Refractive surgery in pediatric patients should be limited to selected cases, requires extreme care

A panel of surgeons discussed the many issues related to this matter, and offered different and sometimes ontrasting views.

ROME – Refractive surgery in pediatric patients is still an open, problematic issue. Surgeons here debated the issue and reached a few consensus guidelines for approaching surgery in these patients.

Italo Cantera, MD, can be reached at Casa di Cura Quisisana, Via Giangiacomo Porro 5, 00192 Rome, Italy; +(39) 06-807-4319; fax: +(39) 06-8069-3092; e-mail: i.cantera@flashnet.it.

“We need to examine the many problems connected with this delicate matter, discuss opinions, compare results. Hopefully, we’ll finally be able to agree on some guidelines,” said Umberto Merlin, MD, chairman of a round table on this subject at the Italian Ophthalmology Society meeting.

The debate was lively, and many different views and feelings were voiced.

“We are explorers,” said Paolo Nucci, MD, a pediatric ophthalmologist with wide experience in this field. “We have the duty to investigate all possible solutions, be active and proactive, but only within well limited boundaries and under the safest conditions possible.”

Who are the patients?

Patient selection was the first matter at issue. The small number of cases treated by each of the surgeons involved was indicative of the prevailing cautious attitude.

The resulting consensus was that refractive surgery should be performed only on young patients intolerant to contact lenses, with high unilateral myopia and amblyopia.

Francesco Carones, MD, can be reached at Carones Ophthalmology Center, via Pietro Mascagni 20, 20122 Milan, Italy; +(39) 02-7631-8174; fax: +(39) 02-7631-8506; e-mail: fcarones@carones.com. Web site: www.carones.com.

“In such cases we cannot delay treatment,” said Michele Fortunato, MD. “A severe anisometropia is often the origin of psychomotor problems, as it causes aniseikonia. Psychomotor problems represent one of the criteria I consider primary in deciding in favor of the treatment.”

He added that some exclusion criteria must be taken into account.

“There are conditions like Down syndrome in which children are notoriously at risk of developing keratoconus, and in which laser refractive surgery is clearly contraindicated,” he said.

Dr. Nucci had the largest case series of unilateral high myopic and amblyopic pediatric patients treated with photorefractive surgery. In a study published in 1999, he presented the results of 14 children between 7 and 14 years.

“We performed photorefractive keratectomy in 12 cases and LASIK in two, and found that both techniques were safe, with no intraoperative or postoperative complications. We had good results on the myopia, but contrary to what some other studies have claimed, no efficacy on the amblyopia could be demonstrated,” he said.

At what age?

Not all panelists agreed on the best age for treating young patients. Some favored early intervention, while others were more inclined to wait until the development of more mature vision.

“The higher the refractive error, the earlier the treatment should be performed,” Prof. Merlin said.

“A satisfactory visual result can be obtained only if we perform refractive surgery early, as we do with congenital cataract. Either we do it as early as possible or we don’t do it at all,” said Francesco Carones, MD.

The key issue is to prevent aniseikonia, that is, to treat the child before this condition develops, Dr. Fortunato noted.

“We know how dramatic it is to perform refractive surgery on adults who have already achieved an optimal monolateral vision but have developed a pseudodiplopia from aniseikonia,” he said.

Cooperation

Age, however, can be a problem in relation to patients’ cooperation and to the technique used.

Roberto Dossi, MD, can be reached at C.so Vittorio Emanuele II 14, 10123 Torino, Italy; +(39) 011-884-00; fax: +(39) 011-888-028; e-mail: studiodossi@ libero.it.

Italo Cantera, MD, uses LASIK and thus prefers to wait until the child is at least 10 years old.

“At that age we can generally obtain reasonable cooperation from our little patients. We can perform surgery under topical anesthesia, ask the child to fixate and, most important, rely on a fairly safe and controllable postoperative course. Younger children inevitably end up scratching their eyes, and very easily incur those little everyday accidents that can cause flap displacement,” he said.

Treating young patients is objectively very difficult, Dr. Fortunato said, despite his extensive experience as a pediatric ophthalmologist.

“We need to develop an effective approach to such patients before, during and after surgery, and also, we must remember that no case is like any other,” he said.

Dr. Nucci said he has been successful in gaining the cooperation of his patients, who were all operated under topical anesthesia.

“I have long talks with them before surgery. Then I show them the instruments, rehearse some of the maneuvers and try the blepharostat to test their reactions and reassure them. I also have one of the parents present during the operation,” he said.

Better with LASIK?

In spite of the more problematic postop management, and the fact that microkeratomes can sometimes be awkward to use in small eyes, quite a few surgeons prefer LASIK for treating young patients.

Michele Fortunato, MD, can be reached at via Polibio 4, 00136 Rome, Italy; +(39) 06-3545-1414; fax: +(39) 06-3540-1971; e-mail: micfortunato@hotmail.com.

“Cell migration and proliferation is faster and more lively in children,” Dr. Cantera said. “This means that healing processes are faster and more efficient, but also that excessive epithelial tissue formation may take place, leading to haze and regression after PRK. This is the main reason why I prefer LASIK.”

