The Retina and Glaucoma
Chat Highlights
July 6, 2010

On Wednesday, July 6, 2010, Dr. Jason Hsu, a glaucoma specialist at Wills, and the glaucoma chat group discussed "The Retina and Glaucoma".

Moderator: Tonight we have a special guest, Dr. Jason Hsu, a retina specialist at Wills Eye Institute. He'll be discussing the retina and glaucoma. Dr. Hsu, perhaps you'd like to start by telling us a little about yourself.

Dr. Jason Hsu: Sure. I'm currently part of the Retina Service of Wills Eye Institute and a clinical instructor at Thomas Jefferson University. I trained at the University of Pennsylvania for medical school. I then completed my fellowship training in vitreoretinal surgery at Wills Eye Institute.

Moderator: Excellent. Let's start with questions then.

P: Is there a correlation between any retinal diseases and glaucoma?

Dr. Jason Hsu: There are certainly several retinal diseases that can be associated with glaucoma. For example, retinal vein occlusions (blockages of the blood vessels that drain blood from the eye) have been associated with people that have glaucoma or elevated eye pressures. Also, we see glaucoma more commonly in diabetic patients who also develop bleeding and swelling in the retina from diabetic retinopathy.

P: Does having glaucoma make any retinal diseases more difficult to treat?

Dr. Jason Hsu: In some circumstances it can affect the decision making process when it comes to treatment options. For example, we often use steroid injections either around the eye (sub-Tenon's) or even in the eye to treat certain conditions where there is inflammation or swelling in the eye or retina. These steroids can often cause elevation in eye pressure, much more commonly so in patients with known glaucoma.

Also, when making a decision to perform retinal surgery, there is some concern that particularly patients with advanced glaucoma may have further worsening of their disease as a result of the higher than normal eye pressures that are often necessary during the procedure.

P: Does long term use of glaucoma medications damage the retina?

Dr. Jason Hsu: Overall, the answer is no, however, there is one class of glaucoma drops that rarely cause swelling in the center of the retina (cystoid macular edema). This usually manifests with painless blurring of just the central vision. This class of drops are the prostaglandin analogues (xalatan, travatan, lumigan). Again, this complication is overall quite rare though.

P: What is the difference between a retinal tear and a detachment?

Dr. Jason Hsu: You can think of the retina as a thin film of tissue paper that lines the back wall of the eye, similar to the film in a camera. A retinal tear usually occurs when the jelly in the eye (vitreous) tugs too hard on an area of the retina where it is attached and actually rips it open. This is usually manifested by symptoms of new floaters and/or flashes of light. Retinal tears can typically be treated in the office setting with laser or a freezing treatment (cryopexy).

A retinal detachment occurs when the retina itself peels away from the back wall of the eye. When this occurs, patients often begin noticing a dark shadow that initially blocks just a portion of the peripheral vision. This can proceed over hours to days to complete blindness in some cases. There are several different types of retinal detachments, but the more common type we see are related to tears in the retina. These tears create a physical hole in the retina through which the fluid in the eye can travel and lift off the retina. Unlike retinal tears, most retinal detachments have to be fixed with surgery in the operating room. Depending on the severity of the detachment, patients may not regain all of the lost vision. As a result, I typically tell patients with new symptoms of flashes or floaters to be seen as soon as possible. It is much easier to treat a retinal tear and this will most likely prevent a retinal detachment and lower the chance of vision loss.

P: Do any of the glaucoma surgeries increase the risk of a detached retina?

Dr. Jason Hsu: In general, glaucoma surgery should not affect the risk of retinal detachment. Rarely, after glaucoma surgery with a fast lowering of the eye pressure, the walls of the eye can swell. We call this a choroidal detachment. This can sometimes be associated with some fluid under the retina called a serous choroidal detachment. In these cases, there is no actual hole or tear in the retina. Often, the glaucoma specialist can just observe this situation if it is not severe since the condition typically resolves spontaneously.

P: Does cataract surgery increase the risk of detachment?

Dr. Jason Hsu: Cataract surgery is associated with a slight increased risk of retinal detachment. While rarely this is due to a complication of the cataract surgery, it can occur in even the best of hands with uncomplicated straightforward surgery. We believe this is due to a change in the vitreous (jelly in the eye) called a posterior vitreous detachment where the jelly pulls away from the back of the eye. As this jelly pulls away, it can rarely tug too hard on the retina and induce a retinal tear that can then lead to the detachment. This posterior vitreous detachment can occur spontaneously as well without any prior surgery on the eyes. It’s essentially an aging phenomenon of the eye where the thick jelly becomes more watery over time.

P: What is a floater?

Dr. Jason Hsu: A floater is often also related to a change in the vitreous gel. As the jelly starts becoming liquefied, other more solid parts can clump together to form the floater. When patients develop a posterior vitreous detachment, they often experience a lot of floaters. Floaters are typically described as dark strings or dots that move around as your eye moves. Sometimes people think they are seeing bugs when none are there.

P: Do they diminish being a problem over time because the brain accepts all the extra eye noise and
movement?

Dr. Jason Hsu: Regarding the second question, yes they do diminish over time. Most patients come in very distressed by the new onset of floaters when they first develop a posterior vitreous detachment. I would say 90-95% of patients over weeks to months report noticing the floaters less and less. When I look in, the floaters are always still there. It's just a matter of the brain adjusting. A good thing is that our brains are still pliable.

P: Can anything be done to rid the eye of floaters?

Dr. Jason Hsu: Yes. I only recommend intervention in extreme cases where the floaters are actually debilitating. In these cases, vitrectomy surgery can be performed where the vitreous gel (along with the floaters) are removed. Some of you may have heard about other techniques, such as laser. I have not found this to work well and am worried that this increases the risk for complications like retinal tears and retinal detachment.

