An eye test can save your life

Modern medicine works by finding evidence to support one or more differential diagnosis at a particular point in time. Sometimes the evidence can come from seemingly unrelated parts of our body. The eye is unique in being the only organ in our body that allows a direct visualisation of its nerve and blood vessels. This offers a peephole view of the state of our health. As such, an eye test is a golden opportunity not to be missed, to gauge our overall physical wellbeing.

Starting from the eyelid and the internal content of the eyeball, all the way to the layers of its walls as well as the six muscles responsible for eye movements, all are closely connected to the rest of our body via their blood supply and innervations. One could say the eye is the “crystal ball” that can foretell our health, providing early clues that should be acted on with appropriate follow-up tests and actions, not just for sight, but also for life-preservation. Several recent examples come to my mind.

First is a very fit patient who had a persistent blurring of vision when reading in one eye and no obvious general health issues. I made a diagnosis of macula swelling secondary to blockage of a branch retina vein at the back of the eye, supported by a thorough eye examination and eye scans. Treatment with eye injections and laser was successful in restoring eyesight. Closing the case after eyesight restoration would be like missing the forest for the trees, as it is usually the underlying cardiovascular health that is the root cause of the eye disease. In fact, in a 2016 meta-analysis endorsed by the American Heart Association and American Stroke association, blockage of the retina vein was found to be associated with a 120 per cent to 450 per cent increase in the risk of stroke, depending on age.

The bigger picture

Recognising the possible bigger picture from a single problem of blurring of eyesight can indeed prompt health-seeking behaviour and ultimately save your life. In fact, my patient is contemplating a career switch from a very stressful job that is felt to be contributing to episodic blood pressure spikes, which almost certainly caused the vein occlusion in the eye.

Another is a patient with a complex intraocular lens problem who also suffered from intractable diabetes and severe diabetic eye disease. A previous cataract surgery in a neighbouring country many years ago could not stand the test of time and the inserted artificial lens implant had become wobbly, to the point of causing terrible visual distortions with every movement. After a rather “heroic” eye surgery lasting several hours, we treated both the dislocated lens implant and detached retina, but subsequent recovery of sight seemed slower than expected.

As a result of the severe diabetic eye disease, in this case, the optic nerve is no longer able to provide clues to possible brain diseases. However, due to complaints of headache and my impression that there could be more to the case, I ordered a brain magnetic resonance imaging (MRI). The result was a sizeable brain tumour that fortunately was still operable, and the final outcome of the case was thankfully a happy ending.

Many patients ask me why their eyes look “smaller” and their eye colour seems to become lighter as they age. The answer is a ring of deposit of oily (lipid) material around the cornea, which is the perceived “black of eye”. The scientific parlance is arcus senilis (pardon the language please) and may indicate a rise in the blood cholesterol level of the body, so it is highly recommended to undergo tests and treatment to manage the cholesterol level.

More than meets the eye

And if becoming senile and demented is a concern, new research also indicated that studying the retina blood vessels may give clues to early Alzheimer’s disease, although diagnosis still needs to be supplemented by neurological tests and brain imaging.

Dry eye disease can be associated with an underlying thyroid problem, and new research has also indicated an association with a lack of Vitamin D which is not rare even in sunny Singapore. I have sent many patients, some even pre-operatively before their planned cataract or laser refractive surgery for blood tests for the above, if suspicion index is high.

Sometimes these tests do turn out to be positive. Proper treatment can then improve their eye symptoms such as eye tiredness and irritation, and improve their general wellbeing too.

I always make it a point to inform young (and sometimes older) patients who sign up for Lasik surgeries which rid them of refractive errors like myopia and astigmatism, if I find any tell-tale signs suspicious of glaucoma, at the risk of sounding like nagging.

One of the associated causes for glaucoma is snoring (sleep apnoea). This may sound innocent enough, but if the end result of continuous neglect is the possibility of complete blindness, my sincere advice is to please get the snoring treated, by the ear nose and throat specialist, as believe me, blindness from glaucoma is real, irreversible and very terrible.

The English poet William Blake once wrote in his famous Auguries of Innocence: To see a world in a grain of sand, and heaven in a wild flower. So too, a quick check of the eyes can reveal more than, well, meets the eye. It may not be possible to hold infinity in the palm of the hand, but here’s wishing that we safely go through the world!

Our Eyes, Our First Defence

As Singapore emerges from the “circuit breaker”, a measured approach and long-term plan for eye care to better prepare for possible future outbreaks should be considered

SGSecure, a national campaign launched in Singapore four years ago for crisis preparedness has been a success in informing residents of the need to be vigilant against terrorist attacks and other civic emergencies. It has a catchy tagline of “Our eyes are our first defence”, with eyeball mascots keeping an eye out for signs of trouble. I cannot agree more, since our sense of sight comprises 80 per cent of our senses.

2020, the year for good vision, has quickly degenerated into the worst public health and financial crisis in a generation, no thanks to Covid-19. As the world hunkers down to avoid what seems to be a threat worse than terrorism, local essential services like healthcare, transport, food supply and infrastructure have soldiered on these two months, including my specialist eye clinic, albeit on a much smaller scale.

