Pediatric cataract surgery poses challenges for successful results

Cataract surgery is a complex procedure in children, with all aspects of the surgical process requiring care and attention.

“Practically every step poses extra challenges,” Dominique Brémond-Gignac, MD, PhD, OSN Europe Edition Editorial Board Member, said.

Preoperative evaluation is crucial to decide what the best approach is based on age, type of cataract, delay between onset and diagnosis, systemic and ocular signs such as microphthalmia, and potential association with mental retardation.

“We have to work on a developing eye. As the eye grows front to back, the lens changes shape to offset the axial growth of the eye. When we do cataract surgery, we are interrupting that growth and ultimately changing the refraction, so we have to plan on that, and it can be very difficult to predict,” M. Edward Wilson, MD, OSN U.S. Edition Pediatrics/Strabismus Board Member, said.

Dr. Brémond-Gignac, head of pediatric ophthalmology at Amiens University Hospital, France, said that children younger than 1 year require a completely different approach from those who are older. In children 2 years of age and older, cataract management is closer to the procedure an adult would receive.

OSN Editorial Board Member Dominique Brémond-Gignac, MD, said that parents’ compliance in their children’s pediatric cataract management is crucial. Image: Brémond-Gignac D

In case of congenital cataract, early intervention is mandatory, according to Michele Fortunato, MD, of Bambin Gesù pediatric eye hospital in Rome. In his opinion, the ideal time range is between 3 weeks and 6 weeks at the latest, because waiting longer might have a devastating effect on the child’s visual development.

“Then we can discuss when we should implant the intraocular lens. We normally wait until 3 to 4 months, but no longer than that, particularly in case of monolateral cataract,” he said.

With bilateral cataract, particularly in eyes with microphthalmia, waiting up to 1 year or 2 years gives the eye time to develop a useful axial length for IOL implantation, according to Dr. Brémond-Gignac.

In the meantime, refractive correction can be done with spectacles or contact lenses. With short delays, such as 3 months, her advice is to use spectacles. But with longer delays, contact lenses are the best option, she said.

IOLs can be implanted safely by 6 months of age, but the ideal age is 6 months to 12 months, according to Dimple Prakash, MBBS, MS, of Dr. Agarwal’s Eye Hospital in Chennai, India.

“By the age of 12 months, all children should have a lens in cases in which it is possible,” she said.

Infant Aphakia Treatment Study

Dr. Wilson is one of the investigators of the Infant Aphakia Treatment Study. The aim of the study is to answer questions about visual outcomes in 114 infants between 1 month and 6 months of age who have a unilateral congenital cataract and are treated with primary IOL implantation vs. contact lens. Researchers evaluated visual acuity and adverse events; contact lenses were used to correct aphakia in those who did not receive IOLs.

Early results of 1-year primary outcome data, presented at Kiawah Eye 2010, showed no statistically significant difference in visual acuity in the contact lens group vs. the IOL group at 1 year, according to Dr. Wilson. However, complications were higher in the IOL group, with patients returning for a second operation more frequently after primary implantation (63% vs. 12%; P < .001). Most of these additional operations were to clear lens reproliferation and pupillary membranes, according to the study published in the July 2010 issue of Archives of Ophthalmology.

Based on these preliminary results, Dr. Wilson said to be “cautious when using IOLs in patients in the first 6 months of life until this study is followed for a longer time. Every child with cataracts will need an IOL, but the question is, when should that happen?”

Lower prevalence, earlier diagnosis

An estimated 1.4 million children are blind worldwide, with 1 million living in Asia and 300,000 in Africa. Congenital cataracts are responsible for about 10% of all vision loss in children. Overall cumulative risk for cataract is one in 1,000 children, according to Dr. Wilson.

M. Edward Wilson

In industrialized countries, the estimated prevalence of bilateral cataract is one to three per 10,000 children, according to a study by Foster and colleagues. Studies conducted in individual European countries confirm that data: In the U.K. and Sweden, the prevalence of congenital cataract is reported to be three and 3.6 per 10,000 births, respectively. According to the same study by Foster, the prevalence of child blindness from cataracts is one to four per 10,000 in developing countries and less than one per 10,000 in the industrialized world.

