New beginnings...at Gleneagles Medical Centre

Me and my new colleagues

I was originally going to post this next week, however, as events transpired I have stopped seeing patients at my original practice at Jerry Tan Eye Surgery.

I have left my position at Jerry Tan Eye Surgery, and I will be practising at Gleneagles Medical Centre from now onwards, with a subspecialty practice called Ophthalmic Consultants.

I was struck by this phrase - 'every new beginning comes from some other beginning's end'-and it encapsulates the mixed feelings I feel about the past four years. Fruitful years, with the ups and downs of human existence aplenty. But I felt the negatives were beginning to outweigh the goodwill and comfort I experienced in that position-surely material for a future post when the emotions are a little less raw.

I have high hopes for the future, and look forward to helping many more with their eye problems!

The bane of dry eyes...

Dry eyes are the bane of life in the 21st century.

A large part of dryness is associated with age, which is not to say that a 30 year old with dry eyes is particularly old! But there are many other contributing factors, such as a dry environment (most commonly caused by air conditioning), prolonged computer use (insufficient blinking while focused on the computer screen), wearing contact lenses, certain medications, and irritating dust or chemicals in the environment.

Dryness can cause all sorts of eye discomfort from the usual grittiness or tightness, to blurring of vision and even teary eyes from 'reflex' tearing. This is not surprising, since tears perform many functions on the eye, including lubrication, nutrition, killing germs, smoothing the corneal surface to improve light focusing and so on.

Another common dry eye situation is first thing on waking in the morning. The eyes may feel tight, sensitive to light and difficult to open for a time-usually from 10-20 minutes. Once the tears start flowing the eye feels normal again.

The pictures below show how dryness affects the corneal surface. From mild, to moderate and severe cases, there are progressively more 'dry spots', which are actually areas where the corneal epithelial cells have gotten unhealthy and dropped off. This is akin to the roughness of the skin when it gets too dry, and the rough corneal surface can lead to blurred vision as it does not focus light well.

Dry eye treatments

Artificial Tears

The simplest treatments for dry eyes are artificial tear eye drops. There are many types of these, but they can generally be differentiated into preservative free types (in individual vials/tubes) and those that are preserved (in bottled form).


For general, regular use, the bottled form is the most cost effective. This is especially true when the patient finishes the contents of a bottle or so each month.

However, occasional users may find their bottle more than half full when the time comes to replace the bottle, generally one month after opening the bottle. For these people, using individual vials as necessary leads to less wastage, and unopened vials can be used at any time before the expiry date which is usually up to a year later.



For some dry eye patients, more liquid preparations do not seem to provide relief for very long. Sometimes the eyes may feel dry again 10-15 minutes after instilling the eyedrop. In such situations, using a thicker preparation would be more effective.

In other patients, dysfunction of the oil glands in the eyelids leads to a poor tear film and increased evaporation from the surface of the eye. In such cases, artificial tears with an oil component such as Endura or Systane Balance (as above) will help address the main underlying problem.

Gels and ointments

Gels and ointments differ from eyedrops in thickness/viscosity. Whereas gels are water based and once diluted feel like other types of eyedrops, ointments can feel oily and smear vision significantly. However, ointments do not evaporate and provide heavy duty lubrication and protection even if the eyes are exposed at night by eyelids that do not close fully. Owing to their effect on smearing vision, both gels and ointments are generally used at night before turning in. Occasionally gels can be used during the day in more severely affected patients.

Punctal plugging

We all have tear glands which produce tears, as well as tear drainage channels which channel excess tears down our nose.

If we wanted our tears to hang around on the eye surface for a longer time, what better way than to plug the drainage channels (like plugging the sink)!

In fact, this method does work quite well and dramatically in some people. Two general types of plugs exist: Permanent silicone plugs, as well as temporary dissolvable ones.

The most commonly used plugs are the silicone plugs, however, they may fall out sometimes or collect debris around the slightly protruding part. The dark blob below represents remnants of eyeliner/mascara stuck onto a silicone plug. The temporary plugs are inserted completely into the tear channel, and so do not tend to collect mucus and debris. The lack of debris and inflammation associated with temporary plugs is also because they slowly dissolve away. In my practice I tend to use the temporary plugs which last for 6 months. If the eye is good initially with these plugs, but get dry again when they dissolve, a more permanent procedure called punctal cautery can be considered to avoid the hassle of repeat plugging every 6 months.

