Glaucoma is a serious eye condition that can eventually lead to blindness.  The optic nerve, the main nerve that transmits all visual information from the eye to the brain, undergoes progressive damage.  Peripheral vision is gradually lost, hence the term “tunnel vision”.  Sadly, in most cases there are no signs or symptoms until glaucoma has reached a moderately advanced stage. The peripheral vision that is lost can never be regained.

A major risk factor for glaucoma is high eye pressure, known as Intra-Ocular Pressure or IOP.  Additionally there are several other types of glaucoma that do not involve high IOP.  So going to a vision or health screening and having “normal pressure” is not good enough.  Another significant risk factor is family history.  Parents and siblings with glaucoma strongly increase risk.

Treating glaucoma can range from simple eye drop medications to complicated types of surgery.  All are aimed at lowering IOP and hopefully slowing the progression of the disease.  Unfortunately there is no real cure. Annual comprehensive eye examinations are the best way to detect glaucoma as early as possible.  Early intervention is very important.

The cornea is the very front surface of the eye.  When we look at someone’s eye we are actually looking through their clear cornea to see their eye color, which is behind it in their iris.  The cornea is one of the key optical elements of the eye.  Its shape and curvature are very important for clear vision.

In keratoconus there is progressive corneal thinning.  This results in bulging and asymmetry of the corneal curvature.  The result is reduced correctible vision and high amounts of astigmatism. The thinning can become so severe that a corneal transplant is required.

Treatment of keratoconus usually involves special types of contact lenses which will correct visual acuity better than eyeglasses.  There is a relatively newer procedure now known as Corneal Crosslinking which hopefully halts the progression of the disease.  Visual correction with either contact lenses or laser correction will still be required.

More in depth information regarding keratoconus can be found at www.NKCF.org

There are different causes of macular degeneration, some of which are genetic and can affect young people.  For this discussion we will limit ourselves to age related macular degeneration, also known as AMD or ARMD.  It is a deterioration or degeneration of the area of the retina known as the macula.

The macula is responsible for both precise visual acuity and color vision.  We are usually not aware that most of our vision is actually peripheral and of low quality versus straight-ahead or central vision.  Peripheral vision is very important, however.  It provides the information needed by the brain that allows it to position the eyes rapidly so that the macula can lock on target.

AMD is now the leading cause of blindness (actually Legal Blindness) in the US for people over 60.  Its prevalence increases with age.  Over age 40 the rate is just under 2%, over 60 almost 13%, and over 80 an alarming 33%.  And the high level of medical care in the US is continually increasing life expectancies.  Living into your 90’s and even 100’s is not uncommon now.  So a healthy macula is more critical than ever.

There are two main forms of AMD , known as Dry AMD and Wet AMD.

The dry form is characterized by small fairly round, yellow deposits in the macula known as drusen.  As they increase in size and number they can dim and distort vision.  Decreased reading vision is often noticed first.  Blind spots in central vision can occur as it progresses.  Treatment is currently nutritional supplements that supply critical macular pigments along with vitamins and minerals.

The wet form is much more serious, involving fluid, bleeding, and disruption of the special layering of the macula.  Traditionally laser treatments were standard, but mostly these are less common now that special medications can actually be injected into the eye itself.

Early detection of AMD is extremely important.  A key instrument in diagnosing early AMD is OCT, which stands for optical coherence tomography.  It uses pulses of special wavelength lasers to image the retina into a series of layers to a definition of about 5 microns.  This is about the size of one red blood cell.

The majority of optometric offices refer out for OCT due to the instrument’s high expense.  It is important for detection and diagnosis of a number or retinal disorder, not just AMD.  It is also a critical Glaucoma test.  We feel it is so important a test that we have had an OCT in our office for 3 years now.  We recommend it to anyone over 40, anyone with certain medical issues or a family history of AMD or Glaucoma.

For more information on AMD we recommend webmd.com