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Flashes & Floaters and Retinal Detachment

Flashes and Floaters - Retinal Detachment

The specialists at Eye Institute are acknowledged leaders in ophthalmology, including vitreo-retinal surgery, refractive surgery, laser, cataract and glaucoma surgery. We also offer expertise in retina, squint, eyelid surgery, eye infections and inflammation, and neuro-ophthalmology.

The eye is a ball of about 2.5cm diameter. The cornea and lens at the front of the eye focus light onto the retina (Figure 1). The eye is similar to a camera, with the focusing lenses in front, and the light sensitive film (retina) lining the back. The retina transforms light into electrical impulses, which travel up the optic nerve to the brain. The vitreous is the clear gel (jelly) which fills up the space inside the eyeball, behind the iris (the blue or brown part) and the lens, while the retina lines the inside of the wall of the eye10


Cataract Surgery Information
Diabetic Retinopathy
Dry Eyes or Sjögren’s Syndrome
Epiretinal Membranes
Eyelid Surgery and Appearance Medicine
Glaucoma - the thief of sight
Flashes & Floaters and Retinal Detachment
Implantable Contact Lens FAQ's
Laser Capsulotomy
Macular Degeneration
Macular Hole
Pterygium & Pinguecula
Retinal Vein Occlusions
Vitrectomy Surgery


Floaters & Flashes
These occur with age changes in the clear vitreous gel. Parts of the gel become liquid, pushing the remains of the gel forward, a condition called posterior vitreous detachment. At the same time opacities frequently form at the liquid-gel interface (Figure 2). 

These are seen as floaters. They are common, and harmless in themselves. However, with this degeneration in the vitreous, there is sometimes associated pulling on the retina, as in places the vitreous is adherent to the retina. Pulling on the retina causes the sensation of flashes. If this pulling is severe enough, a hole or tear may occur in the retina. Then liquid vitreous may pass through the hole, peeling the retina off the back wall of the eye (Figure 3), which is a retinal detachment. Sometimes also there may be enough floaters or they are in such an annoying position that people want to remove them, which can be done.

What should you do if you have floaters or flashes?

  1. If you have had occasional floaters for years, don’t worry. The chance of retinal detachment is small.

  2. If you suddenly notice floaters, or experience at sudden increase in floaters, you should have your eyes examined promptly. This examination is to search for any retinal tears. If a tear is found before a retinal detachment occurs, laser or cryotherapy can be used to weld down the tear and reduce the chance of a later retinal detachment.

  3. If you develop flashing lights, seen usually at night, again you should have your eyes examined promptly. Flashing lights mean pulling on the retina and the risk of detachment is significant. However there are other possible causes of flashes, one of which is migraine. Nevertheless the sudden onset of flashes demands prompt examination of the retina. Floaters and flashes are warning symptoms which demand prompt examination, but most people who experience them never develop a retinal detachment.
FIGURE 2: POSTERIOR VITREOUS DETACHMENT WITH VITREORETINAL ADHESION (arrow) Strong focal traction may cause a retinal tear.

Retinal Detachment
A retinal detachment occurs when the retina peels off the inside of the back wall of the eye. When detached, the retina does not function, so that when part of the retina is detached there is a gap in the vision and when the whole retina is detached the eye is blind. Retinal detachment occurs in about 0.01% of the population, but is more common in myopic (shortsighted) eyes.

Symptoms of Retinal Detachment
Retinal detachment itself causes a sudden loss of part or all of the vision in the eye. It does not cause any pain. In many cases, as explained, a retinal detachment is preceded by floaters and flashing lights.

Treatment for Retinal Tears
As mentioned, retinal tears can be welded down with a laser or cryotherapy (freezing). However a few retinal tears are better left, a decision which needs to be made by your eye specialist. Treatment of retinal tears causes little or no discomfort and is performed as an outpatient.

Treatment for Retinal Detachment

Almost all retinal detachments require surgery, which should be carried out within a few days..

Retinal Detachment Operations
All retinal detachments are different, and the characteristics of the detachment determine the type of surgery. In most cases the surgery is done under local anaesthetic, although general anaesthesia may be preferable in certain circumstances.

  • Pneumatic Retinopexy -
    This technique is reserved for the least complicated detachments. A gas bubble is injected into the vitreous. It prevents liquid from travelling through the retinal tear and thus the retina re-attaches. At the same time or later, either laser or cryotherapy is used to seal the retinal tear to the back wall of the eye. It is necessary to stay in a particular posture for a few days afterwards to keep the bubble in the correct position.

  • Scleral Buckle -
    A piece of silicone is sutured onto the wall of the eye to counteract the force pulling the retina out of place. This is often combined with draining fluid from inside the eye and with injecting gas.

  • Vitrectomy -
    The vitreous gel, which is pulling on the retina, is removed from the eye. This is usually combined with injection of gas or silicone oil, and often also with a scleral buckle. This combined technique is often reserved for more complicated detachments.

After Eye Surgery
There is usually some discomfort after surgery. If gas has been inserted, then it may be necessary to assume a particular head position for a few days. Air travel is unwise with a gas bubble in the eye, as the bubble may expand and cause a dangerous rise in the eye pressure.

Results of Surgery
If the retina can be successfully re-attached, the vision improves. However if the centre of the retina has been detached, the vision may never return fully. The sooner surgery is carried out the better, so it is important to see an eye specialist as soon as you suspect any trouble.

The Complete Eye-Care Specialists
Eye Institute is considered to be Retina Specialists in New Zealand. Our focus on excellence prompted us to develop New Zealand’s first purpose-built day-stay hospital. This enables us to enhance our quality of care while keeping costs amongst the lowest in the eye care field. As an added benefit we also offer a special finance plan to help you with your budgeting.

We provide free video tapes and brochures answering common questions about laser vision correction, cataract surgery, glaucoma, retinal surgeryvitreoretinal surgery, macular degeneration, pterygium, dry eyes and strabismus (squint). Please don’t hesitate to ask for more information.