eyeglob

Today was a day for Cornea Transplants!

Ok, so I had five patients that I ahd to talk today about cornea transplants. A cornea transplant, which replaces damaged tissue on the eye’s clear surface, also is referred to as a corneal transplant, keratoplasty, penetrating keratoplasty (PK) or corneal graft.

A cornea transplant replaces central corneal tissue, damaged due to disease or injury, with healthy corneal tissue donated from an eye bank. An unhealthy cornea affects your vision by scattering light and causing blurred or distorted vision. In some cases, a cornea can be so damaged or scarred that a transplant is necessary to restore your functional vision.

Cornea transplants are performed routinely. In fact, of all tissue transplants, the most successful is a corneal transplant. The National Keratoconus Foundation estimates that more than 40,000 cornea transplants are performed in the United States each year.

A new version of corneal transplant, known as Descemet’s Stripping Endothelial Keratoplasty (DSEK), also has been introduced as a new surgical method that uses only a very thin portion of the cornea for transplant. In certain cases, this type of procedure may be preferred because it has advantages such as being less likely to create an irregular corneal surface (astigmatism) as a side effect.

Now, we may suggest a corneal transplant for reasons varying from diseases to eye injuries, which can include scarring from infections, such as eye herpes or fungal keratitis, eye diseases such as keratoconus, hereditary factors or corneal failure from previous surgeries and complications from LASIK.Typically, corneal transplant surgery is performed on an outpatient basis, meaning that you will not need hospitalization. Local or general anesthesia is used, depending on your health, age, and whether or not you prefer to be asleep during the procedure. With local anesthesia, an injection into the skin around your eye is used to relax muscles that control blinking and movement, and eye drops are used to numb the eye itself.

After the anesthesia has taken effect, the eyelids are held open while the eye surgeon inspects and measures the affected corneal area in order to determine the size of the transplantation. A round, button-shaped section of tissue is then removed from your diseased or injured cornea. A nearly identical-shaped button from the donor tissue is then sutured into place. Finally, the surgeon will place a plastic shield over your eye to protect it from being inadvertently rubbed or bumped. The surgery takes one hour, maybe less.

The total recovery time for a corneal transplant may be up to a year. Initially, your vision will be blurry and the site of your corneal transplant may be swollen and slightly thicker than the rest of your cornea. As your vision is restored, you will gradually be able to return to your normal daily activities.

For the first several weeks, heavy exercise and lifting are prohibited. However, people are able to return to work three to seven days after surgery, depending on your job. Steroid (no, they wont bulk you up) eye drops will be prescribed for several months to help your body accept the new corneal graft.

Your vision will continue to improve up to one year following surgery. But you will need glasses or contact lenses after surgery, because the curve of the corneal transplant cannot match exactly the curve of your natural cornea. After healing is complete and stitches are removed, it is possible to undergo laser vision correction (LASIK or PRK) to improve your vision and decrease your dependence on glasses or contact lenses.

Our population is spending more time staring at computers, cell phones, I-pads and the like. This in turn makes computer eye strain or CVS ( No not the drug store but Computer Vision Syndrome) more of a problem. 

Recently the Wall Street Journal published a very good article on computer vision syndrome entitled Becoming a Squinter Nation. You can follow the link to read the article!

Now, I had published a for a few hints on overcoming eye strain associated to computer use previously, but as a reminder here are a few tips:

Generally, laptops have us looking downward. This allows those of us that wears bifocals to see the screen through the bifocal. Because the screen is directly in front of the keyboard, it is close enough so that the bifocal distance is usually comfortable and in focus. With desktops the placement and location of the monitor becomes impotant.  Most new monitors have adjustable tilting which makes it much easier to place them in a position that allows for easy, comfortable viewing.  The ideal monitor position should be 18-20 inches or more away and sufficiently low that when you are looking straight ahead, your eyes are looking over the top edge of the frame.

