A Pterygium (plural pterygia) is a common disorder of the surface of the eye. A wedge shaped area of abnormal tissue grows from the conjunctiva (the white of the eye) across the cornea (the glassy front surface of the eye). They may arise from the inner and/or the outer aspect of the eye, though inner is much more common. One of both eyes may be affected and they are often asymmetric. The incidence of pterygia is increased with excessive UV exposure, so they are very common in Australia (approximately 1%).
Small pterygia often cause no symptoms and need no treatment. As the pterygium grows it may become red, inflamed and irritated. Cosmetic concerns are common, and soreness and dryness tends to gradually get worse. Larger pterygia may cause progressive astigmatism (distortion of the shape of the cornea) and a need for glasses. Eventually the pterygium may grow big enough to obscure the central part of the cornea which may have a severe impact on vision.
Small asymptomatic pterygia are common and do not need treatment. There is no treatment that will slow down or reverse the progression of a pterygium, though minimising UV exposure with regular sun glass use is recommended. Gentle lubricant tear drops will often help with the irritation, as will avoiding excessive dryness and wind. Some people will try decongestant drops to reduce the redness and irritation such as Naphcon, Visine or Albalon. While these drops may give good short term relief and mask the redness, long term use is not recommended. With regular use your eye becomes more dependant on the drops. These drops are fairly old and the preservatives in them can be quite toxic with regular use. Trying to stop them results in “rebound” redness, where the symptoms become worse than they were before starting treatment due to dependance on the medication developing. Occasional use to treat flare ups of redness is fine, but I do not recommend regular use of these drops.
Once symptoms of irritation and soreness, cosmetic concerns about redness and especially declining vision become significant it is worth considering removal of the pterygium. Surgical removal of a pterygium is usually optional and non-urgent, but if it is growing towards the centre of the cornea and vision is becoming noticeably affected then I would usually recommend removal sooner rather than later. Once the pterygium grows across the visual axis then even successful removal may leave a car which means normal vision is never restored.
Surgery for pterygia has developed a bad reputation, as previously the results were not that good and post-operative pain was common. That is no longer the case. Modern micro-surgical techniques means much less post-operative discomfort and excellent cosmetic outcomes.
If the pterygium is simply removed there is as much as a 40% chance of it growing back - obviously much too high. Previously removal was supplemented with toxic medication or radiotherapy. While these could be effective at reducing the recurrence rate the complications could be severe and they are not usually used anymore. The standard way of reducing recurrence rates now is with a conjunctival graft. A healthy piece of the white of the eye from behind the top lid where there has been no sun damage is sutured over the bed of the pterygium after it has been removed. It is held in place with dissolvable sutures 3 times finer than a human hair and reduces the recurrence rate to 1% or less. It also significantly reduces post-operative discomfort and gives an excellent cosmetic outcome.
Inflammation of the eye is like petrol on a fire for pterygia, and significantly increases the risk of recurrence. Because of this it is important to use steroid eye drops for a significant period of time after surgery - I recommend 8 weeks. In some cases I may also prescribe an anti-inflammatory tablet to help during healing.
Because pterygia are associated with UV damage there is a risk of pre-cancerous or even cancerous change in a pterygium. There is also the rare possibility that what appears to be a pterygium may in fact be something more dangerous. Because of this all excised pterygia are sent for pathological examination. If this microscopic examination reveals any more serious problems then further treatment may be needed.
The majority of pterygium surgery is successful and the outcomes are usually very good. Most cases result in excellent cosmetic appearance and recurrence is rare. If the pterygium has caused astigmatism (distortion) and reduced your vision in most cases you can expect a return to normal vision. If the pterygium has been left too long it is possible that residual scarring may mean you do not get as good a final result.
If there is co-existing pre-cancerous change in the excised pterygium then the simple act of removing the pterygium will often cure this. In some cases further treatment such as with chemotherapy eye drops may be advised.
Every surgery has a risk of complications. Because pterygium surgery is only on the surface of the eye these risks are thankfully low. The most common complication is persisting redness over the site of the original pterygium. This is uncommon, and generally reduces over time. Recurrence of the pterygium is possible, even with conjunctival grafting, but in straightforward cases is only about 1%. Significant inflammation of the eye may increase the risk of recurrence. Most recurrences are small and do not need treatment, but a large recurrence may need re-excision. Much rarer but serious complications of pterygium surgery include reduced vision due to scarring of the central cornea and persisting double vision due to damage to one of the muscles that moves the eye. The larger the pterygium the higher these risks become.
What to expect after surgery
The bigger the pterygium the bigger the operation to remove it so the worse your eye will look and feel. Most small to moderate pterygium surgeries should expect red gritty eyes for 2 weeks or so. Significant pain is nowadays thankfully uncommon. Most people will have surgery on a Thursday and can expect to be back at work that Monday. Antibiotic eye drops are used for 1 week and steroid eye drops for 8 weeks. You should expect your eye to be quite red for 2 weeks following surgery, but in some cases the redness can last a few months.
You will leave the hospital with a patch over your eye which will stay on that night. You will have an appointment with me the next morning and then 1 month later. A final review after 12 months is advisable. 98% of recurrences occur in the first 12 months so if everything looks good after 12 months there is an excellent chance that the pterygium has been permanently cured.
Pterygia are common in Australians due to our high sun exposure. Small pterygia with minimal symptoms are usually best left alone. If a pterygium is causing significant symptoms of redness, irritation and/or blurred vision then surgical removal is usually simple and effective. On the one hand there is no need to treat a pterygium which is not causing any problems, but on the other hand if one is growing and causing symptoms it is usually best to seek advice about treatment before it gets worse. A pterygium which is changing, growing or of unusual appearance should always be examined by an ophthalmologist or optometrist.