The same opinion was shared by Leonardo Mastropasqua, MD.

“Haze is proportional to the number of keratocytes, which is very high in children. Once the keratocytes migrate to the ablation area, they become fibroblasts and inevitably produce haze,” he said.

Dr. Carones presented the case of one patient who had a relatively low myopic correction with PRK and developed severe haze and regression in the 6 months following surgery.

“The problem persisted during the entire 5-year period of the follow-up, until we decided to reoperate him to remove the haze,” he said.

Or PRK?

Dr. Nucci supported PRK, which he said has fewer postop risks than LASIK.

Leonardo Mastropasqua, MD, can be reached at Viale Europa 23, 66100 Chieti, Italy; +(39) 08-7135-8410; fax +(39) 08-7135-8794. e-mail: mastropa@ phobos.unich.it.

“There is no anatomic contraindication to LASIK, because the cornea of a 5-year-old child, contrary to what many of us think, has already completed its growing process, and is therefore thick enough to perform the procedure. However, I simply don’t believe that one can expect a 5-year-old not to scratch his or her eyes,” he said.

None of his 12 PRK patients developed haze, he said, thanks to the advanced technology of the new generation of lasers (he uses a Bausch & Lomb Technolas 217) and also thanks to the regular use of cortisone for 6 months after surgery.

“The cases of haze reported in the literature were connected with the use of older lasers and to the use of NSAIDs instead of cortisone to assist epithelial regrowth,” he said. “We have performed PRK on very high myopic eyes, between 7 and 11 D, and by using cortisone we have had a very rapid re-epithelialization, no haze and no problem of increased IOP.”

In his opinion the main concern, which was raised after a few treatments, is decentration.

“We found that 40% of our first patients had some degree of decentration,” he said.

He explained these results by the underlying fact that unilateral high myopes, who are also highly amblyopic, probably have poor and badly centered fixation. This might of course jeopardize the final results and the efficacy of the procedure.

Anesthesia

Could this problem be overcome by using general anesthesia? Not at all, in Dr. Nucci’s opinion, because with general anesthesia it is almost impossible to understand if the laser is centered on the visual axis.

“With a deep general anesthesia we could assume that the eye is in a fairly straight position, but with the lighter anesthesia we would use there is a slow drift of the eyes upward or downward. We should redirect the eyes to a central position, which is, however, decided arbitrarily,” he said.

The amount of correction

As in pediatric cataract surgery, the refractive surgeon is faced with the problem of how much of the refractive error should be corrected in a child’s eye.

Umberto Merlin, MD, can be reached at Via De Polzer 32, 45100 Rovigo, Italy; +(39) 04-253-5137; fax: +(39) 04-253-0381; e-mail: ummerlin@tin.it.

Dr. Nucci disagreed with the practice of routine overcorrection, which some surgeons prefer to perform in order to prevent the eye from becoming myopic again at a later stage of the growing process.

“I don’t mind a slight undercorrection, if it allows me to use PRK rather than LASIK, since unilateral myopia leads to amblyopia only when the refractive error is high, more than 6 D. With a refraction of about –10 D, I would accept a final result of –2 D, which allows the child to continue using one eye for distance vision and the more myopic eye for reading at near.”

In response, Dr. Carones argued that deciding on the amount of ablation in a child’s cornea is too much of a gamble.

“Treating a myopia over 9 to 10 D is often a problem also in adults. In children problems are greater, and you don’t know what the final result will be in the medium-to-long term. I am convinced that laser refractive surgery is not the answer,” he said.

Phakic IOLs

“I hope we’ll soon be able to open the way to the use of phakic IOLs in children,” Dr. Carones added. “In principle, I don’t see why we should be afraid of using an intraocular refractive procedure, which is not different from cataract surgery. I can imagine that the ideal situation would be implanting a phakic IOL to obtain the result we want at that time and preserve the cornea for future modifications, if needed.”

Paolo Nucci, MD, can be reached at Viale caldara 7, 20122 Milan, Italy; phone/fax: +(39) 02-5518-7517; e-mail: info@paolonucci.it. Web site: www.paolonucci.it.

Dr. Cantera did not share the same optimistic view on this matter. In his opinion, implanting a phakic IOL with the perspective of changing it in case the myopia progresses further, involves risks of irreversible damages that are not worth taking.

Dr. Nucci also recommended caution.

“Unilateral high myopia quite often conceals incipient glaucoma. Angle anomalies might be among the causes of the abnormal growth of these eyes. If this is the case, a phakic IOL could damage the malformed angle even further,” he said.

Preventing problems

Some brief comments concerning the medico-legal side of the issue concluded the debate. Roberto Dossi, MD, who raised the issue, said half of the lawsuits against ophthalmic practitioners reported by SOI in 2002 concerned children.

“Parents are extremely contentious, and we need to think about an informed consent that prevents misunderstandings and false expectations,” he said.

“Parents should be made aware that results are likely to be imperfect and subject to variations due to the physiological changes of growth,” Dr. Nucci added.