Cup-to-disc and arteriole-to-venule ratios in children aged 6-7 and 12-13 years.
OBJECTIVE
Little data exist detailing the normal cup-to-disc (CD) ratios and arteriole-to-venule (A/V) ratios of school age children. In addition, controversy exists in the literature regarding associations between CD and A/V ratios and visual and biometric parameters. The present study investigates the success rates of obtaining useable optic disc images from the portable Nidek Handheld Non-Mydriatic Fundus Camera (NM-200D) from school-age children and describes the distribution of CD ratios and A/V ratios in children aged 6-7 years of age and 12-13 years of age. In addition, the present study explores associations between CD and A/V ratios and a range of visual function and biometric parameters in children.


METHODS
Fundus images were obtained from 195 6-7 year old children and 227 12-13 year old children participating in a wider study of visual function in childhood (Northern Ireland Childhood Errors of Refraction Study or NICER). ImageJ software was used to obtain CD and A/V ratios from the digital images. Visual function measures and biometric parameters were also available for all participants including; cycloplegic refractive error, vision, corneal curvature, axial length, height and weight.


RESULTS
One hundred and eighty fundus images (92.3%) from the 6-7 year olds and 194 images (85.5%) from the 12-13 year olds children were considered useable. Analysis (one way anova) demonstrated statistically significant differences between CD ratios and A/V ratios between the age groups. Participants aged 12-13 years had larger CD ratios and smaller A/V ratios (mean CD ratio 0.37 ± 0.09, mean A/V ratio 0.75 ± 0.10) than 6-7 year old participants (mean CD ratio 0.30 ± 0.09, mean A/V ratio 0.78 ± 0.12). No significant associations were noted between CD ratios and A/V ratio and any visual, ocular or biometric parameters.


CONCLUSIONS
The present study provides novel normative data on CD and A/V ratios in UK school age children for clinicians in practice.
Vision Science Research Group, School of Biomedical Sciences, University of Ulster, Coleraine, UK. jf.mcclelland@ulster.ac.uk
Julie F
JF
McClelland
Lisa
L
O'Donoghue
Marta
M
McIntyre
Kathryn J
KJ
Saunders
D000293:Adolescent; D000367:Age Factors; D000704:Analysis of Variance; D001160:Arterioles / Q000033:anatomy & histology; D001699:Biometry / Q000379:methods; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D009898:Optic Disk / Q000033:anatomy & histology* / Q000098:blood supply* / Q000473:pathology; D012161:Retinal Artery / Q000033:anatomy & histology*; D012169:Retinal Vein / Q000033:anatomy & histology*; D014699:Venules / Q000033:anatomy & histology; D014786:Vision Disorders / Q000473:pathology