Download Evidence base of the effects of smoking on the eye

Smoking and eye disease
Presentation prepared by:
Dr Colm McAlinden BSc (Hons) MSc PhD
Presentation by:
The extent of the problem
►
People associate smoking with lung cancer and cardiovascular disease
rather than eye disease
►
People fear blindness more than other smoking-related conditions
(Loo et al. Clin Exp Optom 2009;92:42Y4)
►
Only a small % of the population appreciates that smoking can lead to
irreversible vision loss
►
From a sample of the US population:
 76% believed the association to be false
 14% did not know
 9% believed the association to be true
(Kennedy et al. Optometry 2011;82:310Y7.)
Addressing the problem
►
“Optometrists are aware of the increased risks associated with smoking
but most do not assess whether their patients want to stop smoking or
provide support for cessation”
(Kennedy et al. OVS 2011;88:766Y71.)
►
“They do not believe it is their role, do not have enough time or forget
to ask” (Thompson et al. OPO 2007;27:389Y93.)
Smoking cessation is not routinely
discussed with patients during eye
examinations
Eye conditions linked with
smoking
►
Age Related Macula Degeneration
►
Cataract
►
Retinal Vein Occlusion
►
Ocular Surface Disease
►
Glaucoma
►
Exacerbation of Diabetic Retinopathy
►
Strabismus and Refractive Error
►
Thyroid Eye Disease
►
Others including:-Leber’s optic neuropathy, Non-arteritic ischemic
optic neuropathy, pterygium
Age-related macular
degeneration (AMD)
►
Widely accepted modifiable risk factor for AMD
(Smith et al. Ophthalmology 2001;108:697-704)
►
Pooled data from North America, Europe and
Australia, obtained from the Beaver Dam Eye
Study, the Rotterdam Study and the Blue mountains Eye Study, on
14,752 participants, disclosed a three-fold increased risk of any type
of AMD associated with current active smoking.
►
The magnitude of risk was higher for neovascular (OR, 4.55; CI,
2.74-7.54) compared with atrophic AMD (OR, 2.56; 1.26-5.20).
►
Thornton et al. and colleagues reviewed 17 AMD studies finding 13
studies demonstrating a statistically significant association between
smoking and AMD (Thornton et al. Eye 2005;19:935-44)
Suggested mechanisms in AMD
►
Oxidative damage to the retina
(Espinosa-Heidmann et al. IOVS 2006;47:729-37)
►
Reduction of macular pigment (Hammond et al. Vision Res 1996;36:30039) which normally protects the retina from oxidative damage
►
Experimental models of choroidal neovascularization (CNV), indicate that
nicotine increases the size and severity of the CNV (Suner et al. IOVS
2004;45:311-7)
►
The effects of smoking are influenced by the presence of specific gene
polymorphisms: complement factor H (CFH) gene Y402H and the
LOC387715 A69S gene (increased risk 2-5.5 times, smoking increased
further)
Suggested mechanisms in AMD
►
Nicotine activates retinal phospholipase A2 and the subsequent
formation of arachidonic acid (a precursor of the pro-inflammatory
mediators prostaglandins and leukotrienes) which increases
inflammation and is thus implicated in the pathogenesis of AMD
►
Smoking may also reduce the choroidal blood flow which would
increase the susceptibility of the macula to degenerative changes
(Klein. AJO 2007 Dec;144(6):961-969)
►
Experimentally, nicotine increases plasma VEGF hence linked with
neovascular AMD (Zhu et al. Cancer Cell 2003;4:191-6)
Cataract
►
Cigarette smoking is a well established
modifiable risk factor for the development
of age-related cataract:
 AREDS Report No. 5. Ophthalmology 2001;108:1400-8.
 Blue Mountains Eye Study. Arch Ophthalmol 1997;115:1296-303.
 Beaver Dam eye study. Ophthalmic Epidemiol 1999;6:247-55.
►
Nuclear > posterior subscapsular > cortical
Cataract
►
Proposed induction by oxidative damage to the lens with subsequent
accumulation of reactive oxygen species
(Bhuyan et al. Curr Eye Res 1984;3:67-81)
►
Cigarette smoke contains large amounts of iron and copper (MussaloRauhamaa et al. Arch Environ Health 1986;41:49-55). Iron may reduce
oxygen to more toxic oxygen free radicals with the subsequent
oxidative damage (Avunduk et al. Arch Ophthalmol 1999;117:1368-72)
►
Hypothesised that smoking could cause cataracts by increasing the
temperature of the lens
(Blue Mountains Eye Study. Arch Ophthalmol 1997;115:1296-303)
Retinal vein occlusion (RVO)
►
Risk factors include: age, hypertension, arteriosclerosis, diabetes
mellitus, hyperlipidaemia, vascular cerebral stroke, blood
hyperviscosity, thrombophilia, raised IOP, changes in the retinal
arteries.
