Information on Common Eye Disorders
 
Retina And Vitreous

Cytomegalovirus Retinitis (CMV Retinitis)
 
CMV retinitis is a serious eye infection of the retina, the light-sensing nerve layer that lines the back of the eye. It is a significant threat to people with weak immune systems, such as people with HIV and AIDS, newborns, the elderly, people taking chemotherapy, and recipients of organ transplants. About 20 to 30 percent of people with AIDS develop CMV retinitis.

Infection with cytomegalovirus, one of the herpes viruses, is extremely common and does not pose a problem for someone with a strong immune system. But when immunity is weak, the CMV can reactivate and spread to the retina through the bloodstream.

First signs of CMV retinitis are loss of peripheral vision or a blind spot which can progress to loss of central vision. Without treatment or improvement in the immune system, CMV retinitis destroys the retina and damages the optic nerve, which results in blindness.

Injection of one or two drugs daily is the current treatment for CMV retinitis. A promising new therapy involves placing a small implant inside the eye that slowly releases the anti-CMV drug ganciclovir.

Warning signs that should be examined by an ophthalmologist immediately are floating spots or spiderwebs, flashing lights, blind spots or blurred vision. Recurrence of CMV retinitis is common so monthly check-ups with an ophthalmologist are important.
Detached and Torn Retina

A retinal detachment is a very serious problem that almost always causes blindness unless treated. The appearance of flashing lights, floating objects, or a gray curtain moving across the field of vision are all indications of a retinal detachment. If any of these occur, see an ophthalmologist right away.

As one gets older, the vitreous, the clear gel-like substance that fills the inside of the eye, tends to shrink slightly and take on a more watery consistency. Sometimes as the vitreous shrinks it exerts enough force on the retina to make it tear.

Retinal tears increase the chance of developing a retinal detachment. Fluid vitreous, passing through the tear, lifts the retina off the back of the eye like wallpaper peeling off a wall. Laser surgery or cryotherapy (freezing) are often used to seal retinal tears and prevent detachment.

If the retina is detached, it must be reattached before sealing the retinal tear. There are three ways to repair retinal detachments. Pneumatic retinopexy involves injecting a special gas bubble into the eye that pushes on the retina to seal the tear. The scleral buckle procedure requires the fluid to be drained from under the retina before a flexible piece of silicone is sewn on the outer eye wall to give support to the tear while it heals. Vitrectomy surgery removes the vitreous gel from the eye, replacing it with a gas bubble, which is slowly replaced by the body's fluids.
Floaters and Flashes

Small specks or clouds moving in your field of vision as you look at a blank wall or a clear blue sky are known as floaters. Most people have some floaters normally but do not notice them until they become numerous or more prominent.

In most cases, floaters are part of the natural aging process. Floaters look like cobwebs, squiggly lines or floating bugs, and appear to be in front of the eye, but are actually floating inside. As we get older, the vitreous-the clear gel-like substance that fills the inside of the eye-tends to shrink slightly and detach from the retina, forming clumps within the eye. What you see are the shadows these clumps cast on the retina, the light-sensitive nerve layer lining the back of the eye.

The appearance of flashing lights comes from the traction of the vitreous gel on the retina at the time of vitreous separation. Flashes look like twinkles or lightning streaks. You may have experienced the same sensation if you have ever been hit in the eye and seen stars.

Floaters can get in the way of clear vision, often when reading. Try looking up and then down to move the floaters out of the way. While some floaters may remain, many of them will fade over time.

Floaters and flashes are sometimes associated with retinal tears. When the vitreous shrinks it can pull on the retina and cause a tear. A torn retina is a serious problem. It can lead to a retinal detachment and blindness. If new floaters appear suddenly or you see sudden flashes of light, see an ophthalmologist immediately.