Eye spots, floaters and flashes

Vitreous detachment and floaters within the eye

Eye floaters are those tiny spots, specks, flecks and “cobwebs” that drift aimlessly around in your field of vision. While annoying, ordinary eye floaters and spots are very common and usually aren’t cause for alarm.

Floaters and spots typically appear when tiny pieces of the eye’s gel-like vitreous break loose within the inner back portion of the eye.

At birth and throughout childhood, the vitreous has a gel-like consistency. But as we age, the vitreous begins to dissolve and liquefy to create a watery centre.

Some undissolved gel particles occasionally will float around in the more liquid centre of the vitreous. These particles can take on many shapes and sizes to become what we refer to as “eye floaters.”

You’ll notice that these spots and eye floaters are particularly pronounced if you gaze at a clear or overcast sky or a computer screen with a white or light-coloured background. You won’t actually be able to see tiny bits of debris floating loose within your eye. Instead, shadows from these floaters are cast on the retina as light passes through the eye, and those tiny shadows are what you see.

You’ll also notice that these specks never seem to stay still when you try to focus on them. Floaters and spots move when your eye and the vitreous gel inside the eye moves, creating the impression that they are “drifting.”

When are eye floaters and flashes a medical emergency?

Noticing a few floaters from time to time is not a cause for concern. However, if you see a shower of floaters and spots, especially if they are accompanied by flashes of light, you should seek medical attention immediately from an optician.

The sudden appearance of these symptoms could mean that the vitreous is pulling away from your retina — a condition called posterior vitreous detachment.

Or it could mean that the retina itself is becoming dislodged from the back of the eye’s inner lining, which contains blood, nutrients and oxygen vital to healthy function. As the vitreous gel tugs on the delicate retina, it might cause a small tear or hole in it. When the retina is torn, vitreous can enter the opening and push the retina farther away from the inner lining of the back of the eye — leading to a retinal detachment.

A detached retina is a medical emergency that requires immediate treatment to prevent permanent vision loss. Treatment consists of surgery to reattach the retina to the back surface of the eyeball, reconnecting it to its source of blood, oxygen and other nutrients.

Posterior vitreous detachments (PVDs) are far more common than retinal detachments and often are not an emergency even when floaters appear suddenly. Some vitreous detachments also can damage the retina by tugging on it, leading to a tear or detachment of a portion of the retina.

What causes eye floaters and spots?

As mentioned above, PVDs are common causes of vitreous floaters, and retinal tears and detachments also can contribute to floaters and spots.

What leads to vitreous detachments in the first place?

As the eye develops, the vitreous gel fills the inside of the back of the eye and presses against the retina and attaches to the surface of the retina. Over time, the vitreous becomes more liquefied in the centre. This sometimes means that the central, more watery vitreous cannot support the weight of the heavier, more peripheral vitreous gel. The peripheral vitreous gel then collapses into the central, liquefied vitreous, detaching from the retina.

It’s estimated that more than half of all people will have a PVD by age 80. Thankfully, most of these vitreous detachments do not lead to a torn or detached retina.

Light flashes during this process mean that traction is being applied to your retina while the PVD takes place. Once the vitreous actually detaches from the retina this traction pressure is eased, and the light flashes should subside.

What causes eye flashes?

Ordinarily, light entering your eye stimulates the retina. This produces an electrical impulse, which the optic nerve transmits to the brain. The brain then interprets this impulse as light or some type of image.

If the retina is mechanically stimulated (physically touched or tugged), a similar electrical impulse is sent to the brain. This impulse is then interpreted as a flash or flicker of light called a photopsia.

When the retina is tugged, torn or detached from the back of the eye, a flash or flicker of light commonly is noticed. Depending on the extent of the traction, tear or detachment, these photopsias might be short-lived or continue indefinitely until the retina is repaired.

Photopsias also may occur after a blow to the head that is capable of shaking the vitreous gel inside the eye. When this occurs, the phenomenon sometimes is called “seeing stars.” In some cases, photopsias are associated with migraine headaches and ocular migraines.

