If you are currently under medical treatment for glaucoma you are well aware of the expense of the eye drops.  In addition, there is the hassle with the insurance company/drug store over which brand is available to you under your plan.  Many people find that the month is longer than the drug supply and have no ability to obtain a resupply.  There are folks who can afford their drops but find it an inconvenience and miss instilling the medication.  Then there are patients who are allergic to all drops and might require surgery for pressure control.

Something to consider; laser surgery to reduce the pressure and thus allow you to eliminate all or some of your drops.  ALT, argon laser trabeculoplasty which I began doing in 1982, has long been the standard for low risk laser reduction of eye pressure.  It has more recently been supplanted by SLT or selective laser trabeculoplasty.  Patients with open angle glaucoma are candidates for the procedure.  The laser (Q-swithced Nd:YAG) fires a fine beam in 3 nanoseconds which is much faster than you can blink (1/10th of a second).  The patient is seated in front of the device, the eye is anesthetised with drops and approximately 100 laser spots are made taking about 10 minutes.  You can drive into the office and drive home; there are no restrictions.  There is a delay in effect so patients must use their regular drops for awhile following the procedure.  I have not experienced any serious complications; there might be a temporary rise in pressure or no effect at all.  In general, the pressure is reduced by about 4-5mmHg which may be enough to eliminate some or all of your medications.  In addition, the procedure can be repeated when necessary.

This approach may not be for everybody but with the spiraling cost of drugs and the availability of insurance coverage for SLT, this may be a new way of looking at your glaucoma management.  I might add that in many locales, patients are offered SLT when they are first diagnosed with glaucoma and thus avoid any drops from the get-go.

If you are currently under medical treatment for glaucoma you are well aware of the expense of the eye drops.  In addition, there is the hassle with the insurance company/drug store over which brand is available to you under your plan.  Many people run out of drops before the month end and have no ability to obtain a resupply.  There are folks who can afford their drops but find it an inconvenience and miss instilling the medication.  Then there are patients who are allergic to all drops and might require surgery for pressure control.

Something to consider; laser surgery to reduce the pressure and thus allow you to eliminate all or some of your drops.  ALT, argon laser trabeculoplasty which I began doing in 1982, has long been the standard for low risk laser reduction of eye pressure.  It has more recently been supplanted by SLT or selective laser trabeculoplasty.  Patients with open angle glaucoma are candidates for the procedure.  The laser (Q-swithced Nd:YAG) fires a fine beam in 3 nanoseconds which is much faster than you can blink (1/10th of a second).  The patient is seated in front of the device, the eye is anesthetised with drops and approximately 100 laser spots are made taking about 10 minutes.  You can drive into the office and drive home; there are no restrictions.  There is a delay in effect so patients must use their regular drops for awhile following the procedure.  I have not experienced any serious complications; there might be a temporary rise in pressure or no effect at all.  In general, the pressure is reduced by about 4-5mmHg which may be enough to eliminate some or all of your medications.  In addition, the procedure can be repeated when necessary.

This approach may not be for everybody but with the spiraling cost of drugs and the availability of insurance coverage for SLT, this may be a new way of looking at your glaucoma management.  I might add that in many locales, patients are offered SLT when they are first diagnosed with glaucoma and thus avoid any drops from the get-go.

Among ophthalmologists, it is said that you have had to have practiced for many years to understand the nature of the disease.  This is because in most cases it is a long, slow process.  However, within that framework, it is the ophthalmologist’s job to identify those individuals who have a more aggressive form of the disease and are at greater risk of vision loss.