This video shows the insertion of a temporary punctal plug. It is a painless procedure and takes a minute or less to do per punctum. This has the potential to make a big difference to the patient's symptoms, however, I avoid doing this if the eye is obviously inflamed.

Other dry eye treatments

Restasis

Restasis is a formulation of Cyclosporin in a castor oil emulsion. It had been noted that dry eye patients often had eye surface inflammation, and through studies which found that the inflammation reduced tear production, efforts were made to produce eyedrops to address this problem. In fact, powerful anti-inflammatory eyedrops like steroid eyedrops do help more severe cases of dry eye, but their potential for side effects usually limits the duration of their use. Topical Cyclosporin eyedrops like Restasis do not have the side effects associated with steroid eyedrops.

Restasis when used regularly twice a day has been found to increase tear production but only after a prolonged interval of several months on average.

Caffeine
For some people, caffeine can stimulate the secretion of tears and so improve a patient's dry eye condition. A cup of coffee or tea in the morning can have beneficial effects over and above what we already knew about! However, more is not necessarily better, as excessive caffeine can cause anxiety, tremors, and insomnia, among other side effects.

Arita et al. Caffeine Increases Tear Volume Depending on Polymorphisms within the Adenosine A2a Receptor Gene and Cytochrome P450 1A2. Ophthalmology 2012;119:972-978

Diquafosol

This is a relatively new compound that stimulates the production of mucin and water from the surface of the eye.

However, it needs to be used 4-6 times a day and contains preservatives, in which case using it may not be so different from using regular artificial tears from a practical point of view.

In short...

If you are suffering with dry eyes,
First, try some artificial tears (things you can find in the pharmacy like Refresh Tears or Refresh Plus) and take care to modify your activities and environment where possible eg take regular breaks from prolonged computer use, and lower the fan speed/set a slightly warmer temperature for the air conditioner.

If these measures are not sufficient, your eye doctor should be able to help by recommending more specific eyedrops, or simple office procedures like plugging the tear drainage channels.

My most popular Youtube video

A couple of years ago, I decided to put a few videos up on Youtube. They were nothing spectacular, and were meant partly as a record of what I have been doing in the clinic, and some others were to demonstrate surgical techniques.

It became apparent within the first year that one of the videos was different. It was getting thousands of hits, while the others were languishing with perhaps a few tens of views.

This is the video: http://www.youtube.com/watch?v=16bSxfCS0wI

It did not have sound. It was about cleaning the eyelids of mucky crusts, and of looking for tiny little mites called demodex. And as of today it has 392456 hits...

I think it boils down to the frustration many patients and doctors feel about the problem of blepharitis and the lack of effectiveness of many of the traditional treatments. When I was training, and even nowadays, a commonly taught technique was to clean the eyelids with diluted baby shampoo. The idea was to use the shampoo to help remove crusts, while it was gentle enough not to irritate the eye even if any of it went in.

However, it made little to no difference for many blepharitis sufferers. The crusts would return almost as quickly as they were removed, and the eyes would often remain irritated and itchy.

About 10 years ago, Scheffer Tseng and others began reporting research done on demodex mites and blepharitis. That piqued my interest and I started looking for them in my patients. I started finding them in many, many people...

Although the mites don't always cause trouble, they certainly have the potential to do so. Back when I first started to become aware of them, I remember a lady who had very bad persistent eye irritation that was resistant to all the dry eye treatments she had been prescribed. I happened to see her and noticed her blepharitis. Remarkably, she felt much better after a single dose of oral Ivermectin that I prescribed. In more recent years, a number of patients did not seem to respond to the oral medication, and finally I asked a compounding pharmacy to produce a topical preparation which has proved very effective. What appears to be current 'mainstream' treatment, tea tree oil, proved to be very irritating for my patients as well as not being very effective at killing the mites.