Eye diseases are rarely life-threatening, even though they can blind one and affect one’s independence and livelihood. Yet the trickle of patients with eye problems, significant enough to leave home to see a doctor for, has told a sobering story of how prevention is truly many times better than cure. Apart from symptoms like seeing floaters and flashes which may be due to unavoidable retina tears that can cause detachment, most other acute eye diseases are arguably avoidable, either by early detection and preventive treatment, or careful management of general health problems that may give rise to eye diseases as a complication.

Flattening the curve
Very few would have predicted that a viral pandemic could bring human activities to such an abrupt halt. Deriving Singapore’s coping strategies from our Sars-hardened political leaders, public health and infectious diseases experts, themselves on a steep learning curve, we do our best to flatten the Covid-19 curve by staying home as much as possible.

Meanwhile, life goes on, and the usual urgent and emergent health problems happen as they normally would, with some exceptions such as reduction in influenza and air pollution-related allergies. On the other hand, as a result of the stay-home campaigns, health-seeking behaviours, other than pandemic-related, are altered and delayed by the healthcare bottlenecks worldwide. As such, there are emerging signs of increased disease severity at presentation in affected specialties, with possibly higher morbidity and mortality.

Even though I fully agree with and have operated by the Ministry of Health’s guidelines on appointments and social distancing during the past crucial weeks, my heart aches when I see otherwise able-bodied patients lose their vision. Chronic diseases like cataracts can sometimes progress faster than what conservative treatment plans for. This has resulted in some patients going from doctor to doctor, seeking surgical relief for functional restoration.

Furthermore, delays in seeking medical attention can cause one’s vision to be permanently damaged from common eye diseases like glaucoma, macular degeneration and diabetic retinopathy, all of which are usually symptomless in the early to moderate stages, where commencement of treatment to preserve sight is effective and strongly advised. In the worst scenarios, patients are unaware until they reach advanced stages of these eye diseases. By then, extensive treatment is indicated, unfortunately often unsuccessful in fully restoring vision. The consequent vision loss can render one unable to adequately manage activities of daily living and to work. It is my sincere wish that the eye care profession can satisfactorily manage the backlog of cases in the coming weeks.

As Singapore emerges from the “circuit breaker” and gradually resumes life as we knew it, my personal opinion is that a measured approach and long-term plan for eye care to better prepare for possible future outbreaks be considered. Ongoing management of acute cases aside, and while safe distancing and all applicable infection control measures are followed for protection of patients and doctors, emphasis should be on eye treatment to restore function as soon as possible for affected patients, so that breadwinners and families can get on with their lives.

Further to that, monitoring of previously diagnosed chronic eye diseases, particularly unstable cases, and eye screening for patients with risk factors should not be long-delayed, so that treatment outcome can be optimised. Efficient use of downtime As food for thought, in Hong Kong and South Korea where pandemic measures are reportedly balanced and infection control generally good, ophthalmologists, particularly those in non-hospital or privately-run settings, had continued to provide “compartmentalised” services for eye care including cataract and refractive laser surgeries.

Such practices, to my knowledge, had reportedly not contributed to a spread of Covid-19, is openly accepted locally and deemed an efficient use of enforced downtime, particularly by patients seeking laser refractive correction, who are typically young adults and more resilient to the pandemic. In other countries, Covid-19 swab tests are carried out as a screening prior to surgeries. In Hong Kong, eye specialists in different sectors seem to close ranks, with counterparts in the private sector proactively contributing to the care of public sector patients.

While practices differ from place to place, I opine that a universal principle should be to improve clinic infection control and time-efficiency so that eye service quality is not compromised. While we wait for sustained stabilization of the pandemic, clinical research, particularly commercial and unrelated to the pandemic, should continue to be scaled back. Certainly, in my practice, tests and procedures that are potentially aerosol-generating such as the airpuff eye pressure test, and that are invasive or prolonged, are currently avoided in favour of those that can achieve similar aims without the downsides.

Similar to how the pandemic forces us to hasten trends at the workplace, in retail and information technology, I believe in time to come, it will shape and perpetuate practice trends in healthcare and ophthalmology too. These trends may be the adoption of telemedicine, increasing use of non-invasive and contact-less diagnostic devices and embracing newer surgical approaches to reduce risks and improve long-term post-operative results, like using laser cataract and refractive laser lenticule techniques.

One thing is for sure, Zoom and webinars have resulted in unprecedentedly large participation in both public education and professional meetings I attended in the past two months, a trend that hopefully will stay for good. As for our first defence against the pandemic in the coming weeks, in addition to face masks, may I please suggest the anti-terrorist mentality of including eye protection, particularly in crowded places, since catching the virus through our eyes is not impossible – be it a wraparound eye shield, face shield or large-framed, close-fitting spectacles, all to be washed regularly. After all, Covid-19 is the most lethal terrorist to date!

