Anophthalmia / Microphthalmia

  This chapter is contributed by researcher at Albert Einstein Medical Centre (AEMC) in Philadelphia.

Anomalies of the eye and central nervous system are among the most common encountered in pediatrics. In the case of Anophthalmia and Microphthalmia, it is thought it is thought to be on a continuum ranging from mild coloboma (a keyhole or a notch like defect in the retina, iris or optic nerve) to severe anophthalmia. Anophthalmia is a medical term used to describe the complete absence of the globe and eye tissue from the orbit. Microphthalmia is defined as small eyes and can range from mild to severe. The terms Anophthalmia and Microphthalmia are often used interchangeably, since CT scan and MRI may show some remnants of either the globe or surrounding tissue. Anophthalmia / Microphthalmia (A/M) may affect only one eye with the other being normal or both eyes, resulting in blindness. 

After congenital cataract, Anophthalmia and Microphthalmia are among the most frequent eye malformations in humans. 

(1)  The exact incidence of A/M is unknown. In a recent study in England, the overall prevalence of A/M was 1.0 per 10,000 births.

(2) Anophthalmia can be congenital (at birth) or acquired later in life (after an injury). Congenital anophthalmia and microphthalmia can occur alone or along with other eye problems (e.g. cataract or coloboma) or birth defects (e.g. heart or brain defects). Anophthalmia and Microphthalmia may result from inherited genetic mutations, sporadic (by chance) genetic mutations, chromosome abnormalities, parental environmental insult (maternal diabetes, infection or alcohol) or other, as yet unknown, factors.

  When a child is born with Anophthalmia/Microphthalmia, a comprehensive health care approach is essential to help the baby and the family to meet the challenges related to A/M and to live as healthy a life as possible. The health care team should include evaluations by the following professionals, either immediately or shortly after birth.

1. Pediatrician – A physician specializing in caring for children.

2. An Ophthalmologist – A physician specializing physician specializing in problems related to the eye. An Ophthalmologist often will make the diagnosis of A/M.

3. Ocularist – A health care professional specializing in prosthetic (artificial) devices for the eye.

4. Oculoplastic surgeon – A physician who specializes in surgery of the eye. Not all people with A/M will require surgery.

5. Geneticist – A physician who is an expert in genetic conditions.

6. Genetic counsellor – A medical professional specializing in support and information.

The genetic team can help the family to co-ordinate special care and early intervention for the child. If a specific diagnosis is made to explain the etiology of A/M, the genetics team can educate the family and health care team and provide anticipatory guidance and prognosis based on the information available from all sources. In addition, the genetics team can discuss the possibility of having another child with A/M.

7. An early intervention specialist/teacher – A professional who works with children who are visually impaired in one or both eyes to learn and develop in a sighted world. An example of an early intervention service is Orientation and Mobility training. Early intervention specialists will determine what services your child may need. Early intervention helps the child to maximize their development and reach their full potential.

 In each cell of our body, are the chromosomes which are tiny structures that carry our genetic information, which tells our bodies how to develop and to function throughout our life. Our chromosomes arranged in 23 pairs (total of 46) with one chromosome of each pair, coming from the mother (X chromosome) and the other from the father (Y chromosome). Our chromosomes contain thousands of genes, which are made up of DNA. Sometimes a change occurs in a gene which is called a mutation. If a mutation develops in the gene concerned with eye development, it could potentially affect how the eye develops during pregnancy. An eye is affected in about one-quarter of all inherited diseases, thus possible genetic defect causes eye malformation, must be considered as a possibility. A/M has many different potential causes including genetic conditions such as chromosomal disorders, single gene disorders and multifactorial disorders.

A chromosomal disorder means there is an extra piece or missing or rearranged piece of all or part of any chromosome. An example of a chromosome disorder is Down syndrome. These individuals have three copies of the chromosome number 21 instead of the usual 2. A chromosome disorder can be determined when you child has their chromosomes analyzed with a simple blood test. However, if your child has a normal chromosome analysis, it does not rule out a genetic cause of A/M. A normal chromosome test only means that the cause is unknown at that time.

A single disorder occurs as a result of a mutation in one gene or both genes of a pair of chromosomes. Examples of a single gene disorders are cystic fibrosis, sickle cell disease and Tay-Sachs disease. Researchers are currently working on locating and analyzing the gene(s) involved in a normal eye development which may lead to answers about A/M and enable geneticists to provide more accurate counselling and recurrence risks.

Multifactoral disorders are the result of a genetic predisposition plus environmental influence that leads to a disease. The exact genes and environmental influences are usually not known. Examples of conditions that are thought to be multifactoral are heart diseases and diabetes.