►
Recent meta-analysis found that smoking also increases the risk of
RVO (Kolar. J Ophthalmol;2014:724780.)
Ocular surface disease
►
Smoking increases dry eye symptoms
►
Smoking known to reduce tear break-up time, change the lipid layer of
the tear film, reduce basal tear secretion, reduce corneal and
conjunctival sensitivity
►
Also increased risk for the development of conjunctival squamous
metaplasia
►
In smokers, contact lens-wearers have an increased risk of developing
corneal infiltrates and a three fold increased risk of ulcerative keratitis
(Lois et al. BJO (2008 Oct;92(10):1304-10)
Glaucoma
►
Two large cohort studies found no increased risk of glaucoma with
smoking
 Kang et al. Am J Epidemiol 2003;158:337–346
 Quigley et al. Arch Ophthalmol 2001;119:1819 –1826.
►
Meta-analysis by Bonovas et al.
found an increased risk of primary
open-angle glaucoma and current
smoking on primary open-angle
glaucoma (Bonovas et al. Public
Health 2004;118:256 –261)
Diabetic retinopathy
►
Smoking would be expected to result in a higher incidence of
diabetic retinopathy because it leads to increased platelet
aggregation and tissue hypoxia, factors hypothesized to be involved
in the pathogenesis of diabetic retinopathy
►
Although data from the majority of
epidemiological studies show no
relationship between cigarette smoking
and the incidence or progression of
diabetic retinopathy.
►
Regardless, diabetic patients should
be advised not to smoke because of
an increased risk of morbidity and
mortality
Refractive error & strabismus
►
Stone et al (IOVS 2006;47:4277-87):
 Children of smoking parents (one or both) had more hyperopic
mean refraction than those of non-smokers
 Smoking by either parent during pregnancy was associated with
more hyperopic mean refraction as well as strabismus
►
Findings supported by previous publications in the literature:
 Hakim et al. Arch Ophthalmol 1992;110:1459-62
 Saw et al. Br J Ophthalmol 2004;88:934-7.
Thyroid eye disease (TED)
Smoking increases the risk of developing TED by 7–8 times
► Smoking also reduces the effectiveness of treatments
► The mechanisms by which smoking affects this disease are unknown
(McAlinden. An overview of thyroid eye disease. Eye and Vision 2014, 1:9)
►
Others
►
Possible link with active cigarette smoking in other eye diseases such
as:
 Leber’s optic neuropathy
(Tsao et al. Br J Ophthalmol 1999;83:577-81)
 Non-arteritic ischemic optic neuropathy
(Chung et al. Ophthalmology 1994;101:779-82)
►
Recent meta-analysis found cigarette smoking was associated with a
reduced risk of pterygium (Rong et al. IOVS. 2014 Sep
4;55(10):6235-43)
Remember
► We
know that epidemiological studies show
smoking is a risk factor for AMD and Cataract - but
many of us are not telling our patients.
► Caution should be taken when advising
supplements to patients: patients should consult
their optometrists or GP before starting any
supplementation; in smokers particularly, they can
lead to an increased risk of lung cancer due to the
high levels of beta-carotene in most supplements.
Ref: Risk Factors for Lung Cancer and for Intervention Effects
in CARET, the Beta-Carotene and Retinol Efficacy Trial.
Omenn et al; Journal of the National Cancer Institute, Vol.
88, No. 21, November 6, 1996
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Lung Cancer in Wales
A detailed analysis of population trends of incidence and
stage of diagnosis up to and including 2012. (Welsh Cancer
Intelligence and Surveillance Unit)
36 new cases of lung cancer are diagnosed each week as
a result of tobacco smoke’s effects
Lung cancer incidence and area deprivation
Lung cancer incidence rate increases steeply moving from the
least to the most deprived areas of Wales – most recently it
was two-and-a-half times higher in the most deprived areas
compared to the least deprived
There were over twice as many lung cancers in the most
deprived areas of Wales compared to the least deprived areas
in 2012
Lung cancer has the strongest association with deprivation of
all the commonest cancers
PROPORTION OF POPULATION AND PRACTICES IN WALES
0.35
0.3
0.25
0.2
PROPORTION WELSH POPULATION
0.15
PROPORTION OPHTHALMIC PRACTICES
0.1
0.05
0
Least Deprived
Next Least
Median (quintile
Next Most
Most Deprived
(quintile 1)
Deprived (quintile
3)
Deprived (quintile
(quintle 5)
2)
4)
2014 Garwood, McAlinden, Corson, PHW Optometry Team
► Across
Wales the population is almost
proportionally equal in each area of
deprivation.
► Our study shows that over 50% of Welsh
practices are located in areas of higher
deprivation.
► Quintile 4 and 5.
► The implication is that since smoking is
highest in the more deprived areas
ophthalmic practices are well situated to
provide these patients with a smoking
cessation service.
To do the best by our patients
we should all be discussing
smoking cessation!
Thank you for listening