AMBLYOPIA (LAZY EYE)

Amblyopia is clinically defined as reduced vision in one or both eyes, caused by abnormal interaction between both eyes during the critical period (age 2-8 years) of visual development. Often, amblyopia is referred to as “lazy eye” by the general public because one eye has reduced vision compared to another eye. It occurs early in life when the developing visual system fails to transmit a sharp image to the brain due to an eye disorder. If it is not treated promptly before the end of the critical period, the brain will begin to ignore the blurred image from the affected eye. This results in poor 3D vision and reduced vision.

Amblyopia usually affects one eye but can also affect both eyes. Risk factors of amblyopia including deprivation of visual stimuli, uncorrected refractive error, and non-corresponding images received by strabismic (squinting) eyes.

Deprivation of stimuli occurs when eye diseases prevent the light stimulus from reaching the retina, thus obstructing the normal visual process. It may occur due to anatomical abnormalities of the eye or abnormal eye movements, such as congenital cataract, blepharoptosis (droopy lid) and nystagmus (shaking eye) disorders.

Most children do not complain about the blurred vision until it significantly affects their daily activities. Some of them only show signs which are noticed by their teachers. A major cause of poor vision amongst children is uncorrected refractive error and if left untreated, amblyopia sets in. The child may develop anisometropia when there is a difference in the state of refraction of at least 1 diopter between both eyes.

A squint, also known as strabismus is where the eyes point in different directions. One of the eyes may turn in, out, up or down while the other look looks straight ahead. As a result, the eyes do not receive equal images, thus causing the visual system to attempt to adapt to this abnormal image interaction. In a child, the brain will tend to suppress the image from the squinting eye to avoid double vision. This causes a restructuring of the visual cortical circuitry in the brain which leads to amblyopia. However, not all patients with squint eye(s) will develop amblyopia.

The current gold standard of treatment for amblyopia is patching of the better eye. This is to “force” the brain to use the weaker “lazy” eye. Depriving the other good eye of vision, forces the amblyopic eye to halt this cortical suppression and to re-establish cortical connections with the corresponding part of the brain for better vision. Alternatives to patching the eye include the use of atropine eye drops or filters, optical defocus spectacles or contact lenses, and dichoptic video games. Children with cataracts, blepharoptosis, strabismus and nystagmus, will usually require surgical correction before any patching therapy.

by Evix Daud Consultant Optometrist & Contact Lens Specialist

We’ve always heard about wisdom teeth but how much do we actually know? They can be really painful and should be extracted as soon as possible, at least that’s as much as I know. With Dr. Sylvia Lim of Phi Dental, let’s take a look at all there is to learn about wisdom teeth together.

Wisdom teeth, also known as third molars, are the last permanent teeth to appear. Usually, they appear when a person is between 17 and 25 years old. Weirdly, we don’t really need them, but most healthcare providers think they’re vestigial. They may have served a purpose at some point, but not anymore. It may be due to the diet of our ancestors that mainly consists of raw plants, hard nuts, and tough meats. Wisdom teeth were necessary to grind these foods properly for digestion.

Today, they can cause certain issues to our oral health. For most, wisdom teeth appear normally and cause no problems. To some, the wisdom teeth become stuck below the surface of the gums, growing in an odd angle, and causing complications. They can become impacted in the jaw and result in infection, causing damage to other teeth roots or bones.

So how do you know if you have wisdom teeth? Well, the gums become swollen or are bleeding, jaw pain, bad breath, unpleasant taste, and difficulty opening the mouth. The best way to treat wisdom teeth is to surgically extract it, especially if it’s causing infection or gum disease (periodontal disease). The good thing is, once you’ve removed the wisdom tooth completely, it’s unlikely to relapse.

I do need to mention, people with wisdom teeth can actually go on with their lives without extracting it. The wisdom teeth don’t usually need to be removed if they’re impacted but aren’t causing any issues. This is because there’s no proven benefit of doing extractions and it can carry the risk of other complications.

At the end of the day, you should always consult your dentist before making any important decisions regarding your oral health.

by Noel Jinguli Image | Unsplash