It turns out that many viewers of my video (and readers of this blog as well...thanks for reading!:)) live outside of Singapore, with many in the United States and Europe. Some viewers have asked about the availability of Ivermectin cream, and unfortunately it is not commercially available at the moment. However, Galderma has recently concluded phase 3 studies for the use of topical Ivermectin in rosacea, and the hope is that this will become commercially available soon.

At least in terms of medical videos on Youtube, it doesn't appear that you always need special effects or a South Korean origin to be popular!

P/S: since that first successful video, I made a more detailed one describing the detection of demodex in the eyelashes as well as the treatment of this stubborn condition, at this address:  http://youtu.be/NskwR1XzTtE

What are 'lazy' eyes?

Many of you may have come across the term 'lazy eye'. What exactly does it mean?

In truth, there is the term that is understood medically, and then there are the other interpretations or myths-which sometimes makes it difficult to know what people mean when they use this term.

Lazy eye medically speaking, refers to the condition called amblyopia. In this situation, the amblyopic eye is unable to see well, even though the eyeball itself is structurally normal. An amblyopic eye develops because connections between the nerves of the eye and the brain are not fully developed at birth. This process requires well focused images on the retina of the eye together with good signals reaching the brain, and continues for several years after birth. The system generally matures around the age of about 8-9 years of age, after which a lazy eye will not develop even if that particular eye develops a disease which prevents it from seeing well.

So, a lazy eye develops because something prevents a well focused image from reaching the retina of the eye and the brain. These possible causes include high longsightedness or astigmatism, a constant (present all the time) squint (eg crossed eyes, which cause double image, resulting in the brain blocking the image), or even more rarely things like corneal scars or cataract.

Do you think the above is a lazy eye?

Answer: Maybe...

The above left eye has drifted outwards, and some would call this a squint. If a squint happens only some of the time, it is very unlikely to have amblyopia, or be 'lazy'. In other words, the eye would be able to see well at whatever it was looking at.

However, if the squint is present all the time, the child would have double vision-so the brain automatically blocks the image from the squinting eye. This blockage, or 'suppression', can cause the eye to become amblyopic, so that this particular 'lazy' eye would be unable to see clearly even if any long/shortsightedness/astigmatism was corrected.

Many children with 'lazy' eyes do not display any outward sign of the poor vision in that eye. This is the case especially when the 'lazy' eye is caused by different and high degrees of spectacle power/astigmatism. That is why screening the vision of young children of 5-6 years of age is so important. In Singapore, schools and kindergartens routinely screen student's eyes once a year.

What 'lazy' eyes are not...

So just to recap, lazy eyes are not squints (although constant squints can cause lazy eyes), and lazy eyes do not mean an eye with very high spectacle power (although an eye with high spectacle power/astigmatism can be lazy). As long as an eye can see well (with or without glasses), then it is not considered 'lazy'. It follows from the explanation above that lazy eyes can only develop in childhood, and that if it is detected much later-eg in adulthood when the visual system is mature, there are no effective cures.

Lazy eye treatments

When 'lazy' eye or amblyopia is detected at a young age less than 7 years of age, treatment is generally straightforward and involves patching the good eye to force the child to see with the poorer, amblyopic eye. The younger the child, the shorter the time needed for patching.

There are several different methods, but in my practice the child patches the good eye one hour /day/year of life (age). So a 3 year old may patch for 3 hours a day, while a 6 year old patches for 6 hours a day. Once the child gets older than 7 years of age, the eye is less responsive to patching, and in some cases even whole day patching may be required for a period of time. For somebody above 12-13 years of age, patching essentially does not work anymore. There exists an FDA approved treatment for amblyopia for those older children and adults, consisting of eye exercises (called Neurovision), however, my personal experience with it is disappointing.

The story of the Symfony lens

About 2 months ago I was chatting with my parents on Facetime. I had helped my father with his cataract surgery in February/March earlier this year (fortunately everything went fine!) and naturally they were still quite in tune with things happening in this area of medicine.

My mum goes, 'Have you heard of the Symfony lens?'

I went,'Umm, sorry, you mean the Synchrony lens? I've never heard of the Symfony lens.'

