B-MODE ULTRASONOGRAPHIC AXIAL LENGTH MEASUREMENT OF NORMAL CHILDREN IN SAGAMU LOCAL GOVERNMENT AREA OF OGUN STATE. SOUTH WEST. NIGERIA
Background: The decision on intraocular lens power calculation and implantation in cataract surgery in children by ophthalmologists is premised on a good knowledge of and precise measurement of relevant parameters of the eyes. However, there is a dearth of data in the environment in children which this current study is being carried out to fill.
Methods: A visual acuity and fundoscopy were done on the children from 3 selected schools in the Local Government Area (LGA) to ascertain the normalcy of their eyes following parental consent and child assent (where possible) after clearance was obtained from the institutional Ethic Health Research Committee. Axial lengths of both eyes were measured using a B-mode ultrasound scanner with a 4-12MHz linear transducer with closed eyelids of the children. This was done in the Radiology department with no anaesthesia or analgesia given as the procedure was done in a child-friendly ultrasound room by the radiologist.
Results: Nine hundred and ninety (990) eyes were scanned, but only 936 eyes of 468 children were assessed with the exclusion of eyes with abnormal visual acuity. There were 235males and 233 females with ages ranging from 2years to 16 years. The mean age of all children in the study was 8.76Â±3.83 years. The mean age of boys was 9 years, 8.5years for girls. The mean ages for boys and girls were not statistically different. The mean Axial Length (AL) in the right eye is 24.9mm Â±0.11mm in boys and 24.5mm Â±0.12mm in girls. The mean AL in the left eyes is 25.0mm Â±0.11mm in boys and 24.6mmÂ±0.13mm in girls. There was a statistical difference between the mean AL in boys and girls in both eyes.
Conclusion: Axial Length is longer in boys and increases with age in a linear fashion. No significant difference is noted within the individual age groups. The study also noted that Nigerian African eyes are generally longer even as children.
KEYWORDS: Axial length, Children, B-mode Sonography, African.