If you have been diagnosed with a retinal problem, you’re not alone.  The retina is a multi-layered sensory tissue, about 1 millimeter thick that lines the back of the eye.  It has the consistency of wet-tissue paper.  It contains millions of photoreceptors that capture light rays and convert them into electrical impulses.  These impulses travel along the optic nerve to the brain where they are turned into images.  The delicate nature of the retina makes it subject to a number of sight-threatening problems which affect millions of people. 

There are two types of photoreceptors in the retina:  cones and rods.  The retina contains approximately 6 million cones.  The cones are contained in the macula, the portion of the retina responsible for central vision.  They are most densely packed within the fovea, the very center portion of the macula. Cones function best in bright light and allow us to appreciate color.

There are approximately 125 million rods.  They are spread throughout the peripheral retina and function best in dim lighting.  The rods are responsible for peripheral and night vision.

This photograph shows a normal retina with blood vessels that branch from the optic nerve, cascading toward the macula. 

Common Retinal Problems
The retina is subject to a number of problems that can result in some type of visual impairment, depending on the area of the retina that’s affected.  Three common retinal problems are macular degeneration, retinal detachment and diabetic retinopathy.  Each problem affects vision differently, and each is treated in a different way. 
Any of these retinal problems can be severe enough to cause legal blindness.  Retinal detachment and diabetic retinopathy can even lead to total blindness if not brought under control.  Legal blindness is a condition of low vision that, unlike total blindness, may be compensated for to varying degrees by using vision aids. 
Fortunately, far more can be done today than even a few years ago to treat most retinal problems and to help preserve vision.  At Clemson Ophthalmology, we strive to help you understand your retinal problem and the very best options to treat it. 

Retinal Breaks and Detachment
Because the retina is such a delicate structure, it is vulnerable to breaks that can often ultimately cause the retinal layers to become detached from each other.  Some people are predisposed by heredity to have retinal breaks.  Early detection and treatment of breaks and detachment can help to prevent blindness and severe damage to vision. 

Diagnosis
Your ophthalmologist will use indirect ophthalmoscopy with scleral depression and a slit lamp to locate any breaks.  If the breaks are insignificant and do not require treatment, your doctor will probably want to see you periodically to follow their progress.  It will be extremely important for you to monitor your own vision, and to report any unusual symptoms – such as a change in the pattern of floaters – to your doctor at once. 

Flashes and Floaters
The eye is filled with a clear jelly called the vitreous gel. The vitreous gel inflates the back part of the eye in the way that water inflates a water balloon. As we age, the vitreous gel begins to dissolve into a more watery form. Once enough of the vitreous gel has dissolved – usually when we are in our late 50’s or early 60’s – the gel pulls free of its attachments to the back of the eye. This sudden and often dramatic event – called a posterior vitreous detachment – often causes a number of symptoms that can be alarming.
 
One common symptom of a posterior vitreous detachment is the appearance of floaters. Floaters are exactly what they sound like – tiny bits of debris that appear when the vitreous gel separated from the back of the eye. These bits of cloudy debris float in the liquefied vitreous like snow in a snow globe. If you have a single small floater, you may have the sensation that a bug is flying in your face. Often in eyes with posterior vitreous detachments, the floaters are bigger and somewhat stringy, and you may describe it as a spider web or cobweb in your vision. Typically, these floaters will move around in your vision, especially when you move your eyes around. Floaters usually do not stay in exactly the same spot in your vision.

Another common symptom of a posterior vitreous detachment is seeing flashing lights in the very periphery of your vision. As the vitreous gel pulls loose from the back of the eye, it tugs on the wallpaper lining the back of the eye. This wallpaper is called the retina. The retina is a thin layer and is like the film of a camera—it is the light-sensing part of the eye. When the retina is tugged on, it generates the sensation of flashing lights in the periphery of your vision.

Floaters are often annoying but not usually a threat to vision. But flashing lights can be a more worrisome sign. Sometimes when the vitreous tugs on the retina as it is pulling loose, it can pull so hard that it makes small rips or tears in the retina. The liquefied vitreous can then pass through the hole and cause the retina to come loose from the back of the eye as well. This is called a retinal detachment. If you have a retinal detachment, you may notice sections of your vision disappearing, as if a curtain or veil is covering parts of your vision. A retinal detachment is an emergency and often requires surgery to repair.

If you have the sudden onset of new floaters in your vision and/or flashing lights in the periphery of your vision, call your eye doctor immediately to arrange a prompt examination. During this examination, your pupils will be dilated to examine your retina to make sure there is no retinal detachment. While they are uncommon, retinal detachments can cause vision loss, and repairing them quickly is the best way to save your vision.

A scene as it might be viewed by a person with retinitis pigmentosa.