Cover StoryFrom OSN APAO

Light for Sight 21 raises awareness, promotes detection and treatment of keratoconus in children with Down syndrome

Within the framework of the Light for Sight 21 initiative, a large nonprofit cooperation of specialized centers worldwide is actively engaged in the effort to eliminate severe visual impairment in children with Down syndrome who have progressive keratoconus.

Light for Sight 21 (lightforsight.org) is a nonprofit organization founded in 2011 by Nikki Hafezi, MAS IP ETHZ, and her husband Farhad Hafezi, MD, PhD, an OSN Europe Edition Board Member.

“I was going through the literature on Down syndrome and found that in this population group, keratoconus had a much higher incident rate than the general population (1:1,500) due to this group’s disposition of having connective tissue disorders compared to the general population,” Nikki Hafezi said. “With this information, I asked Farhad how many Down syndrome patients he had treated. He said that he had treated two children in 8 years, which didn’t quite fit the higher incident rate. From then I knew that something needed to be done.”

Nikki Hafezi, MAS IP ETHZ, is the founder of Light for Sight 21. She said that the aim of the project, besides providing treatment, is to get the word out about possible symptoms of keratoconus in children with Down syndrome and where to seek help.

Image: Hafezi N

Light for Sight 21 has brought together volunteers from 25 countries. More than 40 clinics have been approved as reference sites for screening and treating keratoconus children and adolescents with Down syndrome with cross-linking. The treating ophthalmologist, called an L4S Ambassador, is obliged to waive his or her honorarium if the ambassador deems that the family cannot afford the treatment.

“We want our ambassadors to be able to take care of these patients, but the first crucial step is to get the word out about recognizing possible symptoms and where to seek help when they occur,” Nikki Hafezi said. “We need to work with our media friends and partners to help disseminate information not just amongst ophthalmologists, but general practitioners, pediatricians and patient organizations.”

Farhad Hafezi

Farhad Hafezi said that keratoconus is still a relatively unknown disease among medical professionals caring for children with Down syndrome.

“In spite of the well-documented association between trisomy 21 and keratoconus, very few, even among general ophthalmologists, are aware of it. What happens most of the time is that these kids are tested by an optician or an eye doctor, show high astigmatism and visual acuity of 20/40 or less, and go away with just a pair of glasses,” he said.

Specific protocol and eligibility criteria

Farhad Hafezi created in Geneva a three-level protocol for cross-linking in Down syndrome patients. If the patient is fully cooperative, standard epithelium-off corneal cross-linking is performed. In case of reduced cooperation, the same procedure is done without epithelium removal under local anesthesia.

“The efficacy is not equally high using the epi-on procedure, but we know that there is a major risk of infection if these patients rub their eyes and are not fully cooperative with eye drop administration. Carina Koppen, MD, reported a high rate of infection in a small case series of Down syndrome patients who underwent cross-linking, related to reduced compliance with postoperative medications,” he said.

If the patient has zero compliance, epi-on cross-linking is performed under general anesthesia.

“In the zero compliance instances, we first talk to the parents for consent to administer general anesthesia, examine the eye with a portable Placido topography device, and if we see keratoconus, we immediately do an epi-on procedure,” he said.

Compliance with the Geneva protocol, and therefore the license to perform general anesthesia, is a condition to become a Light for Sight reference center. Other eligibility criteria are a minimum of 100 treatments or 3 years of previous experience with cross-linking. Centers or individual doctors who do not qualify can still be involved by referring patients to their local or national reference sites.

Center in Turkey collects data for study

When the project was first presented at the European Society of Cataract and Refractive Surgeons meeting in 2012, many leading corneal surgeons immediately joined in and are actively contributing in different ways.

Efekan Coskunseven

In Istanbul, Efekan Coskunseven, MD, personally contacted the national Down Syndrome Society and offered to organize information sessions followed by a screening and treatment program.

“We made an agreement with the society. They would help us reach the families of children with Down syndrome, and we would perform all the examinations and treatment when needed without any charges. We were also invited to talk about our project at the society’s national meeting,” Coskunseven said.

The medical personnel of Coskunseven’s department at Dunyagoz Hospital were then educated to understand more about children with Down syndrome and trained to meet their specific needs.

