What is the retina?
The retina has two parts: the peripheral retina and macula. If you imagine the retina as a circle with a bulls-eye at the center, the macula is like the bulls-eye: it is very small. The large area of the retina that surrounds the macula and makes up 95% of the retina is called the peripheral retina.
The peripheral retina gives us vision to the side (peripheral vision). It is this part of the retina that is at work when we see something out of the corner of our eye. Because the peripheral retina is not able to see detail clearly, we cannot use the peripheral vision to read, thread a needle, drive, or even recognize a face. If you see someone off to your side (‘out of the corner of your eye’), you might be able to tell who it is because you recognize the person’s general shape, but you won’t be able to see the expression on the person’s face.
What is the vitreous?
The vitreous is much like the clear white of an egg and it fills the central cavity of the eye. The vitreous is attached to the retina. It is most strongly attached in the back part of the eye to the optic nerve, the macula and the large retinal blood vessels.
Why is retinal or vitreous surgery necessary?
Retinal and vitreous surgery address problems such as Retinal Detachment and Intraocular Infection (see below). Retinal and vitreous problems can cause severe loss of vision or even blindness. In some cases, surgery may be beneficial and – if done at the right time – might prevent severe loss of vision. Most serious retinal problems that require surgery are caused by problems with the vitreous.
Why is a retinal tear considered a serious problem?
When a tear of the retina occurs, the liquid in the vitreous cavity may pass through the tear and get under the retina. The liquid collects under the retina and lifts it up off the back wall of the eye. Little by little, the liquid from the vitreous passes through the retinal tear and settles under the retina, separating it from the back wall of the eye. This separation of the retina is called a retinal detachment.
Vision is lost wherever the retina becomes detached. Because most tears are located in the peripheral (or side of the) retina, the retinal detachment first results in loss of side (peripheral) vision. A patient may notice a dark shadow or a veil coming from one side, above or below. In most cases, after a retinal detachment starts, the entire retina will eventually detach and all useful vision in that eye will be lost.
Who gets retinal detachments?
Certain people have a greater chance of getting a retinal detachment than others: those with a high degree of nearsightedness (myopia), a family history of retinal detachment, or those who once had retinal detachment in the other eye. Patients who have thinning of the retina (lattice degeneration) or other degenerative changes of the retina are also at increased risk. Patients who have had cataract surgery have about a 1 – 2% chance of developing retinal detachment.
A person in any of these high-risk groups should have regular retinal examinations and should see their eye care specialist immediately if they experience loss of peripheral vision, see sudden flashing of lights or spots.
Intraocular Infection (Endophthalmitis)
When an infection occurs inside the eye, it is called endophthalmitis. Endophthalmitis often occurs after intraocular surgery (surgery done inside the eye) or penetrating trauma.
How is endophthalmitis treated?
Endophthalmitis can be treated with antibiotics. These antibiotics can be administered in a variety of ways, from eyedrops to injections. In severe cases, a vitrectomy is performed to remove the infectious material inside the eye. Your doctor will discuss the best method of treatment with you. Vitreoretinal Surgery deals with diseases involving the vitreous humour and the retina.