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: ) ► 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, ) compared with atrophic AMD (OR, 2.56; ). ► 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: ) 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 LOC A69S gene (increased risk 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): ) ► 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:  Blue Mountains Eye Study. Arch Ophthalmol 1997;115:  Beaver Dam eye study. Ophthalmic Epidemiol 1999;6: ► 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 (Mussalo- Rauhamaa 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: ) ► Hypothesised that smoking could cause cataracts by increasing the temperature of the lens (Blue Mountains Eye Study. Arch Ophthalmol 1997;115: )

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: )

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): )

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: ):  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:  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 Sep 4;55(10): )

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

► Trending news ► Lung Cancer in Wales ► A detailed analysis of population trends of incidence and stage of diagnosis up to and including (Welsh Cancer Intelligence and Surveillance Unit) ► 36 new cases of lung cancer are diagnosed each week as a result of tobacco smoke’s effects 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

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