“We first examined 10 children per week and have now totaled about 200. Numbers are constantly increasing as more and more families get to know what we are doing and our good results,” Coskunseven said.

Families are appreciative and highly supportive, he said.

“There are cases where multiple examinations are necessary, and without the effort and support of the families, we could never have done a job as good as we are doing. We are collecting all data and organizing them into a study, which will be the first to be published on CXL in Down syndrome patients,” he said.

Multidisciplinary practice model in Belgium

In Antwerp, Belgium, Marie-José Tassignon, MD, PhD, OSN Europe Edition Associate Editor, and Koppen offered the example of a best practice model with an interdisciplinary Down syndrome team of pediatric ophthalmologists, pediatricians, internists and neuropsychiatrists working together with patients and liaising with patient organizations.

Marie-José Tassignon

“Vision is crucial for the development of children with Down syndrome. If vision problems are not promptly diagnosed and treated, we lose one of the most important stimuli to their cognitive and emotional development. In our university hospital, all children with Down syndrome who are seen by the pediatrician are also sent to us for an eye assessment,” Tassignon said.

Citizens with Down syndrome are entitled to free treatment by the Belgian Ministry of Health. These special provisions create an ideal framework for the Light for Sight 21 program.

Tassignon said that cross-linking is not easy in these patients.

“Poor cooperation and eye rubbing are issues and are made worse by overprotective parents. In some cases we have to keep children under narcosis for a day to allow the cornea to be undisturbed during the first delicate stage of the healing process,” she said.

Although children with trisomy 21 have different personalities and degrees of developmental delay, the most cooperative patients are those with stricter parents who teach and expect age-appropriate behavior.

“Clear boundaries, strict routines and firm guidelines help these children to develop their full potential. It’s not easy for parents, but the worst thing you can do to these kids is to indulge them, make allowances and spoil them because you pity them,” Tassignon said.

Easy accessibility, a familiar environment and contained costs are important for patients and their families.

“Many of the parents told us time and time again, ‘Please do not make us travel a long distance for these treatments,’ because it inflicts fear and expenses and uncertainty for everyone,” Nikki Hafezi said.

Reference site in India part of program

Dr. Agarwal’s Eye Hospital in Chennai, India, is an approved site for implementation of the Tamil Nadu government’s insurance program that offers free treatment to low-income patients. Cross-linking is covered by this scheme, which allowed the implementation of the Light for Sight 21 program.

Amar Agarwal

According to Amar Agarwal, MS, FRCS,FRCOphth, OSN APAO Edition Board Member, cross-linking is the treatment of choice in Down syndrome patients with keratoconus, especially because both lamellar keratoplasty and penetrating keratoplasty may have a higher risk of globe rupture, dehiscence of sutures and rejection due to decreased ability to cooperate. In addition, there may be poorer quality of postoperative hygiene, precautions and care by the patient.

“Our research has focused on developing CACXL, or contact lens-assisted collagen cross-linking. This technology combined when needed with Hafezi’s hypo-osmolar CXL is effective for allowing cross-linking even in patients with corneas that are too thin for conventional cross-linking. This is especially important in patients with Down syndrome who are often diagnosed late and have already thinned out beyond 400 µm, which is the cutoff limit for conventional CXL,” Agarwal said.

“We have been treating such patients before, but the Light for Sight project just works beautifully to motivate children and parents and encourages them as they meet other people with similar challenges. They know that there are doctors who care for them, are sympathetic and are going out of their way to make the best care available,” he said.

Platform for research

Genetic alterations of collagen structure and function are responsible for several conditions affecting Down syndrome patients. These include connective tissue, musculoskeletal, pulmonary and cardiac problems, and most likely keratoconus.

The effects and efficacy of cross-linking in the abnormal collagen of these corneas are still largely unknown, and the Light for Sight 21 project offers a good platform for research.

“Besides our practical involvement in the humanitarian action, we are researchers, so we created an online database where reference sites can directly enter their data in view of a large prospective study. Up to now, we have data on about 50 eyes where we performed ORA, Corvis, aberrometry, Pentacam and keratography measurements to learn more about the cornea of a Down syndrome person. We are still in the preliminary stages, but our database is growing as more and more centers participate,” Farhad Hafezi said. – by Michela Cimberle

References:

Aslan L, et al. J AAPOS. 2013;doi:10.1016/j.jaapos.2012.10.020.