Then she went on to point me to the Daily Mail webpage on the Symfony lens:

I was a little taken aback, because there had been no heads up from the company producing the lens implant. (And I was the supposed eye expert in the family too!)

The aforementioned company had previously  bought over the rights to a lens called the Synchrony accommodating lens implant, however, this had been delayed and then from the looks of things, shelved. (after paying a lot of money...)

In any case, this lens didn't look much different from the currently available diffractive multifocal lenses such as the Tecnis multifocal lens. So my mum asks me: 'wah, so this lens can see far and near without having any halos...'. And I went, 'but it has rings, so the patient will have halos...'. And my mum says, 'but that's not what it says in the article!' And so I capitulated. 'I'll just check with the representative tomorrow'. I felt a bit bad, partly because I wasn't able to answer their query but also I wasn't sure if I had inadvertently left them crestfallen after their high hopes about the new lens.

A week later I had the same query from a patient, and so it was that I was a bit more prepared to discuss the lens. Thank god for my mum who surfs the net!

When I asked the company representative about the lens, unfortunately there was not much information to be had. It was only last week that I found out a bit more about the lens. I understand that this is a new lens, but it achieved the CE mark in June and I think companies in this day and age should do more to coordinate the availability of their products, and also the dissemination of information about their products around the world. The thing is, the world has never been a smaller place...

Update 22 October 2014
2 months down, the Symfony lens has finally arrived in Singapore! It is currently in an evaluation phase with limited lens powers available, however, suitable patients can be considered for this lens. I feel that this is a lens which is likely to be better accepted among patients, and also doctors, as it uses a proven platform which should make IOL power more predictable as well.

Update 5 March 2015
My first cataract patients who opted for this lens implant have been very happy, and reported no problems with halos or driving at night. Near vision has also been good, with the ability to read newspapers without glasses.

The Symfony lens is now generally available in Singapore, and is also available in a toric version so that patients with significant corneal astigmatism will also stand to beenfit from this lens. As there are no significant side effects with this lens, I routinely offer it to my cataract patients nowadays, who have no other eye conditions and who desire spectacle freedom after surgery.

Secrets in the war to stop shortsightedness from increasing

Trying to stop myopia progression is like deciding to go on a diet. Seriously. I'll get to that eventually but before we get too philosophical, let's take a step back.

Currently, more than 50% of twelve year olds in Singapore need to wear glasses because of myopia. And by the time the boys enter the army at 18 years of age, it will have increased to 80%. Unfortunately, myopia is a problem that continues to worsen as children grow up, usually stabilizing by the late teenage years. By this time, it is not uncommon to see patients with myopia of -6D and above. High myopia of course, can give rise to other problems such as an increased risk of retinal detachments and an earlier onset of cataracts.

Myopia or shortsightedness arises because of an imbalance between the focusing power of the cornea and lens of the eye, versus the length of the eyeball. In the type of myopia that arises in children, it is mainly a problem of the eyeball growing too long, ie axial myopia.

For many decades now, research has been ongoing both to find a cause of this abnormal eyeball growth, as well as to find ways to stop it or at least to slow it down. Because the actual cause and mechanism are not known, methods that have been tried are all based on theories or empirical data. Let's take a look at the things that have been tried.

Things that have been tried and failed

1. Timolol eyedrops to lower eye pressure.
Since eye pressure may potentially stretch an eyeball and make it bigger and longer, people tried to see if lowering the eye pressure could stop the eyeball from enlarging. Unfortunately Timolol eyedrops did not work. However, it remains to be seen whether more powerful pressure lowering medications like bimatoprost may have an effect.

Things that may work (either the evidence or effect is weak)
1. Glasses which reduce peripheral hyperopic defocus (Myovision by Zeiss)
These glasses appeared to have an effect in younger children who had myopic parents. Why it would only work in this subgroup of people is unknown but could reflect a weak effect or a chance finding.
Sankaridurg P, Donovan L, Varnas S, et al. Spectacle lenses designed to reduce progression of myopia: 12-month results. Optom Vis Sci 2010; 87: 631–41. 

