Childhood vs. Adult Glaucoma
Chat Highlights
August 9, 2006

On Wednesday, August 9, 2006, Dr. Rick Wilson, a glaucoma specialist at Wills, and the glaucoma chat group discussed "Childhood vs. Adult Glaucoma."

Moderator:   Welcome back to chat, Dr. Wilson.  Tonight we would like to discuss the differences between childhood glaucoma and adult glaucoma.  Let’s start with the diagnosis.

Dr. Rick Wilson:   Infants usually present with the classic triad of abnormally big corneas, tearing, and light sensitivity. Those symptoms occur because the abnormally high IOP (intraocular pressure) in the eye expands the soft eye tissue of the infant like a balloon.   Descemet's layer of the cornea* has the hardest time expanding rapidly enough and suffers breaks. The breaks cause tearing, light sensitivity, and often clouding of the cornea, which is caused by aqueous fluid from inside the eye having access to the middle layers of the cornea. [*Editor’s note:  The cornea is composed of five layers: the corneal epithelium anteriorly, Bowman's membrane, the corneal stroma, Descemet's membrane, and the endothelium.]

As you know, in adults there are no outward signs and no symptoms from the common type of primary open-angle glaucoma (POAG).  Most people with glaucoma in America have primary (no other known cause) open-angle glaucoma.

P:   What do you mean by abnormally big corneas?

Dr. Rick Wilson:   I mean large in diameter, although as the corneas swell with the added fluid, they also become thick.

P:   In 1974 I was diagnosed as being nearsighted, and I’ve worn prescription eyeglasses ever since. Could my glaucoma have been detected and treated back then?

Dr. Rick Wilson:   If your IOP was elevated or the optic nerve -- and possibly the visual field -- had suffered significant damage, then it could have been diagnosed and treated.  I started wearing glasses at age three because I was premature and nearsighted, which had no relationship to glaucoma.

P:   I developed glaucoma secondary to uveitis, which was thought to have been caused by juvenile rheumatoid arthritis. Last year I needed to have surgery because eyedrops and Diamox were not keeping the intraocular pressures low enough.  Even though I am in my late 40's, I ended up seeing a pediatric glaucoma specialist, who performed a trabeculectomy.  My former glaucoma specialist did not have experience treating childhood glaucomas, did not seem to have many adult glaucoma patients, and does not perform goniotomy.  Isn’t the approach to treating children with glaucoma, and also adults with glaucoma since childhood, different?

Dr. Rick Wilson:   Yes, that is correct.  Angle surgery is just starting to be performed on adults, but only a handful of doctors have experience with it.  Since the disease is rare, not that many ophthalmologists have experience with children.  Besides angle surgery, the major difference is the soft, pliable nature of the sclera in the young child and the tendency for more inflammation and scar formation.  Tubes (shunts) in adults usually stay where you put them.  In infants, tubes tend to migrate toward the least resistance, moving through the soft tissue.

P:   Are any tests given at birth to determine eye health?

Dr. Rick Wilson:   The pediatrician usually tests the eyes with a penlight at a young age. Having the child look at the light of a small flashlight shows, by reflection of the light, if the eyes are aligned correctly.  The clarity of the cornea and lens also can be judged with the directed light.

P:   Can glaucoma occur in the womb?

Dr. Rick Wilson:   Yes, children can be born with serious glaucoma.

P:   Is the basic course of treatment the same for all ages?

Dr. Rick Wilson:   No, children are usually treated surgically, if easily possible. In small children, the chances of side effects from medications are greater, and prostaglandins are less effective.  Alphagan is not used in children younger than eight years, unless in desperation, because of breathing problems and the lethargy it can induce.  Therefore, surgery is usually performed first in young children, whereas medications are usually used first in adults.

P:   Do younger patients have more complications than adults?  If so, why?

Dr. Rick Wilson:   The soft tissue, increased inflammatory membranes, and increased healing with the very young give them a poorer prognosis from an IOP perspective.  If children under the age of eight, but especially under the age of 6, can't see well out of one eye or both for any significant length of time, they develop amblyopia (“lazy eye”).  Amblyopia poses an additional risk of operating in this age group, especially as cataract formation is one of the possible complications.

P:   With iridocorneal endothelial syndrome (ICE) and secondary glaucoma, is there any way to tell earlier (rather than at onset at age 30 to 50) if ICE is present?  I remember as a teen having IOP higher in my ICE eye, but it was never high enough to cause panic.