Other conditions associated with eye floaters and flashes

When a PVD is accompanied by bleeding inside the eye (vitreous hemorrhage), it means the traction that occurred may have torn a small blood vessel in the retina.

A vitreous hemorrhage increases the possibility of a retinal tear or detachment. Traction exerted on the retina during a PVD also can lead to development of conditions such as macular holes or puckers.

Vitreous detachments with accompanying eye floaters also may occur in circumstances such as:

  • Inflammation in the eye’s interior
  • Short sightedness
  • Cataract surgery
  • YAG laser eye surgery
  • Diabetes (diabetic vitreopathy)
  • CMV retinitis

Inflammation associated with many conditions such as eye infections can cause the vitreous to liquefy, leading to a PVD.

When you are shortsighted, your eye’s elongated shape also can increase the likelihood of a PVD and accompanying traction on the retina. Shortsighted people also are more likely to have PVDs at a younger age.

PVDs are very common following cataract surgery and a follow-up procedure called a YAG laser capsulotomy.

Months or even years after cataract surgery, it’s not unusual for the thin membrane (or “capsule”) that’s left intact behind the interocular lens (IOL) to become cloudy, affecting vision. This delayed cataract surgery complication is called posterior capsular opacification (PCO).

In the capsulotomy procedure used to treat PCO, a special type of laser focuses energy onto the cloudy capsule, vaporising the central portion of it to create a clear path for light to reach the retina, which restores clear vision.

Manipulations of the eye during cataract surgery and YAG laser capsulotomy procedures cause traction that can lead to posterior vitreous detachments.

How to get rid of eye floaters

Most eye floaters and spots are harmless and merely annoying. Many will fade over time and become less bothersome. In most cases, no eye floaters treatment is required.

However, large persistent floaters can be very bothersome to some people, causing them to seek a way to get rid of eye floaters and spots drifting in their field of view.

But the risks of a virectomy usually outweigh the benefits for eye floater treatment. These risks include surgically induced retinal detachment and serious eye infections. On rare occasions, vitrectomy surgery can cause new or even more floaters. For these reasons, most eye surgeons do not recommend vitrectomy to treat eye floaters and spots.

Laser treatment for floaters

A relatively new laser procedure called laser vitreolysis has been introduced that is a much safer alternative to vitrectomy for eye floater treatment.

In this in-office procedure, a laser beam is projected into the eye through the pupil and is focused on large floaters, which breaks them apart and/or frequently vaporises them so they disappear or become much less bothersome.

To determine if you can benefit from laser vitreolysis to get rid of eye floaters, your optician will consider several factors, including your age, how quickly your symptoms started, what your floaters look like and where they are located.

Many floaters in patients younger than age 45 may be located too close to the retina and can’t be safely treated with laser vitreolysis. Patients with sizable eye floaters located farther away from the retina are better suited to the procedure.

An ophthalmologist who performs laser vitreolysis also will evaluate the shape and borders of your eye floaters. Those with “soft” borders often can be treated successfully. Likewise, sizable floaters that appear suddenly as a result of a posterior vitreous detachment often can be successfully treated with the laser procedure.

What happens during laser vitreolysis

Laser vitreolysis usually is pain-free and can be performed in an eye surgeon’s office. Just prior to the treatment, anesthetic eye drops are applied, and a special type of contact lens is placed on your eye. Then, the surgeon will look through a medical device and deliver the laser energy to the floaters being treated.

During the procedure, you might notice dark spots. These are pieces of broken up floaters. The treatment can take up to a half hour, but it’s usually significantly shorter.

At the end of the procedure, the contact lens is removed, your eye is rinsed with saline and the surgeon will apply an anti-inflammatory eye drop. Additional eye drops may be prescribed for you to use at home.

