PURPOSE: The aims of this study were to examine the distribution of refractive errors and clinical characteristics of strabismus in Korean patients with Down's syndrome. METHODS: A total of 41 Korean patients with Down's syndrome were screened for strabismus and refractive errors in 2009. RESULTS: A total of 41 patients with an average age of 11.9 years (range, 2 to 36 years) were screened. Eighteen patients (43.9%) had strabismus. Ten (23.4%) of 18 patients exhibited esotropia and the others had intermittent exotropia. The most frequently detected type of esotropia was acquired non-accommodative esotropia, and that of exotropia was the basic type. Fifteen patients (36.6%) had hypermetropia and 20 (48.8%) had myopia. The patients with esotropia had refractive errors of +4.89 diopters (D, +/-3.73) and the patients with exotropia had refractive errors of -0.31 D (+/-1.78). Six of ten patients with esotropia had an accommodation weakness. Twenty one patients (63.4%) had astigmatism. Eleven (28.6%) of 21 patients had anisometropia and six (14.6%) of those had clinically significant anisometropia. CONCLUSIONS: In Korean patients with Down's syndrome, esotropia was more common than exotropia and hypermetropia more common than myopia. Especially, Down's syndrome patients with esotropia generally exhibit clinically significant hyperopic errors (>+3.00 D) and evidence of under-accommodation. Thus, hypermetropia and accommodation weakness could be possible factors in esotropia when it occurs in Down's syndrome patients. Based on the results of this study, eye examinations of Down's syndrome patients should routinely include a measure of accommodation at near distances, and bifocals should be considered for those with evidence of under-accommodation.
Adolescent ; Adult ; Child ; Child, Preschool ; Down Syndrome/*complications/epidemiology ; Female ; Humans ; Incidence ; Male ; Prevalence ; Refractive Errors/complications/*epidemiology ; Republic of Korea/epidemiology ; Retrospective Studies ; Strabismus/complications/*epidemiology ; *Vision Screening ; Young Adult

INTRODUCTIONRefractive error remains one of the primary causes of visual impairment in children worldwide, and the prevalence of refractive error varies widely. The objective of this study was to determine the prevalence of refractive error and study the possible associated factors inducing refractive error among primary school children of Malay ethnicity in the suburban area of Kota Bharu, Kelantan, Malaysia.

MATERIALS AND METHODSA school-based cross-sectional study was performed from January to July 2006 by random selection on Standard 1 to Standard 6 students of 10 primary schools in the Kota Bharu district. Visual acuity assessment was measured using logMAR ETDRS chart. Positive predictive value of uncorrected visual acuity equal or worse than 20/40, was used as a cut-off point for further evaluation by automated refraction and retinoscopic refraction.

RESULTSA total of 840 students were enumerated but only 705 were examined. The prevalence of uncorrected visual impairment was seen in 54 (7.7%) children. The main cause of the uncorrected visual impairment was refractive error which contributed to 90.7% of the total, and with 7.0% prevalence for the studied population. Myopia is the most common type of refractive error among children aged 6 to 12 years with prevalence of 5.4%, followed by hyperopia at 1.0% and astigmatism at 0.6%. A significant positive correlation was noted between myopia development with increasing age (P <0.005), more hours spent on reading books (P <0.005) and background history of siblings with glasses (P <0.005) and whose parents are of higher educational level (P <0.005). Malays in suburban Kelantan (5.4%) have the lowest prevalence of myopia compared with Malays in the metropolitan cities of Kuala Lumpur (9.2%) and Singapore (22.1%).

CONCLUSIONThe ethnicity-specific prevalence rate of myopia was the lowest among Malays in Kota Bharu, followed by Kuala Lumpur, and is the highest among Singaporean Malays. Better socio-economic factors could have contributed to higher myopia rates in the cities, since the genetic background of these ethnic Malays are similar.

Child ; Cross-Sectional Studies ; Female ; Follow-Up Studies ; Humans ; Malaysia ; epidemiology ; Male ; Prevalence ; Refraction, Ocular ; Refractive Errors ; complications ; epidemiology ; physiopathology ; Retrospective Studies ; Schools ; Suburban Population ; statistics & numerical data ; Vision, Low ; epidemiology ; etiology ; physiopathology ; Visual Acuity

This study was performed to compare the incidence of posterior capsular opacity (PCO) and refractive errors between hydrophilic (ACR6D, Corneal (R) ) and hydrophobic (MA60BM, AcrySof (R) ) acrylic intraocular lenses (IOLs) over a 3-year follow-up after phacoemulsification surgery. The patients with AcrySof (R) implanted in one eye and Corneal (R) in the other eye were categorized as Group 1 (n=28), while those with one or both eyes implanted with IOLs of the same kind were categorized as Group 2 (AcrySof (R), n=90; Corneal (R), n=95). Refractive errors were evaluated at 3 months and 3 years postoperatively. The incidence of visually significant PCO was investigated 3 years postoperatively. Postoperative refractive values at 3 months were not significantly different between the two groups. However, refractive values at 3 years were significantly different between two IOLs in both groups [AcrySof (R) -0.37 +/- 0.43D, Corneal (R) -0.62 +/- 0.58D in Group 1 (p=0.04) ; AcrySof (R) -0.38 +/- 0.52, Corneal (R) -0.68 +/- 0.54 in Group 2 (p< 0.01) ]. The incidence of visually significant PCO was 14% and 32% in Group 1, and 13% and 28% in Group 2, for the AcrySof (R) and Corneal (R) implants, respectively. The incidence of visually significant PCO of hydrophilic acrylic IOLs was higher than that of hydrophobic acrylic IOLs in the 3-year follow-up. The postoperative 3-year refractive value of Corneal (R) showed myopic shift.
*Acrylic Resins ; Aged ; Cataract/*epidemiology/etiology ; Comparative Study ; Female ; Follow-Up Studies ; Humans ; Hydrophobicity ; Incidence ; Lens Capsule, Crystalline/*pathology ; Lens Implantation, Intraocular ; *Lenses, Intraocular ; Male ; Middle Aged ; Phacoemulsification ; *Postoperative Complications ; Refractive Errors/*epidemiology/etiology