Ask an Ophthalmologist: Dr Errol Chan from Paragon Medical Centre

Ask a Doctor ForumCategory: OphthalmologyAsk an Ophthalmologist: Dr Errol Chan from Paragon Medical Centre
Avatar photoDr Errol Chan asked 2 years ago
I am Dr Errol Chan, Consultant Ophthalmologist at LSC Eye Clinic, Paragon Medical Centre. I am also currently Visiting Consultant Ophthalmologist with the Vitreoretinal Service at the Department of Ophthalmology, National University Hospital. I was formerly Consultant Ophthalmologist, Cataract and Vitreoretinal surgeon in the UK.

I consult for adult and children patients with a wide range of eye conditions. My practice centers on all aspects of general and emergency ophthalmology, with special expertise in cataract and complicated lens surgery, uveitis, and the medical and surgical treatment of retinal diseases. I offer a broad and current range of treatment options for diseases such as retinal detachment, macular degeneration, diabetic retinopathy and retinal vein occlusions.

Born and raised in Singapore, I graduated MBBS from the National University of Singapore with Distinction and placement on the Dean’s List, and completed Ophthalmology specialist training at the National University Health System.

I was awarded a scholarship by the Retina Foundation of Canada to pursue a Vitreoretinal Surgery Fellowship at McGill University in Canada, well-regarded for its high-volume retinal surgery program. I was also accepted in the highly-selective Vitreoretinal Surgery Fellowship, as well as the Medical Retina and Uveitis Fellowship, at the world-renowned Moorfields Eye Hospital London in the UK.

My clinical experience extends to providing a wide range of intraocular lens options for patients with cataracts, particularly individuals desiring spectacle-freedom. As a vitreoretinal surgeon, my special interests also include complex cataract and secondary intraocular lens surgeries, including iris- and scleral-fixated implants. Learn more about me here:
I am excited to be here to share and discuss about eye diseases and eye conditions with everyone. I will be actively answering questions. If you have any questions about cataract surgery, vitreoretinal surgery, retinal diseases, lens surgery, macular degeneration, diabetic eye disease, as well as in retinal vascular, choroidal, and uveitic eye conditions, feel free to ask me! === Want to ask a question? Submit your question at the bottom of this page. Don’t forget to include your name and email address to get notified when the doctor answers your question.
17 Answers
Catherine answered 2 years ago

Hi Dr Chan. I am a 43 years old woman who works in front of the computer screen everyday. I have a high degree of myopia. Most days I wear contact lenses. Recently, I realised my contact lens have been giving me a sharp pain in my temples and they irritate my eyes. I have tried eye drops but they don’t seem to help. What is happening here? Is it because of my screen activity or is my myopia getting worse?

Dr Errol Chan replied 2 years ago

Hi Catherine!

I am sorry to hear that you have been struggling – the most likely explanation for your symptoms is that of digital eye strain.

Frequent use of computers or any digital devices, especially for a long time, do cause quite a bit of eye strain. There are multiple reasons for this – this articles which I’ve authored previously discusses these reasons (

The usage of contact lenses certainly compounds the problem because contact lenses alters the tear film on the eye. In order to see well and to feel comfortable, we need a nice layer of tears coating the eye surface.

Eye strain for near work is particularly felt once one reaches the mid 40s, when the effects of lao hua (i.e., presbyopia) start to become more apparent. So this is just about the time when you may notice problems with near work.

Choosing the most appropriate lubricant drop is important. This article I’ve written previously discusses some of lubricating eye drop options and other strategies (reducing screen time and ensuring your prescription is up to date!) which you can use to alleviate such symptoms (

Having said that, I do think it is quite important that at some point you have an eye examination by an eye specialist to ensure that there is nothing else causing these symptoms. A cataract is quite commonplace, and it is important to ensure that it is you do not have any early cataracts causing a change in your spectacle or contact lens prescription. Also, if surface dryness is found to be significant, then there are several other treatment options that can help with your symptoms.

Marie answered 2 years ago

I recently changed my brand of contact lens and noticed after I did so, I experienced redness in my eyes and saw brown spots floating. This happens even when I am not wearing the new contact lens. Does this mean the contact lens are not suitable for my eyes? Do I need to see an eye doctor?

Dr Errol Chan replied 2 years ago

Hello Marie!

What is slightly troubling to me is that you are having redness even when you are not wearing your contact lenses, and that you were seeing floating brown spots.

I do think it is important that you have a consultation with an eye doctor soon to make sure that you don’t have an infection going on with your eyes relating to these contact lenses.

This would be the first priority before determining if these contact lenses are suitable for you.

Shamol answered 2 years ago

Four months after having cataract surgery, my aunt has been complaining that her eyes always get watery after 1-2 hours of screen time. She also feels a sharp stabbing pain when they get watery. Is this due to tiredness or has it got something to do with her cataracts/cataract surgery?