Sometimes, you may see small dark spots shortly after treatment. These are small gas bubbles that tend to resolve quickly. There also is a chance that you’ll have some mild discomfort, redness or blurry vision immediately after the procedure. These effects are common and typically won’t prevent you from returning to your normal activities immediately following laser vitreolysis.

If you are bothered by large, persistent eye floaters, ask your optician if laser vitreolysis might be a good treatment option for you.

Remember, a sudden appearance of a significant number of eye floaters, especially if they are accompanied by flashes of light or other vision disturbances, could indicate a detached retina or other serious problem in the eye. If you suddenly see new floaters, visit your optician without delay.

 

Source: allboutvision.com

By Marilyn Haddrill; contributions and review by Charles Slonim, MD


Covid19 safety measures in practice update

As the COVID 19 regulations have now eased, we are able to offer routine examinations in addition to examinations for those who may have specific concerns about their vision.

Please contact the practice on 020 7222 0066 or email info@uniaopticians.co.uk to book an appointment.

We are currently available on Monday, Tuesday, Wednesday and Thursday, from 9:30 am to 4.30pm, but please check our website & contact us as these are due to change to allow for more appointments.

We are operating a closed door system, so we can control the number of customers in the practice at any time. All staff are wearing full PPE, and we would request all customers entering the practice to wear a face covering. (This can be provided if patients do not already have one) There are hand sanitiser stations both at the door and throughout the store.

We are able to dispense spectacle frames from our complete range, for prescriptions to be made up, and are sanitising any frames that are tried on after each customer. All equipment & surfaces are also sanitised after each customer visit.

In order to limit face to face contact we are able to carry out OCT scanning & retinal imaging. This enables us to have a fully detailed view of the retina and to detect the potential for many ocular diseases.

We look forward to seeing you soon.

The Unia Team.

 


Cataracts: Types, symptoms and treatments

Cataract is the clouding of the eye’s natural lens. It is the most common cause of vision loss in people over age 40 and is also the principal cause of blindness in the world. Types of cataracts include:

  • A subcapsular cataract occurs at the back of the lens. People with diabetes or those taking high doses of steroid medications have a greater risk of developing a subcapsular cataract.
  • A nuclear cataract forms deep in the central zone (nucleus) of the lens. Nuclear cataracts usually are associated with ageing.
  • A cortical cataract is characterised by white, wedge-like opacities that start in the periphery of the lens and work their way to the centre in a spoke-like fashion. This type of cataract occurs in the lens cortex, which is the part of the lens that surrounds the central nucleus.
Cataract symptoms and signs

At first, a cataract has little effect on your vision. You may notice that your vision is blurred a little, like looking through a cloudy piece of glass or viewing an impressionist painting.

Hazy, blurred vision may mean you have a cataract.

A cataract may make light from the sun or a lamp seem too bright or glaring. Or you may notice when you drive at night that the oncoming headlights cause more glare than before. Colours may not appear as bright as they once did.

The type of cataract you have will affect exactly which symptoms you experience and how soon they will occur. When a nuclear cataract first develops, it can bring about a temporary improvement in your near vision, called “second sight.”

Unfortunately, the improved vision is short-lived and will disappear as the cataract worsens. On the other hand, a subcapsular cataract may not produce any symptoms until it’s well-developed.

If you think you have a cataract, see an optician for an exam to find out for sure.

What causes cataracts?

The lens inside the eye works much like a camera lens, focusing light onto the retina for clear vision. It also adjusts the eye’s focus, letting us see things clearly both up close and far away.

The lens is mostly made of water and protein. The protein is arranged in a precise way that keeps the lens clear and lets light pass through it.

But as we age, some of the protein may clump together and start to cloud a small area of the lens. This is a cataract, and over time, it may grow larger and cloud more of the lens, making it harder to see.

No one knows for sure why the eye’s lens changes as we age, forming cataracts. But researchers worldwide have identified factors that may cause cataracts or are associated with cataract development.