However, although it is no longer a blinding disease in which specialized health care services are available, unilateral congenital cataract is still an important cause of amblyopia and strabismus.

In India, the incidence of blindness due to late diagnosis of congenital and infantile cataract is declining, but the low number of physicians per capita is still a major problem, although the situation is improving, Dr. Prakash said. The high poverty and illiteracy rate in rural areas corresponds with a high number of undiagnosed and untreated cataracts.

“We are setting up outreach programs in these areas. The large eye hospitals — about 30, distributed in the eight metropolitan cities of India — have satellite centers, eye camps and mobile screening units run by ophthalmologists, optometrists and nurses who visit small towns and rural areas, do screenings for cataract and refer the people who need surgery to hospitals,” Dr. Prakash said.

Approximately 50 centers in India have specialized pediatric ophthalmology units that are fully equipped in all surgical management aspects. However, thanks to outreach programs and the better ability of pediatricians in recognizing the signs of cataract in children, blindness from cataract is rare, and most children are diagnosed early enough to have useful vision for regularly attending school and college.

In Western countries, a closer cooperation with pediatricians has been implemented in recent years, leading to better and earlier diagnosis.

“Very often, however, the first diagnosis is done by parents or even grandparents. They notice some anomalous white reflex in the eye and seek help,” Dr. Fortunato said.

Cases of relatively late diagnosis are rare nowadays, but advances in surgical and rehabilitation means and techniques have considerably improved the prognosis of delayed intervention.

“Until a few years ago, there were children whom we considered not worth operating. Now we can tell the parents that some functional results can still be achieved. Improvement is quite extraordinary compared to what we were able to obtain 20, even 10 years ago,” he said.

Crucial role

At all times, parents play a crucial role in the management of pediatric cataract.

“The patient’s outcome is far better if you have involved, committed and educated parents. The more engaged, the better the outcomes,” Dr. Wilson said.

“Psychologically accompanying parents are very important,” Dr. Brémond-Gignac said. “We must explain to them that it is not like adult cataract and that successful surgery is only a first, short step toward the final outcome. They have to do the rest, and it will be a long journey. Parents’ compliance is crucial.”

With preschoolers and older children, teachers should also be involved, Dr. Fortunato said.

Michele Fortunato

“I always write an accompanying letter for the teachers. I explain what patching is, how important it is and how they can do it. I also give instructions on how to do drop instillation in those children who use mydriatics instead of patching. Teachers normally appreciate being informed and involved,” he said.

The follow-up is a crucial and demanding time for the surgeon or referring physician as well.

“We must regularly monitor progress and changes in refraction as well as corneal clarity and size. We must be vigilant about amblyopia and continuously reassess the rehabilitation schedule with patching and refractive correction. Also, we must keep our eyes open for potential complications like glaucoma,” Dr. Brémond-Gignac said. “On the whole, we must be there, for the child and for the parents. It is a long journey for us too.”

Challenges of surgery

Typically, surgery is more difficult in a child because the capsule is more elastic and the anterior chamber is smaller and has a high vitreous pressure. Microsurgical techniques have made surgery easier and safer, but challenges remain.

Dr. Fortunato uses a Buratto double barrel irrigation and aspiration cannula. The lens is always soft and easy to manage with just aspiration. He does not use ultrasound phacoemulsification.

Dr. Prakash utilizes a different approach.

“We use low-energy ultrasound in some cases of harder cataract types, setting a low pulse mode. However, with most cases of soft nuclei, we just use irrigation and aspiration,” she said.

Dr. Prakash uses a pars plana approach to perform lensectomy, followed by anterior vitrectomy in small children not undergoing primary IOL implantation. Glued IOL implantation is performed in children older than 6 months who have been left aphakic. A near limbal clear corneal phaco approach with in-the-bag implantation is used in older children.

Dimple Prakash

“Today’s phaco and vitrectomy tools are so small that we no longer need specific pediatric adaptations. I use 23- and 25-gauge cannulas and needles,” she said.

Agarwal’s glued IOL technique is used at her hospital to fixate the IOL to the sclera. Two sclerotomies are performed under two scleral flaps at 3 o’clock and 9 o’clock, 1-mm to 1.5-mm from the limbus. A foldable lens is injected, and the two haptics are externalized through the sclerotomies and tucked into two scleral tunnels made at the edge of the scleral flaps. The scleral flap is then glued down on the scleral bed, using fibrin glue.

