Glaucoma, the eye disease that causes blindness, is easy to check for and treat, but too few Israelis take the test.
By JUDY SIEGEL-ITZKOVICHdoctor370(photo credit: Judy Siegel-Itzkovich)
It takes no longer than a coffee break – but this simple and painless test can save you from going blind.An ophthalmologist has merely to put some anesthetic drops onto your eyes, wait a few minutes and then, for a second or two, hold a tonometer device against the transparent cornea coating your eyeball.The intraocular pressure in each eye is quickly measured, and if glaucoma is suspected, additional tests are conducted to confirm the diagnosis.Yet many Israelis over 50 (or younger if they have a family history of the disease) avoid going for annual testing, and as a result their optic nerves suffer irreversible damage.Between 80,000 to 100,000 Israelis suffer from some kind or some stage of glaucoma; there are between 5,000 and 7,000 new cases a year. Of the 30,000 to 40,000 blind people here, nearly 5,000 lost their sight to glaucoma.A clear liquid, called “aqueous humor,” that is constantly produced behind the iris (colored part of the eye) fills the front part of the eye. It drains out of the eye through channels in an area called the anterior chamber angle (“the angle” for short). If the exit point is clogged and the intraocular pressure builds up slowly over time, glaucoma results.The intraocular fluid is vital for the health of the eye, as it feeds tissues and prevents the eyeball from collapsing like a deflated beach ball. The eye’s structure includes an amazing maze of drainage channels known collectively as the trabecula.Normally, pressure inside the eye stays constant because fluid production and outflow maintain a balance.When tonometry testing diagnoses the usually painless degenerative eye disease, it doesn’t necessarily mean that lost vision can be recovered, but additional damage to the optic nerve – which transmits information from the eye to the brain – can be prevented with regular checkups, special drops and laser treatment (called iridotomy) or eye surgery. Lowering eye pressure by at least 30 percent can keep the condition from progressing in some patients.Because there is such minimal awareness of glaucoma – many general practitioners don’t even routinely recommend to their middleaged and elderly patients that they go for annual eye exams – Glaucoma Awareness Week was held recently in Israel and the world.
There are four main types of the disease: open-angle (chronic) glaucoma; angle-closure (acute) glaucoma; congenital; and secondary.Open-angle, which tends to run in families and comprises about 95 percent of cases, is referred to as “primary,” as it does not result from other diseases.In open-angle glaucoma, drainage fails to keep pace with the output of new aqueous humor.Pressure on the optic nerve builds as the level of fluid rises. Damaged optic nerve fibers die off one by one, and the nerve bundle begins to resemble a frayed extension cord, no longer able to transmit complete signals from the eye to the brain. This process takes place so gradually that vision loss may be imperceptible until irreversible vision loss has occurred.Angle-closure glaucoma is an emergency in which the drainage of the aqueous humor is suddenly blocked. Unlike the most common kind, the problem causes severe and sudden pain. A sufferer must go for immediate medical care, which is likely to involve eye drops or other medications.Congenital glaucoma occurs in infants and often runs in families, but is rare. Secondary glaucoma may result from taking steroids or other drugs, trauma, certain systemic diseases or other eye diseases.ALMOST EVERY hospital in Israel has a glaucoma clinic, says Dr. Benzion Silverstone, head of the glaucoma unit at Jerusalem’s Sha’are Zedek Medical Center. Due to the aging of the population, the number of patients diagnosed with glaucoma is constantly growing – but would increase even more if the general public were more aware of the disease, he added during an interview with The Jerusalem Post.While excessive pressure is almost always the cause of the disease, there is a minority of cases in which patients have normal intraocular pressure but still get glaucoma.Ophthalmologists still don’t understand why, Silverstone said.The waiting room outside the hospital’s outpatient eye clinics is packed. “We have four glaucoma specialists in the unit, but it’s still hard to keep up,” he admitted. During our interview, so many people wanted to see him or ask questions that he had to lock the doors from both ends to be able to speak uninterrupted.