Visual and ocular alterations in patients with down syndrome

Abstract

Down’s syndrome refers to the set of clinical manifestations produced by a chromosomal numerical alteration named trisomy 21; this one is the most frequent genetic anomaly in the world (one for every 700 to 1.000 born alive). The majority of the cases of trisomy 21 are caused by the failure in the suitable separation of the chromosomes during the meiosis. An epidemiological association exists between mother advanced age and major frequency of births with Down’s syndrome. The phenotype of the patients with Down’s syndrome is variable , being the principal physical characteristics the following: poor muscle tone, flat back of the head, epicanthic fold, upslanting palpebral fissures, nasal flat bridge, facial features, redundant skin in cervical posterior region, single transverse palmar crease, hipoplasia of average phalanx of fifth finger of hands with clinodactilia, a larger than normal space between the big and second toes, the classic phenotype includes also: congenital heart defects (50%), ocular anomalies (60%), obstructive sleep apnea (50-75%), thyroid dysfunction (20 to 40%), deafness (75%), otitis media (50-70%), hip dysplasia (6%), leukemia (1%), Hirshsprung’s disease (1%), among others. The degree of mental delay is variable and the visual and ocular alterations are diverse and of great importance in the morbidity of these patients, being the group of major risk the pediatric population. Different studies have verified a high prevalence of refractive errors, accommodative disorders, amblyopia, cataracts, strabismus, nistagmos and infections among others. These anomalies alter in significative form the quality of life of the patients and their family, in such a way that a better discernment of the visual and ocular alterations associated with Down’s syndrome gives place to the establishment of preventive actions and early treatment that could influence positively in their development and future life.