The eyeball must have an internal pressure in order to function properly just as a basketball needs the proper pressure to bounce correctly.  The normal range of eye pressure is 12 to 21mmHg.  If you press on a healthy eye it will indent only slightly.  Please don’t do this at home.  When the pressure raises above 21mmHg, there is an increased risk of damage to the optic nerve; glaucoma.  There are factors which muddy the water.  Some people have thin corneas and some have thicker corneas, this effects the ability to accurately measure pressure and it effects the eye’s susceptablity to glaucoma.  Using a pachymeter, the cornea thickness can be measured and the normal pressure is adjusted for the individual.  Another confounding issue is that some people with elevated pressure don’t get glaucoma (ocular hypertensives) and some with normal or low pressure do get glaucoma (normal tension glaucoma).  Based on this observation, it is clear that there is more to glaucoma than just eyeball pressure.  But medical science at this moment in time only knows that if you lower eye pressure, patients tend to retain their vision.  Some time in the future we will be directing the treatment at some neural-based regulatory mechanism controlling the circulation in the optic nerve.

Once the diagnosis is made, the question becomes, “how low does this patient’s pressure need to be so as to stop the progression of the disease.”  Not surprisingly, it is different for each individual so the approach is to attempt to lower the pressure by 20% as the initial strategy.  Once the target pressure has been achieved the vision is monitored for further loss of peripheral vision (visual field testing) and the appearance of the optic nerve is checked (optic nerve tomography) for degeneration.  If patients continue to lose perpheral vision and/or optic nerve damage is progressive, the pressure is lowered further.

Pressure control is achieved with one of a number of eye drops which work by reducing the production of fluid within the eye or enhancing the outflow or both.  If one or a combination of drops is not effective then laser surgery might be the next option or possibly traditional glaucoma surgery in the operating room.

In my experience, the majority of patients with open angle glaucoma do quite well with a lifetime of eye drops.  In those people where pressure control is not attainable with conservative means (drops or laser) one must not waste time moving forward with surgical intervention.  This is particularly important in younger individuals with advanced disease.

Glaucoma is relatively easy for the layperson to understand because medical science really dose not understand the disease either and has thereby simplified matters.  Physicians view the disease in terms of eyes with too much pressure but there is a far more complex nature to the disease.  So the condition can be looked at as an eyeball with too much internal pressure to allow for the health of the optic nerve..  As a result, the nerve becomes damaged and vision is lost.

The eyeball is a closed system with fluid (aqueous humor) continually circulating in and out via a highly regulated structure (trabecular meshwork).  If the production of fluid remains constant and there is a problem with the outflow, the pressure must rise.  The optic nerve connects the eyeball and the brain and inserts itself into the back of the eye.  This nerve is very sensitive to pressure changes and if the pressure remains too high, the nerve becomes damaged.  When damage occurs to the nerve, vision is lost in a characteristic pattern; the periphery of the vision is lost long before the center of vision is effected.  If untreated, the central vision is ultimately lost and blindness ensues.

The most common type of glaucoma is open angle and a less common form is narrow angle or closed angle.  The “angle” refers to the region on the inside of the eye where the clear cornea meets the iris (colored part of the eye).  It is in this angle that the fluid passes out of the eye.  In narrow angle glaucoma the iris bulges too far forward and touches the cornea thus obstructing the flow to the angle.  When this occurs, the pressure in the eye raises very quickly causing severe pain and loss of vision.  It becomes a medical emergency.  This relatively rare situation most often occurs without warning in people who are anatomically predisposed, i.e., they have small eyeballs with crowding of the angle.  Sometimes cataract formation in the presence of a small eyeball can precipitate the angle closure.

Open angle  glaucoma is far more common and occurs as a result of a defect in the trabecular meshwork which is the structure in the angle through which the fluid must pass on its way out of the eye.  So here the angle is open but the filtration mechanism does not function properly.  The net result is that the pressure raises above normal but usually in a much more gradual rate.  Since the pressure raise is gradual there is no pain but damage to the optic nerve nevertheless develops.  Since the resulting visual loss occurs in the periphery, most people don’t realize that there is a problem.  I saw an elderly gentleman in the office who had undiagnosed advanced glaucoma.  He had attempted to drive his car between two side-by-side trucks on a four lane highway since he only saw one of them.  This is an example of how bad the disease can become.

If left untreated the vision loss extends to the center of vision.  This is one of the reasons for a routine ophthalmic examination on a periodic basis.

Treatment options will be discussed in a future blog.