Dr Errol Chan replied 2 years ago

Dear Shamol,

Happy to help!

It does sound that your aunt has been having drying of her eye surface based on these symptoms. Paradoxically you will hear us refer to it as “dry eye” despite there being watering, because the watering is in fact the eye’s reflex response to a surface that is lacking moisturisation.

Dry eye syndrome is indeed quite common place, and there are multiple factors that can worsen it, recent surgery and hormonal changes being some of them.

I would recommend an eye surface lubricant according to these suggestions in an article I’ve written ( Equally important is also reducing the amount of screen time as well!

There are several other treatment options that will help improve surface dryness if these first-line measure don’t quite work, and it would be helpful for your aunt to consult with an eye specialist further in order to tailor the treatment accordingly!

Emerlyn answered 2 years ago

Hi Dr Chan. My right eye pupil is noticeably smaller than my left. I haven’t experienced any other symptoms though. Is this a cause for concern?

Dr Errol Chan replied 2 years ago

Dear Emerlyn,

Thanks for reaching out and I can understand your concern.

Indeed this is something that warrants an evaluation by an eye specialist. The prime reason is that a difference in pupil size between the eyes can be an indicator of a more sinister underlying disease condition in the head and neck.

A difference in pupil size has many possible reasons. Pupil size is determined not only by the function of tiny muscles in the iris, but also by the nerves that supply input to the iris muscles. These nerves originate in the brain and travel through a very convoluted route to the eyeball. Some of these nerve fibres even go down into the neck region as well. Disease anywhere along this pathway, even if very slight, can therefore cause a difference in pupil size.

A detailed evaluation by an eye specialist, using a series of eyedrops, and/or imaging of the brain, spinal cord, major blood vessels, and lungs would be important in making sure there isn’t any significant diseases affecting these areas. Important conditions that will need to be ruled out are a lung or brain tumour, abnormally enlarged blood vessels (i.e., aneurysms), or diseases affecting the peripheral nerves.

Having said that, there are indeed patients who have a naturally slightly larger pupil than the other, i.e., these individuals were born with it. These individuals are normal and do not have disease. This difference in pupil size goes unnoticed until one day, which could well be the case in your situation.

The bottom-line message I have is that you will need to be seen by an eye doctor soonest to have this assessed appropriately!

Boon Teck answered 2 years ago
Hello doctor. I have a 6 year old daughter who loves swimming. Over the weekend, after swimming, her eyes were unusually red. Yesterday morning, there was a lot of tearing and wax discharge from her eyes. We gave her eyedrops from a pharmacy. This morning, the redness is relieved, but she said her eyesight is blurry. Does this sound like a serious condition? Should I bring her to an eye specialist?
Dr Errol Chan replied 2 years ago

Dear Boon Teck,

Great that your daughter enjoys swimming!

Based on the information you have provided, it is very possible that your daughter could have developed a bit of corneal chemical toxicity from the chlorine in the pool, or an infection. An infection is however less likely unless she has been swimming in a fresh water pond. Chlorinated pool water if in prolonged contact with the eyes can irritate the eyes, causing eye redness as well as numerous dry spots on the cornea. These dry spots on the cornea can blur the vision.

There are drops from the retail pharmacy i.e. Naphcon-A which help relieve eye redness but do not deal with the underlying cause (i.e., be it infection or chemical toxicity) causing the redness.

In the first instance, I would suggest using an over the counter lubricant (e.g., Refresh plus or Tears naturale preservative-free) for a day every 2-3 hourly first. It is important that you use lubricants which do not contain preservatives since these preservatives often irritate the eyes as well. These drops can be bought at the usual retail pharmacies. If the blurry vision symptoms do not subside it would make sense for her to have a consultation with an eye specialist.

Ruth Liu answered 2 years ago

I have undergone cataract surgery for both of my eyes. The first surgery was in January, and the second one was last month. I have been feeling fine. But two days ago, I felt like my eyes were itchy all the time and as a result, I kept rubbing my eyes. This morning, both of my eyes were painful. Is this related to my cataract issue? Should I just apply eye drops or see an ophthalmologist?

Dr Errol Chan replied 1 year ago

Hello Ruth!

Sorry to hear about your eyes. Your symptoms are most likely not related to your cataract surgery procedures. Inflammation, infections, or drying of the eye surface, or blockage of the oil-producing ducts can all cause a combination of itchiness and pain.

What you could do for a start is to use some eye lubricants (e.g., Systane or Refresh) a couple of times a day, as well as some warm compresses to the eyelid. If these are not better it is more likely than not that something more significant is causing these symptoms – I am happy to see you in clinic!

Ganesh answered 2 years ago
My mother was diagnosed with Diabetic Retinopathy. I’ve heard that the treatment for it cannot cure it, and is only for management of the condition. Is that true? Can the condition be managed only by managing her diabetes?
Dr Errol Chan replied 1 year ago

Hi Ganesh!

