Monthly Archives: March 2015

Should you have laser eye surgery (PRK or LASIK)? Answer these three questions.

By | Laser vision correction, LASIK, Ophthalmologist, PRK, Refractive Surgery, Uncategorized | No Comments

1. Do the benefits outweigh the risks (low but not zero)?

The vast majority of people who have laser vision correction (PRK or LASIK) are satisfied with the outcome, and in a large FDA study of LASIK (PROWL 1&2) <1% of people experienced “a lot of” difficulties following surgery.  The most common side effects at 3 months in that study were dry eye and some increase in halo at night; these side effects may improve in some people beyond 3 months.  If this sounds like a reasonable risk versus benefit then read on; if you need a 100% guarantee of the outcome of PRK or LASIK then laser eye surgery may not be a good choice for you.  If you would like to have laser vision correction and are looking for the lowest risk then PRK may be your best choice.  This no-flap treatment avoids cutting into the cornea to create a LASIK flap.  Eliminating the need for a LASIK flap will avoid any complications that could happen when cutting the flap and also will eliminate the risk of a LASIK flap shift in the future if you suffer an eye injury even months or years after surgery.  For some people with high risk occupations PRK is a better choice.  Surface PRK also does not disturb the cornea as deeply and may be a better alternative in thinner corneas.  Surface PRK does involve a longer recovery (7-10 days) before returning to usual activities, but provides equally good results without the need to cut a corneal flap.

2. Do you have the right expectations?

The goal of laser vision correction is for you to function as well without glasses or contact lenses as you do now with your corrective lenses.  PRK or LASIK will not be expected to make your vision better than it is with your glasses or contacts.  If you already need reading glasses over contact lenses or a bifocal in your glasses, then laser eye surgery can correct for distance but you will still need reading glasses.  For people that have PRK or LASIK at a younger age, they will need reading glasses in their mid-forties as the focusing declines naturally with age.  This is called presbyopia and there is no treatment available for this natural age change that has been shown to be effective at this time.  In most people their night vision will be similar to what it was with glasses or contact lenses before surgery, but it does take longer (up to 6 months or longer for some people) to improve than vision during the day or in bright light.  For most people if they have dry eye with glasses and contact lenses this means their eyes will be dry after surgery.  Dry eye can also be worse for the first three to six months and generally returns to baseline – PRK and LASIK do not cure dry eye (some people think that if they can get rid of the contact lenses then the dry eye will be solved, but this is usually not the case).  There are a number of treatments for dry eye, so if this is a problem then working with your eye care provider to improve your comfort is recommended before considering PRK or LASIK.

3. How do you find out if you qualify for laser eye surgery?

There are some eye conditions and also systemic conditions that may disqualify you from PRK or LASIK.  An assessment with specialized corneal mapping and other testing is the next step if you answered yes to the first two questions.  During the assessment a medical history is also taken.  If your testing shows that you are a good candidate then there will be an opportunity to discuss any questions and to learn more about laser eye surgery.  At Western Laser Eye Associates Dr. Anderson Penno will examine your eyes at the assessment and answer any questions that you may have about laser eye surgery.  Once you have all the information you can make the choice that is right for you.

If you have questions about laser vision correction or wish to book a complimentary evaluation with Dr. Anderson Penno, contact Western Laser Eye Associates.

 

What is up with that White&Gold (or is it Blue&Black) Dress?

By | Fashion, Food for thought, Ophthalmologist, Uncategorized | No Comments

Most people who spend even a little time on the internet will have seen this photograph of the striped dress that has created a firestorm of debate about the true colors.  This explanation from an article on the New York Times site is probably the most concise, however it is not completely understood even by eye specialists why there is such a difference in perceptions between different people viewing the same picture.  Interestingly there is still a difference when the picture is printed which means that the viewing angle when looking at an electronic display versus paper does not completely explain the effect.  Although not a scientific study, in a small sample size of ophthalmologists and engineers, the ophthalmologists all saw the dress as White and Gold and the engineers all saw Blue and Black.

There have been reports that the split is from 70% white and gold to 50/50 in on each side.  It is possible that there may be genetic tendency to view the dress as one color or the other due to either retinal differences (the retina lines the back of the eye like film in a camera and the center of the retina is responsible for color vision) or due to differences in the brain or both.  Another interesting fact is that for some people the dress changes from white and gold to blue and black which indicates some adaptation in the brain’s interpretation of the images that are formed on the retina.  How Your Eyes Trick Your Mind shows a number of different optical illusions and explains some of the science behind them.  In some cases MRI images will show the involvement of specific parts of the brain when people are viewing an optical illusion.  The White/Gold/Blue/Black dress is a bit different than classic optical illusions in that it involves color.

In many ways we ultimately do see with our brains.  For example it is well established that people can adapt to glasses that turn everything upside down.  This is called perceptual adaptation. Another well known phenomenon is inattention blindness. This is an effect where when attention is focused on a specific detail a person will not see things that may be right in front of them.  There is likely to be continued debate about why this particular photograph of what should be referred to simply as the “striped dress” for now creates such a large difference between viewers.  For now it is nice to know that these perceptual differences are a normal part of the visual system (and whether you see it Blue&Black or White&Gold you are not right or wrong – just different).

If you have questions about laser vision correction or wish to book a complimentary evaluation with Dr. Anderson Penno, contact Western Laser Eye Associates.