Singapore Medical Specialists Centre Breaks New Grounds In Vision Enhancement

One of the most common applications for lasers in the treatment of eye problems is in refractive correction. Due to its high safety and efficacy, laser vision correction for refractive errors has today become a mainstream approach. Providing freedom from glasses and contact lenses, it is sought after not just for convenience and cosmetic effect, but also for practical reasons, such as facilitating participation in sports, enhancing one’s career, and lifestyle pursuits. In many cases, quality of life is significantly improved following successful laser vision correction.

Compared to the first generation of laser vision correction treatments, such as the flapless Photorefractive Keratectomy (PRK) which is associated with post-op pain, longer recovery, and side effects of haze, the newer treatments, such as the flap-based Laser-assisted In Situ Keratomileusis (LASIK), are vastly more popular as they result in much shorter downtime and a higher satisfaction rate. While some patients may experience some degree of dry eyes, particularly in the treatment of higher eye power, they generally recover with proper post-operative care.

Third generation technology, such as the still-maturing Small Incision Lenticule Extraction (SMILE), a keyhole operation combining the flaplessness of PRK with the quick recovery of LASIK, can deliver even more stable results. Any small chance of eye power regression and cornea weakening (ectasia) can also now be prevented by corneal collagen cross-linking (XTRA).

Swiss Ziemer LDV™ Z8 Technology
A recent addition to the armamentarium in the refractive surgery world is the highly innovative and mobile FEMTO LDV™ Z8 Laser by Ziemer, an advanced technology that has brought a new level of accuracy, flexibility, speed, and mobility to laser eye surgeries. With its low energy (the lowest amongst all femtosecond lasers), it comes on the back of a highly respectable and continuous lineage. As an established FDA-approved femtosecond laser purpose-built for LASIK and corneal and lens surgeries, it has its roots in versions Z2, Z4, and Z6. The unique LASIK performed on the Ziemer platform is called Z-LASIK. Distinct from other makes of femtosecond lasers, the proprietary FEMTO LDV Z8 uses extremely fast, short pulses of low range pulsed light, which gives rise to a faster creation of the corneal flap (the first step of the Z-LASIK procedure) – within just 30 seconds.

The nanojoule laser allows for a gentle approach that produces an extremely smooth interface, reducing the stress on corneal tissue and post-treatment inflammation. As a result, patients can expect more rapid healing and improved vision in a shorter time frame. The laser’s small footprint and mobility also means that patients are not required to shift during different steps of the treatment, improving patient comfort and streamlining the surgical process. The flap creation is then followed by excimer laser treatment in the second step of LASIK (SMSC uses a proven NASA excimer technology, iDESIGN 2.0 VISX STAR S4, including wavefront-guided LASIK treatment).

What is interesting is that the FEMTO LDV™ Z8 does not just deliver bladeless all-laser LASIK for the treatment of refractive errors such as myopia, hyperopia, astigmatism, and presbyopia with high precision. Its adjustable 3D LASIK flap configuration is also versatile and customisable, like the Z6, with the additional advantage of an Optical Coherence Tomography (OCT) to visualise the Bowman membrane and previous LASIK interfaces, a feature of Z8 that enables finer precision work, such as LASIK retreatments or thinflap femtosecond LASIK (femtosecond sub-Bowman’s keratomileusis).

In lens surgeries, the Z8 laser delivers documented excellent results in Femtosecond-assisted Cataract Extraction Surgery. With its low energy levels, the
laser cuts are fine and precise, allowing for safe surgeries even in complex lens exchange and cataract operations. The mobility of the laser unit allows it to be positioned in the operating theatre right next to the patient, doing away with patient movement between equipment changes, creating a more comfortable experience. The Z8 is the only laser that is feasible when bilateral sequential femtosecond-laser assisted cataract surgery is opted for.

In addition to the above indications, the Z8 is able to perform femtosecond arcuate keratotomy for the treatment of astigmatism using a non-invasive method. Furthermore, Ziemer is on the cusp of releasing its Z-lenticule extraction treatment (yet to be formally named), its own version of SMILE, with added ability for centration, projected improvement in accuracy, and precision. Anticipated in the first quarter of 2020, it will be an attractive option for laser vision correction candidates seeking a flapless alternative.

Ziemer Z8 + Galilei G6
The breakthrough Z8 femtosecond laser can coordinate with the FDA-approved Galilei G6 scanner to create a complete Ziemer ecosystem. The Galilei G6, built on the G4 model, is a dual-Scheimpflug imaging/scanning device that captures up to 300,000 spots on the cornea on both its front and back surfaces and incorporates an optical biometer and Artificial Intelligence assessment technologies. It is precise for assessments for LASIK and SMILE/Zlenticule and for lens implant treatments like the Implantable contact lens (ICL), lens exchange, and cataract surgeries. The unique combination of the Galilei G6 scanner and Ziemer Z8 laser streamlines the application of pre-operative measurements, thereby improving LASIK and SMILE/Z-lenticule as well as ICL, lens exchange, and cataract surgery pre-planning, providing a clearer picture to achieve a safe and great visual outcome.

The Singapore Medical Specialists Centre is proud to be the first in Singapore to have the Ziemer Z8 combined with the Galilei G6. With OCT guidance for LASIK, we are confident we can enhance your vision with increased precision.