Good pupil dilation is often difficult to obtain in children. Phenylephrine is not recommended, and mechanical dilators have to be used in some cases. Particularly in very young children, capsulorrhexis can be challenging, Dr. Fortunato said. Capsulotomy is a safer and easier alternative.

Anterior vitrectomy and posterior capsulorrhexis/capsulotomy should always be performed to avoid inflammation and capsule opacification, according to Dr. Brémond-Gignac.

Recently, Dr. Fortunato has changed his approach and prefers to leave the posterior capsule untouched for better in-the-bag IOL stability and for avoiding vitreous remnants accessing the anterior chamber.

“If secondary opacification occurs, as it does in most cases, I treat it later, as I would do in adults. I don’t use the YAG laser, but a 23-gauge or 25-gauge vitreous cutter, which allows me to perform a very precise capsulorrhexis/capsulotomy,” he said.

A delay of no more than 2 weeks is advisable when operating on bilateral cataract in two separate sessions. Dr. Brémond-Gignac and Dr. Fortunato do not perform simultaneous surgery, except in cases with anesthesiology problems. Dr. Prakash does consecutive surgery with a short interval of 4 days to 5 days between eyes.

IOL choice

Foldable hydrophobic acrylic IOLs are the current gold standard for implantation in young eyes. They have replaced PMMA IOLs, which were once commonly used.

Multifocal IOLs have advocates and opponents.

“Visual development needs a clear and stable retinal image, and this is not possible with multifocal IOLs. Eyeball axial length is not predictable, so multifocal IOL power cannot be calculated precisely. In addition, at this time there is no study proving that multifocality is useful in young children,” Dr. Brémond-Gignac said.

“Multifocal IOLs are first choice in our department,” Dr. Fortunato said. “They recreate a condition that is nearer to natural vision, and we have the best functional recovery and management of amblyopia. We should consider that young children’s activities are mostly at near.”

Diffractive multifocal lenses are the best option because they are not pupil-dependent, and a +4 add is ideal for children, he explained.

“We implanted the first multifocal lens in a child in 1989, and since then we have used them in more than 1,000 cases, constantly updating to new models. I believe this is the largest series worldwide,” he said.

Dr. Fortunato said that adaptation to multifocality is natural and easy in eyes that are still developing, and none of the problems experienced by adults have been reported in his young patients.

“We have used multifocal IOLs in some cases, but they were older children, around 10 years of age, who needed to study and read and had monolateral cataract. They can be a good choice in these cases to balance the other eye. But I don’t believe all younger children need them,” Dr. Prakash said.

In an article in Transactions of the American Ophthalmological Society, Dr. Wilson reported the results of a survey of American Association for Pediatric Ophthalmology and Strabismus members who were asked if they would consider implanting a multifocal IOL in children. Responses were distributed almost equally between yes, no and not sure. Many respondents commented on their concern about the use of multifocal IOLs in children.

Dr. Wilson said he was in favor of the implantation of multifocal IOLs in the second decade of life.

“Multifocal IOLs also have appeal for older children [because] they have the potential to provide simultaneous distance and near focus. More than one teenager has remarked to us about how embarrassing it is to reach for reading glasses (‘granny glasses’) while on a date at a restaurant. Children and teenagers are also very adaptable and may not be bothered by glare and halos as much as some adults are. Our experience has borne this out,” he wrote.

Postoperative management

Postoperative management of pediatric cataract requires higher doses of steroids because of the stronger immune response. Corticosteroid therapy should be started 3 days to 4 days before surgery and continued for at least 1 month postoperatively, six to eight times a day, Dr. Brémond-Gignac said.

“I also put all my patients on long-term IOP-lowering medications, usually beta-blockers or acetazolamide, to prevent the risk of secondary glaucoma,” Dr. Fortunato said.

Dr. Brémond-Gignac works in a large ophthalmology unit where more than 4,000 surgical procedures are performed every year. About 400 are in children, 80% less than 4 years of age. Congenital cataracts are approximately 60 cases per year.

