Thyroid eye disease in Malaysian and Southeast Asian patients: what the local studies show about smoking, lower eyelid retraction and how it looks

Most of what is written about thyroid eye disease comes from Western patients. In Malay it is "penyakit mata tiroid", or "mata terkeluar" when the eyes look pushed forward, and people who search for it here often land on pages that describe someone else's face. Local studies do exist. This piece reads two of them, a Malaysian study from 2008 and a Singapore series from 2015, alongside the national Malaysian guideline, and says what they can and cannot tell you.

Both studies are small and old, and they describe averages across groups. They cannot tell you what your own two eyes are doing.

How common is thyroid eye disease in Malaysian patients with Graves disease?

About one in three, in the main Malaysian study. Graves disease is an overactive thyroid caused by the immune system, and thyroid eye disease is the same immune process reaching the muscles and fat behind the eye. In 2008 Lim and colleagues examined 167 consecutive patients with Graves disease at two endocrine clinics, all seen by a single examiner. Using American Academy of Ophthalmology criteria, 34.7 per cent had thyroid eye disease.

Earlier reports had suggested the disease was less common in Asian populations. This study found a rate close to what is reported in Caucasian patients, and the Malaysian guideline, issued in 2019 by the Malaysian Endocrine and Metabolic Society with the Ministry of Health, quotes the same figure and gives 25 to 50 per cent for Caucasians. The National Eye Institute in the United States puts it at about 1 in 3 people with Graves disease.

One caution. These were patients attending endocrine clinics, so the figure describes people with Graves disease who are already under care, not the whole population.

Does it look the same in Malay, Chinese and Indian patients?

Not in every detail, but the studies are too small to turn into rules. In the Malaysian study the rate was higher than expected in Chinese patients, but the difference was not statistically significant, which means it could easily be chance.

The Singapore series reviewed the records of 174 patients seen over ten years at a multidisciplinary thyroid eye clinic. It was 80.5 per cent Chinese, 10.3 per cent Malay and 6.3 per cent Indian, which works out to about 18 Malay and 11 Indian patients. The mean reading on the exophthalmometer, the instrument that measures in millimetres how far the eye sits forward, was 18.8 mm, and Malay patients had the highest reading.

The authors also report that mean readings, upper eyelid retraction and lid swelling were lower in their East Asian patients than in Caucasian patients. Because most of the series was Chinese, it speaks mainly for East Asian patients. It says little about any one person, and I would never tell a reader that their eyes look "normal for an Asian". The disease is judged against your own baseline, not a population average.

What is lower eyelid retraction, and why did the Malaysian study count it?

Lower eyelid retraction means the lower lid sits lower than it should, so a strip of white shows between the coloured part of the eye (the iris) and the lid. The Malaysian authors counted it because it was common: it was present in 60 per cent of patients who had other signs of the disease.

Counting it changed the result. Adding lower lid retraction as an alternative criterion raised the prevalence from 34.7 to 46.7 per cent. The authors proposed that in Chinese, Malay and Indian patients it should count as a diagnostic criterion. That is their proposal from one study, not a settled rule. The most common sign in their patients was exophthalmos, which is the eye pushed forward, followed by lid retraction.

The Malaysian guideline lists eyelids that look abnormally wide, upper or lower, among the points that favour the diagnosis. The eyelid changes are covered in thyroid eye disease: signs and treatment.

A white strip below the iris on its own is not a diagnosis. Some people have always had it. What matters is whether it is new, and whether it arrived with a thyroid problem.

What should I look for in an old photograph?

Compare a photograph from a year or two ago with a recent one taken in similar light, looking straight at the camera. You are checking for change, not for a feature. The guideline lists changes that favour the diagnosis: eyelids that look abnormally wide, new bags in the upper or lower lid, or a change in how the eyes and lids look, especially a bulge forward.

Early symptoms in the same guideline are redness of the eyes or lids, swelling or a feeling of fullness in the upper lids, and pain in or behind the eyes. A wide-open look, sometimes called a thyroid stare, is on the list too.

If the two sides do not match, that is common and has its own explanation in why one eye looks different. A photograph is a reason to book an examination, not a way to make the diagnosis at home.

Does smoking really make thyroid eye disease worse?

Yes. In the Malaysian study, smokers with Graves disease had 2.75 times the risk of thyroid eye disease compared with non-smokers, and the national guideline gives it as an odds ratio of 2.754. Smoking was recorded at the time of the Graves diagnosis.

Male sex looked like a risk on a simple comparison but not once other factors were accounted for. That matters here, because 79 per cent of the men in the study smoked, so smoking and sex are hard to pull apart. The guideline also lists unstable thyroid function, especially hypothyroidism, as a risk.

The European guideline (EUGOGO, 2021) goes further. It says smokers have more severe disease, that progression after radioactive iodine treatment is more frequent in smokers, and that smokers have a delayed or worse outcome from immunosuppressive treatments. It says quitting is possibly associated with a better outcome. The Malaysian guideline advises avoiding cigarette smoke, active or passive, and urges every patient with Graves disease to stop smoking.

I would not turn that into blame. If you smoke, tell the doctor managing your thyroid, and ask what support to stop is available to you. That is the one part of this condition you can change yourself.

What did the Singapore series find about lashes turning in?

It found that lashes rubbing the eye were a real problem. Acquired epiblepharon, a fold of skin and muscle that pushes the lower lid lashes up and in toward the eye, was recorded in 11.5 per cent of patients, and corneal erosion in 29.3 per cent. A corneal erosion is a scratch on the clear front window of the eye. The authors concluded that corneal erosion secondary to acquired epiblepharon is a common sign in East Asian patients with thyroid eye disease.

Epiblepharon is most familiar in children, where it is present from birth and often improves as the face grows. AAPOS, the paediatric eye society, describes lashes pointing toward the eyeball and rubbing it, with redness, tearing, irritation and light sensitivity. Little Eyes 101 covers the children's version in lashes turning in (epiblepharon). In adults a different mechanism can give the same rubbing, described in entropion, the inward-turning eyelid.

The same series shows how varied the disease is. Mild disease was 71.3 per cent, moderate 20.7 per cent and severe 8.0 per cent. Eight patients (4.6 per cent) had dysthyroid optic neuropathy, where the optic nerve is squeezed by swollen tissue and vision is at risk. A dry or scratched surface that will not settle is covered in eyes that will not close.

Who should look at my eyes, and how soon?

The doctor managing your thyroid, and an eye doctor if anything above applies. In Malaysia that is often an endocrinologist, a doctor who specialises in glands and hormones. The national guideline says all cases except mild ones should be referred to specialised care, and so should any case where the diagnosis is doubtful.

It asks for urgent referral if the disease may threaten sight: unexplained deterioration of vision, a change in the quality or intensity of colour vision, an eye that has slipped forward past the lids, a cloudy cornea, an eyelid that cannot close, or a swollen optic disc. These are the reasons not to wait for the next routine appointment.

The guideline also asks for normal thyroid levels to be restored as soon as possible, and avoiding hypothyroidism. It describes the natural history as a rapid worsening followed by gradual improvement toward baseline, sometimes with residual signs. The National Eye Institute says symptoms usually last 1 to 2 years and often go away on their own. How active the disease is decides the treatment, which is covered in steroids and controlling disease activity. The wider background is in the guide to what makes eyes look tired, and the other orbital conditions are under orbit and thyroid eye disease.