A comprehensive genetics evaluation may yield a diagnosis of a syndrome or disorder with A/M as one of its findings. If a diagnosis is made, the recurrence risk of that disorder can be explained. Unfortunately, many times it is difficult to make a diagnosis. Without a specific diagnosis, genetic counselling and determination of recurrence risks are difficult. At this time, parental testing to look for normal eye and lens development is available only in the form of high level ultrasound. Genetic counselling is recommended prior to a future pregnancy.

  Facial development occurs very rapidly in an infant and young child. It is believed that 90% of orbital growth is completed by the age of 5 years. Growth and development of the face depends on the presence of an average size eye in the orbital cavity. If an eye is very small or if it is totally absent, the face cannot grow properly. Therefore, treatment for A/M should begin as early as possible.

Treatment begins with an Ocularist. They may decide to use two basic approaches. The first, most common approach to treatment is the insertion of a conformer. A conformer is a tiny plastic device that looks like a ball with a stem. The conformer helps to support the growth of the eye socket and facial bones and to expand the eyelid opening.

The second approach is to make a custom-made conformer using the impression technique. This approach allows the conformer to be shaped exactly as per the child’s orbit cavity. One can also make an artificial eye with the impression technique instead of a conformer, which will help give an improved cosmetic appearance along with help expansion of the socket and orbit. In some cases, the Ocularist will need to examine the child under general anesthesia in an operating room. At the same time he will make an impression of the eye socket in order to make a custom made prosthetic device.

The Ocularist will decide which treatment approach is best for the child, depending on the individual needs of the child. In both approaches the prosthetic device will need to be changed frequently as the child grows.

During the examination, the Ocularist will need to hold the baby still in order to fit the conformer. The examination is not usually painful but may be disturbing for the child who does not understand what is happening to it. The Ocularist will separate the baby’s eyelids in order to examine the socket. The baby may cry and resist examination (by a stranger), even with the most gentle handling.

The prosthetic eye/conformer does not make a person with A/M see. With our current knowledge and science, there is no device that will allow a child with A/M to see. Anophthalmia is a condition that requires visiting the Ocularist throughout life. During the child’s first year, many ocular devices will be needed as the child grows and as the socket size changes. The child may need weekly, bi-weekly or monthly visits to the Ocularist. As the child grows older the frequency of visits will decrease.

The actual number of visits required differs from individual to individual. It may take some time for the child to get used to wearing prosthesis. It should not cause pain but if the child’s eye looks red or the child indicates pain by frequent rubbing or pulling at the eye you should contact your Ocularist immediately. Never remove the prosthesis without the knowledge of your Doctor or Ocularist. Children may remove and play with the prosthesis. You should replace it (in the socket) following the procedure taught by your Ocularist. If you are not able to replace it, contact your Ocularist without delay, as the socket may begin to shrink if the prosthesis is not in place.

Over time and through necessity, everyone can learn to care for the baby’s eye prosthesis and needs. Any concerns and feelings should be discussed with your Ocularist, who is used to dealing with concerns about these very important topics.

 Every eye socket is different and can be monitored and controlled with custom conformers to direct the growth of the eye socket.

At Shekhar Eye proprietary designed conformers with expandable materials, conformers with spring action, conformers with special edge designs and hydrogel conformers are customized for individual eye socket and growth is directed in desired direction for long term development and possible cosmetic, social and physiological rehabilitation.

Children may be born with A/M only, while others, may have additional associated findings. It is suggested that any child born with A/M have the following evaluations and studies carried out. These evaluations and studies will monitor for potential problems associated with A/M and help to ensure that children with A/M live as healthy a life as possible. This may be a helpful list to give to the Pediatrician. 

1.  Ophthalmologist / Oculoplastic surgeon.  2.  Ocularist.

3.  Clinical Geneticist. 

4.  Early intervention specialist and vision therapist (even for  children with only one eye affected). 

5.  Cardiology evaluation if a murmur is heard. 

6.  MRI or CT of brain and orbits.  

7.  Chromosome study. 

8.  Hearing evaluation. 

9.  Renal ultrasound.  

10.TORCH titers (infection studies). 

11. Dental examination when teeth erupt (especially for males). 

12. Ophthalmology examination of BOTH parents (in order to rule out eye problems that may not be affecting vision, such as coloboma which can result in a more severe condition in a child).

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The international children’s anophthalmia network (ican) is a support group of healthcare professionals and family members of persons with anophthalmia and microphthalmia. Icanoffers support to parents and family members, educational materials, quarterly newsletters and bi-yearly family conferences. Ican can be contacted through their hotline +1-800-580-ican (4226) or their internet web page at www.ioi.com/ican