• By: Galton Vasconcelos, MD; Luciene C. Fernandes, MD
    Low Vision

    Definition

    Cataract in children is any lens opacity that reduces vision in a child from birth to 18 years.1

    Magnitude

    Cataract is one of the most frequent ocular abnormalities in children.1,2 It is estimated that it is responsible for 10% to 38.8% of all preventable and treatable blindness (corrected visual acuity less than 20/400 or 0.05 logMar in the better-seeing eye) in children around the world. The prevalence of blindness by congenital cataracts in children is 1 to 4/10,000 in developing countries and about 0.1 to 0.4/10,000 in developed countries. It has an incidence of 1/2,000 live births and 10 new cases/million population/year. It is considered that 40% to 50% of patients with congenital cataracts present with low vision.1,2

    Etiology

    Cataract in children can be idiopathic; about half the cataract in children are idiopathic or can be related to various factors such as

    • Association with other syndromes (Trisomy 21, Bardet-Biedl)
    • Metabolic factors (galactosemia, hypoglycemia, hypocalcemia)
    • Maternal infection (rubella, toxoplasmosis)
    • Medications (corticosteroids, chlorpromazine)
    • Prematurity
    • Genetic factors
    • Other eye diseases (aniridia, intraocular tumor, retinopathy of prematurity)
    • Trauma

    Pediatric, neurological or other additional evaluation might be required for diagnosis of associated systemic disease and clinical geneticist consultation as well.

    Symptoms and Signs

    • Decreased visual acuity (VA)
    • Leukocoria
    • Decreased or absent red reflex

    When the cataract is dense, there is a visible opacification of the crystalline lens. However, for an early diagnosis and appropriate treatment of congenital cataracts, all newborns should have red-reflex testing performed through the direct ophthalmoscope by a neonatologist or pediatrician.3

    Treatment

    This is covered in detail in the chapter on pediatric cataracts.

    Special Considerations for Children with Cataracts or Cataract-Related Amblyopia

    Early Intervention

    Early intervention is a therapeutic, educational, and social method that improves the process of visual development in children from birth to 3 years of age and involves the participation of a transdisciplinary team. Infants and toddlers (birth to 3) must be accompanied in the early intervention program and visual stimulation instituted as early as possible.

    Visual Rehabilitation: Preschool and Older

    For preschool children (3–5 years), the relative size magnification obtained by enlarging the object and relative distance magnification are particularly useful. As children progress to higher grades, print size might be too small to read with ease and efficiency, and optical devices, a video magnifier and audio books might be needed.4

    For children at school age, low-vision devices are recommended. These children should have a clinical low-vision evaluation, receive prescription of optical and/or electronic devices, and be given proper educational training in the use of them.4,5 The school-age child might need different types of magnifiers and telescopes can be incorporated at this age. Video magnifiers and computer devices are widely accepted.4

    Nonoptical aids should be considered for all low-vision students: good lighting, comfortable working position with adjustable desk or reading stand, reading guides, material in high-contrast and color-contrast, absorptive lenses, cap or visor, bold-line pens and papers, and more.

    Children who have extremely poor vision or a disorder that causes progressive vision loss can be introduced to tactile methods for sensory stimulation that can be a prelude to learning Braille. Pre-Braille training should be instituted if available.

    Good prognosis is expected with low-vision rehabilitation for children with a history of cataracts or with amblyopia following removal of the cataract. VA ranges from normal to markedly impaired. Most of the time there is a normal visual field and normal color discrimination. Glare and contrast might be affected and should be evaluated regularly. Usually there is an adequate response to low-vision devices. It is important to emphasize the importance of an early diagnosis and intervention to reach a better quality of life.6

    References

    1. World Health Organization (WHO) and the International Agency for the Prevention of Blindness (IAPB). VISION 2020.
    2. Toledo de Paula CH, Vasconcelos GC, Nehemy MB, Granet D. Causes of visual impairment in children seen at a university-based hospital low vision. J AAPOS. 2015;19:252‑256.
    3. American Academy of Ophthalmology. Preferred Practice Patterns: Vision Rehabilitation.
    4. Sterns GK, Hyvarinen L. Addressing Pediatric Issues. In: Fletcher DC. Low Vision Rehabilitation: Caring for the Whole Person. American Academy of Ophthalmology. 1999. 107‑119.
    5. Watson GR. Using Low Vision Effectively. In: Fletcher DC. Low Vision Rehabilitation: Caring for the Whole Person. American Academy of Ophthalmology.1999. 61‑87.
    6. Faye EE. Clinical Low Vision. 2a. Ed. Boston/Toronto: Little, Brown, and Company. 1984. 272‑273.