Besides advancing age, cataract risk factors include:

  • Ultraviolet radiation
  • Diabetes
  • Hypertension
  • Obesity
  • Smoking
  • Prolonged use of corticosteroid medications
  • Statin medicines used to reduce cholesterol
  • Previous eye injury or inflammation
  • Previous eye surgery
  • Hormone replacement therapy
  • Significant alcohol consumption
  • High myopia (short sightedness)
  • Family history

One theory of cataract formation is that many cataracts are caused by oxidative changes in the human lens. This is supported by nutrition studies that show fruits and vegetables high in antioxidants may help prevent certain types of cataracts.

Cataract prevention

Though there is significant controversy about whether cataracts can be prevented, a number of studies suggest certain nutrients and nutritional supplements may reduce your risk of cataracts.

One 10-year study of female health professionals found that higher dietary intakes of vitamin E and the carotenoids lutein and zeaxanthin from food and supplements were associated with significantly decreased risks of cataract.

Good food sources of vitamin E include sunflower seeds, almonds and spinach. Good sources of lutein and zeaxanthin include spinach, kale and other green, leafy vegetables.

Other studies have shown antioxidant vitamins such as vitamin C and foods containing omega-3 fatty acids may reduce cataract risk.

Another step you can take to reduce your risk of cataracts is to wear sunglasses that block 100 percent of the sun’s UV rays when you are outdoors.

Cataract treatment

When symptoms begin to appear, you may be able to improve your vision for a while using new glasses, strong bifocals, magnification, appropriate lighting or other visual aids.

Think about surgery when your cataracts have progressed enough to seriously impair your vision and affect your daily life.

Many people consider poor vision an inevitable fact of ageing, but cataract surgery is a simple, relatively painless procedure to regain vision.

During surgery, the surgeon will remove your clouded lens and in most cases replace it with a clear, plastic intraocular lens (IOL).

New IOLs are being developed to make the surgery less complicated for surgeons and the lenses more helpful to patients. Presbyopia-correcting IOLs potentially help you see at all distances, not just one. Another new type of IOL blocks both ultraviolet radiation and high-energy visible blue light, which research indicates may damage the retina.

Eyewear after cataract surgery

In most cases, unless you choose presbyopia-correcting IOLs, you will still need reading glasses after cataract surgery. You may also need progressive lenses to correct mild residual refractive errors as well as presbyopia.

For the best vision and comfort possible with glasses prescribed after cataract surgery, ask your optician to explain the benefits of anti-reflective coating and photochromic lenses.

 

Source:

www.allaboutvision.com/en-gb/conditions/cataracts/


Hayfever – a guide to looking after your eyes

The hay fever season runs from spring through to autumn and affects nearly 18 million people in the UK. Hay fever sufferers have allergic reactions to different types of pollen, which include itchy eyes and nose, sneezing, runny or blocked nose and difficulty in breathing. Pollen grains can set off an allergic reaction as the conjunctiva (the transparent membrane covering the white of the eye) becomes inflamed causing watery, red, itchy eyes. The whites of your eyes may swell up and you may also experience a gritty feeling in your eyes.

Managing your hay fever:
  • Stay indoors – when there is a high pollen count, keep windows and doors closed and keep surfaces clear with a damp duster. Avoid going out in the early evening and midmorning when the pollen count is at its highest.
  • Wear sunglasses when you are outdoors – wraparound glasses offer more protection from pollen.
  • Wear glasses rather than your contact lenses – especially when the pollen count is high.
  • Change your clothes and have a shower – if you have been outside for a while, you may have pollen on your clothes, skin and hair. Taking a shower and changing your clothes can help.
    Bathe your eyes regularly in cold water.
  • Apply petroleum jelly to your nostrils – this will trap pollen.