2. Rigid gas permeable (RGP, or semi hard) contact lenses
At the age of about 11 I was introduced to 'hard' or RGP contact lenses in the hope that it could slow down the rate of increase of my myopia. In fact in my case, it wasn't that successful in this regard. A well conducted trial showed that RGP lenses do not slow down the growth of the eyeball, but may have an effect by reducing the steepening of the cornea.# This may be only a temporary effect from the pressure of the lens on the eyeball.
#Walline et al. A randomized trial of the effects of rigid contact lenses on myopia progression. Arch Ophthalmol. 2004 Dec;122(12):1760-6.

3.Orthokeratology
Orthokeratology (OK or Corneal Refractive Therapy/CRT) takes the concept of corneal flattening using pressure from a lens one step further. In this method, RGP lenses of a special shape are worn to sleep. The lenses press on the patient's cornea during sleep, so that during the day the lens can be removed, and the cornea retains the ideal shape which corrects the long/shortsightedness and astigmatism. After a few days of not wearing the lens to sleep, this effect is lost, so the power lowering effect is temporary.

But does it stop myopia from increasing?

Walline JJ, Jones LA, Sinnott LT. Corneal reshaping and myopia progression. Br J Ophthalmol. 2009 Sep;93(9):1181-5.

The above study showed that yes, it seemed that orthokeratology can slow down the growth of the eyeball compared with soft contact lenses. This effect is not as strong as 1% atropine eyedrops (0.25mm elongation with OK versus -0.02+/-0.35 mm with atropine at 2 years).

In other words, OK lenses had an effect somewhere between soft contact lenses and 1% atropine, but without the side effects of the atropine. Do consider though, that wearing contact lenses to sleep is generally felt to increase the risk of eye infections.

Things that work (with strong evidence and strong effect)

1. Atropine
The idea of using atropine came about because of its well known ability to relax the ciliary muscles in the eye (which are used for near focusing). Since as the theory goes, too much near work is related to shortsightedness, and near work results in prolonged contraction of this muscle, would relaxing the muscle have an effect on myopia progression? The results of well conducted studies show that yes, indeed atropine has a powerful effect on slowing or stopping the worsening of myopia.

There are two concentrations in common usage: 1% (stronger) and 0.01% (weaker). The 1% concentration is very effective but has side effects of causing sensitivity to bright lights and temporary inability to focus for near. These are reduced by using special progressive glasses that turn dark in bright light. With the 0.01% concentration, there are no side effects but the effects of slowing down myopia are not as pronounced. Which specific medicine is used depends on the degree of shortsightedness, how fast it is progressing and the child's tolerance to the side effects of the stronger concentration. Read more about this at my other post on atropine and myopia.

2. Outdoor time
2 generations ago, it was much less common to see a shortsighted person in Singapore, despite people having essentially the same set of genes. Other things have changed, notably our environment and activities.

Increasingly, evidence points to the importance of outdoor activities in reducing the rates of myopia and its progression.# What is it about being outdoors that slows myopia? Many people think it is because we get to see things far away when we step outdoors, but this effect of distance versus near visual work has been shown to be only a weak one.*
#Rose KA, Morgan IG, Ip J, et al. Outdoor activity reduces the prevalence of myopia in children. Ophthalmology 2008; 115: 1279–85.
*Mutti DO, Mitchell GL, Moeschberger ML, Jones LA, Zadnik K. Parental myopia, near work, school achievement, and children’s refractive error. Invest Ophthalmol Vis Sci 2002; 43: 3633–40.

In fact, it is likely to be due to the difference in amount of light being seen by the eye, when comparing being indoors versus outdoors.

When we step outdoors, even at 5 or 6pm in the evening, we are typically being exposed to much more light than we get even with the brightest lamps indoors. It has been shown that bright light leads to the release of more retinal dopamine, a chemical which may play a role in controlling eye growth. It is intriguing that using a chemical to block dopamine in animals can also block the protective effect of bright light.#
#Ashby RS, Schaeff el F. The eff ect of bright light on lens compensation in chicks. Invest Ophthalmol Vis Sci 2010; 51: 5247–53.

