The retina is the innermost layer of the eye or internal tunic and composed of nerve tissue which senses the light entering the eye. The retina can be compared to a camera – the pictures being captured by the eye and reflected on the screen of the retina (the macula within the retina) hence, we “see” with our brains, with our eyes merely collecting the information.
The retina has two types of cells, the rods and cones. The cones are responsible for color vision while the rods provide black and white and night vision. The macula is in the center of the retina. As we focus on an image such as reading, light is focused onto our macula where millions of cells change the light into nerve signals and relays to the brain what we are seeing. The light receptors lay on a layer of cells called Retinal Pigment Epithelium layer or RPE which contains a black pigment to minimize light reflection to give a clearer image.
Having an understanding of what the retina is, let us now take a look at one of the problems our retinas may encounter – retinal detachment.
What Is Retinal Detachment And What Causes It?
Retinal detachment occurs when the retina experiences a tear or break. The “vitreous fluid”, or the liquid inside the center of the eye, then enters that tear or break and pushes the retina from behind and lifts it out of position. Retinal detachment is an urgent condition because the retina, just like any other tissue, dies when they detach from their source of nutrients and can lead to permanent damage that will cost you your vision. Central vision becomes severely affected if the macula, the part of the retina responsible for fine vision, becomes detached.
What Are The Symptoms of Retinal Detachment? How Do You Know When To Seek Treatment?
It is very important to recognize signs and symptoms of retinal detachment so that early treatment can be sought. These could include:
1. Seeing floaters or silver bugs
2. “Curtain drop” – vision goes dark like a “veil” or “curtain” dropping before your eyes
3. Sudden blurring of vision
4. Bright flashes of light or visual distortions such as:
Photopsia – perceived flashes of light
Metamorphopsia – appear to be distorted, usually due to a defect in the retina.
5. Loss of peripheral vision – appears as a dark, moon-shaped area in the corner of the eye
6. Slight feeling of heaviness or pressure in the eye
Traditionally, diagnosis of RD has relied on direct examination of the retina using an ophthalmoscope. However, a number of factors may make traditonal examination difficult or impossible to the timely diagnosis of RD due to:
Contraindications to the use of mydriatics in patients with narrow-angle glaucoma
Head-injury sustained by the patient
Periorbital trauma or soft tissue swelling
Hyphema or Vitreous hemorrhage (in which case b-scan ultrasound will make it possible to assess the retina)
There are three forms of retinal detachment: Rhegmatogenous retinal detachment (RRD), Exudative or serous retinal detachment (ERD), Tractional retinal detachment (TRD)
>Rhegmatogenous Retinal Detachment (RRD)
Rhegmatogenous retinal detachment is where the vitreous fluid, which is the liquid inside the center of the eye, enters the retinal break. This is most prevalent in adults between the ages of 40 and 70. A family history of rhegmatogenous retinal, nearsighted males as well as those who have already experienced this condition in the other eye is at much higher risk than the general population.
>Exudative or serous retinal detachment (ERD)
ERD results from fluid accumulation under the sensory retina without a retinal break. Exudative detachments do not generally present with photopsia but may be associated with moderate vision loss, metamorphopsia or a visual field deficit.
>Tractional retinal detachment (TRD)
TRD results from the pull of proliferative fibrovascular vitreal strands. Tractional detachments are typically asymptomatic unless central vision is threatened, in which case the patient can suffer severe and abrupt vision loss.
Retinal detachment causes and Risk Factors
1. Genetic inheritance – Juvenile boys are particularly affected by a genetic condition called X-linked Retinoschisis. Differentiating retinal detachment vs retinoschisis is important since retinal detachment almost always requires treatment while retinoschisis never itself requires treatment and leads to retinal detachment only occasionally. Having severe short sightedness or Myopia is also associated with over 60% of cases of retinal detachment. Having retinal detachment in one eye also increases the risk of retinal detachment in the other eye.