Vision 20/20: viewing the world perfectly

AT the dawn of a year and decade, it is fitting to review and renew our goals. 2020 holds special meaning for everyone who appreciates the sense of sight and especially for me as an eye specialist. “20/20 vision” is medical parlance for normal or optimal visual sharpness: what a healthy eye should be able to see clearly, at 20 feet. “Vision 2020: The Right to Sight” is also the name of a World Health Organization (WHO) project that was launched in 1999 as part of an ongoing project commenced 30 years ago, with the aim of eliminating avoidable blindness globally by 2020.

A global guidance and blueprint for eye care systems, Vision 2020 started with advocacy for intervention against eye diseases such as cataract, glaucoma, diabetes, Vitamin A deficiency and trachoma (parasitic river blindness prevalent in Africa) as its first priorities. To sum up Vision 2020, WHO published its comprehensive World Report on Vision last year, freely available on the Internet. Although unmet needs still exist, the project has seen unprecedented progress and is deemed successful by most yardsticks. There has been a very significant reduction in cases of eye infections and blindness from Vitamin A deficiency, as well as the ongoing reduction in prevalence of blindness among adults, including treatable causes.

Nevertheless, continuous focus is necessary as these results can’t keep pace with the growth of an ageing population. The report includes the global magnitude of the issues, successes, what remains to be done, recommended strategies and paths charted for the future. The causes of vision impairment and their impact on financial burden are of particular interest to me. The figures are staggering: at least 2.2 billion people have vision impairment globally. At least one billion of these (an underestimation according to the report) could have been prevented or are unaddressed, with 123.7 million suffering from unaddressed refractive errors.

Cataract comes in second at 65.2 million. These eye conditions are projected to increase due to population ageing, as well as environmental and lifestyle changes. From the report, the cost of the coverage gap for global unaddressed refractive errors and cataract was estimated to be US$14.3 billion. In the world, there are an estimated 2.6 billion people with myopia (of which 312 million are under 19 years old) and 1.8 billion with presbyopia. These contributed to losses in annual global productivity estimated to be US$244 billion and US$25.4 billion, respectively. The prevalence of myopia is the highest in East, South and Southeast Asia. It was reported in these regions that the economic burden of uncorrected myopia was more than double that of other regions and equivalent to one per cent of gross domestic product (GDP).

A simple calculation should convince one of the highly cost-effective outcomes for addressing treatment of myopia, presbyopia and cataract – my three main areas of practice in ophthalmology – in any health care system. There are several points in the report that strike a pertinent yet sensitive note. First, the issue of funding for management of the commonest eye condition, that is, refractive errors, which in many countries are mostly out-of pocket. These include the costs of spectacles, deemed an assistive device, as well as contact lenses and refractive surgeries such as LASIK. Second, the potential role for public-private partnerships to improve eye care services. What is new for this decade is the focus of “integrated people-centred eye care” as a continuum of health intervention.

This is a new addition to the WHO project’s action plan to now include integration of eye care into health care systems, ideally across all sectors, and, for this, four important strategies are proposed. These are to empower and engage people and communities, reorientate model of care, coordinate services within and across sectors, and create an enabling environment. In my mind, these are applicable to both policymakers and the public. Integration of eye care into health care is here to stay. For the general public, it should translate to ensuring good eye care and visual habits from the groundup, starting in the family, schools, public institutions, at work and at leisure.

It also means having eye protection in sports and in relevant occupations and attending eye screenings regularly even when the eyes feel fine, as some eye diseases are silent in the initial stages where they can be controlled and potentially reversed. Ensuring good general health and lifestyle is key in maintaining good eye health. Our eye clinic also welcomes the new decade with an addition of the services provided. Incorporating a Refractive and Cataract Surgery service  on site has long been our aim. We look forward to deliver safe, effective and integrated eye care with the addition of the trusted Johnson and Johnson Star S4 iLASIK excimer laser with FDA approved wavefront guided treatment via its latest iDesign 2.0 and the Swiss-made Ziemer Z8 femtolaser for OCT-guided thin flap LASIK surgery, being the first in Singapore, as well as for laser cataract surgery.

These will help address the most common eye conditions in the world – namely myopia, presbyopia and cataract – in an efficient and affordable manner.
The Ziemer Z8 also looks forward to providing further innovations in flapless refractive lenticule treatment for myopia in the near future. Eye screening enabled with artificial intelligence for front-of-eye diseases by dual-Scheimpflug imaging and back-of-eye diseases by digital angiography and fundal camera remains our go-to option, a sign of the times.

Dr Daphne Han
Senior Consultant Ophthalmologist
MBBS (Melbourne), MMed, MRCS, FRCS (Edinburgh), FAMS


Guarding against diabetes-linked eye disease

Early and regular eye screening is the best defence for diabetics against loss of vision

Several years ago, while volunteering as a consultant to teach local eye doctors for a charitable organisation in rural China, I was eager to share the strategies applied in healthcare in Singapore against the rise of diabetes mellitus, an increasingly common disease. I believed that our emphasis on public education, early screening and management of diabetes with a view to prevent and delay complications work well. To my fellow ophthalmologists in the Chinese hospitals, I recommended our methods of early and regular eye screening for detection of diabetes- associated eye diseases, such as cataracts, glaucoma and diabetic retinopathy, the latter being an eye disease that affects the retina, the receptors of light at the back of the eye.

