an unexpected association between childhood hyperopia and parental smoking dr elaine yh wong ms...
TRANSCRIPT
An Unexpected Association between Childhood Hyperopia
and Parental Smoking
Dr Elaine YH Wong
Ms Leanne Finch
Dr Christine Chen
Dr Lionel Kowal
Background
• Effects of nicotinic antagonists on ocular growth and experimental myopiaStone RA, Sugimoto R, Gill AS, Liu J, Capehart C, Lindstrom JM
Invest Ophthalmol Vis Sci. 2001 Mar;42(3):557-65
– 1-week old chicks, injected with nicotinic antagonists – Chlorisondamine & mecamylamine
– Inhibition of ocular growth and shifting refraction toward hyperopia
Background
• Childhood myopia and parental smoking.Saw SM, Chia KS, Lindstrom JM, Tan DT, Stone RA
Br J Ophthalmol. 2004 Jul;88(7):934-7. – N=1334, 8-11 yo school children– Maternal smoking is suggestive of being
associated with hyperopic refraction in children (p=0.03; but only 1.7% of mother smoked)
– Paternal smoking is not associated with refractive error or axial length
Background
• Associations between childhood refraction and parental smoking. Stone RA, Wilson LB, Ying GS, Liu C, Criss JS, Orlow J, Lindstrom
JM, Quinn GEInvest Ophthalmol Vis Sci. 2006 Oct;47(10):4277-87.
– 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
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. 2008 Apr;115(4):678-685. – 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
The Pilot Study
• Aim– 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 0 -12 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
Associations between Childhood Refraction and Parental Smoking
Patient’s cycloplegic refraction: Right Eye: _______________________ Left Eye: ___________________________ QUESTION 1. Parents’ race (please tick): Father: Caucasian______Asian: ______ Mother: Caucasian: ______ Asian: ______ Other (please write): _____________ Other (please write): ______________ QUESTION 2. Are either of the patient’s parents long or short-sighted (tick which)? Father: hyperopic _____ Mother: hyperopic _____ myopic _______ myopic _______ unknown: _____ unknown: _____ QUESTION 3. Do either of the patient’s parents smoke? Father: yes / no / former smoker Mother: yes / no / former smoker If both parents answered no to question 3, the questionnaire is now complete. QUESTION 4. If yes, how long have you smoked for? Father 1: _______ years Mother: _______ years QUESTION 5. Did you smoke during the patient’s gestation? Father: yes / no Mother: yes / no QUESTION 6. If you have since quit, at what age was the patient when you stopped? Father: ________ years Mother: _________ years
Patient Label
Results
• N = 142 participants– Mild hyperopia (+0.25 - +1.75) = 59– Moderate hyperopia (+2.00 - +5.75) = 59– Severe hyperopia (>+6.00) = 15– Myopia = 8
• Mean age = 5.29, SD = 2.99, Range 0-12yo• 52% female• 21% mother smoke; 16% smoked during pregnancy• 26% father smoke; 32% smoked during pregnancy• 32% have either parent smoking now• 38% have parent smoking during pregnancy
Results
Adjusted for age & ethnicity
Odds Ratio 95% CI Significance
Parental Smoking 0.25 0.03-1.99 0.19
Father Smoking 1.77 0.15-20.50 0.65
Father ExSmoking 2.44 0.43-13.95 0.32
Mother Smoking 19.75 1.65-236.51 0.02
Mother ExSmoking 3.90 0.66-23.08 0.13
Gestational Smoking 2.02 0.11-36.15 0.63
Father Smoking 0.42 0.02-8.96 0.58
Mother Smoking 0.11 0.01-0.18 0.07
Refraction
Father hyperopia 0.94 0.22-3.96 0.93
Father myopia 0.59 0.21-1.68 0.32
Mother hyperopia 2.09 0.56-7.79 0.27
Mother myopia 0.32 0.13-0.80 0.02
Discussion
• 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 folds
• Mother with myopia is protective of a child having > moderate hyperopia
Discussion
• This is a biased population and a small sample• Larger study will be 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 ([email protected]) or
Elaine Wong ([email protected])