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Pediatric Cataract Update on Pediatric Cataract SurgeryThe latest information on surgical and non-surgical advances from an expert in the field.David B. Granet,
MD This article will highlight these recent advances in the field of pediatric cataracts, as well as several directions for future pursuit. The Incision As a group, pediatric ophthalmologists tend to be cautious about adopting new techniques, and for good reason: Our work must remain effective for the next 70 to 80 years. For instance, most of us resist no-stitch cataract surgery, despite good solid wounds, because using such an approach in children makes us nervous in a patient population likely to self-traumatize. Moreover, a new technique that yields promising results for three or four years can, in the final analysis, turn out not to be so good for the lifetime of the child. Nevertheless, a significant number of pediatric ophthalmologists have switched from the standard scleral tunnel incision to a temporal clear corneal incision. Though still somewhat controversial, the early results seem excellent. I, too, have made the switch and have had terrific outcomes and happy patients. They have less inflammation and are more comfortable. Lens Implantation Implanting an intraocular lens (IOL) in cataract patients above the age of two or three has become standard among most pediatric surgeons. An increasing number of MDs, however, have begun implanting IOLs in children younger than two years of age. Surgeon Scott Lambert of Emory University headed up a planning study looking at the safety and efficacy of implanting IOLs in children less than six months of age who have a unilateral congenital cataract. Of course, these are precisely the patients in whom we have had the least success. They often lack good vision due to difficulties in compliance with patching and the wearing of a contact lens and glasses. Theoretically, a lens implant will decrease the amount of time these children will go without clear vision, thereby improving the success of amblyopia treatment and prevention. The Infant Aphakia Treatment Study will, therefore, be crucial to our understanding of lens implantation in these children and to our future surgical practices. It awaits funding approval from the National Eye Institute.  The planning study involved 16 centers and about 45 patients per year over the course of three years. Initial data shows excellent results. In patients who received an IOL, investigators achieved good visual outcomes but had slightly more complications and reoperations. Lens implantation does not appear to increase the risk of glaucoma, nor does it seem to change the growth of the eye. Until we know the results of studies like this one, pushing the age limit on implantation must be an individual decision. As in the other subspecialties, advances in our understanding of the pediatric eye has raised more questions. We now better comprehend children’s growth curves and changes in refractive power, but debate continues over the lens power at which we should leave a child as he or she grows and changes. The Lens Serious debate continues over the lens power at which surgeons should leave a child as he or she grows and changes. In San Diego, Scott McClatchey, MD, has done yeoman’s work on developing algorithms that predict a child’s future refraction. His efforts have yielded invaluable information on children’s growth curves and changes in refractive power, but questions remain. Should surgeons leave their patients plano when they are one, four, five years of age? Should they select an IOL power that minimizes amblyopia at the time of surgery or one that makes them less likely to be amblyopic later in their lives? Does a good refractive outcome lead to a good visual outcome? Naturally, a surgeon’s choice depends in part on the patient’s age. I tend to leave kids who are one to two years of age somewhat hyperopic, because I know that their refraction will change. Younger patients make a surgeon’s decision much more difficult, since the refraction in their first year of life can change 10 D. For these reasons, M. Edward Wilson Jr., MD, has actually started piggybacking lenses. He puts in two lenses, and, at about one year postop when the patient’s refraction changes, he explants the second lens, adjusting the child’s refraction automatically. With regard to lens material, an increasing number of pediatric surgeons have shifted from polymethylmethacrylate (PMMA) to foldable acrylic lenses. Both materials are similarly biocompatible, but acrylic IOLs appear to limit posterior capsular opacification (PCO) better—possibly due to their edge design. Another advantage is the ability to insert the lenses through a smaller incision, which produces less trauma. Some ophthalmologists, like David Stager Jr., MD, have been using foldable lenses in children for quite a while and report excellent results. I usually insert a 6-mm, foldable acrylic lens through a 3- to 4-mm incision, which seals well. Capsulorhexis In the past, when surgeons did not even consider the possibility of a lens implant in children, they often removed the entire capsule and performed a generous anterior vitrectomy. Today, many MDs choose to perform some form of capsulorhexis, and patients seem to do extremely well.  In South Carolina, Dr. Wilson prefers the vitrectorhexis in very
young patients; he uses the occutome vitrector instrument carefully to chop a
circle in the capsule. Others, like myself, opt for a continuous curvilinear