For the far-flung corners of the land, I showed them examples of mobile eye screening services, on a bus, that several countries such as Britain and Singapore employ. It was my sincere wish that my suggestions would be heeded by the hospital I visited, as the cases of diabetic eye disease that I witnessed there were very advanced and some beyond hope of repair. And I counted my blessings of being both a provider and user of the Singapore medical system. Let’s refresh ourselves about diabetes and the importance to guard against it. Just two years ago, a single medical condition, diabetes mellitus, was flagged for the first time, to my knowledge, at the National Day Rally by Prime Minister Lee Hsien Loong, as a national priority that needed to be addressed.


A metabolic disease that affects the control of sugar in our bodies, diabetes can result in complications such as blindness, kidney failure and gangrene, consequently requiring amputations. It also makes diseases like heart attacks and strokes more common. One in nine adults aged 18-69 here suffer from it, and the figure increases in the older age group. Type II diabetes affects the majority of the sufferers especially those over 40 yet is highly preventable by lifestyle modification. It costs taxpayers S$1 billion a year, and the figure is expected to increase yearly.

For my part, where the eyes are concerned, once diabetes has been diagnosed, usually from a referring doctor, it is imperative that the patient begins a lifelong routine of eye screening and examinations. This is so that any diabetes-related eye diseases, particularly diabetic retinopathy, can be detected and treated early. Diabetic retinopathy, a form of microvascular disease, stems from ischaemia (a lack of oxygen supply to the affected tissues), which can eventually result in the sprouting of abnormal blood vessels in the retina and elsewhere.

These abnormal blood vessels tend to bleed and scar, obscuring vision and causing further complications such as raised eye pressure, in a condition called neovascular glaucoma which can result in a painful blind eye, irreversible in its advanced stages. Diabetes can also cause retina detachment, a stage of disease so advanced that even surgery often fails to restore a patient’s sight. Yet other diabetes sufferers lose vision at an earlier stage through diabetic maculopathy, where the macula, an area of the retina akin to its “heart”, becomes swollen. Diabetes, as mentioned above, also increases the likelihood of getting cataracts and glaucoma.

The eye screenings, in the early years of diabetes, may be performed as part of a general health check in clinics equipped with eye photography services (fundal photography), even without doctors on site. This service can be found at many clinics, in the government and private sectors, and is increasingly being introduced into premises such as optical centres. A major trend is for Artificial Intelligence to assist in the interpretation of the images obtained, to reduce redundant clinic attendances.

Once signs of diabetes-related eye diseases are detected, it is important to then present to an eye clinic for further management, which may include more frequent eye examinations or commencement of treatment. Treatment of diabetic retinopathy and maculopathy usually involves firstly managing the underlying diabetes. Strict blood sugar control is vital to stabilising the related eye diseases. Beyond that, either lasers or injections into the eye of a family of medicine called anti-vascular endothelial growth factors (anti-VEGF) are then prescribed. The anti-VEGFs, albeit costly, are wonderful game changers in the treatment of diseases affecting the retina in the past 15 years.

Severe scarring

Without it, many patients would be doomed to blindness. This is due to the fact that despite the effectiveness of retinal lasers in stabilising diabetic retinopathy, they can result in severe scarring that jeopardises vision, a side-effect that can be largely avoided by the anti-VEGF injections. Fast forward to November 2019, and I found myself rather piqued in my eye clinic by a recent case of a patient who consulted me for a second opinion for a cataract operation. The patient’s diabetic eye disease had been up until recently managed by a local tertiary eye clinic. As part of routine pre-operative screening for my patient’s cataract operation, a thorough eye examination and pre-operative tests are compulsory.

For diabetes sufferers, I also highly recommend undergoing a blood test called the HbA1C to check for long-term control of the disease, as poor control of diabetes can complicate the recovery and results of eye surgeries such as for cataracts. For this patient, these tests yielded evidence of mild diabetic retinopathy but under-the-radar sub-optimally controlled diabetes. In this case, the elective cataract surgery is rescheduled pending stabilisation of diabetes by the medical team, a best practice preference.

As an ophthalmologist, I believe that although my focus is on eye care, it is a holistic healthcare that we should aim for, hence the team-based multi-disciplinary approach in my current medical practice. Indeed, the eyes are the windows to our health. Yet, although the eyes don’t lie, even with the sharpest eye, one does need to take a step back to see the full picture.

Here’s to a full picture for all our diabetes patients, with stable, healthy eyes!

Dr Daphne Han
Senior Consultant Ophthalmologist
MBBS (Melbourne), MMed, MRCS, FRCS (Edinburgh), FAMS


Safeguarding your eyes from the ‘thief of sight’

Glaucoma is a silent disease, and opportunistic screening and regular monitoring are recommended to detect it early

The recent haze ended as quickly as it began and the skies in Singapore are blue again. In medical parlance, such episodic problems are usually termed an “attack”, such as a heart attack, a gout attack or more relevant to my profession, a glaucoma attack. After each annual episode of “haze attack”, our region seems to bounce back, finger-pointing subsides and life returns to normalcy, until the attack repeats again the following year.