If the monitor is too high  you have to tilt your chin up to focus with the intermediate portion of your progressive lens.  If you are only at the computer for a few minutes this will probably have no effect, but if you sit at the computer for a prolonged period of time, a neck ache is sure to appear.  This spells an eminent appointment with my dear friend  Dr Glenn Silver at Silver Chiropractic in Richardson! If you don’t tilt your chin up to use your bifocal to focus the monitor you are looking though the top part of your glasses instead of the intermediate zone and thus straining your eyes.  Neither option is acceptable for any reasonable length of time as they are both uncomfortable.

Computer glasses are a great problem solver!  Progressive or bifocal computer glasses are generally not really necessary for most people, now if you spend more than a couple hours a day staring at the computer monitor, you could benefit from computer glasses.  Computer glasses could be single vision focused to the computer distance or progressive lenses where the top part is focus at computer distance, and the bottom focused for reading.  A good anti-reflective coating will eliminate reflections and make it more comfortable.

Setting up your workstation ergonomics will also help. In the old days, we would not suggest you set up our workstation on the desk and the monitor sitting on top of the CPU. With new and smaller CPU units you could place the CPU on the desk and the monitor directly above thus lifting the monior. Now, do not place your monitor where there is a bright light behind it such as a window and having a window directly behind you may cause bothersome glare and reflections. One way to help with that is to have a filter with an antireflective screen on your monitor.

Lastly, a good, comfortable adjustable chair is great!  Having a chair that adjusts vertically will allow you to further improve your eye gaze position.

 This is an earlier post on the same subject: http://odphysician.com/computer-strain/

Ok, so today I had this teen girl that was tanning and didn’t protect her eyes properly, long of it short, she has a very mild UV induced corneal inflammation (we call it a keratitis) luckily for her, it should be healed within the next few days and no long term damage to the eyes.

Now, let us look at what is going on. A tanning bed is a device with UV lamps in which people lay down flat and have the rays of the sunlamps “cook” the skin to acquire a tan. Tanning beds emit 2 types of Ultra Violet (high energy packing) radiation, UV-A and UV-B rays (read these as skin cancer causing rays too). In general, tanning beds predominantly emit UV-A radiation. However, from what little information I gathered the new “quick tan beds” have emit higher levels of UV-B rays, this speeds up the tanning process.

The human cornea and physiological lens of the eye absorb UV radiation. The amount of sunlight activates the various mechanism of the eyes such as constriction of the pupil and squinting reflex, which minimizes penetration of the sun’s rays into the eye. When a person is exposed to UV radiation under controlled conditions such as a tanning bed, the body reacts in such a way that the defense mechanism of the eyes will be minimal. This can then result in a ultraviolet induced keratitis. Excessive exposure to UV rays is the cause of arc welders blind eye and snow blindness, which are a more extreme form of photokeratitis.

Various researches show that UV radiation levels to the eye is about 100 times greater in a tanning bed than outside in the sun. OUCH! Thus with the newly increased exposure to UV-B from the new systems, there is an increase the risk of developing certain types of skin and eye problems including cataracts. In cataract formation, UV radiation energy is absorbed by the small proteins inside the lens, these proteins get “cooked” and accumulate as pigments and finally may cause the internal opacity we know as a cataract.

Some studies show that the risk of this happening can be reduced to 40% if ocular exposure to UVB is decreased, but then tanning time is increased! What a problem for the industry!

Over exposure can also cause other external eye problems such as pterygium and internal problems such as macula degeneration. Pterygium is tissue growth on the white part of the eye and macula degeneration is damage to the inside of the retina.

Bottom line is, UltraViolet radiation is a well known carcinogen for the skin and has been linked to multiple eye problems. Wearing eye glasses or keeping the eyes closed might not be sufficient to keep some of this damage from happening, but if you do nothing else, you need to protect your eyes! If you tan, DON’T LOOK!