Ophthalmologic abnormalities in mentally retarded

Abstract

Purpose: To determine the prevalence and types of ophthalmologic abnormalities in mentally retarded subjects.

Methods: Seventy-three institutionalized mentally retarded subjects (41 boys and 32 girls) aged 5 to 19 years (mean: 11.5 years) were examined ophthalmologically during a three month period (from May to July 1999). The eye examination consisted of visual acuity testing (illiterate Snellen E-chart or acuity card procedures), pupillary reflex and motility evaluation, cover test for phoria and tropia, examination of adnexa and anterior segment (magnifying glass or slit-lamp biomicroscopy if indicated and possible), retinoscopy and direct ophthalmoscopy. All subjects were evaluated pediatrically, neurologically, psychologically and otorhinolaryngologically if indicated.

Results: Ophthalmologic abnormalities were found in 60.2% of the subjects. Eyelid abnormalities accounted for 21.7%, fundus abnormalities for 21.6%, refractive errors for 15% and ocular motility disorders for 13.6%. Taken separately, optic atrophy (16.4%) was the most frequent disorder, followed by refractive errors (15%), hypertelorism (12.3%), epicanthus (10.9%) and nystagmus (8.2%). Strabismus and mongoloid obliquity of lids were seen in 5.4% each other while ptosis was disclosed in 4.2% of cases. Visual acuity tested in 60 subjects revealed that 25 (41.6%) had visual impairment. Of all subjects 10.9% required corrective glasses while 9.6% needed corrective surgery for strabismus and ptosis.

Conclusion: This study shows a high prevalence of ophthalmologic abnormalities in mentally retarded subjects. This is in agreement with the results of several other previous studies. It's therefore essential to screen mentally disabled subjects ophthalmologically.