Vision Issues

Strabismus (crossed eyes)

Strabismus is the condition where the eyes are misaligned. Different types of strabismus include crossed eyes (esotropia, the most common type in children), out-turned eyes (exotropia), or vertical misalignment (hyper or hypotropia). The problem may be present intermittently or constantly. Treatment options depend upon the type of strabismus, and may include glasses, prism lenses, and/or surgery.
To read more about strabismus, go here.

after surgery; photo courtesy of mmmmaaaayyyy on flickr


Amblyopia (lazy eye)

Amblyopia, commonly known as lazy eye, is the eye condition noted by reduced vision not correctable by glasses or contact lenses and is not due to any eye disease. The brain, for some reason, does not fully acknowledge the images seen by the amblyopic eye. This almost always affects only one eye but may manifest with reduction of vision in both eyes. It is estimated that three percent of children under six have some form of amblyopia.



Glaucoma

Glaucoma is a disease caused by increased intraocular pressure (IOP) resulting either from a malformation or malfunction of the eye’s drainage structures. Left untreated, an elevated IOP causes irreversible damage the optic nerve and retinal fibers resulting in a progressive, permanent loss of vision. However, early detection and treatment can slow, or even halt the progression of the disease.

left: shows a normal range of vision, unaffected by glaucoma
right: the same view with advanced vision loss from glaucoma





glaucoma diagram and above photos available through

the Creative Commons license, courtesy of Wikipedia


Cataracts

Congenital cataract is a lens opacity that is present at birth or shortly after birth.

Congenital cataracts may be sporadic, or they may be caused by chromosomal anomalies, metabolic disease (eg, galactosemia), or intrauterine infection (eg, rubella) or other maternal disease during pregnancy. Cataracts may be located in the center of the lens (nuclear), or they may involve the lens material underneath the anterior or posterior lens capsule (subcapsular or cortical). They may be unilateral or bilateral. They may not be noticed unless the red reflex is checked or unless ophthalmoscopy is done at birth. As with other cataracts, the lens opacity obscures vision. Cataracts may obscure the view of the optic disk and vessels and should always be evaluated by an ophthalmologist.

Removal of a cataract within 17 wk after birth permits the development of vision and cortical visual pathways. Cataracts are removed by aspirating them through a small incision. In many children, an intraocular lens may be implanted. Postoperative visual correction with eyeglasses, contact lenses, or both is usually required to achieve the best outcome.

After a unilateral cataract is removed, the quality of the image in the treated eye is inferior to that of the other eye (assuming the other eye is normal). Because the better eye is preferred, the brain suppresses the poorer-quality image, and amblyopia develops. Thus, effective amblyopia therapy is necessary for the treated eye to develop normal sight. Some children are unable to attain good visual acuity because of accompanying structural defects. In contrast, children with bilateral cataract removal in which image quality is similar in both eyes more frequently develop equal vision in both eyes.

Some cataracts are partial (posterior lenticonus) and opacify during the 1st decade of life. Eyes with partial cataracts will have a better visual outcome.