Traumatic and Inflammatory Glaucomas
Chat Highlights
April 9, 2003

Norma Devine, Editor

On Wednesday, April 9, 2003, Dr. Rick Wilson, a glaucoma specialist at Wills, and the glaucoma chat group discussed "Traumatic and Inflammatory Glaucomas."

Moderator:  How does inflammatory glaucoma differ from primary open-angle glaucoma?   

Dr. Rick Wilson:  Inflammatory glaucoma is tough, because the inflammation can either raise or lower the IOP (intraocular pressure).  Inflammation causes white cells to form in the liquid in the front of the eye.  The cells get trapped in the trabecular meshwork (the "drain"), blocking it.  The fluid also becomes thicker and less likely to pass through the drain, and the strands that make up the drain swell, making the pores between them smaller.  Inflammation can also release prostaglandins that increase the flow of fluid out between the muscle bundles of the eye.

Moderator:  Why are steroids used to treat the inflammation?  

Dr. Rick Wilson:  Steroids can make the eye more healthy, so it makes more fluid, increasing the IOP.  Conversely, steroids can decrease the thickness of the fluid, and the swelling of the strands in the drain increases outflow, lowering IOP.

Moderator:  Why do steroids cause a rise in IOP in some people and not in others?  

Dr. Rick Wilson:  Steroids given over a prolonged period to people who are sensitive to its effects (steroid responders) can cause a rise in IOP.  The reason is not understood yet, but may be due to a build-up of debris in the eye.

P:  How effective are the non-steroidal inflammatory drops compared with the steroidal drops in controlling inflammation?

Dr. Rick Wilson:  Non-steroidal drops are good in that they don't cause the IOP rise that can happen in some people, but they are not as effective as steroids in decreasing inflammation.  Non-steroidals can also occasionally harm the cornea.  

P:  What does inflammation in the eye look like to the doctor?    

Dr. Rick Wilson:  You can see white cells floating in the clear fluid in the front of the eye, or in the jelly-like vitreous in the rear of the eye.  There's also the Tindel effect.  In a smoky room with a high ceiling and a ray of sunlight, you can see the ray of light in the smoke.  Similarly, when you pass a small beam of light through the aqueous in the front of the eye, you can see the increased protein.  If there is no inflammation, then there is no protein in the fluid, and it appears completely clear.

P:  Does inflammation always lead to glaucoma?

Dr. Rick Wilson:  Inflammation does not always lead to glaucoma, but usually does if it is chronic.  Prolonged inflammation may damage the part of the eye that makes the fluid, so it makes less fluid and the IOP can actually become too low.  

P:  What are the most common causes of inflammation?  

Dr. Rick Wilson:  We are not able to determine at least 50% of the causes of intraocular inflammation.  Other causes can be viruses, other organisms like toxoplasmosis, or systemic illnesses like sarcoid.  It is said that infected teeth or sinuses can cause inflammation in the eye.

P:  So an inflamed sinus might inflame the eye?  How about something further away from the eye, like inflammation in the joint of a lower extremity?

Dr. Rick Wilson:  If the inflammation in the joint is autoimmune or infectious,  I think it can cause a sympathetic inflammation in the eye.

P:  What are the symptoms of  inflammation in the eye?

Dr. Rick Wilson:  The eye is red and light sensitive.  If the infection is serious, vision is usually decreased, as well.

Moderator:  If glaucoma is caused by inflammation, and the inflammation is controlled, will progression stop?  

Dr. Rick Wilson:  Usually, unless too much damage has been done to the drain (trabecular meshwork).

P:  Could chronic osteomyelitis (bone infection) cause glaucoma?

Dr. Rick Wilson:  I haven't heard of it doing so, unless it involves the bones around the orbit.

P:  Can allergies cause intraocular inflammation?

Dr. Rick Wilson:  It's possible, but I am not sure the association is clear. 

P:  Is ICE (iridocorneal endothelial) syndrome considered a type of inflammatory glaucoma?  It is thought that herpes may be responsible.

Dr. Rick Wilson:  It is not due to inflammation, but to the virus causing the cells lining the cornea to run amok and cover the drain and iris of the eye.

P:  You mentioned viruses.  Could shingles (herpes zoster) cause intraocular inflammation?

Dr. Rick Wilson:  Herpes is a common cause of ocular inflammation, both outside and inside the eye.  That is true for both herpes zoster (shingles) and herpes simplex.

P:  Could the drug usually given initially for shingles cause an increase in IOP?

Dr. Rick Wilson:  One of those drugs is a steroid, which can cause an IOP rise in susceptible patients.  The other ones usually do not.

P:  Could chicken pox also cause inflammation in the eye?

Dr. Rick Wilson:  Yes, chicken pox is also herpes zoster and does cause intraocular inflammation.

P:  Would a vitrectomy help a patient who has uveitis and glaucoma? 

Dr. Rick Wilson:  It could, if the uveitis is due to an intraocular infection or if the vitreous is clogged with inflammatory debris.

Moderator:  What kinds of trauma to the eye can cause glaucoma?

Dr. Rick Wilson:  All kinds of trauma can cause injury to the trabecular meshwork, leading to glaucoma.  For instance, a penetrating injury, say a sharp pencil tip, can allow fluid to escape from the eye.  The front of the eye  collapses to the point that the iris comes forward, contacts the drain, and sticks to it, blocking it.  

Moderator:  How does blunt trauma affect the eye?

Dr. Rick Wilson:  Blunt trauma can tear and scar the trabecular meshwork, making it nonfunctional.  I have a seven-year old patient in the hospital now who was hit with a ball that caused a hemorrhage in the eye.  The hemorrhage blocked the drain and the IOP went up.  The IOP can go up directly, or later, after the iris sticks to the drain, or the eye becomes healthy enough to make a normal amount of fluid.  The boy will have at least a 5% chance of getting chronic glaucoma, even if his IOP returns to normal.

P:  Is traumatic damage to the trabecular meshwork visible during a regular eye exam?  If so, what do you see?

Dr. Rick Wilson:  If the damage is severe, it appears as tears in the drain or between the muscles in the eye, which are torn apart.

P:  Typically, where does a person first notice a visual field defect?  

Dr. Rick Wilson:  Most people have a very hard time noticing any change in their visual field, until it becomes gross.  That's because change in the visual field happens very slowly.  It's like watching hair grow.  A person with vision in only one eye has a much better chance of seeing the changes.  The first, usually imperceptible, change would be a generalized decrease in visual sensitivity, followed by localized gray or dark spots.

P:  At what cup-to-disc ratio do visual field defects form?

Dr. Rick Wilson:  That varies considerably.  Some people have a 0.1 cup-to-disc ratio, and that is normal for them.  My son has a 0.85 cup-to-disc ratio, and that is normal for him.

P:  Many patients think the first vision they lose is peripheral, which to them means vision way off to the side.

Dr. Rick Wilson:  The first localized loss is usually between 15 to 30 degrees from the center of the vision, not all the way off to the side.  In fact, side vision is the last to go.

End of highlights for April 9, 2003.

On April 16, Dr. Wilson discussed "Primary Open-angle Glaucoma" in the Chat room. Click here for highlights of that meeting.

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