However, unlike the haze, human organs once “attacked” usually decline in function, causing ill-health that may become irreversible to the point of demise. A glaucoma attack is an acute disease that the eye may suffer from, which can be associated with irreparable damage. For the uninitiated, glaucoma is a group of eye diseases typically characterised by elevated eye pressure, loss of field of vision and a classic glaucomatous appearance of the eye nerve ending, visible only through an examination of the back of eye.

Field of vision is a concept that warrants explanation to many people. Each eye has its own field of view – the area that it can see – and in combination they provide comprehensive navigation of our environment. A minimum visual field criterion denoted as at least 120 degree of angle horizontally with either single or both eyes is legally required for driving.

Mixed bag of subtypes

As a disease, glaucoma comprises a mixed bag of subtypes, arising from various causes. These may be as innocent as being born with the genes for glaucoma whose effect manifests as one age, or simply being anatomically predisposed. It may arise as an association of general diseases such as diabetes or as a side effect of prolonged use of steroid medications. It may even be a result of other local eye diseases such as ischaemia (a lack of oxygen), inflammation or injury.

What ties these various subtypes together is the ultimate destiny of the eye nerve: that there is thinning and loss of the nerve cells as a result of the eye pressure, which in some cases may be deceptively normal on measurement but high for the individual eye nerve  (to each eye nerve its own eye pressure, so to speak). Unchecked, glaucoma can surreptitiously lead to irreversible blindness.

By year 2020, as the third leading eye disease, it will affect an estimated 80 million people worldwide. Of these, 3.2 million is estimated to be blind from glaucoma. Being the top irreversibly blinding eye disease, public education of glaucoma is one of the leading ophthalmic priorities. Nevertheless, compulsory glaucoma screening has not been deemed cost-effective in public health policies worldwide. Opportunistic screening is hence the usual approach.

In general, glaucoma is divided into two broad categories based on the shape of the outflow apparatus of the eye (yes, there is a plumbing system in the amazing design of the human eye). These two categories are the open angle type versus the closed angle type. Although the open angle variety is commoner worldwide, closed angle glaucoma has a higher incidence in East Asians and Caucasians compared to Africans, due to racial differences and anatomical features.

Both types are silent diseases, with few warning signs of the loss of field of vision, hence nicknamed “the thief of sight”. However, the closed angle variety of glaucoma is notorious for being associated with episodes of not-so-silent attacks during which the eye pressure becomes acutely elevated due to vicious cycles of outflow blockage within the eye. During an attack, one would experience a red, painful and blurry eye, often with severe accompanying headache, nausea and vomiting, so much so that confused sufferers had on occasions been misdirected to the gastroenterology department for the prominent symptoms suspicious of a stomach flu.

Disclaiming any intended ageism and sexism, the classic scenario of an attack of angle closure  glaucoma is of a little old lady watching television at night: advanced age, being female and in the dark are indeed risk factors, although televisions are commonly swapped for mobile phones these days. While the management of an acute attack of glaucoma is considered a gift question in the eye specialty board examinations, real life cases are not as straightforward.

After a glaucoma attack is “broken” or stopped, much else needs doing, including prevention of recurrence, repairing sight and safeguarding the fate of the fellow eye. Ramifications affect the front and back of the eye as the high pressure affects them all. Closely associated with vascular diseases, glaucoma has a higher incidence in those who suffer poor circulation in the extremities (cold hands and feet). A big drop in night-time blood pressure, snoring or sleep apnoea are possible contributors too.

Certain yoga postures involving inverse poses were documented to be associated with elevated eye pressures (particularly the sirsasana pose), hence glaucoma-sufferers should consider modifications to these poses. In terms of treatment of glaucoma, there are roles for topical eyedrops, laser   treatments and surgical therapies, with recent advances in minimally-invasive glaucoma surgery, all of which target lowering of the eye pressure to halt progression of visual field loss.

Preventive care

However, the mantra remains “prevention is the best medicine”. Opportunistic screening and regular monitoring are highly recommended particularly when there is a positive family history or significant risk factors. Detection of strong signs of suspicions of glaucoma is followed by management strategies unique to each subtype of disease. Preventive treatment involving lasers and surgeries such as early cataract extraction is recommended for closed angle glaucoma.

The latter represents a shift in management strategies as a result of large-scale multinational studies conducted in the recent years, and is believed to be a more cost-effective treatment to lower the risk of an attack. As I resign myself to the high probability of a repeat haze “attack” next September, I find solace in the thought that in healthcare, active steps can be taken by the individual to prevent acute phases by monitoring and managing chronic conditions, in an evidence-based manner, before devastating problems arise.

The best defence may indeed be a good offence, in the form of an eyecheck, for a start!

