Eye Library

The information provided in our Eye Library is a service to our patients and their families searching for general information about their conditions. Because each case is unique, the Eye Library is not a substitute for discussing questions or concerns with the physician who understands the patient’s specific condition.

Posterior Vitreous Detachment

What is the vitreous?
The vitreous is a jelly-like substance which fills the posterior aspect of the eye, the space behind the lens and in front of the retina. The vitreous is attached to the retina, most strongly at its base, which is in the periphery of the retina.

Why does the vitreous detach?
As a patient ages, the vitreous liquefies and pulls away from the retina, creating a posterior vitreous detachment (PVD). This is a common condition which usually occurs in patients older than 50. It can occur in younger patients, typically after trauma. Nearsighted patients are also at increased risk.

What are the symptoms of a PVD?
Although some patients are asymptomatic, symptoms can include flashing lights or floaters. Flashes occur as the vitreous tugs on the retina. The pull of the vitreous stimulates the retina, causing the sensation of flashing lights. Floaters appear as lines, dots, circles, or cobwebs. Floaters can be distracting, but the brain does tend to adapt to them with time, allowing patients to learn to ignore them.

Do I need to have my eyes examined if I think I have a PVD?
Yes. A PVD in itself does not cause visual loss, but retinal tears and detachments may occur in the setting of a PVD. These conditions must be treated promptly and thus, you should call your physician if you are experiencing flashes or new floaters.

How often will I need to be examined?
If no retinal tears or detachments are present, an initial exam is usually followed by an examination in 4 to 6 weeks. Of course, if symptoms worsen between visits, you should contact your physician promptly.

Retinal Tear

What causes a retinal tear?
As the vitreous pulls away from the retina in the setting of a posterior vitreous detachment, a retinal tear (Figure 1) may form. This occurs in areas where the vitreous is attached very firmly to the retina. Symptoms of a retinal tear can include an increase in the number or size of floaters, an increase in flashes of light, a shade/ shadow in your vision, or decreased vision. A prompt dilated examination is essential.

What is the treatment for a retinal tear?
A complete and thorough dilated fundus examination is performed. All retinal tears are identified. The tears are then treated in the office with either laser or cryopexy. The goal of both therapies is to create a scar around the tear so that fluid from the vitreous cavity cannot track through the retinal tear and under the retina to cause a retinal detachment.

Laser treatment can be performed either at the slit lamp or with the indirect ophthalmoscope. Topical medication is used to numb the eye. The patient is positioned at the slit lamp and a contact lens is placed on the eye. The laser is then placed while the physician views the tear through the slit lamp microscope. With the indirect laser, the physician places the head piece on his/her head and applies the laser.

Cryopexy, freezing treatment, is used when tears are difficult to reach with the laser or in situations where the visibility of the tear is compromised due to conditions such as cataract or vitreous hemorrhage.

Why is it so important to have a retinal tear treated right away?
As stated above, a retinal tear can lead to a retinal detachment which can cause permanent visual loss.

Retinal Detachment

What is a retinal detachment?
A retinal detachment is a serious and sight-threatening event, occurring when the retina becomes separated from its underlying supportive tissue. If not promptly treated, permanent vision loss may occur.

There are three types of retinal detachments. The most common, rhegmatogenous (Figures 2 and 3), occurs when there is a break or tear in the retina. Fluid seeps through this tear, causing the retina to detach. Tractional retinal detachments (TRD) are the second most common type. In diseases such as diabetes, scar tissue can develop on the surface of the retina. When the tissue contracts, it pulls on the surface of the retina, creating a TRD (Figures 4 and 5). The third type is a serous retinal detachment. Fluid collects underneath the retina causing it to detach. This web page will only discuss rhegmatogenous retinal detachments.

What are the symptoms of a retinal detachment?
Symptoms include an increase in floaters, flashes of light, a "curtain" over a part of the vision, or decreased vision. These symptoms require a prompt dilated eye examination.