Caporossi A, et al. Cornea. 2012;doi:10.1097/ICO.0b013e31822159f6.

Chatzis N, et al. J Refract Surg. 2012;doi:10.3928/1081597X-20121011-01.

Fimiani F, et al. Eur J Ophthalmol. 2007;17(5):817-822.

Fong AH, et al. Br J Ophthalmol. 2013;doi:10.1136/bjophthalmol-2012-302327.

Karlica D, et al. Coll Antropol. 2011;35(4):1115-1118.

Kim JH, et al. Eye (Lond). 2002;doi:10.1038/sj.eye.6700208.

Koller B, et al. Cornea. 2014;doi:10.1097/ICO.0000000000000000.

Koppen C, et al. J Refract Surg. 2010;doi:10.3928/1081597X-20100824-01.

Liza-Sharmini AT, et al. Singapore Med J. 2006;47(1):14-19.

Vinciguerra P, et al. Am J Ophthalmol. 2012;doi:10.1016/j.ajo.2012.03.020.

Wong V, et al. Pediatr Neurol. 1997;doi:10.1016/S0887-8994(97)00029-5.

Wroblewski KJ, et al. Cornea. 2006;doi:10.1097/01.ico.0000226053.61884.91.

For more information:

Amar Agarwal, MS, FRCS, FRCOphth, can be reached at Dr. Agarwal’s Eye Hospital, 19 Cathedral Road, Chennai, India 600086; email: dragarwal@vsnl.com.

Efekan Coskunseven, MD, can be reached at the at Dünyagöz Eye Hospital, Istanbul, Turkey; email: efekan.coskunseven@dunyagoz.com.

Farhad Hafezi, MD, PhD, and Nikki Hafezi, MAS IP ETHZ, can be reached at ELZA Institute AG, Webereistrasse 2, 8953 Dietikon, Switzerland; email: info@elza-institute.com and nhafezi@groupadvance.com.

Marie-José Tassignon, MD, PhD, can be reached at Antwerp University Hospital, Wilrijkstraat 10, 2650 Edegem, Antwerp, Belgium; email: marie-jose.tassignon@uza.be.

Disclosure: The sources report no relevant financial disclosures.

 

POINTCOUNTER

Does modern IOL technology offer feasible solutions to improve vision in children with Down syndrome who have cataract and astigmatism or keratoconus?

POINT

Toric IOLs may be used in specific cases

Daphne Han, MD
Daphne Han

Toric IOLs may be an option in children with astigmatism, but they should be avoided if the axis of cylinder is unstable. They should especially be considered in impending severe meridional amblyopia intolerant of glasses or contact lenses.

In principle, toric IOLs should only be considered in cataract surgery with fairly regular corneal astigmatism in the optical zone and good potential visual acuity. In adults, cases of highly irregular astigmatism or keratoconus will benefit from other treatments to regularize the cornea, such as topography-guided excimer treatment in the former and cross-linking or lamellar keratoplasty in the latter.

In a child with Down syndrome who is often plagued by significant astigmatism, eye growth and overzealous eye rubbing can cause changes in both magnitude and axis of the cylinder. If a toric IOL were to be considered, it is vital to demonstrate on topography fairly regular and stable corneal astigmatism, particularly in the axis, because future shifts in axis can worsen blur and amblyopia in the susceptibly young, more so than in magnitude.

In the event that conditions are favorable for toric IOL implantation in a child with Down syndrome who has stable and regular cornea astigmatism and good family support, good surgery then comes into play. Examinations under anesthesia for refraction and biometry, self-sealing microincision phacoemulsification (possibly down to sub-2 mm to avoid creating astigmatism and higher-order aberrations), trypan blue to reduce elasticity of the continuous curvilinear capsulorrhexis, a smaller primary posterior continuous curvilinear capsulorrhexis, limited anterior vitrectomy, and posterior buttonholing of the optic to capture the IOL in the required axis and to prevent PCO (a technique learned from Dr. Michael Snyder at Cincinnati Eye Institute, USA) are all useful. Postoperative care is important, as are teamwork with pediatric ophthalmologists and vigilant follow-ups, with prompt amblyopia treatment and spectacle or contact lens wear for residual and future refractive errors.