Dr. Rick Wilson:   If ICE is suspected, corneal endothelial photography with great magnification may identify diseased cells earlier than they can be picked up looking at the cornea with a slit lamp microscope, as used in the ophthalmologist’s office.

P:   If ICE had been detected early, could anything have been done to slow the progression?

Dr. Rick Wilson:   Nothing we know of slows down the progression of the disease in the corneal lining.  Our present aim is to prevent damage to the optic nerve from high IOP.

P:   Many youngsters play video games for many hours.  Would that have any effect on a youngster with glaucoma?

Dr. Rick Wilson:   Not on the eyes; maybe the brain.

P:   I hear many parents mention cup size in the eye.  Is it or is it not important at any age?  And can it change over time?

Dr. Rick Wilson:   People inherit a cup size, and there is a normal range of cup sizes.  Cups gradually increase in size over time, but not a lot, unless there is glaucoma damage or another disease.

P:   I recently had a goniotomy, which hurt. Is that a good way to follow up on glaucoma suspects?  Is it true that the procedure could cause corneal abrasion?

Dr. Rick Wilson:   You had gonioscopy, not goniotomy.  During a gonioscopy, the doctor uses a mirrored lens to look into the drainage angle of the eye.  A goniotomy is a surgical procedure in which the doctor opens up the tissue over the trabecular meshwork and often exposes the Canal of Schlemm to fluid from the inside of the eye.

Gonioscopy can lead to a corneal abrasion, but that is usually only seen if the corneas are dry and the patient is looking around a good deal.  Gonioscopy is usually not at all painful.  There are new imaging devices that can see the angle from the outside of the eye, but most doctors don't have them in their offices.

P:   What are those new imaging devices to view the angle called?

Dr. Rick Wilson:   The two newest are the ultrasound biomicroscope (UBM) and the OCT (ocular tomography).  The OCT can now also look at the angle structures.

P:   What is being done to educate pediatricians to help them recognize glaucoma in infants and children?

Dr. Rick Wilson:   Their pediatric society is educating them.  The problem is, since the disease is rare, pediatricians forget to look for it if it has been years since they have seen a case or not seen a case since their training.

P:   Is it true that every glaucoma specialist treats congenital glaucoma differently?  For example, why do some doctors start with a goniotomy, while others go straight to shunt surgery?

Dr. Rick Wilson:   Doctors do what they are comfortable doing. Therefore, if they were trained with goniotomy and have good results with it, they try that first.  The alternative is usually a trabeculotomy in a patient less than three years old. If neither of them work, then either a trabeculectomy or a shunt is tried, again depending upon the doctor's past experience.  The type of shunts chosen also varies.

P:   Finding an experienced doctor was a long process for me. I had to be referred out of a hospital network.  What is the best way for a patient or parent of a child to find an experienced glaucoma specialist?

Dr. Rick Wilson:   First, I would ask the ophthalmologist taking care of the child for referrals, and then look up the doctors to see if they are known for pediatric experience.  Another approach is to check out the nearest training program to see if the doctors have expertise in pediatric glaucoma. If not, ask where their patients with serious pediatric glaucoma problems are sent.

P:   Does pregnancy have any effect on glaucoma or the cornea?

Dr. Rick Wilson:   Estrogen in pregnancy increases the outflow through the trabecular meshwork, and the IOP is usually lower during pregnancy and the early post-partum period.

P:   Since most children have to be under anesthesia for eye examinations, isn’t it difficult to get a good examination of a three-month-old child?

Dr. Rick Wilson:   Actually, it is more difficult to get cooperation from a one- to two-year-old child.  As a last resort, a three-month-old baby can be overpowered.  Evaluations under anesthesia are necessary if an accurate IOP is in doubt and if a photo of the optic nerve is needed.

Moderator:   Dr. Wilson, that’s all the questions we have time for tonight.  Earlier I told the group that, starting in September, these chats with you will only be held on the 1st and 3rd Wednesday of each month.

Dr. Rick Wilson:   Since we have had fewer and fewer attendees, we will start having doctors at the chats on just the 1st and 3rd Wednesday of each month, with open patient chats on the other Wednesdays.  If there is a hue and cry and more interest is shown, we can always increase the number of chats.

P:   Thanks, Dr. Wilson, for everything we've learned these many Wednesday nights.

Dr. Rick Wilson:   Good night.  Have a good week.

On August 16, Dr. Wilson discussed "Late-onset Bleb Infections" in the Chat room. Click here for highlights of that meeting.

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