Pediatric Eye Conditions
Introduction
Anatomy
The anterior chamber is located behind the cornea and in front of the iris. The anterior chamber is filled with a fluid that maintains eye pressure, nourishes the eye, and keeps it healthy. The iris is the colored part of your child’s eye. Eye color varies from person to person and includes shades of blue, green, brown, and hazel. The iris contains two sets of muscles. The muscles work to make the pupil of the eye larger or smaller. The pupil is the black circle in the center of the iris. It changes size to allow more or less light to enter your child’s eye.
After light comes through the pupil, it enters the lens. The lens is a clear curved disc. Muscles adjust the curve in the lens to focus clear images on the retina. The retina is located at the back of your child’s eye.
The inner eye, the space between the posterior chamber behind the lens and the retina, is called the vitreous body. It is filled with a clear gel substance that gives the eye its shape. Light rays pass through the gel on their way from the lens to the retina.
The retina is a thin tissue layer that contains millions of nerve cells. The nerve cells are sensitive to light. Cones and rods are specialized receptor cells. Cones are specialized for color vision and detailed vision, such as for reading or identifying distant objects. Cones work best with bright light. The greatest concentration of cones is found in the macula and fovea at the center of the retina. The macula is the center of visual attention. The fovea is the site of visual acuity or best visual sharpness. Rods are located throughout the rest of the retina.
The eyes contain more rods than cones. Rods work best in low light. Rods perceive blacks, whites, and grays, but not colors. They detect general shapes. Rods are used for night vision and peripheral vision. High concentrations of rods at the outer portions of the retina act as motion detectors in your child’s peripheral or side vision.
The receptor cells in the retina send nerve messages about what your child sees to the optic nerve. The optic nerves extend from the back of each eye and join together in the brain at the optic chiasm. From the optic chiasm, the nerve signals travel along two optic tracts in the brain and eventually to the occipital cortex,where vision is processed and perceived.
Causes
Refractive errors occur when light does not reflect on the retina correctly because of the shape of the cornea or lens. The most common refractive error is nearsightedness, which means distant vision is poor. Children with farsightedness have difficulty seeing things that are up-close, such as when reading. Astigmatism is a focusing problem. Objects may appear blurry up-close, far away, or both. Refractive errors are treated with glasses or contacts.
There are some eye conditions that are more concerning and require immediate attention. Premature babies are at risk for retinopathy of prematurity. This condition can cause the blood vessels in the retina to grow abnormally, to bleed , and can lead to retinal detachment. All premature babies in the United States are screened for retinopathy of prematurity.
Some babies are born with eye conditions, such as infantile cataracts, congenital glaucoma, or retinoblastoma. Infantile cataract is a clouding of the lens that causes blurred vision and may lead to vision loss. Congenital glaucoma is a rare condition in which the drainage canals in the eye do not function properly, and as a result, the pressure in the eye increases. The pressure increase can affect vision. Retinoblastoma is a cancerous tumor that usually appears in the first three years of life. The tumor affects the retina and may cause vision loss. A sign of retinoblastoma is whitening of the pupil.
Symptoms
Diagnosis
You should have your child’s eyes examined if he or she shows the signs or symptoms of a vision problem. It may be difficult to determine how well a newborn baby sees. A newborn’s vision is naturally blurry up until about 6 months of age. After that, babies develop stereo vision, which means both of their eyes work together to create an image. Newborns and premature infants receive eye examinations after birth.
Infants or children do not need to be able to talk to have an eye examination. There are eye charts and evaluation methods that are used just for children. Visual acuity testing can be completed with shapes instead of reading letters or numbers from a chart to determine your child’s ability to see near and far distances. Refraction is used to determine the degree of the refractive error. The information is used to write a prescription for glasses.
The American Academy of Optometry recommends that children receive vision examinations and screenings at approximately age 3 ½ and again at age 5. School age children may receive routine eye checks at school or their doctor’s office. Children that wear prescription glasses or contacts should be checked each year for vision changes.
Treatment
The treatment for pediatric eye conditions depends on the type, extent, and urgency of the problem. Some conditions, such as a lazy eye may be monitored, whereas tumors, cataracts, or glaucoma require immediate medical attention.
Refractive errors are easily corrected with glasses or contacts. It is recommend that children help pick out their own glass frames. Contacts are generally considered for children that are at least 11 years old. They need to be able to understand and carry out the instructions for wearing contacts responsibly.
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This information is intended for educational and informational purposes only. It should not be used in place of an individual consultation or examination or replace the advice of your health care professional and should not be relied upon to determine diagnosis or course of treatment.
The iHealthSpot patient education library was written collaboratively by the iHealthSpot editorial team which includes Senior Medical Authors Dr. Mary Car-Blanchard, OTD/OTR/L and Valerie K. Clark, and the following editorial advisors: Steve Meadows, MD, Ernie F. Soto, DDS, Ronald J. Glatzer, MD, Jonathan Rosenberg, MD, Christopher M. Nolte, MD, David Applebaum, MD, Jonathan M. Tarrash, MD, and Paula Soto, RN/BSN. This content complies with the HONcode standard for trustworthy health information. The library commenced development on September 1, 2005 with the latest update/addition on February 16, 2022. For information on iHealthSpot’s other services including medical website design, visit www.iHealthSpot.com.
