Distinct Ocular Expression in Infants and Children With Down Syndrome in Cairo, Egypt

Abstract

IMPORTANCEThe study establishes the importance of genetic background for the expression of Down syndrome phenotype.OBJECTIVE To define the ocular manifestations of Down syndrome in infants and children in Cairo, Egypt, a historically isolated region, and compare them with systemic features and with findings in other geographic groups. DESIGN AND PARTICIPANTSWe prospectively studied the ocular status and systemic features of 90 infants and children with Down syndrome and monitored all patients for 3 years. The complete ophthalmic examinations were performed along with ultrasonography, if media opacities were evident. Thyroid and cardiac status were assessed. An extensive literature search for comparison was performed.SETTING Outpatient clinical genetics department at the National Research Centre in Cairo, Egypt. MAIN OUTCOMES AND MEASURESOcular and systemic manifestations of Down syndrome in infants and children in Cairo, and comparison of these features with patients with this anomaly from other geographic regions and ethnic populations.RESULTS Fifty-two infants or children (58%) had at least 1 abnormal ocular finding identified at the first visit. Significant refractive errors (in 37 [41%] patients) were the most common. Nasolacrimal duct obstruction, blepharoconjuctivitis, or conjunctivitis was found in 18 (20%), strabismus in 13 (14%), cataract in 5 (6%), nystagmus in 3 (3%), and optic nerve dysplasia in 2 (2%). Brushfield spots were not found. Additional ocular features developed over time. Thirty-six patients (40%) had congenital heart defects, and many (31 [86%]) had associated ocular disorders; a statistically significant correlation with myopia was established. Chromosomal translocations were high. The phenotype in Cairo was distinct.CONCLUSIONS AND RELEVANCE More than half of infants and children with Down syndrome in Cairo had ophthalmic abnormalities; myopia was correlated with congenital heart defects. Comparison of the specific ocular features in our population with those in previous worldwide studies shows differences that may be related to overexpression or polymorphisms of key, modifying genes or other mutations in this historically isolated region along the Nile River. Down syndrome is more common in the highly consanguineous and multiparous Middle Eastern populations, and our Cairo findings underscore regional differences.

Effects of bifocals on visual acuity in children with Down syndrome: a randomized controlled trial

“…The ocular findings (incidences, means and ranges) in our study population are listed in Table 2. The distribution and kind of refraction errors, strabismus and nystagmus closely match those of the general population of children with DS as have been reported in other studies over the last three decades (see Watt et al 2015 andAfifi et al 2013; for review; Table 1). Randomization resulted in groups with no statistically significant differences in baseline (T0) measurements ( Table 2).…”

“… and Afifi et al. ; for review; Table ). Randomization resulted in groups with no statistically significant differences in baseline (T0) measurements (Table ).…”

“…Although neural deficits at least partly constrain the visual acuity (VA) of children with DS, there are ocular disorders that further limit their visual functioning (Borstlap et al 2011). Compared to other children, many ocular findings in DS occur more frequently and in a more severe form (Creavin & Brown 2009;Little et al 2009b, Afifi et al 2013Aslan et al 2014;Watt et al 2015). In literature, the following prevalences have been reported: reduced visual acuity (poorer than 0.3 LogMar) in 80-100% and poor contrast sensitivity in almost all DS children (John et al 2004;Morton 2011;Little et al 2013;Watt et al 2015;Zahidi et al 2018).…”

“…Hence, there is far more esotropia than exotropia (9:1) in DS, and more acquired strabismus than congenital (7:3). In addition, nystagmus occurs in 6-33% (Creavin & Brown 2009;Afifi et al 2013;Weiss et al 2016).…”

Restoration of Severely Impaired Eyesight in an Adolescent with Down Syndrome and Bilateral Cataract in South Asia

“…Children with DS face serious challenges trying to keep up with things on an intellectual level, and the frequent impairment of eyesight (e.g. due to astigmatism, strabismus, retinal abnormalities, hyperopia/myopia, amblyopia, nystagmus, and cataract) [4, 5, 6, 7] raises the bar for social participation considerably.…”