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Explore the impact of tobacco on eye health, focusing on cataracts & age-related macular degeneration, with insights on smoking cessation benefits.
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TOBACCO AND THE AGING EYE (CATARACTS AND AGE-RELATED MACULAR DEGENERATION) Mini Lecture 2 Module: Tobacco and Sensory Organs
Objectives of the Mini Lecture GOAL OF MINI LECTURE: Provide students with knowledge about the relationship between tobacco use and cataracts and macular degeneration. LEARNING OBJECTIVES Students will be able to: • List the eye diseases impacted by tobacco use • Understand how tobacco causes different types of eye diseases • Understand the importance of smoking cessation in reducing the risk of eye diseases
Contents Core slides • Global Epidemiology: Blindness • Epidemiology: Blindness (Indonesia) • Epidemiology: Blindness (India) • Impact of Smoking on the Eye • Tobacco and Cataract: Evidence from India • Smoking and Cataract: Suggested Mechanisms • Smoking Cessation and Cataract • Smoking and Age-Related Macular Degeneration (AMD) • Smoking and AMD Mechanisms • Smoking Cessation and AMD • Cessation Messages Optional slides • Cataract Management • Smoking and Graves’ Ophthalmology (GO) or Thyroid Eye Disease (TED) • Smoking and Graves’ Ophthalmology: Mechanism • Cessation and Graves’ Ophthalmology (GO) or Thyroid Eye Disease (TED)
CORE SLIDES Tobacco and the Aging Eye (Cataracts and Age-Related Macular Degeneration) Mini Lecture 2 Module:Tobacco and Sensory Organs
Global Epidemiology: Blindness • Leading cause for global disability • 45 million people in 2000; 76 million by 2020 • 135 million people have severely impaired vision in both eyes • Cataracts are the major cause of blindness • Representing 48% of global blindness.1 www.answers .com/topic/cataract 1. Foster and Resnikoff 2005
Indonesia Epidemiology: Blindness1 • National figure for blindness proportion: 0.9% • Range from: • The lowest: 0.3% (East Kalimantan Province) • The highest: 2.6% (South Sulawesi Province) • National figures for cataract in individuals aged 30>: 17.3% • Already diagnosed with cataract: 1.8% • Persons with main symptoms of cataract (blurred vision and increased sensitivity to light): 15.5% 1. RISKESDAS 2007
India Epidemiology: Blindness • India has a large cataract burden accounting for 44% of total blindness.1 • The annual incidence of cataract blindness is about 3.8 million.2 • The cost of treating all cases of cataract blindness in India is Rs. 5.3 billion.3 1. Dandona et al. 2001; 2. Vajpayee et al. 1999; 3. Shamana et al. 1998
Impact of Smoking on the Eye • Smoking is an independent and modifiable risk factor for development of a range of eye diseases, including: • Cataract • Age-related macular degeneration (AMD) • Graves’ ophthalmology (GO) or thyroid eye disease (TED).1 • Smoking is a modest risk factor for the development of nuclear cataract.2 • Current smokers are three times more likely to develop cataracts than never smokers, with the risk increasing with number of cigarettes smoked.3 1. Astbury 2006; 2. Tan et al. 2008; 3. Kelly et al. 2005
India Tobacco and Cataract:Evidence from India • Compared with never smokers, cigarette smokers had a higher prevalence of any cataract and were more likely to report a prior history of cataract surgery.1 • Smokers develop cataracts at an earlier age than non smokers.2 • Smokeless tobacco use was more strongly associated with cataracts.2 1. Krishnaiah et al. 2005; 2. Raju et al. 2006
Smoking and Cataract:Suggested Mechanisms Exact mechanism remains unclear: • Free radicals in tobacco smoke cause oxidative damage to the retina and reduce choroidal blood flow. • Oxidative stress on the lens through reduction of antioxidant levels. • Morphological and functional changes to the lens and retina by atherosclerotic and thrombotic effects on ocular capillaries. • Heavy metals in tobacco cause direct toxicity. 1. Kelly et al. 2005; 2. Astbury 2006; Krishnaiah et al. 2005