Although these measures may not be the final surgical interventions needed if astigmatism or keratoconus were to progress, they may save the child from permanent loss of sight from amblyopia.

 

Daphne Han, MD, is a consultant ophthalmic surgeon, Singapore National Eye Centre and Laser Vision Center, Singapore. Disclosure: Han reports no relevant financial disclosures.

COUNTER

Keep it simple and implant monofocal IOLs

Vishal Jhanji, MD
Vishal Jhanji

Toric IOLs have been shown to be an excellent option in patients with astigmatism and coexisting cataract in several studies. Down syndrome is often associated with high amounts of astigmatism, which in turn is frequently associated with keratoconus. Keratoconus progresses very fast over the teen years and tends to stop progressing with age. Consequently, if the refraction is stable, we could theoretically use a toric IOL in well-selected cases. However, in children with Down syndrome, I would be skeptical to implant a toric IOL for a number of reasons.

Preoperatively, it is difficult to assess astigmatism accurately in this subgroup of patients because they are not cooperative. Postoperatively, accurate assessment of refraction is challenging as well. Moreover, as keratoconus progresses, astigmatism fluctuates and the overall refraction changes.

If a child has keratoconus, I would rather stick to a standard monofocal IOL. Modern IOL technology definitely offers feasible solutions, but key to success is accurate measurement of astigmatism and the astigmatic axis. If the conditions were not ideal, a toric IOL would lead to more harm than benefit. Even a slight mistake in the axis measurement would make the astigmatism increase and create serious problems with vision.

There is more than one component to make the story complex: We have a child, and the child has keratoconus and Down syndrome. So, we follow the old rule in these complicated cases: Keep it simple and implant monofocal IOLs. If cataract is present, even with different degrees in both eyes, we prefer to perform surgery bilaterally to avoid exposing the child to repeated general anesthesia, following a strict surgical protocol to prevent infection.

 

Vishal Jhanji, MD, is an associate professor, Chinese University of Hong Kong, China. Disclosure: Jhanji reports no relevant financial disclosures.

Within the framework of the Light for Sight 21 initiative, a large nonprofit cooperation of specialized centers worldwide is actively engaged in the effort to eliminate severe visual impairment in children with Down syndrome who have progressive keratoconus.

Light for Sight 21 (lightforsight.org) is a nonprofit organization founded in 2011 by Nikki Hafezi, MAS IP ETHZ, and her husband Farhad Hafezi, MD, PhD, an OSN Europe Edition Board Member.

“I was going through the literature on Down syndrome and found that in this population group, keratoconus had a much higher incident rate than the general population (1:1,500) due to this group’s disposition of having connective tissue disorders compared to the general population,” Nikki Hafezi said. “With this information, I asked Farhad how many Down syndrome patients he had treated. He said that he had treated two children in 8 years, which didn’t quite fit the higher incident rate. From then I knew that something needed to be done.”

Nikki Hafezi, MAS IP ETHZ, is the founder of Light for Sight 21. She said that the aim of the project, besides providing treatment, is to get the word out about possible symptoms of keratoconus in children with Down syndrome and where to seek help.

Image: Hafezi N

Light for Sight 21 has brought together volunteers from 25 countries. More than 40 clinics have been approved as reference sites for screening and treating keratoconus children and adolescents with Down syndrome with cross-linking. The treating ophthalmologist, called an L4S Ambassador, is obliged to waive his or her honorarium if the ambassador deems that the family cannot afford the treatment.

“We want our ambassadors to be able to take care of these patients, but the first crucial step is to get the word out about recognizing possible symptoms and where to seek help when they occur,” Nikki Hafezi said. “We need to work with our media friends and partners to help disseminate information not just amongst ophthalmologists, but general practitioners, pediatricians and patient organizations.”

Farhad Hafezi

Farhad Hafezi said that keratoconus is still a relatively unknown disease among medical professionals caring for children with Down syndrome.

“In spite of the well-documented association between trisomy 21 and keratoconus, very few, even among general ophthalmologists, are aware of it. What happens most of the time is that these kids are tested by an optician or an eye doctor, show high astigmatism and visual acuity of 20/40 or less, and go away with just a pair of glasses,” he said.

