We live in the Instagram era, when even a simple cup of coffee suddenly becomes one of the most artistic things to be photographed. After sharing your shot with all your friends on the web (so that you’ll have shown that you DO have a social life, yop!), you put back your Reflex (the best camera ever for shooting cups of coffee, we all know that) and notice that its lens is a bit misted up. Inside. So you’ll never be able to get rid of it and all your shots will look blurry. You’ll be able to post only photos of blurry coffee served in blurry cups on blurry tables. You’ll be a blurry person, forever.
Now, transpose this “blurriness” to one of your eyes. Imagine you have one eye which “works” perfectly, like HD vision, and the other one with some misted up lens inside, so that everything you see looks blurry. This is clearly a much worse problem than not being able to shoot cool photos. This problem is called Cataract and nowadays is the most common cause of vision loss in people aged over 40.
Human eye is composed of different layers. Without giving too many details, a very important component of the eye is a transparent tissue known as crystalline lens. This lens is able to change its thickness so that the eye is able to focus on objects at various distances. The changes of thickness are controlled by a suspensory ligament, called Zonule of Zinn, that connects the crystalline to the ciliary body of the eye. Their combined movements are really important for correctly focusing light onto the back of the eye (the retina) so that images appear clear and without distortion.
The crystalline lens is made mainly of water and proteins and it is nourished by the aqueous fluid that is present between the cornea and the crystalline lens. Metabolic changes of the crystalline lens fibers over time lead to the development of opacifications, mainly due to the proteins that clump together. As a consequence, the lens gets “clouded” and this clouding is actually known as Cataract. This process normally worsens the way light enters the eye and, as a result, our sight is blurry.
Nowadays, modern cataract surgery is one of the safest and most effective surgical procedures. Over 90% of operations are successful in restoring useful vision, with a low complication rate. The operation itself is typically performed using only local anesthesia and in one-day hospitals. Very often, the postoperative recovery is really quick and can greatly reduce the patient’s dependence on eye glasses.
The most common surgical procedure for removing cataract is the so called phacoemulsification.
By using a microscope, the surgeon focuses on the lateral side of the eye and makes a small incision on the cornea.
Then, a tiny ultrasound probe is inserted into the eye in order to break the lens. The high vibration frequency (40 kHz) of the probe tip causes the emulsification of the lens material, which gets broken in very small fragments.
By accessing the eye always through the same incision, the crystalline pieces are removed through an aspiration probe.
Next, the same tool is employed again, this time to insert an artificial intraocular lens that actually replaces the crystalline. The artificial lens is usually made of plastic, silicone or acrylic compounds and is supposed to remain in place for the rest of the patient’s life. No stitch is generally necessary, just a protective shield is usually placed over the eye to keep it safe in the early recovery stages.
Recently, lasers have been approved for use in cataract surgery: they improve the accuracy of the surgery, since they reduce the need for surgical blades and other hand-held tools. Moreover, they result to be more efficient than ultrasonic probes for crystalline fragmentation. Laser-assisted cataract surgery is fairly new and significantly increases cataract surgery cost. However, medical consultation is always the best way to evaluate all the possible surgical risks.
sources: one, two and three