“Today, our unit is the largest in the city. We see 60 to 100 patients a week,” he explained.The ophthalmologist, who was born in Mexico, studied general medicine there and then came on aliya. His internship was at Sha’are Zedek, where he has worked for 35 years. His wife is from South Africa, where he did two years of advanced studies at the University of the Witwatersrand. As blacks have a high rate of glaucoma, he learned a lot about the disease there. One of the world’s top experts in glaucoma was at the South African university. “I preferred ophthalmology because I liked doing delicate surgery,” he said.Your risk is higher if you have a parent or grandparent with open angle glaucoma; you are well advised to go by age 40 for screening in this case.There is a clear ethnic connection to the prevalence of glaucoma, with those of African descent being three times more likely to contract the disease. Many people of East Asian descent are at higher risk of developing angle-closure glaucoma due to shallower anterior chamber depths, while women are three times more likely than men to develop acute angle closure glaucoma because their anterior chambers are more shallow.Even dogs and other animals can contract glaucoma, and undergo treatment very similar to that of humans.“We perform between 50 and 60 operations a year on glaucoma patients, some also with cataracts.When YAG lasers are used, it takes only a few minutes to open up the ducts. We have only about two operations a year on infants with the congenital type, which affects fewer than one baby out of 10,000,” Silverstone said.When asked whether the excessive fluid could be “vacuumed” out of the eye, the ophthalmologist smiled and noted there’s an unusual form of the disease called pigmentary glaucoma, for which German experts indeed use a tiny vacuum cleaner to suck out the colored fluid, but added that this technique cannot be used for any other kind of glaucoma.Ideal intraocular pressure is between 12 and 22 millimeters of mercury. “High pressure is bad, but low pressure is also not good,” he said. Optic nerve damage that results from inadequate fluid pressure in the eye is called low-tension glaucoma.Silverstone introduced at his unit new surgical techniques, such as deep sclerectomy, and no longer performs the standard operation, called trabeculectomy, that was first developed in the 1960s. “The new techniques involve fewer complications such as bleeding or infections,” he explained. A number of new, experimental techniques to treat glaucoma, such as the implantation of tiny tubes in the angle to facilitate drainage, are being developed, and this should eventually bring good news to patients.Most glaucoma patients can be stabilized with eyedrops, but not all the medications are in the basket of health services, said Silverstone.“The new ones not provided yet by the health funds are those without the preservative known as BAK.These offer better results than those with preservatives, which can cause allergies in patients, but there is only one type of eye drops without BAK in the basket.”Glaucoma could be a natural result of aging, he continued, but there has still been no breakthrough in the understanding of the reasons for the disease. “Some genes are thought to be involved because it tends to run in families. But the researcher who discovers all the causes would surely receive the Nobel Prize.”The majority of patients who have open-angle glaucoma receive a variety of eye drops, not just one type, to control the pressure. The latest drops cause fewer side effects than the previous generation of medications.Medication not in the form of eye drops can be administered orally or through a vein.SHA’ARE ZEDEK has the only mobile unit in the country for the diagnosis of glaucoma, says Dr. Amos Mazover, who runs it in the Jerusalem area. It was established by the late Sam Rothberg, a major leader and philanthropist of the American Jewish community who lived in Peoria, Illinois, and died six years ago at the age of 94. He established two such outreach centers – one at the Goldschleger Eye Institute at Sheba Medical Center and the other at Sha’are Zedek, but the mobile unit at Sheba closed a few years ago, Mazover said. Rothberg’s daughter, who was interested in the product, continued to fund Sha’are Zedek’s mobile unit through the Jerusalem Foundation.Mazover noted that even though family physicians routine ask older patients to undergo a stool test to detect colorectal cancer, many do not remind them to go for an annual eye pressure test.He drives to government and private offices, factories, community centers, old age homes and hospitals and with a nurse and a volunteer provides free tonometry tests. The mobile unit is a van containing equipment that is unloaded to perform eye tests. It roams not only through the capital but also as far as Beit Shemesh, Ma’ale Adumim (and once reached Modi’in).“One can go to one’s eye doctor and take a test by paying the NIS 22 copayment; the problem is that so few people do this on an annual basis. So we come to them. We check for intraocular pressure in a few minutes, but we have also detected cataracts and even found signs of a brain tumor,” Mazover said. “As glaucoma rarely causes pain, people don’t bother to go to check for it.”