 

Treating your hay fever:
  • Anti-allergy eye drops – these act as a protective defence. If you wear contact lenses remember to check if you can use the drops while your lenses are in. The College has produced an infographic which gives guidance on the best time to start taking eye drops depending on your allergy.
  • Antihistamines – in people with allergies, the body mistakes something harmless, such as pollen, for a threat and produces histamine, which causes symptoms such as rashes, a runny nose and/or sneezing. Taking Antihistamines before you come into contact with pollen can prevent this happening or can help reduce the severity of the symptoms if taken afterwards.
  • Steroid eye drops – these are very effective but can have serious side effects, such as glaucoma, cataracts and damage to the cornea. They are only available on prescription.

Source:

College of Optometrists website . Lookafter your eyes – Hay fever


Aritificial intelligence used to develop an early warning system for AMD

Researchers at Moorfields Eye Hospital and UCL Institute of Ophthalmology have developed an artificial intelligence (AI) system that can help predict whether people with age-related macular degeneration (AMD) will develop the more serious form of the condition in their ‘good eye’. This is part of our wider, ongoing partnership with DeepMind and Google Health.

AMD involves damage to the macula, the central part of the retina at the back of the eye. AMD causes loss of central vision, affecting the ability to read, drive, watch television, recognise faces, and many other activities of daily living. It is very common that patients develop wet AMD in one eye and start receiving treatment, before later developing it in their other eye.

Macular degeneration mainly affects central vision, causing “blind spots” directly ahead (Macular Society).

 

The AI system developed by Moorfields, researchers from DeepMind, and Google Health, may allow closer monitoring of the “good eye” in patients at high risk, or even guide use of preventative treatments in the future.

Pearse Keane, consultant ophthalmologist at Moorfields Eye Hospital, said:

“Patients who have lost vision from wet AMD are often particularly worried that their “good eye” will become affected and, as a result, that they will become blind. We hope that this AI system can be used as an early warning system for this condition and thus help preserve sight.”

“We are already beginning to think about how this will let us plan clinical trials of preventative therapies – for example, by treating eyes at high risk earlier.”

“With this work, we haven’t solved AMD, but we believe we have found another big piece of the puzzle.”

Reena Chopra, research optometrist at Moorfields Eye Hospital, said:

“We found that the ophthalmologists and optometrists in our study had some intuition into which eyes will progress to wet AMD. The AI was able to outperform them, indicating there are signals within OCT scans that only the AI can detect. This unlocks new areas of research into a disease where there are still many unanswered questions about how it develops.”

Source:

Read the paper in Nature Medicine.

Read the Google Health blog and DeepMind technical blog.


How Does the Eye Work?

The human eye is a wonder of engineering. It consists of many different parts that work together to provide visual information to the brain, which then translates it into information that is useful to the body.

Parts of the eye

1. The cornea

The first step in this complex process occurs when light passes through the clear slightly convex cornea at the very front of the eye. This is the transparent part of the eyeball.

A thick white sheath called the sclera surrounds the rest of the eyeball. The cornea refracts light slightly. The narrow, liquid-filled space behind the cornea is called the aqueous humor. This drains through spaces at the medial corner of the eye, and is constantly renewed.

2. The iris

The iris is a colored diaphragm of thin circular and longitudinal muscle fibers just behind the cornea. It has an aperture in the center. This can expand or contract to let in more or less light, respectively, depending on the light in the surroundings.

This opening is called the pupil. Light passing through the cornea and the pupil falls on the anterior surface of the lens. The aqueous humor keeps the iris from sticking to the lens behind and the cornea in front.

3. The lens

The lens is a clear crystalline globe which almost touches the posterior surface of the pupillary opening. The ciliary muscles are attached to the surface of the lens. The help the lens to change shape in order to focus.

As they contract, they cause the lens to become more round or long, so that the rays bend more or less, according to need. If the object focused on is far away, the lens needs to bend the light rays from it more sharply, to make them fall on the center of the retina, where vision is sharpest. For objects close-up, the lens becomes elongated so that light rays are bent less.

4. The posterior chamber

The refracted rays now pass through the jelly-like tissue that fills out the eyeball behind the lens. This part is called the posterior chamber. At the back, the eyeball is bounded by the choroid, a network of capillaries which nourishes all the structures of the eye.

