Posted by Dr. J. R. Lacey, Therapeutic Optometrist
Exercise with Some Limits is Believed to be Beneficial for Glaucoma Patients
In most cases exercise is good for glaucoma patients if performed properly. Although there are a few exceptions, some research supports the benefits of moderate exercise for glaucoma patients. The exercise should be moderate and not extreme since there is now research showing extreme exercise creates large amounts of free radicals within the body, which can have its own set of problems.
Current treatment for glaucoma strives to lower intraocular fluid pressure (IOP) within the eye using eye drop medicine, laser procedures or specialized glaucoma procedures. Lowering the IOP helps maintain the health and integrity of the optic nerve. Glaucoma is a disease of the optic nerve and anything that helps the optic nerve can help a glaucoma patient. The optic nerve requires sufficient blood flow to maintain proper function and avoid neuronal degeneration. Poor blood circulation or low blood pressure can create damage to the optic nerve especially when the IOP is high. Therefore, anything a glaucoma patient can do to improve circulation can aid the health of the optic nerve.
In general, exercise tends to lower IOP and certainly improves blood circulation. So, if you have glaucoma or are one of the millions of Americans that are glaucoma suspects, try moderate exercise!
Exercise Guidelines for Glaucoma Patients
- Exhale during periods of maximum exertion such as when lifting
weights. Inhale when lowering the weight. This will help you avoid the Valsalva effect, which is when a person exhales forcefully with a closed mouth or held nose and the windpipe is blocked by the closed epiglottis. The Valsalva effect can increase pressure dramatically sometimes up to 300% of the normal IOP. The same also applies to playing a musical wind instrument, which can substantially raise IOP.
- Yoga and Pilates participants must be extremely careful and will need to limit their scope of movements. Holding breath going into or out of a pose raises IOP significantly.
- Avoid all inverted positions including headstands and inversions for back relief, etc. since all inverted positions raise IOP substantially.
The long term effect of exercise on glaucoma progression is not known, but anything that improves overall health and helps in maintaining the integrity of the optic nerve is a positive benefit.
Posted by Dr. J. R. Lacey, Therapeutic Optometrist
The iStent is a Promising New Treatment for Glaucoma Patients that also Need Cataract Surgery
It is a promising era for glaucoma patients. On June 25, 2012, the Food & Drug Administration (FDA) approved the iStent Trabecular Micro-Bypass Stent System, Model GTS100R/L. The iStent is the first device ever approved to be used in conjunction with cataract surgery for adults with moderate open angle glaucoma.
What Causes High Intraocular Pressure in the Eye?
In typical open angle glaucoma, aqueous fluid is continually created in the epithelium (outer layers) of the ciliary body in the eye and then circulates through the anterior part of the eye. The aqueous fluid normally drains from the anterior chamber of the eye. This fluid flows out of the eye through a tissue meshwork called the trabecular meshwork that encircles the iris. After filtering through the trabecular meshwork the aqueous fluid exits the eye via Schlemm’s Canal, which flows into the bloodstream.
When the trabecular meshwork doesn’t function properly it slows the drainage and exit of the aqueous fluid so the pressure builds higher inside the eye. The higher intraocular pressure can damage the fibers of the optic nerve (glaucoma) and lead to vision loss.
iStent Increases the Outflow of Aqueous from the Eye and Lowers Eye Pressure
The iStent is an extremely small titanium tube about 1 mm in length with an opening of only 120 microns. It is so small that it is believed to be the smallest implant of any kind ever
placed in the human body. The iStent is placed directly through the trabecular meshwork creating a tube-like opening for aqueous to flow into Schlemm’s Canal to help reduce intraocular pressure.
Worldwide Studies Prove the Effectiveness of the iStent
FDA studies proved the safety and effectiveness of the iStent. However, numerous other studies in Europe and Canada provide even more proof of its effectiveness. Discussions with a leading glaucoma specialist in Canada, who is very experienced with the iStent, reveal that using 2-3 iStents per eye is his procedure of choice for moderate glaucoma patients that also need cataract surgery. There is a moderately steep learning curve implanting the iStent and complications can occur because of that need to truly know how to implant the iStent. Therefore, it is advised to seek only a glaucoma specialist experienced with the iStent.
The iStent Trabecular Micro-Bypass Stent System is manufactured by Glaukos Corporation of Laguna Hills, Calif. The author has no financial interest in the iStent device or in the manufacturer of the device.
Posted by Dr. J. R. Lacey, Therapeutic Optometrist
FDA Approves a New, Effective Glaucoma Medicine
The first preservative free prostaglandin ophthalmic solution eye drop medicine used to treat glaucoma has been approved by the U.S. Food and Drug Administration. The new preservative free glaucoma medicine is known as ZIOPTAN™ (tafluprost ophthalmic solution 0.0015%). ZIOPTAN (pronounced zye-OP-tan), distributed by Merck (NYSE: MRK) is approved for reducing elevated intraocular pressure (IOP) in patients with open-angle glaucoma, the most common type of glaucoma.