Who is at risk for a retinal detachment?
A retinal detachment is more likely to occur in patients who have had retinal tears or holes, have lattice degeneration, are highly myopic (nearsighted), have a family history of retinal detachments, have had cataract surgery, have had a prior retinal detachment, or who have had trauma to their eye.

What is the treatment for a retinal detachment?
Retinal detachments are treated with surgical procedures: pneumatic retinopexy, vitrectomy, or scleral buckle. Over 90% of retinal detachments can be repaired, although recurrent detachments can occur, requiring repeated surgery. It is difficult to predict visual outcomes. Visual results are best if the detachment is repaired before it affects central vision. Continued visual recovery can occur for several months following surgical repair.

What is a pneumatic retinopexy?
A pneumatic retinopexy is an in-office surgical procedure used to repair retinal detachments which are located in the superior, nasal, or temporal quadrants of the retina. After a thorough retinal examination, a local anesthetic is used to numb the eye. The retinal tears are treated with cryopexy. A gas bubble is then injected into the vitreous cavity to tamponnade the tear. Fluid is subsequently removed from the anterior chamber of the eye. The patient is asked to position their head to keep the gas bubble over the tear. The positioning is maintained for up to one week. A repeat examination is scheduled for the day after the procedure. Continued close monitoring is essential.

What is a vitrectomy?
A vitrectomy is a surgical procedure performed in the operating room. Three tiny incisions are made in the sclera, the white of the eye, and the vitreous is removed with a cutting instrument. Gas is often injected to replace the vitreous and reattach the retina. The gas pushes the retina back against the wall of the eye. In the postoperative period, the eye produces fluid which gradually replaces the gas. Laser and/or cryotherapy are also placed during the procedure.

What is a scleral buckle?
A scleral buckle is a small synthetic band that is placed under the eye muscles and around the eye. This band gently pushes against the wall of the eye to reattach the retina. This procedure is also done in the operating room. It can be performed alone or in conjunction with a vitrectomy. The buckle is not visible and remains permanently attached to the eye.

Why is silicone oil sometimes used instead of gas?
Silicone oil is used in complicated or recurrent retinal detachments. The vitreous is replaced with silicone oil, which holds the retina in place. The vision is poor when the oil is inside the eye. A second procedure is later performed in the operating room to remove the oil once the retina has stabilized.

Epiretinal Membrane

What is an epiretinal membrane (ERM)?
Also known as macular pucker or cellophane maculopathy, an epiretinal membrane (Figures 6 and 7) is a growth of fibrous tissue over the macula, the central portion of the retina responsible for central vision. This scar tissue contracts, distorting the retina which in turn, causes decreased vision.

What are the symptoms of an ERM?
Straight lines appear wavy. Blurred or distorted vision.

What is the treatment for an ERM?
The treatment for an ERM depends on the amount of visual distortion the patient is experiencing. If the patient is only experiencing minimal distortion or if the patient is not interested in surgical repair, surgery is not required. Continued close observation is suggested in these cases. If on the other hand, symptoms are bothersome to the patient, surgery can be performed to improve the vision.

Epiretinal membranes are removed in the operating room. A vitrectomy is first performed to remove the vitreous from the back of the eye. Extremely fine instruments are then used to grasp the membrane and peel it off of the surface of the retina.

Macular Hole

What is the macula?
The macula is the central region of the retina, responsible for the sharp central vision that is essential for reading, driving, and seeing fine detail.

What is a macular hole?
A macular hole (Figures 8 and 9) is a break in the center of the macula which causes blurred and distorted central vision.

What causes a macular hole?
As we age, the vitreous contracts and pulls away from the surface of the retina. If the vitreous is firmly attached to the retina, the increased tension can lead to a macular hole.

What is the treatment for a macular hole?
Some macular holes can seal themselves and require no treatment, but most cases require surgical repair to improve vision.

To repair a macular hole, the patient is taken to the operating room for a vitrectomy. Three tiny incisions are made in the sclera, the white part of the eye. The vitreous is removed in order to relieve the tension on the macula. The vitreous is replaced with a large gas bubble. This bubble tamponnades the macular hole to help allow it to close.

