and its visual implications CHARGE and its visual implications

What is it? A genetic pattern of disorders that are diagnosed at birth. It is a very complex syndrome which can differ from child to child and also carries many medical and physical difficulties.

History The collective name of recognizable patterns of birth defects was coined with the acronym CHARGE in 1981. The acronym is associated with each system that can be affected by the disorder.

Coloboma of the eyes (affecting areas of the eye including the iris, retina, or disc) Heart defect Atresia of the choanae (closure of the passages from the back of the nose to the throat) Retardation of growth and/or development Genital Hypoplasia (under developed or deformities of the genitals) Ear malformations

Cause CHARGE is an autosomal dominant genetic disorder which is typically caused by the mutation or deletion of the CHD7 gene . The cause of CHARGE is not known. It typically does not occur in more than one person in a family.

Major Features Feature Includes Frequency >50% Common 90% Coloboma of the eye Coloboma (sort of like a cleft) of the iris, retina, choroid, macula or disc (not the eyelid); microphthalmos (small eye) or anophthalmos (missing eye): CAUSES VISION LOSS 80%-90% Choanal atresia or stenosis The choanae are the passages that go from the back of the nose to the throat. They can be narrow (stenosis) or blocked (atresia). It can be unilateral (one-sided) or bilateral (both sides), bony or membranous 50%-60% Cranial nerve abnormalities Missing or decreased sense of smell Swallowing difficulties, aspiration  Facial palsy (one side or both) 90-100% 70%-90% 40% CHARGE outer ear CHARGE middle ear Short, wide ear with little or no lobe, "snipped off" helix (outer fold) Malformed bones of the middle ear (ossicles): causes Conductive Hearing Loss >50% Common CHARGE inner ear Malformed cochlea; small or absent semicircular canals: cause hearing loss and balance problems 90%

Visual Implications Children with CHARGE often have vision impairments due to colobomas. Most children with colobomas have a visual field loss, typically in the superior (upper) field. There may be blind spots and acuity problems in addition to visual field loss.

Visual Implications Iris colobomas can result in extra sensitivity to bright lights, even indoors. In many cases, one eye is more severely affected than the other, causing monocular vision and lack of depth perception.

Visual Implications Colobomas of the retina can cause a defect in the upper visual field. There may also be a predisposition to retinal detachment .

Visual Implications Colobomas of the macular and or optic disc usually affects visual acuity significantly.

Visual Implications With a field loss or monocular vision, it is difficult to follow a line smoothly or a series of lines systematically. Reading or any type of precise near reading work is both challenging and fatiguing.

Visual Implications A visual field loss also requires a child to scan systematically in order to receive the full visual picture. In an educational setting, visual information may come from: teacher instruction/chalkboard (distance), handouts (close up). computer projections (distance)

The Charge Syndrome Foundation Coloboma of the iris Photos courtesy of The Charge Syndrome Foundation

The Charge Syndrome Foundation Normal Retina Photos courtesy of The Charge Syndrome Foundation

The Charge Syndrome Foundation Retinal Coloboma Photos courtesy of The Charge Syndrome Foundation

Compensatory Strategies Large print, bold lines, underlining, or a line marker can be Overlays Glasses Magnifying bars and binoculars Sunshades ( if sensitive to light) Placement of material in the upper or lower visual field depending on the location of the deficit

Treatment Since symptoms of CHARGE vary by child, treatments vary. However, it is important that appropriate screenings/ tests, therapies, medications, etc are accessed in a timely manner and maintained.

References http://www.chargesyndrome.org/about-charge.asp http://emedicine.medscape.com/article/942350-overview http://www.tsbvi.edu/seehear/issue11-96/CHARGE%20Syndrome.htm Bent, Donna. CHARGE syndrome information: vision. Retrieved July 18, 2011 from http://www.chargesyndrome.org/professional%20packet/9%20vision.pdf Pagan, Roberta. 1999.The eyes in CHARGE: For the Ophthalmologist. Retrieved from http://www.chargesyndrome.org/manual/Eyes.pdf