Dr. Bill Astle's face lights up when he talks about his job. Dr Astle, Regional Director of Pediatric Ophthalmology and Strabismus at the Alberta Children's Hospital, and a team member of the Children’s Traveling Low Vision Clinic, is in the business of helping children see, and it's clear he gets lots of satisfaction from what he does. He describes one instance when he was at the movies with his wife and daughter. A young boy who Dr Astle had helped using laser eye surgery spotted him across the darkened theatre and came over to say hello. "That's when I knew this was working," he says with a wide smile. "That kid was functionally blind when he came to us and now he's spotting me across a dark theatre and he's not wearing glasses!"
Dr Astle teams with Dr. Peter Huang, a corneal surgeon, to pro¬vide laser eye surgery to children with vision problems so severe they are often misinterpreted as developmental problems. The pair also works with developmentally delayed children whose conditions are made worse by poor eyesight.
"One of the first things I noticed was a big pool of patients, kids developmentally delayed, autism and Down Syndrome," says Astle. "Partly because of the extreme amount of near-sightedness they had, a lot of them had astigmatism and, combined with all their other health issues, they just wouldn't wear glasses and contacts were out of the question, so they were functionally blind. "Some of them are so extremely nearsighted, that it causes a lot of distortion with glasses, especially if they have a lot of astigmatism. "Combined with everything else, they just wouldn't wear them. When they're functionally blind like that, it can induce behaviours similar to autism. So if they're seeing better, they're going to do better."
Dr Astle and Dr Huang are among only a handful of doctors in the world doing laser eye surgery on children and are easily the most prolific. With close to 400 children already helped (the pair perform laser surgery on 15-18 children each laser day), they are attracting patients from across Canada, the U.S. and even England.
Dr Astle and Dr Huang don't work solely with developmentally delayed children. Some kids are born extremely near-sighted, while others might have perfect vision in one eye and terrible vision in the other. In the latter case, glasses often don't work as the weight and power of the lenses are vastly different. The brain then shuts down the weak eye (known as “Amblyopia”) and the child will often display behaviours that indicate developmental problems. Dr Astle and Dr Huang have recently published a journal article on this issue and have published numerous other papers on laser eye surgery for children.
Most of these children require general anesthesia but the general anesthetic is light and short, with the procedure only taking 5- 10 minutes depending on whether it is one or both eyes. “We made a conscious decision with this group of patients to only do surface laser ablations”, says Dr Astle.
The more common LASIK technique seen advertised virtually everywhere, evolved to get busy adult professionals back to work quickly. LASIK involves cutting a surgical flap in the cornea, and then applying the laser to the bottom half of the remaining cornea, then replacing the top half of the corneal flap back down. When LASIK works, it usually works well, but problems can arise with the LASIK technique. The cornea is avascular and clear, not having a direct blood supply, so it is slow to heal. LASIK flaps in the adult laser world have been known to rub off even 2-3 years after the original laser procedure, and have sometimes crinkled and folded at high altitude. As well, the LASIK flap cut leads to a small circular scar that in darkened conditions, where the pupil dilates, can scatter light coming into the eye and induce halos around lights and glare, especially at night. “Because our groups of children have multiple developmental and visual issues, plus extreme amounts of laser correction usually required, we made a decision not to consider LASIK, to avoid these types of complications”, mentions Dr Astle.Instead there is a newer, safer technique that represents a good combination of the old PRK surface laser and LASIK, known as LASEK. PRK lasers on the surface, but leaves a painful abrasion for 2-3 days while it heals, plus more potential for surface haze to develop in the lasered cornea, leading to a less optimal visual result. Conversely LASEK, developed by an Italian laser surgeon, combines the best of PRK and LASIK. LASEK is a surface ablation technique, allowing the full thickness of the cornea to be used, without the need for a corneal flap, as in LASIK, or the need for expensive instrumentation. It also decreases the pain experienced with the old PRK laser technique, and decreases the amount of haze seen with PRK during the healing phase. “We use the LASEK technique exclusively now in our complex pediatric cases”, says Dr Astle, “and we can now safely laser extreme amounts of near-sightedness, far-sightedness, and astigmatism safely, and without any major complications in most cases!”
However, the bottom line with these techniques are the visual and perceptual results. While it can be a difficult group to obtain objective visual measurements, the research papers published by Drs Astle and Huang have shown clearly that LASEK in these complex pediatric ophthalmology cases improves the patients vision and their depth perception overall. “We have had children with autism start feeding themselves, children with cerebral palsy start walking, and children that could not see a 3-D movie effect suddenly see it!”, stated Dr Astle. Many medical and neurologic conditions associated with poor vision and strabismus have been turned around positively by Dr Astle and Dr Huang, using a combination of laser refractive surgery and strabismus surgery. Many children previously labeled as untreatable have had their vision improved and their depth perception restored in this fashion, and are now functionally dramatically better in the own environments. “Many parents have told me that after LASEK, it was like having a new child in the house, as these children were seeing better and functioning so dramatically better!”, says Dr Astle.
Both Dr Astle and Dr Huang feel that LASEK should be considered as a useful adjunct to treating children with complex visual problems when tradition methods using glasses, contact lenses, patching and drops do not work. “There may come a day soon where laser refractive surgery becomes the first line treatment for children with these complex types of visual disorders”, says Dr Astle. “It is quick, effective, and can literally change a child’s life around!” states Dr Astle. When one considers the cost of glasses and contact lenses over a lifetime, laser refractive surgery is a very affordable procedure.
While their work makes a massive difference in the lives of many children, it is not without controversy. Dr Astle has met resistance to what he does from the medical community, mostly because of the fact he puts his patients to sleep for the surgery. “Doctors as a group tend to be highly conservative and resistant to change, with some change only occurring on a generational basis, as old doctors retire and new ones come in having learned these newer techniques”, says Dr Astle. "Laser refractive surgery in children is not well accepted yet, even after a decade of research and experience with us here in Calgary" he says. “It can be hard for Doctors to think outside the box, but we have 10 years of proof that this works extremely well in these more complex children” "Sometimes we're considered to be laser cowboys, but if it works, it works……. and this works really well.” "We're making a big difference in these kids' lives!"
Astle WF, Fawcett SL, Huang PT, Alewenah O, MD, Ingram AD. Long-term Outcomes of Laser Refractive Surgery (PRK & LASEK) in Children. J Cataract Refract Surg 34:411-416, 2008
Astle WF, Rahmat J, Ingram AD, Huang P Laser-Assisted Subepithelial Keratectomy for Anisometropic Amblyopia in Children. J Cataract Refract Surg 33: 2028-2034 Dec 2007.
Astle WF, Papp A, Huang PT, Ingram AD. Refractive Laser Surgery in Children with Co-existing Medical and Ocular Pathology J Cataract Refract Surg 32: 103-108, 2006
Astle WF, Huang PT, Ingram AD, Farran RP. Laser Assisted Sub-Epithelial Keratectomy (LASEK) in Children. J Cataract Refract Surg 30 (12): 2529-2535, 2004
Astle WF, Huang PT, Ells AL, Cox RG, Deschenes MC, Vibert HM: Photorefractive Keratectomy (PRK) Laser in Children. J Cataract Refract Surg 28: 932-941, 2002