Specific protocol and eligibility criteria

Farhad Hafezi created in Geneva a three-level protocol for cross-linking in Down syndrome patients. If the patient is fully cooperative, standard epithelium-off corneal cross-linking is performed. In case of reduced cooperation, the same procedure is done without epithelium removal under local anesthesia.

“The efficacy is not equally high using the epi-on procedure, but we know that there is a major risk of infection if these patients rub their eyes and are not fully cooperative with eye drop administration. Carina Koppen, MD, reported a high rate of infection in a small case series of Down syndrome patients who underwent cross-linking, related to reduced compliance with postoperative medications,” he said.

If the patient has zero compliance, epi-on cross-linking is performed under general anesthesia.

“In the zero compliance instances, we first talk to the parents for consent to administer general anesthesia, examine the eye with a portable Placido topography device, and if we see keratoconus, we immediately do an epi-on procedure,” he said.

Compliance with the Geneva protocol, and therefore the license to perform general anesthesia, is a condition to become a Light for Sight reference center. Other eligibility criteria are a minimum of 100 treatments or 3 years of previous experience with cross-linking. Centers or individual doctors who do not qualify can still be involved by referring patients to their local or national reference sites.

PAGE BREAK

Center in Turkey collects data for study

When the project was first presented at the European Society of Cataract and Refractive Surgeons meeting in 2012, many leading corneal surgeons immediately joined in and are actively contributing in different ways.

Efekan Coskunseven

In Istanbul, Efekan Coskunseven, MD, personally contacted the national Down Syndrome Society and offered to organize information sessions followed by a screening and treatment program.

“We made an agreement with the society. They would help us reach the families of children with Down syndrome, and we would perform all the examinations and treatment when needed without any charges. We were also invited to talk about our project at the society’s national meeting,” Coskunseven said.

The medical personnel of Coskunseven’s department at Dunyagoz Hospital were then educated to understand more about children with Down syndrome and trained to meet their specific needs.

“We first examined 10 children per week and have now totaled about 200. Numbers are constantly increasing as more and more families get to know what we are doing and our good results,” Coskunseven said.

Families are appreciative and highly supportive, he said.

“There are cases where multiple examinations are necessary, and without the effort and support of the families, we could never have done a job as good as we are doing. We are collecting all data and organizing them into a study, which will be the first to be published on CXL in Down syndrome patients,” he said.

Multidisciplinary practice model in Belgium

In Antwerp, Belgium, Marie-José Tassignon, MD, PhD, OSN Europe Edition Associate Editor, and Koppen offered the example of a best practice model with an interdisciplinary Down syndrome team of pediatric ophthalmologists, pediatricians, internists and neuropsychiatrists working together with patients and liaising with patient organizations.

Marie-José Tassignon

“Vision is crucial for the development of children with Down syndrome. If vision problems are not promptly diagnosed and treated, we lose one of the most important stimuli to their cognitive and emotional development. In our university hospital, all children with Down syndrome who are seen by the pediatrician are also sent to us for an eye assessment,” Tassignon said.

Citizens with Down syndrome are entitled to free treatment by the Belgian Ministry of Health. These special provisions create an ideal framework for the Light for Sight 21 program.

Tassignon said that cross-linking is not easy in these patients.

“Poor cooperation and eye rubbing are issues and are made worse by overprotective parents. In some cases we have to keep children under narcosis for a day to allow the cornea to be undisturbed during the first delicate stage of the healing process,” she said.

Although children with trisomy 21 have different personalities and degrees of developmental delay, the most cooperative patients are those with stricter parents who teach and expect age-appropriate behavior.

“Clear boundaries, strict routines and firm guidelines help these children to develop their full potential. It’s not easy for parents, but the worst thing you can do to these kids is to indulge them, make allowances and spoil them because you pity them,” Tassignon said.

Easy accessibility, a familiar environment and contained costs are important for patients and their families.

“Many of the parents told us time and time again, ‘Please do not make us travel a long distance for these treatments,’ because it inflicts fear and expenses and uncertainty for everyone,” Nikki Hafezi said.

