Blog

Computer Use and Eyestrain

Fri, 27 Apr 2012 15:39:00 GMT

Staring at your computer screen, smartphone, video game or other digital devices for long periods won’t cause permanent eye damage, but your eyes may feel dry and tired. Some people also experience headaches or motion sickness when viewing 3-D, which may indicate that the viewer has a problem with focusing or depth perception.

What causes computer-use eyestrain?

· Normally, humans blink about 18 times a minute, but studies show we blink half that often while using computers and other digital screen devices, whether for work or play.

· Extended reading, writing or other intensive “near work” can also cause eyestrain.

What to do:

· Sit about 25 inches from the computer screen and position the screen so your eye gaze is slightly downward.

· Reduce glare from the screen by lighting the area properly; use a screen filter if needed.

· Post a note that says “Blink!” on the computer as a reminder.

· Every 20 minutes, shift your eyes to look at an object at least 20 feet away, for at least 20 seconds: the “20-20-20” rule.

· Use artificial tears to refresh your eyes when they feel dry.

· Take regular breaks from computer work, and try to get enough sleep at night.

Computer-use eyestrain can be made worse by:

Sleep deprivation. When you get less sleep than you need, your eyes may become irritated. During sleep our eyes rest for an extended period and are replenished by nutrients. Ongoing eye irritation can lead to swelling and infection, especially if you wear contact lenses.

· If you have to be at your computer for a marathon work session, take regular rest breaks or “power naps,” if possible.

· Apply a washcloth soaked in warm water to tired, dry eyes (with eyes closed).

· Use tired or sore eyes as a signal that it’s time to stop working and get some rest or sleep.

Incorrect contact lens use. If you wear contact lenses, it’s important that you use and care for them properly — especially if you use a computer and other digital-screen devices often. This helps avoid eye irritation, swelling, infection and vision problems.

· Give your eyes a break: wear your glasses!

· Don’t sleep in your contact lenses, even if they are labeled “extended wear.”

· Always use good cleaning practices.

There are some important things to keep in mind when cleaning your contact lenses. You should:

· Avoid touching the lenses with water; use fresh solution every time for cleaning and storing.

· Rub your contacts when you clean them, even if you use a no-rub solution.

· Clean your storage case regularly (with fresh solution, not water) and replace it every 2 to 3 months.

Stop wearing your contact lenses and see an ophthalmologist (Eye M.D.) right away if you develop any of these problems: Eyes that are red, blurry, watery, sensitive to light, or sore; eye swelling or discharge.

Higher-Order Aberrations: WaveScan WaveFront Technology and Quality of Vision

Thu, 22 Mar 2012 15:21:00 GMT

The goal of a refractive laser surgeon is to improve the quality of vision and increase the level of satisfaction for all patients. As surgeons, we want our patients to avoid experiencing post-LASIK complications such as night vision problems or unwanted halos and glares. To achieve these goals, each patient’s higher-order aberrations (HOAs) need to be measured and addressed effectively.

One way to improve patient outcome is by using the WaveScan WaveFront System, an integral part of the iLASIK Technology Suite. Just as a person’s fingerprint is unique, the same is true for each patient’s eye measurements. While most treatments concentrate only on addressing the lower-order aberration, WaveScan WaveFront Technology also addresses the unique challenge of HOAs.

Simulated Effect of Residual HOAs

There is a long-standing debate about the prevalence of HOAs. I have seen prevalence rates ranging from 6% all the way up to 73% (HOAs above 3 μm) in LASIK candidates — any number in between is reason enough to believe that HOAs are a concern in the LASIK population. I am a firm believer of treating every patient’s HOAs, and by taking this approach we can treat every patient with the very best technology for them.

Clinical Study of Low-to-Moderate Myopia Shows Higher Post-Op Patient Satisfaction
(Very Satisfied/Satisfied) with the Advanced CustomVue Procedure

In summary, I am an advocate of globally rehabilitating the eye, which includes correcting not only defocus and cylinder, but also HOAs. Our patients deserve the best possible correction that offers them the greatest opportunity to enhance their quality of vision. This is why I choose to use iLASIK Technology to individualize treatments for my patients.

Recent Studies Show Even Faster Visual Recovery with iFS Technology

Thu, 22 Mar 2012 15:21:00 GMT

Background

I became a believer in femtosecond flap creation in 2005. While this technology was initially made available to my practice in 2000, I elected to allow the learning curve to progress before committing myself to any surgical changes. By 2005, the IntraLase 30-kHz femtosecond laser became available with reduced flap creation time of approximately 30 seconds and advances in post-operative inflammation and visual recovery. However, my main initial attraction to the femtosecond flap creation was safety. We all know the challenges that flap complications with the microkeratome can cause both patients and surgeons, so I was very interested in a technology that would remove this challenge from the LASIK equation. Another unexpected benefit I noted with the femtosecond flap was the almost complete elimination of epithelial ingrowth and significant flap striae.

By 2007, the IntraLase 60-kHz femtosecond laser had become available, which reduced the flap creation time to approximately 20 seconds. It further improved the post-operative results with less flap edema and inflammation and delivered faster visual recovery. At this point, I could no longer justify using the microkeratome. Furthermore, we discovered that patients were very receptive to the concept of flap creation with the “laser” rather than the “blade,” which offered us a competitive advantage. For these reasons, in 2007, I elected to use the IntraLase System exclusively.

The iFS Femtosecond Laser

Since 2010, I have been privileged to use the latest iFS Laser. The iFS Laser is a 150-kHz femtosecond laser, reducing flap creation to 10-12 seconds. While any reduction in surgical time is welcomed, I think this is the least significant of the femtosecond improvements featured in the iFS System. The density of the laser pulses can now be increased to a 7x7 spot line separation compared to the 8x8 spot line separation of the 60-kHz and the 30-kHz femtosecond lasers. Clinically, this means the flaps are about 50 percent easier to lift. The reduced energy per pulse means a further reduction in flap edema and inflammation with improved visual recovery. The high-resolution, heads-up video display has proven to be very beneficial, as it allows clearer identification of the meniscus. The iFS Laser allows for an inverted side cut (I have been using it at 110 degrees for the last year) which has been shown to increase the flap stability, enhance the post-operative healing and reduce post-operative dry eye. Finally, the iFS Laser allows for the creation of oval or ellipsoid flaps as originally described by Kerry Assil, MD. This allows the flap to be customized to the oval shape of the normal cornea and the oval ablation pattern associated with astigmatism.

Faster Visual Recovery

I have been impressed with the rapid visual recovery of IntraLase Technology, and this recovery continues to advance with each evolution of the platform. The reasons for this powerful benefit are grounded in solid science. First, the flap created is planar with a uniform thickness, unlike the microkeratome, which creates a meniscus flap that is uneven. When the flap is put back in place after the excimer correction, it fits precisely because of the well-defined side cut. These two improvements reduce the incidence of microstriae.
The result? A safer procedure with quicker visual recovery (Figure 1).

Summary

After 15 years of performing LASIK, I am very pleased to witness the improvement of our results to the point that now the pre-operative BCVA has been surpassed by the post-operative UCVA. In fact, in a recent study conducted with the iFS Laser at our practice, 98.4% of our patients are 20/20 at day one. The bottom line? The iFS Laser delivers even better visual recovery than previous IntraLase lasers and microkeratomes.

Reference

Tanna M, Schallhorn SC, Hettinger KA. Femtosecond laser versus mechanical microkeratome: a retrospective comparison of visual outcomes at 3 months.
Refract Surg. 2009;25(7 Suppl):S668-S671.