You have likely heard someone say “we will all get cataracts if we live long enough!” That is true generally, however, we must also appreciate that how we live, and what we do with our eyes, can influence cataract formation. To understand what I am about to tell you, we must first appreciate that the eye is brain. It is formed, embryologically, beginning the first month of gestation, as an out pouching of the frontal lobe of the brain, forming the optic vesicles. We have all been taught that the Optic Nerve connects the eye to the brain, yet the Optic Nerve is really not a nerve in a true anatomic sense. It is a fiber tract of the Brain itself.
If we begin by understanding that the eye is brain, the role of oxygen becomes clearer. Diabetes, glaucoma, macular degeneration and several other debilitating eye problems are actually oxygen deprivation syndromes to various and specific blood, and thus oxygen delivery to the eyes.
Water (H2O) makes up about 70% of our tissues; less well recognized is that water is 80% oxygen. We can live many days without water, but only a few hours without oxygen!
This is important in that the little brain, (our eyes), is very dependent on the health of our bodies, good posture and the ability of our lungs to capture oxygen from the air we breathe.
We have discussed the connection of our little brain to the big one and to our bodies. We have emphasized the importance of oxygen. But what’s a body to do without oxygen?
Let us now understand the lens of the eye, and we will quickly learn its fate.
During the first and second months of gestation, the optic vesicles protrude from the forebrain to touch the skin tissue of the developing embryo’s forehead (ectoderm). This touch by brain tissue (neuro-ectoderm) causes a disc of forehead skin (the lens placode) to turn inside out. This invagination forms the human lens, whereby the cells that divide are inside a capsule (a basement membrane). The lens is therefore a cyst! A cyst continues to grow and will increase in size and mass unless it is confined. When this lens is forming it has a blood supply. Before birth, however, the blood supply withers, like a vine without water, and the cystic lens is left to make its own energy without delivered oxygen. You may have heard of the Krebs’ cycle (anaerobic glycolysis). It is the making of sugar for energy without oxygen.
Thus, two things are now happening to the little cyst we call our lens. The more we work it, the more energy it must manufacture. The longer we grow it, the bigger it gets. But, the eye stops growing at about 20. The lens continues to grow all our life. It runs into things, like the jelly (vitreous body) behind it, or the color of our eye (iris) and the fluid (aqueous) in front of it.
It ultimately gets squeezed, and the water within its cells is displaced from the oldest lens fibers in the center (the nucleus) which then becomes hard (sclerotic.) Most of us experience this change as presbyopia, or the need to remove our glasses or contacts to read if we are nearsighted, or the need for reading glasses or bifocals if we are farsighted. Most of us do not appreciate that this process (nuclear sclerosis) is the manifestation of a cataract!
The word cataract, from its Greek origin, means waterfall! Water, of course, wherever it is, will fall towards gravity. If you think of the lens like the shape of an M & M when young, as the water falls it sags, and warps, like a teardrop. This causes lenticular or cataract induced astigmatism. We can no longer correct this with external devices like contacts, glasses or even LASIK.
Hopefully, I have helped you to understand that all of us will likely experience cataracts. The important message is not IF they should be removed, but WHEN. Several reasons that involve the permanence of visual correction for high refractive errors like nearsightedness, farsightedness and/or astigmatism, or to enhance the management of glaucoma, diabetes, retinal disorders or certain corneal infections related to decreased oxygen in the tear film are specific. Each could play a part in the decision of WHEN or WHY you elect to have a cataract removed.
This brings us to the fix. At present, the only solution is to remove a cataract from its capsule and replace it with a bionic lens (an intra ocular lens implant) specifically selected for a precise, desired correction. These lenses can be single vision, multifocal, accommodating, or astigmatic. While we still live with some limits of prescription and function, almost all eyes with intra ocular lenses can be optically refined by Laser Vision adjustment of the cornea after surgery, if necessary.
Currently, diamond micro-knives are most commonly used to make the largest incision (about 2mm, less that 1/10th of an inch) in the cornea to remove a cataract by a combination of ultra-sound and suction. Lasers are now also being used to make these incisions, and to separate the hardened nucleus of the cataract.
So, what of the pill? Perhaps now you know that it is naive to expect a pill to stop the lens from growing, unless, of course it contains Arsenic!
At present, the diamond is a better option.
Wes Herman, MD
Founder and Principle Surgeon: Vision Quest
Medical Director: SurgEyeCare, Inc.
EyeCare and Surgery Center
5421 La Sierra Drive
Dallas, TX 75231
(214) 361-1443 Ext 110