Glaucoma as Neurologic Disorder Rather Than Eye Disease?

 

ScienceDaily (Mar. 7, 2012) -   A new paradigm to explain Glaucoma is rapidly emerging, and it is   generating brain-based treatment advances that may ultimately vanquish   the disease known as the "sneak thief of sight." A review now available   in Ophthalmology, the journal of the American Academy of   Ophthalmology, reports that some top researchers no longer think of   Glaucoma solely as an eye disease. Instead, they view it as a neurologic   disorder that causes nerve cells in the brain to degenerate and die,   similar to what occurs in Parkinson disease and in Alzheimer's. The   review, led by Jeffrey L Goldberg, M.D., Ph.D., assistant professor of   ophthalmology at the Bascom Palmer Eye Institute and Interdisciplinary   Stem Cell Institute, describes treatment advances that are either being   tested in patients or are scheduled to begin clinical trials soon.

Glaucoma is the most common cause of irreversible blindness   worldwide. For many years, the prevailing theory was that vision damage   in Glaucoma patients was caused by abnormally high pressure inside the   eye, known as intraocular pressure (IOP). As a result, lowering IOP was   the only goal of those who developed surgical techniques and medications   to treat Glaucoma. Creating tests and instruments to measure and track   IOP was crucial to that effort. Today, a patient's IOP is no longer the   only measurement an ophthalmologist uses to diagnose Glaucoma, although   it is still a key part of deciding how to care for the patient.   IOP-lowering medications and surgical techniques continue to be   effective ways to protect Glaucoma patients' eyes and vision. Tracking   changes in IOP over time informs the doctor whether the treatment plan   is working.

  But even when surgery or medication successfully lowers IOP, vision   loss continues in some Glaucoma patients. Also, some patients find it   difficult to use eye drop medications as prescribed by their physicians.   These significant shortcomings spurred researchers to look beyond IOP   as a cause of Glaucoma and focus of treatment.

  The new research paradigm focuses on the damage that occurs in a type   of nerve cell called retinal ganglion cells (RGCs), which are vital to   the ability to see. These cells connect the eye to the brain through the   optic nerve.

  RGC-targeted Glaucoma treatments now in clinical trials include:   medications injected into the eye that deliver survival and growth   factors to RGCs; medications known to be useful for stroke and   Alzheimer's, such as cytidine-5-diphosphocholine; and electrical   stimulation of RGCs, delivered via tiny electrodes implanted in contact   lenses or other external devices. Human trials of stem cell therapies   are in the planning stages.

  "As researchers turn their attention to the mechanisms that cause   retinal ganglion cells to degenerate and die, they are discovering ways   to protect, enhance and even regenerate these vital cells," said Dr.   Goldberg. "Understanding how to prevent damage and improve healthy   function in these neurons may ultimately lead to sight-saving treatments   for Glaucoma and other degenerative eye diseases."

  If this neurologically-based research succeeds, future Glaucoma   treatments may not only prevent Glaucoma from stealing patients'   eyesight, but may actually restore vision. Scientists also hope that   their in-depth exploration of RGCs will help them determine what   factors, such as genetics, make some people more vulnerable to Glaucoma.

  http://www.sciencedaily.com/releases/2012/03/120307094659.htm

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    The above story is reprinted from materials provided by American Academy of Ophthalmology.

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