Smoking Cessation and Cataracts • Ex-smokers have lower risk of cataract, indicating beneficial impact of cessation.1 • Smoking cessation has a protective effect for cataract development.2 • Those who stopped smoking for >25 years had a 20% lower risk for cataract.3 • Promoting tobacco cessation among ophthalmic patients could contribute to significant improvements in eye health.4 1. Kelly et al. 2005; 2.Christen et al. 2000; 3. Weintraub et al. 2002; 4. Krishnaiah et al. 2005
Smoking and Age-Related Macular Degeneration (AMD) A 3-4 fold increase in risk of AMD among current smokers compared with never smokers.1 • Risk of developing any type of AMD was 2–3 times higher among smokers compared with never smokers.2 • Risk of developing neo- vascular AMD was 4 times higher among smokers compared with never smokers.3 http://topnews.us/images/Smoking-deteriorates-AMD.jpg 1. Smith et al. 2001; 2.Thornton et al. 2005; 3. Khan et al. 2006
Smoking and AMD Mechanisms Suggested mechanisms: • Reduced macular pigment and antioxidants leading to increased oxidative stress on the macula impairing its defense mechanisms. • Interference in the nutrient exchange between the retinal pigment epithelium and its blood supply. • Vascular insufficiency. 1. Smith et al. 2001; 2. Thornton et al. 2005; 3. Khan et al.2006
Smoking Cessation and AMD Cessation: • Risk of developing AMD among ex-smokers who had not smoked for 20 years was reported to be similar to never smokers, indicating benefit of cessation. historyfilms.net/health_and_wellness/index.htm 1. Smith et al. 2001; 2. Thornton et al. 2005; 3. Khan et al.2006
Cessation Messages • The general public, including teens, need to become aware of the ocular risks of cigarette smoking.1 • Importantly, even the majority of eye patients remain largely unaware of the strong link of tobacco with blindness.2 • The fear of going blind may be more motivational to help people quit smoking than health warnings and advice from ophthalmologists. Messages about blindness could potentially facilitate cessation.3 1. Moradi et al. 2007 2. Kelly et al. 2005; 3. Astbury 2006
OPTIONAL SLIDES Tobacco and the Aging Eye (Cataracts and Age-Related Macular Degeneration) Mini Lecture 2 Module: Tobacco and Sensory Organs
Cataract Management • No medical treatment exists to prevent, delay, or reverse cataract development in healthy individuals. • Cataract management: • Surgical extraction with intraocular lens implantation. • Significant health resource consumption for individuals and societies. • Modifiable risk factors such as tobacco use could potentially help in prevention. 1. Kelly et al. 2005; 2. Krishnaiah et al. 2005
Smoking and Graves’ Ophthalmology(GO) or Thyroid Eye Disease (TED) Recent metanalysis reported substantial evidence that smoking causesGO: • Smokers have 1.3 times increased risk of developing GO. • Smokers have higher risk of progression to more advanced GO. • Smokers were also more likely to experience disease progression or poorer outcome of treatment. 1. Thornton et al. 2006; 2. Pfeilschifter et al.1996
Smoking and Graves’Ophthalmology: Mechanism Suggested mechanisms: • Increase in tissue hypoxia • Alterations in immune surveillance, resulting in decreased control of naturally occurring clones of T-helper cells that are directed against thyroidal or orbital antigens • Proliferation of retro-ocular fibroblasts, causing orbital oedema www.revophth.com/index.asp?page=1_14136.htm 1. Thornton et al.2006; 2. Pfeilschifter et al.1996
Cessation and Graves’ Ophthalmology (GO) or Thyroid Eye Disease (TED) Cessation: • Ex-smokers have lower risk of developing GO than current smokers. • Response to treatment delayed and poorer among continuing smokers with GO. • Lower risk of GO in those Graves’ Disease (GD) sufferers who have quit smoking before the manifestation of GD compared to current smokers. www.revophth.com/index.asp?page=1_14136.htm 1. Thornton et al.2006; 2. Pfeilschifter et al.1996.
The most important health message a doctor can give to patients is to quit smoking.