Reference site in India part of program

Dr. Agarwal’s Eye Hospital in Chennai, India, is an approved site for implementation of the Tamil Nadu government’s insurance program that offers free treatment to low-income patients. Cross-linking is covered by this scheme, which allowed the implementation of the Light for Sight 21 program.

Amar Agarwal

According to Amar Agarwal, MS, FRCS,FRCOphth, OSN APAO Edition Board Member, cross-linking is the treatment of choice in Down syndrome patients with keratoconus, especially because both lamellar keratoplasty and penetrating keratoplasty may have a higher risk of globe rupture, dehiscence of sutures and rejection due to decreased ability to cooperate. In addition, there may be poorer quality of postoperative hygiene, precautions and care by the patient.

“Our research has focused on developing CACXL, or contact lens-assisted collagen cross-linking. This technology combined when needed with Hafezi’s hypo-osmolar CXL is effective for allowing cross-linking even in patients with corneas that are too thin for conventional cross-linking. This is especially important in patients with Down syndrome who are often diagnosed late and have already thinned out beyond 400 µm, which is the cutoff limit for conventional CXL,” Agarwal said.

“We have been treating such patients before, but the Light for Sight project just works beautifully to motivate children and parents and encourages them as they meet other people with similar challenges. They know that there are doctors who care for them, are sympathetic and are going out of their way to make the best care available,” he said.

Platform for research

Genetic alterations of collagen structure and function are responsible for several conditions affecting Down syndrome patients. These include connective tissue, musculoskeletal, pulmonary and cardiac problems, and most likely keratoconus.

The effects and efficacy of cross-linking in the abnormal collagen of these corneas are still largely unknown, and the Light for Sight 21 project offers a good platform for research.

“Besides our practical involvement in the humanitarian action, we are researchers, so we created an online database where reference sites can directly enter their data in view of a large prospective study. Up to now, we have data on about 50 eyes where we performed ORA, Corvis, aberrometry, Pentacam and keratography measurements to learn more about the cornea of a Down syndrome person. We are still in the preliminary stages, but our database is growing as more and more centers participate,” Farhad Hafezi said. – by Michela Cimberle

References:

Aslan L, et al. J AAPOS. 2013;doi:10.1016/j.jaapos.2012.10.020.

Caporossi A, et al. Cornea. 2012;doi:10.1097/ICO.0b013e31822159f6.

Chatzis N, et al. J Refract Surg. 2012;doi:10.3928/1081597X-20121011-01.

Fimiani F, et al. Eur J Ophthalmol. 2007;17(5):817-822.

Fong AH, et al. Br J Ophthalmol. 2013;doi:10.1136/bjophthalmol-2012-302327.

Karlica D, et al. Coll Antropol. 2011;35(4):1115-1118.

Kim JH, et al. Eye (Lond). 2002;doi:10.1038/sj.eye.6700208.

Koller B, et al. Cornea. 2014;doi:10.1097/ICO.0000000000000000.

Koppen C, et al. J Refract Surg. 2010;doi:10.3928/1081597X-20100824-01.

Liza-Sharmini AT, et al. Singapore Med J. 2006;47(1):14-19.

Vinciguerra P, et al. Am J Ophthalmol. 2012;doi:10.1016/j.ajo.2012.03.020.

Wong V, et al. Pediatr Neurol. 1997;doi:10.1016/S0887-8994(97)00029-5.

Wroblewski KJ, et al. Cornea. 2006;doi:10.1097/01.ico.0000226053.61884.91.

For more information:

Amar Agarwal, MS, FRCS, FRCOphth, can be reached at Dr. Agarwal’s Eye Hospital, 19 Cathedral Road, Chennai, India 600086; email: dragarwal@vsnl.com.

Efekan Coskunseven, MD, can be reached at the at Dünyagöz Eye Hospital, Istanbul, Turkey; email: efekan.coskunseven@dunyagoz.com.

Farhad Hafezi, MD, PhD, and Nikki Hafezi, MAS IP ETHZ, can be reached at ELZA Institute AG, Webereistrasse 2, 8953 Dietikon, Switzerland; email: info@elza-institute.com and nhafezi@groupadvance.com.

Marie-José Tassignon, MD, PhD, can be reached at Antwerp University Hospital, Wilrijkstraat 10, 2650 Edegem, Antwerp, Belgium; email: marie-jose.tassignon@uza.be.