P: What is the difference between a floater and a Weiss ring?

Dr. Jason Hsu: A Weiss ring is a circular opacity in the vitreous jelly. This is indicative of patients having had a posterior vitreous detachment, since this ring represents where the jelly used to be attached around the optic nerve. Technically, to the patient, a Weiss ring will look just like any other floater but maybe a bit larger.

P: Do genetics play a factor in retinal issues such as detachments and tears?

Dr. Jason Hsu: In some cases, they can. More often though, most patients have no family history of retinal tears and detachments. There are several known conditions that vastly increase the risk for retinal detachments and tears, such as Marfan's syndrome and another called Stickler's syndrome. These overall are rather rare.

P: If ones retina detaches in one eye, is the other more prone to having same event occur in the future?

Dr. Jason Hsu: Yes. I tell patients that both eyes are typically created with the same "protoplasm." The statistics definitely seem to bear this out as well. The risk is still low that the other eye will detach but higher than the general population. Therefore, in patients with retinal detachment in one eye, I will often treat any suspicious areas where the retinal looks weakened in the other eye with laser.

P: A couple of weeks ago, for just a couple of days, when I turned the light out a night I saw a pattern of flashing sparkles similar to retinal flashes, They only lasted a couple of minutes, and this only happened for a couple of nights. Would this be a retinal phenomenon, and is it something to be concerned about?

Dr. Jason Hsu: Did you notice any new floaters?

P: I can't say that I did. This was also in both eyes at the same time.

Dr. Jason Hsu: I typically tell patients that the flashes to worry about are usually very intense, almost like lightning bolts. They can often come multiple times. I don't get the sense that the phenomenon you're describing are typical of the flashes we hear about from patients with retinal tears.

P: My mother had detachments in both eyes and because of the speed of the actions by the doctors that treated her, she sees normally today.

Dr. Jason Hsu: That's great. Definitely, time is of the essence when it comes to retinal detachments. If we can fix the detachment before the center of the retina (macula) comes off, typically patients will retain their normal good vision. However, once the center detaches, the chance of getting 100 percent of the vision back goes down, especially if the center is detached for more than seven to10 days.

P: Is there any relationship between central vision loss from glaucoma and loss from age-related macular degeneration? Is the vision loss in the same area for both diseases?

Dr. Jason Hsu: Age-related macular degeneration typically only affects the central vision. Even in end-stage advanced macular degeneration, you'll often see that patients can still walk around and do a lot of activities. That's because their peripheral vision is intact. However, glaucoma often affects the peripheral vision first before coming into the center (though this is not always the case).

P: Can food choices affect the health of a retina? Can vitamins help in maintaining a healthy retina as we age?

Dr. Jason Hsu: We have done quite a number of studies looking at nutrition and the retina, mainly in regard to age-related macular degeneration. A ground-breaking study called the Age-Related Eye Disease Study (AREDS) proved that a combination of vitamins A, C, E, and zinc could reduce the risk of progression from moderate to advanced macular degeneration by about 25 percent. More recently, a women's health study seemed to show that B-complex vitamins (B6, B12, folic acid) may help to slow down the actual onset of macular degeneration. There has also been a lot of interest focused on omega-3 fish oil and lutein / zeaxanthin. Population studies with macular degeneration have shown that people that eat the most foods containing these substances (oily fish like wild salmon contain the fish oil; lutein is found in dark green vegetables like spinach), have the lowest rates of advanced macular degeneration. As a results, we are currently looking at omega-3 fish oil as well as lutein/zeaxanthin supplementation in a large national clinical trial.

P: I lost the vision in one eye due to a detachment - is there anything I can do to prevent this from happening to the other eye?

Dr. Jason Hsu: Its essential to be aware of any visual changes in your fellow eye, especially new floaters, flashes, or a shadow developing and be seen as soon as possible if this ever happens. I think it's a good idea to have regular monitoring. If any areas of weakness (e.g., lattice degeneration) are noted in your good eye, I usually recommend laser treatment prophylactically.

P: Does LASIK earlier in life increase the probability of retinal problems later in life?

Dr. Jason Hsu: As retinal specialists, we go back and forth on this issue. Some LASIK studies have suggested an increased risk of retinal detachment following the procedure while others have not. The problem is that most people getting LASIK are myopic (near-sighted). These are the patients that are at highest risk of also developing retinal detachments even without LASIK or any other surgeries. Other than retinal detachment, I'm not aware of any late-onset retinal conditions that are associated with LASIK.

P: What is difference in the flashing of a detached retina or an ocular migraine?

Dr. Jason Hsu: It can sometimes be difficult to distinguish, especially in patients that are having their first episode of ocular migraine. However, classically, the flashes seen from an ocular migraine follow a pattern and time course. Typically, ocular migraine flashes are described as bright flashes that often obscure the vision in the center first. Over 10-15 minutes, the flashes begin to move off to the side of the vision. Retinal flashes typically do not block the vision, nor do they last continuously for such a long period of time.

P: Can eye massage to maintain a bleb open after a trab or needling hurt the retina?

Dr. Jason Hsu: Probably not. Physical impacts to the eye often have to be very forceful, such as a punch in the eye, to cause retinal damage.

Moderator: Thank you, Dr Hsu for your time. This was a very informative chat. Thanks again for being here!

Dr. Jason Hsu: Great. Thank you for having me as a guest!

On July 21, Dr. Pro discussed "Glaucoma and other Medications" in the Chat room. Click here for highlights of that meeting.

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