2. Illnesses – illnesses such as cytomegalovirus retinitis, toxoplasmosis and complications from herpes simplex I cause the retina to inflame the retina, creating retinitis. People with immune deficiencies may be most at risk for retinal complications.
3. Diabetes – Having proliferative diabetic retinopathy or proliferative retinopathy of sickle cell disease.
4. Aging – Macular degeneration related to aging is where retinal pigment epithelial cells stops normal functioning and deterioration of cells. As a result, sharp, central vision essential for daily tasks such as reading and driving is lost.
5. Trauma – Trauma can be any form from a blunt force trauma to the face, or injury to the eyeball such as a boxer’s punch. In some cases, it can also result from vigorous blowing of the nose. Trauma can also be due to iatrogenic causes such post-cataract surgery or after pneumatic retinopexy, cryotherapy, laser retinopexy, scleral buckling, or vitrectomy. Proliferative vitreoretinopathy (PVR) is the most common cause of failure in retinal detachment surgery.
When Is Retinal Detachment Surgery Recommended?
A retinal detachment is considered a surgical emergency, however, surgery may not be needed if you do not have symptoms or have had the detachment for a while. The most common methods of repairing a detached retina include:
In this form of surgery, the doctor sews a piece of plastic or silicone to the white, outer part of the eye to “secure ” the retina back in place. This is often combined with pneumatic retinopexy, wherein a gas bubble is injected into the eye to help press gently against the retinal tear, and help keep the formerly detached retina in place. The ophthalmologist then uses a laser or freezing probe to seal off the tear in the retina.
In this procedure, tiny instruments are inserted into the vitreous cavity to remove the vitreous gel and fill the eye with a gas bubble or silicon oil. Vitrectomy gives ophthalmologists better access to the retina to repair large tears, and it is often also combined with laser treatments and gas injections to help repair the damaged retina.
>Cryopexy or cryotherapy or “freezing”
Intense cold is applied to the area with an ice probe to help a scar form, which holds the retina to the underlying layer.
This is performed after pneumatic retinopexy to permanently seal the tears or holes in the retina.
Placing a gas bubble in the eye to help the retina float back into place
Sealing the tear using an argon laser
Retinal Detachment Recovery
Full recovery generally takes about 3 months but you can often return to work within 1-2 weeks of surgery if cleared by your doctor. A few things to keep in mind to ensure a smooth recovery are:
>Avoid strenuous physical activity that increases Intra-ocular pressure until allowed by your doctor.
>Do not remove the patch until instructed to do so. Be sure to follow your doctor’s instructions.
>Keeping your head in a certain position as instructed and maintaining the position even when eating, sleeping, and bathing.
>Do not allow your eye to come into contact with running water until allowed by your doctor.
>Follow-up doctor’s appointments to monitor your recovery.
>For Retinopexy, it would take 2 to 8 weeks for the gas bubble to go away.
Health or Fitness Tips To Avoid Retinal Detachment
Taking vitamin-rich foods can improve eye health in general. However, our daily intake of food does not provide all the vitamins and nutrients that we need. Below is a list of vitamins and minerals to keep your eyes healthy. However, it is recommended that you consult an eye specialist first even though these vitamins are available over the counter.
Vitamin A, C and E
Vitamins A, C and E are anti-oxidant vitamins which can be found in fruits and vegetables, eggs and dairy products. Vitamin A provides good night vision and impedes possibilities of cataracts. Vitamin C helps prevent the accumulation and crystallization of foreign molecules in the eyes which can cause blurred vision. Vitamin E reduces the advancement of a very serious progressive eye disease called macular degeneration which entails limited vision and total blindness.
Lutein and Zeaxanthin
Lutein and zeaxanthin belong to the “carotenoids” and are said to lower risks of having age-related macular degeneration or AMD. Natural sources of carotenoids are sweet peppers, yellow peppers, corn, lettuce, spinach, kale and bilberries.
Omega 3 Fatty Acids
Research show that taking omega 3 oils reduce the chance of getting dry eyes. Excellent food sources are salmon, flax seeds and walnuts .