Amblyopia

Also known as lazy eye, amblyopia commonly develops in children and is a condition where vision does not properly develop in one eye. It indicates decreased vision due to abnormal visual development in infancy and early childhood. This condition generally affects one eye, however may affect both. In children, lazy eye is the major cause of vision loss and if left untreated may result in severe damage. Lazy eyes generally develop before the age of 6. This condition develops only in children.

The condition of amblyopia may not look to be obviously abnormal. However if left untreated, vision impairment becomes permanent. As the brain matures, it will begin ignoring the messages coming from the eye with poor vision. The healthy eye is subject to trauma thus causing vision loss in that eye. When the nerve pathways between the brain and eye are not completely stimulated, it leads to lazy eye or amblyopia. Due to this reason the brain favors the strong eye as the other eye has poor vision. The weaker eye keeps wandering and thus the brain ignores the signal received from the lazy eye.

Lazy eye is usually treated with an eye patch, eye drops, glasses and contact lens. In a few cases surgical intervention may be essential. A child has to be treated when around 7-9 years of age. It is important to remember that lazy eye does not go away naturally, it needs to be treated.

Amblyopia types

Depending on the cause of the condition, amblyopia is classified into three types:

Refractive amblyopia: Significant difference between the vision in each eye causes lazy eye. Near sightedness, far sightedness or imperfection in the eye surface can cause this problem. These vision problems can be corrected with the help of glasses.

Strabismic amblyopia: An imbalance in the muscles of the eye that position each eye. This causes the eye to cross in or turn out, this muscle imbalance may not allow the eyes to synchronize and look at things.

Deprivation amblyopia: If one of the eyes has a cloudy area, then this problem may show up. This condition deprives the child from normal vision.

Symptoms of Amblyopia

• Eyes may not seem to move together.
  
• Eye wanders inwards and outwards.
  
• Depth perception may not be appropriate.
  

Diagnosis of Amblyopia

The physician generally checks for lazy eye through:

• Physical examination
  
• Checking for wandering eyes.
  
• Checking for difference in vision in the eyes.
  
• Checking for poor vision in the eyes.
  
• Tests like red reflex test help identify the condition in kids.
  

Treatment for the condition depends upon the severity of the condition. Based on the severity the following treatment options are available.

Eye patches: Eye patch is used over the strong eye so as to stimulate the weaker eye. Children aged above 4 years benefit from wearing this patch for 3-6 hours a day. Wearing the patch helps in developing the part of the brain that manages the vision development.

Corrective eyewear: If conditions like far sightedness, near sightedness or imperfection in the eye surface contribute to lazy eye, they can be corrected using corrective glasses or contact lenses.

Surgery: In extreme cases surgery is recommended to repair the eye muscles.

Eye drops: Eye drops are prescribed to blur the vision of the strong eye thereby encouraging the child to use the weaker better.

If left untreated, amblyopia can lead to permanent visual defect in the affected eye, visual defect in normal eye and loss of depth perception.

Pediatric Ophthalmologist

Pediatric ophthalmology is a sub specialty of ophthalmology concerned with vision care and eye diseases in children. A pediatric ophthalmologist provides comprehensive care in diagnostic, treatment and management of infant vision and common childhood vision disorders. Surgery to correct ocular misalignment and double vision in children are also performed by a pediatric ophthalmologist. Pediatric ophthalmologists are physicians who have completed a three year residency in ophthalmology after the medical school and one year internship and one or two year fellowship in pediatric ophthalmology and strabismus. Pediatric ophthalmology fellowships are accredited by the American Association for Pediatric Ophthalmology and Strabismus in the US.

Role of a pediatric ophthalmologist in child vision care:

• It could be opined that in young infants and children the visual system is not fully mature. As such, equal input from both eyes is required for proper development of visual centers in the brain in a human being. There could be the danger of permanent irreversible loss if the child's growing eye does not provide clear and focused image to the developing brain. A pediatric ophthalmologist provides early detection and effective treatment under such circumstances.
  
• Children suffer from reduced vision in one or both eyes from Amblyopia, uncorrected refractive errors and misalignment of the eyes called strabismus. It is the domain of the pediatric ophthalmologist to detect such innate errors in children and provide effective and efficient treatment. Among the vision problems that the pediatric ophthalmologist evaluates for the child include:
  
• Amblyopia: This is caused in an infant whose brain does not recognize the sight from the eye. In other words, there is poor vision in the eye appearing normal.
  
• Strabismus: This is misalignment of the eyes in any direction. About 4% of the children are affected by this disorder.
  
• Refractive errors: Such errors can cause decreased vision resulting in visual discomfort, eye strain and also Amblyopia.
  
• Genetic disorders: Approximately about 8% of genetic syndromes affect the eyes of children. Examination by a pediatric ophthalmologist helps to diagnose such genetic conditions. Sometimes certain eye conditions such as high internal pressure 'intraocular pressure' which can lead to glaucoma can be inherited in family members even when they are young. It is imperative on the part of the parent to inform the pediatric ophthalmologist about such conditions. Many pediatric ophthalmologists participate with multi disciplinary medical teams that treat children with genetic syndromes.

Tests conducted by pediatric ophthalmologist

• Penlight Eye Inspection: A small penlight is aimed into the child's eye, beginning with the newborn infants. The pediatric ophthalmologist checks and makes sure that the eye structures and eyelids appear normal and also if the eyes react appropriately to the presence of light. The pediatric ophthalmologist also checks for any early signs that eyes might be misaligned.
  
• Red Reflex test: The internal eye structure in particular, the red reflection from the inner back of the eye where the light sensitive retina is located is examined for the presence of any eye disease. This is done using an ophthalmoscope.
  
• Snellen Eye chart: This eye check contains letters and numbers which are used to test the sharpness of vision. This test can be done on children above the age of three years depending upon their comprehension. Sometimes certain cards with pictures are used to test for visual acuity testing.
  

Orthoptist

An Orthoptist diagnoses and treats sight-related disorders such as amblyopia (lazy eye), strabismus and ocular motility. Other conditions managed by an orthoptist include cataract, retinal disease and glaucoma. Orthoptists are involved in diagnostic techniques such as tomometry and ultrasound of the eye. An orthoptist helps in managing neurological disorders or eye defects. Typically an orthoptist deals with children and their vision-related problems. This include teaching them how to use pediatric lenses and using eye patches.