Dr Daphne Han
Senior Consultant Ophthalmologist
MBBS (Melbourne), MMed, MRCS, FRCS (Edinburgh), FAMS


Keeping an eye on dry eye syndrome

Keeping an eye on dry eye syndrome

Eye complaints are becoming more common especially when the weather is hot, dry and hazy

A Patient of mine who suffered from dry and allergic eyes and eyelids told me recently that she deemed me a role model because of my “sparkly eyes”. As an eye doctor of 20 years and counting, it was the first compliment of its kind, amidst the usual polite comments on my youthful appearance or “nice eyes” I received.

As I pondered it, it drove home to me how precious having healthy eyes is. Aside form seeing well, with good quality of vision, eye health also encompasses healthy appearance and eye comfort, which together contribute to a good quality of life.

It is probably no coincidence that some of the common eye complaints I manage are eye irritation and discomfort. In times of hot, dry spells and haze, eye clinics including ours see even more such cases.

Majority of these are in working adults, but they do come in all ages, including children. They are caused by a combination of eye dryness and allergic conjunctivitis, a condition that plagues the conjunctiva, the superficial lining of the visible part of the white of eye. Accompanying symptoms are blurring of vision, tired eyes and even headaches.

Often relegated to primary eye care, in my experience, these conditions are becoming commoner in recent years, due to the increasing and prolonged use of personal digital devices, computerization of workplace, possibly an increase in airborne particles in our environment and insufficient eye hygiene. The latter is likely contributed to by a multi-billion dollar eye cosmetics industry, several times that of dry eye treatment.

As we gear up against global warming and climate change, it is apt to consider how it relates to our health, including the eyes.

The World Health Organization regularly studies and responds to climate change and human health. For ocular health related to climate change, experts in recent years predicted an exacerbation of symptoms of dry eye disease.

Dry eye specialists classify the sub-types of dry eyes into tear production deficiency versus evaporative eye dryness, in a nutshell.

On the ground, the picture is often mixed. It is suffices to note that dry eye disease is usually chronic and multi-factorial. Apart from the garden variety of dry eyes, arising from a combination of ageing, hence slowing of tear gland production, and increased evaporation, more severe forms may result from diseases such as the autoimmune Sjogren’s syndrome that may cause dry mouth too. Thyroid disease, rheumatoid arthritis, lupus and diabetes are also associated with dry eyes, as are certain medications like anti-histamines, antidepressants and isotretinoin for acne.

Relief for sufferes

The average dry eye sufferers can improve their conditions through several simple measures. These include keeping themselves well hydrated, limiting their onscreen duration, taking more frequent visual breaks, positioning their computers at the lowest height possible to reduce exposed eye surface area, and avoiding direct drafts of air such as fan or air-conditioning from desiccating their ocular surface.

In addition, over-the-counter medications such as tear supplement eye drops and mild versions of anti-allergy eye drops can provide sufficient relief for milder cases.

If these failed to work, specialist care from an eye doctor is recommended, especially for detailed diagnosis to rule out any underlying eye, connective tissue or general health disease, which may contribute to persistent and severe eye dryness.

Sometimes diagnosis merits a variety of examinations including blood tests for related diseases. Treatment will then be targeted again the pertinent issues, such as managing eyelid inflammation or concurrent allergic eye diseases.

Supplements such as oral Vitamin D and omega-three fatty acids are sometimes also advocated, the details of which warrant in-clinic discussions.

More severe dry eyes will required further management, potentially with novel treatment options and even eye surgery. It is important to note that dry eyes can lead to complications such as cornea infections in severe cases, which in turn ricks scarring and spreading in the eye, particularly in ill patients.

In general, the cost of treatment of dry eye disease other than those of higher severity is shared by both the sufferers as well as healthcare sponsors. The global economic and quality of life burden of dry eye diseases had been studied by Dr Marguerite McDonald, published in The Ocular Surface, April 2016, and results suggested that is is a substantial economic burden.

Dry eye disease was found to contribute to loss of work productivity as well as substantial negative impact on physical and also psychological function. An American study by Schiffman et al in 2003 found that in severe cases, its impact on quality of life was comparable to that from having severe angina or chest pain.

Seeing that the global market for treatment of dry eyes is reported to be in the billions currently and expected to increase steadily, health promotion strategies, in my personal opinion, will be well-served to include prevention and management of dry eye syndrome.

In my clinic, in association with the laser refractive and cataract surgery I performed, I highly recommend routinely keeping an eye on dry eye management for improved results.

Long-term care

Screening, pre-treatment, appropriate selection of microsurgical techniques to reduce post-operative dry eyes, compliance to dry eye treatment, patient education and lots of patience from the doctor as well as patients are factors that can lead to success in long-term care of dry eye disease and improved surgical satisfaction.

As for sparkly eyes, my thoughts are that it has to do with my having enough sleep the previous night. Any other factors observed (apparently wisdom also show in sparkly eyes) would be a bonus!

Straits Times Life
24-25 August 2019

Set your sights on eating right

Set your sights on eating right

Have you ever eaten “with your eyes”? The chances are yes.  Apart from odor and taste, the sight of food contributes significantly to our assessment and enjoyment of food.  In fact, the glamourised appearance of a particular food item often becomes the single most powerful advertisement, especially on social media, to the extent that it becomes commonly called food pornography.  As such, eating with our eyes is certainly a true fact, underlining the importance of our sense of sight in the quality of life.

