1. Dr Elaine YH Wong Ms Leanne Finch Dr Christine Chen Dr Lionel Kowal
An Unexpected Association between Childhood Hyperopia and Parental Smoking
Dr Elaine YH Wong
Ms Leanne Finch
Dr Christine Chen
Dr Lionel Kowal

2. Background
Effects of nicotinic antagonists on ocular growth and experimental myopia
Stone RA, Sugimoto R, Gill AS, Liu J, Capehart C, Lindstrom JM
Invest Ophthalmol Vis Sci Mar;42(3):557-65
1-week old chicks, injected with nicotinic antagonists – Chlorisondamine & mecamylamine
Inhibition of ocular growth and shift of refraction towards hyperopia

3. Background Childhood myopia and parental smoking.
Saw SM, Chia KS, Lindstrom JM, Tan DT, Stone RA
Br J Ophthalmol Jul;88(7):934-7.
N=1334, 8-11 yo school children
Maternal smoking ? associated with hyperopic refraction in children (p=0.03; but only 1.7% of mothers smoked)
Paternal smoking is not associated with refractive error or axial length

4. Background
Associations between childhood refraction and parental smoking.
Stone RA, Wilson LB, Ying GS, Liu C, Criss JS, Orlow J, Lindstrom JM, Quinn GE
Invest Ophthalmol Vis Sci Oct;47(10):
N=323 from tertiary paediatric clinic
If one or both parents ever smoked, their children had a lower myopia prevalence (12.4% vs. 25.4%; P = 0.004) and more hyperopic mean refractions (1.83±0.24 vs 0.96±0.27 diopters; P =0.02)
Smoking by either parent during the mother’s pregnancy had a similar effect

5. Background
Prevalence of hyperopia and associations with eye findings in 6- and 12-year-olds.
Ip JM, Robaei D, Kifley A, Wang JJ, Rose KA, Mitchell P
Ophthalmology Apr;115(4):
N = 1765 (6 yo); N = 2353 (12yo)
Maternal smoking associated with moderate hyperopia in 6 yo but not 12 yo
Smoking during pregnancy – borderline significant with moderate hyperopia (p=0.055)
Not significant when controlled for ethnicity
Moderate hyperopia is significantly associated with amblyopia, strabismus, poor stereoacuity and abnormal convergence

6. The Pilot S tudy Aim Methods
To explore the relationship between hyperopia and parental smoking in a population who present to a subspecialty strabismus practice
Methods
Patients between the age of undergoing a cycloplegic retinoscopy were recruited
A short questionnaire was administered to the accompanying parent[s]
Information regarding parental smoking status, gestational smoking status, parental refractive error and ethnicity were collected

8. Results N = 142 participants Mean age = 5.29, SD = 2.99, range 0-12y
Mild hyperopia ( ) = 59
Moderate hyperopia ( ) = 59
Severe hyperopia (>+6.00) = 15
Myopia = 8
Mean age = 5.29, SD = 2.99, range 0-12y
52% female
21% of mothers smoke; 16% smoked during pregnancy
26% of fathers smoke; 32% smoked during pregnancy
32% have either parent smoking now
38% have a parent smoking during pregnancy

9. Results
Adjusted for age & ethnicity

10. Discussion In this cohort…
Gestational smoking is NOT associated with hyperopia
Having a mother who is smoking now increases the odds of moderate to severe hyperopia (>+3 DS) by nearly 20 fold
Mother with myopia is protective of a child having > moderate hyperopia

11. Discussion This is a biased population and a small sample
A larger study is required, hopefully from sources other than a private strabismus practice
Relationship of smoking, hyperopia and strabismus will need to be explored
If anyone like to contribute patients, please contact
Lionel Kowal or
Elaine Wong