ZIOPTAN is one of several prescription eye drops in a category called prostaglandin analogs. Other medicines in this glaucoma treatment category include Travatan Z, Lumigan and Xalatan. A prostaglandin analog is typically the first type of medicine prescribed by an eye doctor in the treatment of open angle glaucoma. The significance of Zioptan is that it is the first and only preservative free prostaglandin analog. It is often believed that preservatives in the eye drops can possibly cause side effects that cause problems with the outer ocular surface such as the cornea and conjunctiva.
ZIOPTAN and other Prostaglandin Glaucoma Medicines are Considered the Most Potent Eye Drops for Lowering Intraocular Pressure
Prostaglandin eye drops including Zioptan are typically prescribed to be used in the evening in the affected eye using only ONE drop per eye. In fact, prostaglandins may not work as well if more than one drop is used per day. However, it is acceptable to use other types of glaucoma eye drops along with the prostaglandin analog drops.
Because Zioptan is preservative free, the medicine is packaged in individual unit dose vials that are to be used once in each eye and then discarded. Extra vials are to be stored in the refrigerator. Once the vials are removed from the refrigerator they should be used or discarded within 28 days and any amount remaining in a used vial should be discarded because of sterility reasons.
Possible Side Effects of ZIOPTAN
ZIOPTAN may cause serious side effects just like other prostaglandin eye drops including:
Changes in the color of the eye (iris). The iris may become more brown in color while using ZIOPTAN. This color change may not go away if Zioptan is discontinued. If ZIOPTAN is used in one eye only, the color of that eye may always be a different color from the color of the other eye. The long term effects of increased pigmentation are not known. Iris color change may not be noticeable for several months to years. Typically, the brown pigmentation around the pupil spreads concentrically towards the periphery of the iris.
Darkening of the color of the skin around the eye (eyelid). These skin changes often go away when ZIOPTAN is discontinued.
Increasing the length, thickness, color, or number of eyelashes. These eyelash changes usually go away when you stop using ZIOPTAN. This is the effect that is caused by Latisse, which is used to thicken and lengthen eyelashes when the medicine is applied directly to the eyelashes. Latisse is the same medicine as the glaucoma drug, Lumigan .03%.
The most common side effect of ZIOPTAN is redness of the conjunctiva (clear tissue covering the white of the eye), which occurred in 4-20% of patients. Other ocular adverse reactions reported at an incidence of ≥2% in these clinical studies included:
- ocular stinging/irritation (7%)
- ocular itching including allergic conjunctivitis (5%)
- cataract (3%)
- dry eye (3%)
- ocular pain (3%)
- eyelash darkening (2%)
- growth of eyelashes (2%)
- blurred vision (2%)
Other adverse reactions in the clinical studies in patients treated with Zioptan (tafluprost 0.0015%) were headache (6%), common cold (4%), and cough (3%).
These side effects are very similar to the side effects of other eye drop medicines in the prostaglandin category.
Posted by Dr. J. R. Lacey, Therapeutic Optometrist
Thin Corneas are a Major Risk Factor for Glaucoma
A major national study called the Ocular Hypertension and Treatment Study (OHTS) proved that the thickness of the cornea is one of the most powerful predictors for the development of glaucoma. Eyes with a corneal thickness of 555 microns or less (thinner corneas) had a 300% greater risk of developing glaucoma than those eyes with a corneal thickness of 588 microns or more.
Eyes with thicker corneas show artificially higher intraocular pressure (IOP) readings when measured; and conversely, eyes with thinner corneas show artificially lower IOP readings. LASIK patients must always advise their eye doctors of their LASIK procedure so that the true IOP's can be calculated. This is perhaps the underlying issue of "normal tension (pressure) glaucoma" which accounts for 25-33% of all glaucoma patients. Normal tension glaucoma patients virtually always have thin corneas!
Ultrasonic Corneal Pachymetry
Measurement of corneal thickness is not a routinely performed test in a general vision exam. The most common test used to measure the thickness of the cornea is by ultrasonic technology (corneal pachymetry). Topical anesthetic drops are instilled on the cornea of the eye. A probe is then touched to the cornea and the reading is completed. The accuracy and reproducibility are somewhat difficult to duplicate since the corneal thickness varies and increases toward the periphery. Additionally, the probe must be perpendicular to the corneal surface for maximum accuracy.
Because corneal thickness is such an important test it should be performed at least once on everyone over the age of 40 or those with other glaucoma risk factors so your eye doctor is able to accurately assess the true intraocular pressure of your eye.
Corneal Ultrasonic
Pachymeter used to
measure corneal thickness