In front of it lies the retinal pigment epithelium, a layer of melanin-rich cells which supplies special nutrition to the sensory layer of the eye. The retina is nourished and renewed by the pigment epithelial cells.

5. The retina

The retina is a multilayer membrane comprising a sensory photoreceptor array, a few layers of connecting neurons and an inner ganglion cell layer. The axons from the ganglion cells travel backward to pierce the retina and leave the eye through the optic nerve. There is a blind spot in the retina where the ganglion cells pass through.

Rods and cones

The photoreceptors in the eye consist of rod and cone cells. The rods are found mostly in the peripheral part of the retina and are responsible for perception of light and dark, including shades of gray. They are more numerous than cones, and are very sensitive to light.

The cone cells are responsible for visual acuity and color vision, and millions of them are closely assembled in the central part of the retina, also called the macula. At the fovea, which is the central point of the macula, only cones are present, and normal vision uses this point to achieve sharp vision at maximum resolution.

The pathway of vision
As the light rays fall on the photoreceptor cells, changes occur in the pigments they contain. This leads to bleaching of the pigments, and electrical impulses are generated. These are transmitted through a chain of neurons to the ganglion cells which carry the impulses to the visual cortex of the brain. There they are processed and the object is seen.

Each eye receives information from half of the visual field. Thus the middle parts of both fields overlap, and this leads to binocular vision. However, the difference in the peripheral parts of the left and right fields of vision lead to depth perception or three-dimensional vision. It helps in gauging distances accurately and estimating the depths and dimensions of objects.

Sources:

The Structure and Function of the Eyes, www.merckmanuals.com/…/structure-and-function-of-the-eyes
Healthy Eyes Facts, https://nei.nih.gov/health/healthyeyes
Eye and its Function, http://www.pages.drexel.edu/~dh329/bmes212/eyeFunction.html
Last Updated: Feb 26, 2019

Written by Dr. Liji Thomas


Covid19 safety measures in practice

As guidelines continually change, we are now open for emergency and essential eyecare.
This means that if you have any concerns about your vision or you are feeling anxious about your
eyes, we are now able to see you, on an appointment only basis.

This also includes circumstances where you would like to update your prescription where a change
has occurred, if you require a spare pair of glasses, repairs, wish to purchase sunglasses or where
your contact lens supply is due.

However, it is still necessary for you to call or email the practice first so that we can best manage
appointments to minimize face to face contact.

Where a prescription is out of date, in the absence of any problems, a telephone consultation/video
call can be arranged to verify that all is well before the glasses are dispensed.
All routine eye examinations remain suspended in the UK.

In order to maintain social distancing within the practice, we are operating a closed-door policy.
We would like to reassure you that we are following strict hygiene and sanitizing practices within the
consulting room and throughout the store so that everyone remains safe and all staff will be wearing
the necessary PPE.

Currently, the frames may not be directly accessible to touch on the shelves, however they can still
be viewed and tried on, as many as desired. All frames that have been handled, will be thoroughly
sanitized to ensure safety for successive patients. Wherever possible, when ready, spectacles will be
posted to patent’s homes to avoid unnecessary travel/risk.

Contact lens patients will be able to reorder a routine supply of contact lenses and in most cases,
these can be delivered directly to homes. Where a contact lens after care is due, in the absence
of any problems, a telephone/video call can be arranged to verify that all is well before the lenses
are ordered. Patients will then be asked to return for a full after care appointment once guidelines
change/as necessary.

Contact lens solutions, eye drops, supplements and other accessories will still be available.
Again, these can be posted out to patient homes to prevent unnecessary travel to the practice.
If you are feeling unwell or have been in contact with someone with Covid 19 we advise you not
to attend the practice until it is safe to do so. If any patient is unsure of their symptoms, they are
advised to call NHS 111 for advice.

We look forward to welcoming you back soon, albeit to a new ‘normal’

Best wishes

The Unia Team