Randall T. Jose, O.D., director of the Low Vision Center at the University of Houston College of Optometry, examines a young girl for vision problems. Photo courtesy of Vision Advantage, Inc.

[Editor's Note: The following is excerpted from the author's just published book, Dispensing Pediatric Eyewear, which provides a comprehensive, hands-on guide to caring for and meeting the visual needs of your youngest patients. The selections below are from the two chapters that deal with handling kids with serious vision problems.]

We have a responsibility to the children we serve and to their parents. We must constantly strive to improve both the products we dispense and the methods we use to dispense them. If we fit an adult incorrectly, she may be uncomfortable and never return to the dispensary. However, if we fit a child improperly, we can do permanent harm.

Here's a look at some of the more difficult vision problems you are likely to encounter with children and how we handle them at my pediatric dispensary, A Child's View. We'll also look at some specific products and how they can help.

Conditions and Treatment

Here's a look at just some of the conditions that can impact children, and how these problems affect their vision.

• Cataracts. Congenital cataracts us a leading cause of vision impairment in young children. For optimum results, surgery should be performed before eight weeks of age. Visual rehabilitation should be initiated immediately following surgery and involves glasses or contact lenses. As unilateral cataracts almost always result in amblyopia, occlusion therapy is prescribed in conjunction with contact lenses. However, parents must be cautioned to return to the doctor for regular monitoring of visual acuity.
• Achromatopsia. This rare genetic condition affects the cells of the retina responsible for daytime and color vision through either the absence of all cones or a deficiency in the function of the cone system. Symptoms include extreme photophobia, nystagmus, and poor vision. No known cure exists. However, achromats can be made more comfortable by dark red lenses, contact lenses, mirror coating, and side shields.
• Albinism. The absence of pigment may be partial or complete. There is a tendency towards moderately high hyperopia, astigmatism, nystagmus, strabismus, and loss of visual acuity. Protection against the effects of UV light is mandated.
• Aniridia. Although aniridia implies the absence of an iris, a small portion remains. Children with aniridia have many other associated ocular abnormalities and are legally blind.
• Down syndrome. In addition to the characteristic faces, mental retardation, and low-set ears, the ocular abnormalities include strabismus, high refractive errors, keratoconus, nystagmus, and blepharitis.
• Glaucoma. Congenital glaucoma (also known as buphthalmos) is marked by increased intraocular pressure with enlargement of the eyeball and protrusion of the cornea.
• Retinitis pigmentosa. Its first symptom, night blindness, is usually seen in children and adolescents.
• Retinopathy of prematurity. ROP is a retinal vascular disease usually due to a combination of premature birth, very low birth weight, and supplemental oxygenation. Lighting in the neonatal ICU also has been implicated as a possible factor. In addition to retinal manifestations children tend to have amblyopia, strabismus, cataracts, glaucoma, nystagmus, and corneal problems.
• Stickler syndrome. Stickler syndrome is one of the most common systematic disorders associated with high myopia. Children with this disorder commonly have flattened faces, high myopia, retinal detachment, cataracts, cleft palate, and mental retardation.

Using Special Products

Following are some of the more commonly prescribed special products for severe vision problems, as well as information about their availability, use, and application. Special needs children in particular sometimes require the use of specialized products that may or may not be related to another fitting limitation. However, these products are essential to providing a functional pair of glasses.

Tints for photophobia. Several conditions have symptoms that can be reduced by the use of specialized tints. The Younger PLS 530(tm) and the BPI Diamond Dye 527(tm) are colors effective in the management of diabetic retinopathy, corneal dystrophy, and albinism. The Younger PLS 550(tm) and the BPI Diamond Dye 550(tm) are effective in the management of macular degeneration, retinitis pigmentosa, aniridia, glaucoma, and achromatopsia.

Some tints will be more effective indoors but inadequate in full sunlight. Lighting conditions must be considered as well as the possibility of detrimental side effects. For example, certain tints affect color perception and decrease acuity.

Many times, effective colors are found by trial and error and may come from the most unlikely sources. Parents, desperate to relieve their child's discomfort, have tried toy sunglasses, welding lenses, ski tints, and even color celophane. Oddly, some of these materials have even been successful.

Once a spectrometer reading of the sample color is obtained, the prescription polycarbonate lens can be ground and the color properties duplicated. It is not enough just to simply compare color. A spectrophotometer reading of the prescription polycarbonate lens must be compared with the sample.

A difficulty encountered when replicating the effects of a particular color in the polycarbonate is in the density attainable. Greater effect may be possible with poly when specialized tints are combined with multi-layer AR coatings.

If the color to which the child is most sensitive can be isolated and an opposing color added to the lenses to prevent absorption, the effect can be quite dramatic.

Use of side shields. Children with albinism, achromatopsia, and other conditions have greatly increased light sensitivity. Side shields can be very effective in blocking the light around the frame and are cut easily from vinyl that is available at any fabric store.

The vinyl can be purchased in colors to coordinate with the glasses. If given a choice in density, use the lightest weight opaque vinyl available. The side shield is inserted and glue to the upper eyewire. The remaining panel is placed along the lower eyewire and held in place by the lens, allowing the lens to be removed and reinserted without disturbing the side shield.

Iseikonic lenses. Also known as size lenses, they are selected specifically to produce a difference in image magnification between the left and right eyes by using specific base curves and thicknesses. They are used to benefit the wearer optically as opposed to those lenses selected to cosmetically match the magnification of minification of the eye.

Press-on prisms and powers. These are used effectively for a variety of conditions where frequent changes in power or prism are required. Although usually intended for short-term use, press on optics can be used long term to reduce the weight and thickness of ordinary lenses or to produce specialized lenses not otherwise available.

AR coatings. These are especially beneficial to special needs children, and the dispenser is more concerned here with lens reflections that reduce acuity and less concerned with the cosmetic reflections appearing on the surface of the lenses. While the added care required for AR coatings may obviate the routine use on other children, the potential for improved acuity makes their use on special needs children more the standard than the exception. However, use of AR on glasses for children who cannot physically or mentally benefit is inappropriate. EB

Katheryn Dabbs Schramm is a pediatric optician and president of A Child's View, with locations in Mission Viejo, Brea, and Huntington Beach, Calif. She is also a member of the Eyecare Business Editorial Advisory Board. This article is excerpted from Schramm's book, Dispensing Pediatric Eyewear, which is being released this month. For more information or to order the book, call Butterworth-Heinemann at 800-366-2665 or e-mail at orders@bhusa.com.