Retinal Detachment In One Eye

Introduction

Retinal detachment is when the thin layer at the back of the eye pulls away from its normal position like wallpaper peeling off a wall. It mostly happens in people around 60 or older and usually only affects one eye, but it can affect both.

What is the retina?

The retina lines the back of the eye (behind the lens) and absorbs the light that travels through the pupil. It converts the light to an electrical signal which is sent to the brain via the optic nerve. The brain can then interpret the signal as images.¹ In the centre of the retina is a small area called the macula which allows us to see up close. Between the lens of the eye and the retina is a cavity called the vitreous humour which is filled with a jelly-like substance called vitreous gel.² 

When the retina becomes detached it is separated from the underlying tissue that contains layers of blood vessels that provide oxygen to the eye. Without this nourishment, the retina will no longer function and result in sight loss. Usually, retinal detachment will start with a tear or hole in the retina. If caught early, full retinal detachment can be prevented and the risk of permanent damage is lessened.

Symptoms of retinal detachment in one eye

The most common symptom of a detached retina is vision changes which could manifest as flashing lights, floaters, blurriness and, more seriously, shadows. Symptoms are painless but can happen suddenly over hours, days or weeks.

• Flashes of light (Photopsia) – Can be described as brief, white, vertical flashes of light in the edge of vision. They are due to tugging on the retina caused by changes in the vitreous gel
• Floaters – Debris floating in vitreous gel which casts shadows on the retina that can appear as black dots, rings, spider’s legs or cobwebs³
• Blurred vision – Vision is not sharp or crisp, progressively getting worse
• Shadows – Often appear as a curtain covering part of the vision. They can be stationary and in the peripheral vision or move into the centre of the vision 

If caught early, symptoms may be explained by less serious conditions such as changes to vitreous gel or a retinal tear. However, these can quickly progress to a detached retina, a medical emergency. Once central vision has been compromised, permanent visual impairment is likely.

Causes of retinal detachment in one eye

Retinal detachment can be categorized into 3 different types. Each of these types has different causes and therefore different risk factors:

1. Rhegmatogenous retinal detachment (RRD)

Rhegmatogenous (reg-mat-o-gus) is the most common type of retinal detachment, said to occur in around 1 in 10,000 people per year. The name is derived from the Greek word Rhegma meaning break or fissure.⁵ It is caused by a retinal tear or hole which allows fluid to collect under the retina. As this fluid builds up it can cause detachment.  

The causes/risk factors associated with RRD are:⁵

• Aging – The most common risk factor is ageing. As we age, the vitreous gel in the eye can start to change consistency or shrink and separate from the retina; a condition known as posterior vitreous detachment (PVD). PVD is increasingly common after 40 years old and, in itself, may not cause any problems. However, as the vitreous gel peels off the retina, it can cause a tear which may then lead to retinal detachment. Only 10-15% of people with symptomatic PVD risk developing a tear
• Myopia – Myopia is extreme near-sightedness and is often the cause of retinal detachment in young people. Those with myopia have longer eyeballs and therefore the edges of their retinas are thinner and more prone to tearing
• Previous eye surgery – Surgery such as cataract removal can disturb the vitreous gel leading to a tear in the retina
• Trauma/injury – Trauma to the eye can also cause the retina to tear. The retina may also detach straight away
• Family history – If a close family member has experienced retinal detachment then you are more likely to develop it too
• Previous eye conditions – Retina detachment can be caused by previous/already present eye diseases such as Lattice Degeneration – thinning of the retina that can cause tears to form – and Retinoschisis – separation of the retina into two layers
• Other underlying health conditions – e.g. connective tissue disorders such as Marfan syndrome and Stickler syndrome

2. Tractional retinal detachment

Tractional retinal detachment is when scar tissue grows on the retina causing traction which can lead to the retina pulling back. The most common cause is diabetes retinopathy, a complication of diabetes, which damages blood vessels in the retina and eventually leads to scarring. Eye injury or disease can also cause scarring on the retina.