Following the surgery, the patient must remain in a face-down position in order to keep the bubble against the macula. There are devices that help patients maintain the face-down position. Ask your doctor how to obtain these devices.

With time, the gas bubble reabsorbs and the vitreous cavity refills with fluid produced by the eye. Maintaining this face-down position is critical to the success of the surgery.

Is there harm in waiting to have the surgery?
People who have had a macular hole for less than six months have a greater chance of visual recovery as compared to those who have waited longer for surgical repair.

What is the chance that I will develop a macular hole in my other eye?
There is a 10% chance that a macular hole will develop in your second eye during your lifetime.

Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of vision loss worldwide and typically affects individuals 50 years of age or older. As life expectancy increases, the disease is becoming a significant problem. The disease affects the part of the retina called the macula, which is responsible for central vision. Central vision enables us to read, drive, sew and perform other tasks that require detailed vision. Vision loss from AMD typically occurs gradually and can affect both eyes at different rates. Even though macular degeneration can cause visual impairment, the disease usually does not cause peripheral (side) vision loss or lead to total blindness.


The two common types of macular degeneration are non-exudative ("dry") and exudative ("wet").


  • "Dry" form - the most common form of macular degeneration (85%) is caused by aging and thinning of the tissues of the macula. It develops slowly and usually causes mild vision loss. As this form of the disease develops, people often notice a dimming of vision while reading.

  • "Wet" form – less common (15%), but more severe. The wet form of the disease causes new blood vessels to grow beneath the retina, which leak fluid and blood, often creating a large blind spot in the center of the visual field. May progress rapidly causing significant central vision loss.

The causes of macular degeneration are not completely understood. Some scientists believe heredity may play a part, as well as UV light exposure, nutrition, and cigarette smoking. Studies are ongoing.


  • A dark area or a "white-out" appears in the center of vision
  • Blurred or fuzzy vision
  • Color perception fades or changes
  • Straight lines, such as sentences on a page or telephone poles, appear wavy or distorted


  • "Dry" form - There is no proven effective treatment for dry macular degeneration. Low vision rehabilitation can help those with significant vision loss to maintain excellent quality of life. High dose antioxidant vitamin therapy may help prevent some patients with dry macular degeneration from developing the wet form of the disease.
  • "Wet" form - a variety of therapies are available for wet macular degeneration including: intravitreal injection of pharmacologic agents (i.e. anti-VEGF agents), photodynamic therapy, and rarely laser photocoagulation.
  • ECM actively participates in clinical trials investigating anti-VEGF therapy
  • Rohit R. Lakhanpal, MD is the Principal Investigator for the LEVEL study for wet AMD

Low Vision Rehabilitation
Can help people who have experienced mild to severe vision loss adjust to their condition and continue to enjoy active and independent lifestyles. Low Vision Rehabilitation may involve anything from adjusting the lighting in your home to learning to use low vision aids to help you read and perform daily tasks.

Diabetic Retinopathy

The cells in persons with diabetes mellitus have difficulty using and storing sugar properly. When the blood sugar gets too high, it can damage the blood vessels in the retina. This damage may lead to diabetic retinopathy.

Types of Diabetic Retinopathy

  • Background or nonproliferative diabetic retinopathy - blood vessels in the retina are damaged and can leak fluid or bleed. This causes the retina to swell and decreases the central vision.
  • Many patients may not notice any change in their vision when they develop this early form of the disease, but it can lead to other more serious forms of retinopathy that severely affect vision. Fluid collecting in the macula is called macular edema and may cause difficulty with reading and other close work.
  • Proliferative diabetic retinopathy - new, fragile blood vessels grow on the surface of the retina. These new blood vessels are called neovascularization, and can lead to serious vision problems, because the new vessels can break and bleed into the vitreous. When the vitreous becomes clouded with blood, light is prevented from passing through the eye to the retina. This can blur or distort vision and frequently causes sudden and severe loss of vision. The new blood vessels can also cause scar tissue to develop, which can pull the retina away from the back of the eye. This is known as retinal detachment, and can lead to blindness if untreated. In addition, abnormal blood vessels can grow on the iris (the colored part in the front of the eye), which can lead to high intraocular pressures and severe glaucoma.