SO.....
It is said that in losing weight, '..., you must accept that this is your new lifestyle of eating healthy and being physically active...' http://www.webmd.com/diet/features/10-diet-secrets-lasting-weight-loss-success

And equally, in trying to control myopia, the patient must accept a new lifestyle of regular outdoor activity (in sunlight) and being more active. At least 1-2 hours everyday. As a follow on from that, it's also important to ensure that when indoors/doing near work, that the child has a brightly illuminated environment. It does not matter what type of light it is (eg sunlight by the window, fluorescent, LED etc), as long as it is bright. Failing which, the most effective treatment so far is atropine eyedrops.

No, wait..... Actually it's easier to control myopia than to go on diet. If only our waistlines would stabilise after a certain age (like myopia), so that we don't have to worry about it any more after that!

References:
Lancet 2012; 379: 1739–48
Ophthalmology 2002;109:415–427

Conjunctivitis: What you should do if you get pink/red eye...

Have you ever had one eye inexpicably and rapidly turn red, swollen and sticky in a day or so, and then horror of horrors, the same thing starts to happen in your other eye?

This condition, medically termed conjunctivitis, is also known as 'red eye' or 'pink eye'. It is an eye infection, affecting the outer 'skin' covering the eyeball called the conjunctiva (hence conjunctiv-itis). There are many different germs that can cause this infection. Most cases are caused by viruses, while occasionally we see cases that are caused by bacteria. Among the viruses that cause this condition, the more common ones include adenoviruses and coronaviruses.

Occasionally this condition is mild, and the eye gets better within a few days. However, many cases of viral conjunctivitis can take much longer to recover fully from. In my experience, the eyes can be red, swollen and sticky for up to 2 weeks before improving.

When things go well, usually the stickiness starts to get less, and the swelling improves. The eyes then become less red, and finally everything including vision goes back to normal.

Complications of conjunctivitis

Sometimes though, complications occur. Some patients get a layer of mucus and dead cells stuck to the inner surface of the eyelids. This is called a 'pseudomembrane' (below), and can make the patient feel very uncomfortable as the pseudomembrane, if located at the upper eyelid, rubs the cornea with each blink.

Another complication is unusual in that it actually occurs as the redness is going away and the eye is starting to feel better. This condition is called 'nummular' (coin shaped) keratitis, and consists of little white spots appearing on the cornea of the eye. This condition can cause vision to become hazy/smoky, and can cause glare in bright lights.

How we treat conjunctivitis

The vast majority of cases have a viral cause, and these are typical in having copious discharge that is watery/mildly sticky and whitish to slightly yellowish in colour. The eyes can be very swollen and red, and on the inner surface of the eyelids there can be small bumps called follicles. These cases are typically treated with combined antibiotic and steroid eyedrops. The steroids help to avoid excessive inflammation and reduce the risk of pseudomembranes. Although the antibiotics do not actually kill the virus, they are a commonly prescribed when steroids are used and may help to reduce the risk of secondary infection by bacteria. There is unfortunately not a lot of evidence to support treatment this way, but patients do seem to feel more comfortable using these medications.

If a patient gets nummular keratitis and little white spots that block vision, then steroids are needed to eliminate the white spots. Unfortunately, once the steroids are stopped, the spots can recur sometimes. Occasionally patients with this complication end up needing a little steroids (eg once a day) for many months to avoid blurry vision. Fortunately most patients recover without experiencing this issue.

The other extremely important issue in managing these infections is to break the transmission cycle ie to avoid spreading it. I advise my patients to observe the following:

1. Wash their hands frequently, and especially every time after touching their affected eye eg when they are instilling eyedrops or cleaning the eye

2. Avoid touching the unaffected eye, and 

3. To tell their family members/close contacts not to touch their eye unless they wash their hands first

4. To tell their family members/close contacts not to apply any eyedrops in the hope of 'preventing' an infection. In fact by instilling eyedrops (especially if contaminated) there is the risk of transmitting the infection to that eye!

Sometimes the virus causing conjunctivitis gets into the throat and causes sore throat/flu like symptoms, in which case that is treated as usual with lozenges, paracetamol (panadol/tylenol), and good old rest.