3. Exudative retinal detachment

Exudative retinal detachment is caused when excessive fluid leaks from the blood vessels and builds up between the retina and the underlying tissue. ⁶ Retinal detachment is only characterised as exudative when no tears or traction are associated. The fluid accumulation can be caused by a variety of reasons including injury/trauma, age-related macular degeneration (AMD), tumours, and inflammatory, infectious and vascular diseases.

Diagnosis of retinal detachment in one eye

Retinal detachment can be diagnosed by an eye doctor (ophthalmologist) or optician (optometrist). They will ask about symptoms and medical history and perform an eye exam in both eyes, even if there are just symptoms in one. 

Eye exam

The eye exam will involve bright light and special lenses to examine the back of the eye to look for holes, tears or detachments. It may involve eye drops or pushing on the outside of your eye which might be uncomfortable. If a tear is not detected you may be asked to return in a few weeks to look for a delayed tear. 

Imaging tests

You may be referred for further tests such as an ultrasound or an optical coherence tomography (OCT) scan. In an OCT scan a machine will take cross-section pictures of your retina. It may involve eye drops to dilate your eyes which could make your eyes sensitive to light for several hours but it will not be painful. 

Treatment of retinal detachment in one eye

For a retinal tear that hasn’t yet progressed to a retinal detachment, you may be offered outpatient treatment such as laser therapy or freezing.

Laser Therapy

Also known as photocoagulation, a laser beam is directed through your pupil and burns around the tear to weld the retina to the underlying tissue.

Freezing

Also known as cryopexy, a freezing probe is placed on the white of the eye, over the tear, causing a scar that helps the retina attach to the eye wall. 

If your retina is detached then you will likely need retinal reattachment surgery. The three most common surgeries are pneumatic retinopexy,  scleral buckling and vitrectomy.⁵

Pneumatic retinopexy 

A bubble of air or another gas is injected into the vitreous cavity. The bubble pushes the retina against the eye wall to press it back into place. This may be coupled with cryopexy (freezing) to ensure the retina reattaches. You may be required to keep your head in a specific position after the surgery to keep the bubble in the right place. The bubble is reabsorbed after a few weeks. In the UK, this surgery is not commonly carried out as it is less successful than others.

Scleral buckling

The surface of the eye over the affected area is indented with silicone to push the inside of the eye against the detached retina. This is coupled with laser therapy or cryopexy to seal around the area. If the damage is extensive, the silicone is used to encircle the entire eye like a belt. The silicone is permanent and does not block vision. 

Vitrectomy

The vitreous gel in the eye is drained and/or replaced to reduce tugging on the retina. This may be coupled with pneumatic retinopexy or scleral buckling. 

After surgery, you may be prescribed topical antibiotics and corticosteroids to prevent infection and inflammation. You may experience sore eyes, that can be treated with painkillers, and blurred vision. You should take some time off work and may be unable to drive. If you have a bubble in your eye, you must avoid flying and other high altitudes.

How well your vision recovers depends on how much of your retina detached, if the macula was affected, how long it was detached and whether you have any other underlying conditions. 9/10 people don’t require another surgery.

Prevention of retinal detachment in one eye

As ageing is the biggest risk factor, retinal detachment is not completely preventable but early detection is key. ⁹ If caught when the retina has a tear or hole and hasn’t developed to detachment then the prognosis is massively improved. The most important thing you can do is seek medical advice as early as possible if you think you may have symptoms. Some other preventative measures you can take are:

Regular eye exams

You should attend regular eye exams that can detect tears before your vision is affected.

Eye protection

When doing DIY or dangerous sports you should wear eye protection to prevent injury to the eyes.

Management of underlying health conditions

Keeping health conditions that affect the eyes, such as diabetes, under control is extremely important for your eye health and preventing retinal detachment. 

Summary

Retinal detachment happens when the retina pulls away from the eye wall. It is commonly caused by ageing and begins with a tear progressing to detachment. If a tear is caught early it can be treated by laser therapy or freezing, however, retinal reattachment surgery is usually required. Prevention involves recognising the symptoms early, namely changes in vision, and seeking medical attention straight away. An optician can diagnose a tear through an eye exam and refer you to a retina specialist. If you are worried that you may have a retinal detachment, don’t hesitate to seek urgent medical attention; the quicker it is detected the lower the risk of vision loss.