In the Bambin Gesù hospital in Rome, 80 to 90 congenital cataracts are treated per year. Considering other types of pediatric cataract, mainly post-traumatic, the number grows to approximately 140 per year.

“If we consider that these operations generate a series of secondary procedures for posterior capsulotomy and, more rarely, other complications, the number at least doubles,” Dr. Fortunato said.

Dr. Agarwal’s Eye Hospital serves a large area, and approximately 15,600 cataract procedures are performed each year. Of these, about 80 are pediatric cataracts. – by Michela Cimberle and Tara Grassia

Considering the high risk of secondary glaucoma after pediatric cataract surgery, do you adopt surgical or medical preventive measures?

References:

• Brémond-Gignac D, Copin H, Lapillonne A, Milazzo S; European Network of Study and Research in Eye Development. Visual development in infants: physiological and pathological mechanisms. Curr Opin Ophthalmol. 2011;22 Suppl:S1-S8.
• Foster A, Gilbert C, Rahi J. Epidemiology of cataract in childhood: a global perspective. J Cataract Refract Surg. 1997;23 Suppl 1:601-604.
• Gogate P, Khandekar R, Shrishrimal M, et al. Delayed presentation of cataracts in children: are they worth operating upon? Ophthalmic Epidemiol. 2010;17(1):25-33.
• Infant Aphakia Treatment Study Group, Lambert SR, Buckley EG, Drews-Botsch C, et al. A randomized clinical trial comparing contact lens with intraocular lens correction of monocular aphakia during infancy: grating acuity and adverse events at age 1 year. Arch Ophthalmol. 2010;128(7):810-818.
• Kushner BJ. Simultaneous cataract surgery for bilateral congenital cataracts: are the cost savings worth the risk? Arch Ophthalmol. 2010;128(8):1073-1074.
• Lin AA, Buckley EG. Update on pediatric cataract surgery and intraocular lens implantation. Curr Opin Ophthalmol. 2010;21(1):55-59.
• Mickler C, Boden J, Trivedi RH, Wilson ME. Pediatric cataract. Pediatr Ann. 2011;40(2):83-87.
• Rahi JS, Dezateux C; British Congenital Cataract Interest Group. Measuring and interpreting the incidence of congenital ocular anomalies: lessons from a national study of congenital cataract in the UK. Invest Ophthalmol Vis Sci. 2001;42(7):1444-1448.
• Rychwalski PJ. Multifocal IOL implantation in children: is the future clear? J Cataract Refract Surg. 2010;36(12):2019-2021.
• Wilson ME, Trivedi RH. Multicenter randomized controlled clinical trial in pediatric cataract surgery: efficacy and effectiveness. Am J Ophthalmol. 2007;144(4):616-617.
• Wilson ME, Trivedi RH, Burger BM. Eye growth in the second decade of life: implications for the implantation of a multifocal intraocular lens. Trans Am Ophthalmol Soc. 2009;107:120-124.
• Zetterström C, Lundvall A, Kugelberg M. Cataracts in children. J Cataract Refract Surg. 2005;31(4):824-840.

• Dominique Brémond-Gignac, MD, PhD, can be reached at Ophthalmology Department, Saint Victor Centre, Amiens University Hospital, 354 Boulevard Beauvillé, 80054 Amiens, France; +33-3-22-82-41-08; fax: +33-3-22-82-40-61; email: bremond.dominique@chu-amiens.fr.
• Michele Fortunato, MD, can be reached at Via Polibio 4, 00136 Rome, Italy; +39-06-39742614; email: micfortunato@hotmail.com.
• Dimple Prakash, MBBS, MS, can be reached at Dr. Agarwal’s Eye Hospital, 19 Cathedral Road, 600 086 Chennai, India; email: dimplerprakash@yahoo.co.in.
• M. Edward Wilson, MD, can be reached at Albert Florens Storm Eye Institute at the Medical University of South Carolina, 167 Ashley Ave., Charleston, SC 29425, U.S.A.; +1-843-792-7622; fax: +1-843-792-1166; email: wilsonme@musc.edu.
• Disclosures: Drs. Brémond-Gignac, Fortunato and Prakash have no relevant financial disclosures. Dr. Wilson is a consultant for Bausch + Lomb and Alcon. He receives book royalties from Springer.