But have you ever thought of eating “for your eyes”?

Eating to see well follows universal dietary principles, which are to have a varied, broad-based diet and preferably fresh food from uncontaminated sources.  In addition to this, several unique food apply to visual health.  I would divide them into two categories, broadly-speaking: eating for the health of the front of eye and the back of eye.

Firstly, the front of eye.  The ocular surface comprising the cornea and conjunctiva is what meets the environment.  The cornea, a transparent tissue, permits light through, and provides structural integrity to the front of our eyes, while the conjunctiva is the lining of the white of our eyes.  These are usually protected by a thin layer of fluid called the tear film, which can dry out when blinking rate drops due to prolonged visual attention.

Modern, desk-bound lifestyle sees many of us glued to computer screens and for way toolong. The consequence of that is an increase in what is termed “digital eye strain”, which causes tired eyes and sometimes, blurring of vision due to dryness and exposure.  Coping mechanisms are none other than reducing the duration of near work and taking frequent visual breaks.  Dietary supplements in the form of omega-three fatty acids, either fish oil or plant-based in origin, are commonly prescribed for dry eyes syndrome.  Simplified, they work in a two-pronged way: strengthening the external oily layer of the tear film to prevent early evaporation of the tear, and also to improve the health of the oil glands at the lid margin, a vital part of our eye surface.  These supplements are, in my experience, truly helpful for low to moderate grades of dry eyes, and are generally very safe to be consumed long term.  They are available over the counter in most pharmacies, with several formulae produced specifically for dry eyes, even though generic formulae are often just as effective.  .

From my understanding, the amount of these fatty acids acquired from modern day regular meals are usually insufficient, and there are no issues in taking supplements in the form of capsules for these.  I occasionally suggest oil forms of these supplements, added to salads or soups.  I routinely recommend these supplements to my cataract and LASIK patients, who usually will encounter a short duration of dry eyes post-operation.  However, severe grades of dry eyes should also be treated medically with prescription eyedrops.

Eye problems arising from nutritional deficiency such as night blindness and xerophthalmia (very severe dry eyes) from severe lack of Vitamin A are very rarely encountered nowadays due to the improved diet in our society.  There is some evidence that adequate Vitamin C from natural food sources has protective effects against cataract formation.

For the back of eye, the central area of the retina called the macula is where photoreceptors are the most concentrated and hence the most sensitive area of our retina.  The macula is the site of insult of two common eye diseases: diabetic retinopathy and age-related macula degeneration.  This area, when affected by these diseases, may swell up, bleed internally and collect deposits of waste substances.  The damage caused to sight can be grave, as central vision and reading are affected.  Other than the macula, the rest of the retina may also be affected by diabetes.

Dietary guidelines for diabetic eye disease sufferers are identical to other diabetes sufferers.  Studies have, however, shown that a tight control of blood glucose level helps to maintain vision, as the tiny blood vessels of the retina succumb easily to poor diabetes control, resulting in sprouting of new and fragile blood vessels that bleed and scar, causing retina detachment and blindness in the advanced stages.

Often, a visit to a dietitian helps to plan a diabetic diet.  A diet composed of regular meals to prevent extreme blood sugar swings is the aim, while keeping intake of calories and body weight in check is definitely a plus.  Further attention to types of carbohydrate consumed may also result in maintaining an even keel.

As for age-related macular degeneration, a disease affecting the elderly in which the macula area is affected by deposits of waste material which result in abnormal blood vessels, the link between diet and vision is much studied.  These studies showed that a regular intake of lutein and zeaxanthin (carotenoids, or pigments found in naturally colourful food), zinc and vitamin A, C and E can reduce the incidence of disease and reduce the risk of disease progression by up to 25 percent.  The dietary recommendations resulting from the oft-quoted large-scale Age-Related Eye Disease Study 2 (AREDS2) form the basis of several oral supplements for macula health, available fairly readily over the counter and in most specialist eye clinics.  For natural sources of lutein and zeaxanthin, look no further than the usual colourful fruits and vegetables, including kale, spinach, papaya, blueberries, goji berries and peppers.  These colourful foods help to maintain colourful vision.

Care in avoiding the wrong food can also bode well for our sight.  Infrequent reports of severe blindness from toxicity to the optic nerves, due to accidental ingestion of methanol are still encountered in the region, even in Singapore.  Possible ocular side effects of medications such as steroids and some oral drugs for cardiac and rheumatoid diseases should also be monitored by the eye specialist, to prevent vision impairment.

Healthy eyes and vision are some of the best gifts in life.  Why not repay our eyes the enjoyment we derive from it, by eating right for our sight?

Have a date with our Specialists at 360 Health Management Seminar on 30 Mar 2019, Saturday 10am to 2pm at SPH News Centre Auditorium. Our Specialists will be sharing various health issues that you might be facing. Register online at

Dr. Daphne Han
Senior Consultant, Ophthalmologist
Singapore Medical Specialists Centre

The Business Times, Sunday, 2 March 2019