capsulorhexis, although this can be a very difficult technique in children. I
personally find it often to be the slowest part of the case, because it is hard
to make sure the tear progresses correctly. To ease this situation, some
ophthalmologists have recently begun using indocyanine green to color the
capsule, which makes the tear easier to see.Though still a controversial decision, a significant number of pediatric ophthalmologists have made the switch from the standard scleral tunnel incision to a temporal clear corneal incision. In children with congenital cataracts for whom primary IOL implantation is not appropriate, more and more surgeons are leaving an anterior and posterior shelf, making anterior and posterior capsulorhexes, and removing the anterior hyaloid face. They take the anterior hyaloid face, because it commonly opacifies in children. Later, when the child’s refraction has stabilized, the surgeon can implant a lens. These patients seem to do extremely well. Dr. Wilson, who has done a lot of this work in cataracts, has actually been able to separate the anterior and posterior capsules’ leaflets from one another and put the lens implant back in the bag, not just on top of the shelf. Not everyone has or can do that, but they almost certainly can implant the lens anterior to the anterior/posterior capsule in the ciliary sulcus. Surgeons who leave the posterior capsule, however, focus on adequate removal of cortical material, since research indicates that such residue in the bag, in part, causes PCO. David Apple, MD, and his fellow investigators have been looking at whether IOLs with squared-off edges do a better job at preventing PCO. Dr. Stager and other investigators are working to determine at what age the posterior capsule may be left in children such that there is a reasonable chance of their not developing significant PCO. So far, it seems that the anterior hyaloid face and at least part of the posterior capsule must be removed in patients under four years of age in order to get a clear visual axis. When PCO occurs in patients over the age of four, YAG capsulotomy yields fairly good results without a secondary reopacification of the anterior hyaloid face. Diagnosis Perhaps one of the biggest advances in the field is a capability for the prenatal diagnosis of cataracts. Special ultrasonographic techniques now allow us to diagnose certain types of cataract in utero. To date, we have no way to treat these cataracts, but knowing that a child will be born with a cataract does enable us to arrange for immediate treatment after the birth.  Nevertheless, all our techniques still mean very little for children whose congenital cataract is not caught until they are one or two years old. I have kids like that in my practice. Everybody does. They break our hearts, because we could have helped these patients if their cataracts had been diagnosed earlier. More and more pediatric surgeons are shifting from PMMA IOLs (pictured above) to foldable acrylic lenses. Both materials are similarly biocompatible, but acrylic IOLs appear to limit posterior capsular opacification (PCO) better, a difference possibly related to edge design. While not every child has a pediatric ophthalmologist, each should have a pediatrician. Unfortunately, the education at medical schools in the United States normally includes an appallingly small exposure to ophthalmology. Without the proper training, pediatricians are far less likely to look for the red reflex or recognize what they see if they do look, from the newborn visit onward. To ensure better care for our future patients, it lies with pediatric ophthalmologists to argue for and support better educational efforts—ones that instruct students and practicing pediatricians on how to use a direct ophthalmoscope to do a Brückner reflex. Parents Advances in pediatric cataract care also must involve the family. We live now in an era of educated parents. The Internet has changed for the better people’s ability to obtain information, but it has unfortunately also increased the availability of misinformation. Today’s pediatric ophthalmologist, like other physicians, bears the responsibility to educate parents about their choices. The days of the authoritative doctor, who drops his voice very deep and tells a family what it must do, should be over. Parents can and should be partners in the care of their child. The result is actually better patient care. Recently, for example, I had a family come in and ask me about lens implantation in their 3-day-old. After an extended discussion, they decided to proceed with surgery that left a shelf of anterior/posterior capsule so that, later on, they will have the option of implanting a lens. They carefully monitor their child’s contact lens power and follow up with me regularly. The child is doing wonderfully. Educating them was worth every bit of time it took. Well-informed parents comply better with instructions, because they understand the motivation for these instructions. They know, for instance, why it is important not to have the child go without his contact lens for a week or two while they order a new one. As research continues, I have no doubt we will have better options to discuss with parents. But one thing won’t change: The parents have a harder job than we do. Dr. Granet is director of pediatric ophthalmology and strabismus surgery for the UCSD/Ratner Children’s Eye Center. He is an associate professor of both ophthalmology and pediatrics at the University of California, San Diego.
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