation.
Nutritional deficiency in the early stages of life can cause cataracts.
Treatment
Cataract surgery is a proven, tried and tested treatment for cataracts. With the latest technology and careful selection of the cases, the success rate goes as high as 95%. It is a day procedure, you bring your pet empty stomach to the clinic. Though the actual surgery time is only 10-20 minutes per eye, there is a lot of pre and post operative preparation involved. So the pet will be in the clinic almost the whole day.
A preoperative ERG (electro-retinogram) and an ocular ultrasound will be performed before the surgery to make sure that the retina is in good health. These tests take around 1 hour.
Cataract surgery is done through a very small 2.8mm incision with a phacoemulsification technique. In this technique, a specialised needle is passed inside the eye to break the lens into small pieces and is sucked out simultaneously through the same needle. After the cataractous lens is removed, a new foldable intraocular lens is injected through the same small incision. The incision is sutured with a very fine suture material.
Postoperative care
You are going to go home with a lot of eyedrops and medications. The first week after the surgery is the most important week post op. During this week, some of the eyedrops will have to be instilled four times daily.
After the first week, the frequency of the drops will be reduced after a careful examination and if everything is on the right tract.
The eyedrops will continue for a month and some drops will continue for life (if needed)
Vision after the cataract surgery
If the intraocular lens is placed in the eye during the surgery, vision is perfect from day one.
Sometimes if the original lens is unstable, we cannot place a new lens in, as it increases chances of complications after the surgery. Eg. Luxation of the new intraocular lens in the eye which means another surgery to remove the lens.
Pets without a new intraocular lens do fine. They can see medium to big objects and can live their life to the fullest. These patients take about a week to adjust to their new vision.
Possible Complications
Any intraocular surgery can have certain complications which we expect and hence postoperatively we treat the operated eye with different medications targeting those conditions.
1. Uveitis Intraocular inflammation: When the eye is surgically entered to remove the cataract, it leads to inflammation inside of the eye. This happens with each eye operated for cataract surgery and hence we will be treating the eye with a few anti-inflammatory eyedrops as well as systemic anti-inflammatory medications.
2. Glaucoma: increased intraocular pressure. This is a common postoperative complication; hence we measure the pressure upto 4 hours after the surgery and next day. Each post-operative check will involve an intraocular pressure check. The patient will be sent home with antiglaucoma eye drops.
3. Corneal ulceration: wound on the cornea. Sometimes the cornea gets ulcerated after the procedure. This can be treated very effectively if diagnosed early.
4. Wound dehiscence: corneal surgical wound breaking down. Corneal surgical site is sutured with very thin suture material with only one stitch. This wound heals within 5-7 days and we need to be very careful to protect this wound.
5. Intraocular lens dislocation: Artificial lens can dislocate into the front of the eye, if the patient shakes it’s head vigorously in the immediate post-operative period.
Though the above complications are rare, it is important that the owners are aware of it, so that they can inform us in case they notice something important at home.