Cataract

Cataract is a normal age related condition that causes a gradual cloudy or misty change to the lens of the eye. The lens is a clear transparent structure located behind the iris and the pupil. The clouding and misty change to the lens prevents light from reaching the retina, thus affecting vision. Cataract can occur in one eye but most people will eventually develop cataract in both eyes, however, one eye can be affected more than the other.

The word cataract actually means a large waterfall or sudden downpour of water, there is even a cataract river in Canada. The term cataract was originally used in relation to the eyes because, in the days before surgery was a viable option, the cataracts would into a milky white colour most commonly in a spoke like patter (as seen in the picture to the right) making it look to the naked eye like a waterfall. These types of cataracts are rarely seen in the UK as the cataract will be treated before they ever develop to the extent where they cause significant sight loss. In fact there is evidence to carry out cataract surgery earlier as, as the lens mists it becomes tougher and harder in nature and, therefore, more difficult to remove leading to a much riskier operation.

The symptoms of a cataract are simply that of slowly deteriorating vision. The vision can be hazy, dull and blurry, as if looking through a frosted window and the colours seen through the cataract can look washed out and pale. This will become very apparent when a patient has had one cataract operation and is waiting for the other eye to be done. Other symptoms can be problems with glare from the sun and from oncoming headlights when driving at night.

One of the main reasons for developing cataract is ageing. Everyone is bound to develop cataract in their life. The lens within the eye continues to grow throughout your lifetime. Because it is encapsulated within a closed organ, the eyeball, it cannot shed any dead or excess tissue, therefore, it grows in on itself creating a compacted centre of old tissue. #After many years of doing this there comes a point where the old tissue becomes so compacted that it starts to become opaque, causing a cataract. This point of misting occurs at different times in everybody so much so that there is no given age for developing a cataract but the average age is between 60 and 80 years of age. There are, however, some other causes that can induce cataract to develop earlier:

Systemic conditions such as diabetics can cause a person do develop cataract at an earlier age Medications such as steroids
Trauma to the eye or surgery for another condition
Inflammation of the eye
Excessive exposure to UV light without protection
Genetically inherited cataracts

The colour of the lens in early life

The colour of the lens after many years growth

The most common form of cataract is this Cuniform Cortical, spoke-like Cataract.

This image is that of an unusual cataract, it's name is very descriptive... "Christmas tree cataract", so name for it's glistening appearance much like the twinkling lights or tinsel of a Christmas tree.

Types of Cataract

Cataract changes can occur in different areas of the lens giving rise to very different types of cataract. The most common type is the cortical spoke like variety (seen above) but here are others. A Nodal cataract can be quite troublesome as it affects the very central vision with a very dense dot right in the centree of the lens.

Others are more unusual such as the "Christmas Tree" Cataract seen above. There is also a lamella cataract which forms a "Y" shape in the centre of the lens and a "Blue Dot" cataract which is indicative of an inherited condition where a child can be born with small blue dots scattered through the lens and a "Snowflake" Cataract with white spots throughout the lens is usually only found in those who suffer with diabetes.

Treatment

This image is that of an IOL implant lens that has been placed before the iris and pupil. This will have been done for a specific reason during the operation whereby the surgeon felt that placing the lens behind the eye would not have been successful or would cause further complications. It serves to illustrate the shape and size of the modern implants used in these operations.

Cataract surgery is a relatively simple procedure which normally takes about 15-20 minutes. It may take longer for complicated cases. The operation is done under local anaesthesia and in certain circumstances such as a physical or health complications, it can be done under general anaesthesia. This will all be determined prior to the date of the surgery where biotmetric measurements and general health assessments will be conducted at the hospital.

Before the surgery, a number of drops will be instilled to the eye: a dilating drop to enlarge the pupil, an anaesthetic to numb the eye and an antibiotic to prevent infections. The most common procedure done is called phacoemulsification. A small self-healing incision is made on the edge of the cornea. A small probe with a high ultrasound frequency is inserted into the incision, which then emulsifies or breaks up the cataract lens. The probe is then removed and another probe is used to vacuum and suck up the lens fragments, leaving an empty capsular bag behind. A folded up intraocular lens (IOL) is then implanted using a special injection probe and unfolds into the natural position of the previous lens. In the vast majoriy of cases no stiches are needed after the procedure and the vision is instantey better following the surgery.

Although steps are taken to calculate the implant lens power to be correct for your eye, there are inherent errors within the calculations. This means that glasses are still needed after the surgery, at least for reading vision, although the distance vision can improve significantly without glasses. However, they may still be needed for driving and TV, etc.

Cataract surgery currently is the most performed surgical intervention in the world. The procedures are very well researched and managed and complications occur in overall less than 2% of cases. It is a highly successful operation, however, as with all surgery complications are possible. The majority of these complications are minor and easily dealt with but more serious and rarer conditions can occur.

Post-capsular opacification is the most common complication of cataract surgery and can happen a couple of months to years following the procedure, but usually within 2 years. The capsular bag left behind during the procedure can become irritated and thicken causing blurring of vision and can feel another cataract. It is easily and quickly treated with a laser.
In about 1% of people the wound used to perform the operation can leak leading to a drop in pressure of the eye and possible dislodging of the intra-ocular lens implant. This is very unlikely to occur after the first 48 hours.
Corneal swelling occurs in about 10% of patients and usually settles within the first 48 hours. Corneal swelling will cause a misty or blurred vision.
A rise in eye pressure occurs in about 8% of patients within the first 48 hours, this can settle but if continues would be picked up in the routine post-operative check-ups an dealt with either eye drops or a further operation to relieve the eye pressure.
Macula swelling can occur and does in about 1% of cases. This is a fluid build up in the retina causing a blurred central vision. This condition can resolve of it’s our accord, however, eye drops can be prescribed to settle the swelling quicker.
Retinal detachment occurs in about 0.1% of cases but can be more of a risk in patients who are very short-sighted. Please see our retinal detachment information page for the symptoms of retinal detachment. This can be surgically repaired, however, rapid intervention is necessary for a full recovery.
Endophthalmitis is a very severe internal ocular infection that can lead to blindness. It is very rare, occurring in 0.1% of cases. Always be suspicious of a painful red and blurry eye. Seek advice if you are concerned.

We currently perform post-operative aftercare appointments for the Fylde Coast Cataract Service. Any concerns we have will be brought to the attention of the hospital eye service automatically, however, if you are at all concerned following your cataract surgery please fee free to contact us for advice, or alternatively you can contact the place of surgery.

Back to the top

If you are at all concerned please contact the practice so that one of our Optometrists can advise you of the best course of action. See the section on Emergency Eyecare for more information on how we can help.