Disclosure: The sources report no relevant financial disclosures.

 

POINTCOUNTER

Does modern IOL technology offer feasible solutions to improve vision in children with Down syndrome who have cataract and astigmatism or keratoconus?

POINT

Toric IOLs may be used in specific cases

Daphne Han, MD
Daphne Han

Toric IOLs may be an option in children with astigmatism, but they should be avoided if the axis of cylinder is unstable. They should especially be considered in impending severe meridional amblyopia intolerant of glasses or contact lenses.

In principle, toric IOLs should only be considered in cataract surgery with fairly regular corneal astigmatism in the optical zone and good potential visual acuity. In adults, cases of highly irregular astigmatism or keratoconus will benefit from other treatments to regularize the cornea, such as topography-guided excimer treatment in the former and cross-linking or lamellar keratoplasty in the latter.

In a child with Down syndrome who is often plagued by significant astigmatism, eye growth and overzealous eye rubbing can cause changes in both magnitude and axis of the cylinder. If a toric IOL were to be considered, it is vital to demonstrate on topography fairly regular and stable corneal astigmatism, particularly in the axis, because future shifts in axis can worsen blur and amblyopia in the susceptibly young, more so than in magnitude.

In the event that conditions are favorable for toric IOL implantation in a child with Down syndrome who has stable and regular cornea astigmatism and good family support, good surgery then comes into play. Examinations under anesthesia for refraction and biometry, self-sealing microincision phacoemulsification (possibly down to sub-2 mm to avoid creating astigmatism and higher-order aberrations), trypan blue to reduce elasticity of the continuous curvilinear capsulorrhexis, a smaller primary posterior continuous curvilinear capsulorrhexis, limited anterior vitrectomy, and posterior buttonholing of the optic to capture the IOL in the required axis and to prevent PCO (a technique learned from Dr. Michael Snyder at Cincinnati Eye Institute, USA) are all useful. Postoperative care is important, as are teamwork with pediatric ophthalmologists and vigilant follow-ups, with prompt amblyopia treatment and spectacle or contact lens wear for residual and future refractive errors.

PAGE BREAK

Although these measures may not be the final surgical interventions needed if astigmatism or keratoconus were to progress, they may save the child from permanent loss of sight from amblyopia.

 

Daphne Han, MD, is a consultant ophthalmic surgeon, Singapore National Eye Centre and Laser Vision Center, Singapore. Disclosure: Han reports no relevant financial disclosures.

COUNTER

Keep it simple and implant monofocal IOLs

Vishal Jhanji, MD
Vishal Jhanji

Toric IOLs have been shown to be an excellent option in patients with astigmatism and coexisting cataract in several studies. Down syndrome is often associated with high amounts of astigmatism, which in turn is frequently associated with keratoconus. Keratoconus progresses very fast over the teen years and tends to stop progressing with age. Consequently, if the refraction is stable, we could theoretically use a toric IOL in well-selected cases. However, in children with Down syndrome, I would be skeptical to implant a toric IOL for a number of reasons.

Preoperatively, it is difficult to assess astigmatism accurately in this subgroup of patients because they are not cooperative. Postoperatively, accurate assessment of refraction is challenging as well. Moreover, as keratoconus progresses, astigmatism fluctuates and the overall refraction changes.

If a child has keratoconus, I would rather stick to a standard monofocal IOL. Modern IOL technology definitely offers feasible solutions, but key to success is accurate measurement of astigmatism and the astigmatic axis. If the conditions were not ideal, a toric IOL would lead to more harm than benefit. Even a slight mistake in the axis measurement would make the astigmatism increase and create serious problems with vision.

There is more than one component to make the story complex: We have a child, and the child has keratoconus and Down syndrome. So, we follow the old rule in these complicated cases: Keep it simple and implant monofocal IOLs. If cataract is present, even with different degrees in both eyes, we prefer to perform surgery bilaterally to avoid exposing the child to repeated general anesthesia, following a strict surgical protocol to prevent infection.

 

Vishal Jhanji, MD, is an associate professor, Chinese University of Hong Kong, China. Disclosure: Jhanji reports no relevant financial disclosures.