What are non-refractive errors?
The following are some causes of non-refractive errors:
Glaucoma occurs when the normal fluid pressure inside the eyes (intraocular pressure, or IOP) slowly rises. This happens because the fluid aqueous humor, which normally flows in and out of the eye, can't drain correctly. Instead, the fluid collects and causes pressure damage to the optic nerve. This nerve connects the eye to the brain. This condition also causes vision loss. Glaucoma is classified according to the age when it starts. Glaucoma that begins before age 3 is called congenital (present at birth) glaucoma. Glaucoma that happens in a child is called childhood glaucoma.
Symptoms may include excessive tearing, light sensitivity (photophobia), closing one or both eyes in the light, a cloudy and enlarged cornea, one eye being larger than the other, and vision loss. Treatment often includes surgery. Without treatment, blindness may happen.
A cataract is a clouding or unclear (opaque) area in the lens of the eye. This area is normally clear (transparent). As this clouding happens, it prevents light rays from passing through the lens and focusing on the retina. The retina is the light-sensitive tissue in the back of the eye. This clouding is caused when some of the protein which makes up the lens clumps together and interferes with vision. Cataracts can affect one eye (unilateral) or both eyes (bilateral). Cataracts in children are not common. A child may be born with cataracts (congenital). Or the condition may develop later in life (acquired). Possible causes of cataracts include the following:
Other childhood diseases, such as rheumatoid arthritis
Complications from other eye diseases, such as glaucoma
Most congenital cataracts (those present at birth) occur in children who also have other eye problems or other health problems. In about 25% of children born with congenital cataracts, the condition is due to a genetic cause, such as a metabolic disorder (caused by an inherited enzyme deficiency) or a chromosome abnormality (such as Down syndrome).
Symptoms of a cataract may include the following:
White pupil on flashlight exam
Eyes don’t line up
Involuntary rhythmic movements of the eyes back and forth, up and down, around, or mixed (nystagmus)
Cloudy or blurry vision
Lights seem too bright or present a glare or a surrounding halo
Treatment often includes cataracts surgery.
Retinoblastoma is a rare cancer of the retina. The retina is the innermost layer of the eye. It's located at the back of the eye. It receives light and images needed for vision. About 250 children in the U.S. are diagnosed with this type of cancer each year. It mostly happens in children the age younger than 5. Most cases happen between infancy and age 2. Both boys and girls are affected equally. Retinoblastoma can happen in either eye. But in about 1 in 4 cases, the tumor is in both eyes.
Symptoms of retinoblastoma may include:
Leukocoria. A white light reflex that happens at certain angles when light is shown into the pupil.
Crossed eyes (strabismus). This is when the eyes don’t line up. One or both eyes don’t seem to be looking in the same direction. It's also called wandering eye.
Pain, swelling, or redness around the eyes.
Treatment for retinoblastoma may include one or more of the following:
Surgery (removal of the eyeball which may be followed up with an artificial eye implant)
Heat treatment (uses extreme heat directed toward cancer cells)
Laser therapy (uses light to destroy the blood vessels that nourish the tumor)
Cryotherapy (uses a freezing process to destroy the tumor)
Additional follow-up treatments may include:
Fitting and training for a prosthesis (artificial eye)
Blind or decreased vision adaptation training
Supportive care (for the side effects of treatment)
Antibiotics (to prevent or treat infection)
To protect your child, the American Pediatric Association recommends eye exams at all well-child visits. This means every age group, from newborns to teenagers. If your child complains of any vision problems, or if you notice vision-related issues, contact your provider right away.