Happy to discuss your mother's situation. I will provide some general comments, however if you need more specific advice it would be helpful to have your mother's scans on hand.

The specific management plan tailored for each patient with diabetic retinopathy hinges on how severe the condition is. Diabetic retinopathy can range from very mild (involving tiny blood vessel changes), to moderately severe (fluid leakage, or sprouting of abnormal blood vessels), to very severe (overt bleeds into the vitreous gel, or scarring on the retinal surface causing retinal detachments).

It is important to mention that the mildest form of the disease does not affect vision. At this stage, diabetic retinopathy can be successfully managed simply with good diabetes management. The blood vessel changes can well resolve if sugars, blood pressure and cholesterol levels are consistently controlled well.

If diabetic retinopathy is more severe and affects vision, then laser treatment or injection of medications into the eye. Such treatment can certainly improve vision, however I must equally emphasize that the success of treatment also hinges on good diabetes control as well. Vitrectomy surgery is performed for patients with significant bleeds, retinal scarring, or retinal detachments.

Patrick answered 1 year ago

My uncle has just developed glaucoma. I read online that the procedures, both surgical and non-surgical, do not aim to cure glaucoma but only serve to stop the regression. Is that true? What is the best thing we can do to treat it?

Dr Errol Chan replied 1 year ago

Dear Patrick,

Thank you for writing.

Glaucoma is a very common degenerative condition of the nerve responsible for vision, and high pressures within the eyeball (this is not the same as blood pressure!) is the main reason causing that degeneration. The risk of glaucoma increases with age. When diagnosed early, glaucoma affects the peripheral vision, and thus the patient is at first unaware of even having the condition. Glaucoma in its late stages progresses on to affect the central vision, and it is at this stage that patients experience profound losses in vision.

You are quite right to say that any treatment for glaucoma does not cure the condition, because whatever established degeneration of the nerve remains. Further treatment of controlling the eye pressures at an acceptable level preserves existing nerve tissue, and prevents further damage. Your eye doctor would usually advise on a target level of eye pressure to achieve. Glaucoma is a life-long condition from the point of diagnosis, just as diabetes and hypertension are, and requires longer-term monitoring. The silver lining for all this is that despite being a chronic condition, glaucoma if diagnosed early is eminently treatable, in that with treatment and regular and appropriate clinical monitoring, there is no good reason why any glaucoma patient would lose their vision from this disease.

Non-surgical treatment refers to eye drops to lower pressures within the eyeball, or laser treatments. Medications are usually the first-line treatment, and certainly, some patients may require more than one type of eye drop. Selective laser trabeculoplasty (SLT) can be used to relieve the eye drop medication burden on patients who are on several medications. In angle closure glaucoma, a subtype of glaucoma due to a narrow outflow pathway, laser peripheral iridotomy (LPI) is effective in improving the outflow.

If eye drops do not sufficiently lower the eye pressure, then surgery would usually be required. Surgical treatments aim to create an alternative outflow pathway allowing easier exit of the fluid from within the eyeball, so lowering eye pressures.

The best advice I can give for a patient with glaucoma is to take your eye medications as prescribed, and do keep up with regular follow-up monitoring visits! Also – as is sometimes asked by my glaucoma patients – there is in general no specific dietary or activity limitation to be adhered to.

Thiam Teck answered 1 year ago

Dr Chan, I have astigmatism. I don’t remember when it first started, but I think I’ve had it since childhood. I am now 23 years old and have also developed a lazy eye in my left eye. Is there still time for me to fix the astigmatism and the lazy eye? Will my eye condition get worse if i leave it untreated?

Dr Errol Chan replied 1 year ago

Hi Thiam Teck!

Many normal individuals actually have a greater or lesser degree of astigmatism so astigmatism per se is not considered to be an actual “eye disease”. However, high astigmatism raises some concern, especially when it is quite different from the astigmatism level in the other eye, because this is one of the signs of keratoconus, which is fairly common corneal degenerative condition affecting younger individuals in the teens to early adulthood.

I think it is quite unusual for you to have developed a “lazy eye” whilst in your teens or early adulthood. A lazy eye by definition develops during the period of visual development, i.e., before the age of 7 years. It is an eye that despite the best possible spectacle prescription, still cannot see well. Which probably means that any poor vision in your supposed “lazy eye” may in fact not be a true “lazy eye”, and came about because of some new development in the last couple of years.

Based on your account, I do think that it is important that you see an eye specialist to have the appropriate testing done to ensure you do not have keratoconus, or any other significant eye disease affecting your eye with poorer vision! This needs to be clarified first before any discussion on what treatments can be done to help improve your vision, and also before answering any questions whether your condition would get worse!

Savitah answered 1 year ago

When I am tired, my eyelids twitch and my temples throb. I will also experience blurry vision. Is this normal?

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