Treatment of Diabetic Retinopathy
Good control of diabetes with intensive management and control of blood sugar will delay, and possibly prevent, both the development and progression of diabetic retinopathy.

Patients with diabetic retinopathy frequently need to have special photographs of the retina taken. This series of photos is called fluorescein angiography.

  • Laser photocoagulation is one of the most common treatments for diabetic retinopathy. Focal photocoagulation consists of laser directed at the retina to seal leaking blood vessels in patients with background diabetic retinopathy. Panretinal photocoagulation consists of laser spots scattered through the sides of the retina to reduce abnormal blood vessel growth (neovascularization) and help seal the retina to the back of the eye in patients with proliferative diabetic retinopathy. This can help prevent retinal detachment. There is little recuperation needed after laser surgery for diabetic retinopathy. Laser surgery may require more than one treatment to be effective.
  • Vitrectomy surgery is performed for patients with very advanced proliferative diabetic retinopathy or retinal detachment. In vitrectomy, the surgeon removes the blood-filled vitreous and replaces it with a clear solution. This allows light to pass through the clear fluid to the retina, where the images are conveyed to the brain.
  • Pharmacotherapy: Increasingly, a variety of medications are being used to treat the manifestations of background and proliferative diabetic retinopathy. These involve intravitreal injections of small amounts of medication into the eye.

The type of retinopathy, as well as the patient’s general health and eye structure will determine the kind of treatment needed and the type of anesthesia utilized.

Flashes & Floaters

Some people may occasionally see small specks or clouds moving in your field of vision. These are called floaters. Floaters are actually tiny clumps of gel or cells inside the vitreous, the clear jelly-like fluid that fills the inside of the eye. While these objects look like they are in front of the eye, they are actually floating inside.

When people reach middle age, the vitreous gel may start to thicken or shrink, forming clumps or strands inside the eye. The vitreous gel pulls away from the back wall of the eye, causing a posterior vitreous detachment. Posterior vitreous detachment is more common in people who:

  • Are nearsighted
  • Have undergone cataract operations
  • Have had YAG laser surgery of the eye
  • Have had inflammation inside the eye

When the vitreous shrinks, it tugs on the retina, creating a sensation of flashing lights. The flashes of light can appear off and on for several weeks or months. As we grow older, it is more common to experience flashes.

As the shrinking vitreous gel pulls away from the wall of the eye, it can cause a retinal tear in places where the vitreous gel sticks too tightly to the retina. This sometimes causes a small amount of bleeding in the eye that may appear as new floaters. A torn retina is always a serious problem, since it can lead to a retinal detachment.

Retinal Tear & Detachment

What is a retinal detachment?
As the vitreous gel in the back of the eye starts to liquefy, it can separate from the retina, a condition called vitreous detachment. If the vitreous gel adheres too firmly to the retina, a retinal tear can occur with a vitreous detachment. A retinal detachment occurs when fluid leaks through the tear and separates the retina from the back of the eye.

Patients with a retinal tear or detachment often, but not always, have flashes and floaters as their first symptoms. This occurs as the vitreous gel detaches from the back of the eye. Other patients may have very few symptoms. Patients may describe a "curtain" being drawn across the peripheral vision or decreased peripheral vision. If untreated, most retinal detachments will cause progressive loss of vision and eventually total blindness.

In most instances, retinal tears are treated with laser photocoagulation which acts to "spot weld" the retina to the back of the eye. In some cases pneumatic retinopexy is used to treat retinal detachment in the office without the need of surgery. In most cases, however, surgery is usually required. This consists of scleral buckling (placing a silicone belt loop around the outside of the eye), vitrectomy, or a combination of the two procedures. These are usually performed as outpatient surgeries and may involve using a gas bubble to help push the retina back into position.