Laser surgery made simple

June 29, 2013

 

San Diego-The education program at the American Optometric Association ended appropriately with a look toward the future. On Saturday afternoon, Nathan Lighthizer, OD, and Michelle Welch, OD, presented Looking Toward the Future: Laser Therapy in Optometry.

Dr. Welch, who is from Oklahoma and graduated in 1995, said of lasers: “This has always been my world.” So for her, lasers aren’t new. But for most of the audience, lasers were not part of the past.

Dr. Lighthizer used an ARS system to ask the audience: “If you were just diagnosed with glaucoma what would you want for your eyes?” Some 61% said selective laser trabeculoplasty (SLT), 39% drops, and 0% said surgery.

As the presenters illustrated, there are several good uses for lasers. One of them is YAG capsulotomy to treat posterior capsular opacification (PCO). Dr. Lighthizer said PCO is seen in 10%-80% of eyes following cataract surgery. It can form anywhere from a few days to years post surgery, and younger patients are at higher risk. Acrylic lenses seem to cause less PCO, added Dr. Welch.

The Nd:YAG laser literally means neodymium: yttrium aluminum garnet laser. It is a photodisruptive laser. Basically, high light energy levels cause the tissues to be reduced to plasma, disintegrating the tissue. A large amount of energy is delivered into very small focal spots in a very brief duration of time
 (about 4 nanoseconds).

The YAG capsulotomy preoperative exam must include the following:

  • Visual acuity, glare testing, PAM/Heine lambda
 (vision should be 20/30 or worse)

  • Slit lamp exam

  • IOPs

  • Dilation (enables better visualization of the PCO)

  • Posterior segment exam of the macula 
and periphery

  • Educating the patient

  • Having the patient sign an informed consent

Any time clinicians put laser energy into the eye, the two most commonly encountered side effects are IOP spike and inflammation. This is most often transient. In the event of inflammation, use Pred Forte QID X 1 week. Floaters, retinal detachment, and permanent vision loss are also potential YAG capsulotomy risks.

The day of the procedure, the patient receives pre-op drops: dilating drops
 and 1 drop Alphagan or Iopidine 15-30 minutes prior.

Ensure the patient is seated comfortably
, and adjust the laser for your comfort. Then, instill proparacaine in both eyes
 If you are using a laser lens, place it on the eye with goniosol or celluvisc. The advantages of the laser lens are that it stabilizes the eye and gives the clinician control.

After placing the laser lens, focus Helium-Neon (HeNe) beams on the PCO and perform the procedure, which is usually done in a cruciate pattern. There is no pain for patients, but he or she may feel popping/snap/clap in the ears.

Post-op care involves removing the laser lens
 rinsing and cleaning up the eye, and instilling 1 drop of Alphagan or Iopidine post-laser. Take IOP measurements 15-30 minutes post-laser. Post-op drops are Pred Forte QID to surgical eye X 1 week. Educate the patient and advise a follow-up visit at 1 week.

At the 1-week post-op exam, check visual acuity and perform an anterior segment exam. Check for cell/flare, check IOP again, and 
dilate as well. Check for holes, tears, and retinal detachments; discontinue Pred Forte
.

In addition to YAG capsulotomy, Drs. Lighthizer and Welch perform laser peripheral iridotomy (LPI or PI), argon laser trabeculoplasty (ALT),and selective laser trabeculoplasty (SLT).ODT