Cataract and Lens Opacity

diabetic฀patients฀was฀not฀signiicantly฀affected฀by฀additional฀smoking฀ [164] .฀Cataract฀oper- ations฀lens฀nucleus฀extraction฀in฀female฀smokers฀were฀associated฀with฀a฀risk฀of฀more฀ frequent฀complications฀ [165] .

7.2.3 Graves’ Ophthalmopathy

Graves’฀ophthalmopathy,฀a฀condition฀commonly฀encountered฀in฀hyperthyroidism,฀is฀criti- cally฀inluenced฀by฀the฀release฀of฀interleukin-1฀IL-1฀ [166] ,฀and฀smoking฀is฀known฀to฀ increase฀the฀production฀of฀IL-1,฀and฀of฀IFN-g฀and฀TNF-a฀ [166,฀167] . The฀increased฀risk฀for฀Graves’฀ophthalmopathy฀associated฀with฀cigarette฀smoking฀is฀2.4฀ CI:฀1.12–5.18,฀and฀Europeans฀have฀a฀substantially฀greater฀risk฀of฀developing฀this฀compli- cation฀than฀have฀Asians฀ [168] .฀These฀results฀are฀conirmed฀by฀a฀study฀conducted฀in฀Taiwan฀ [169] .฀Cigarette฀smoking฀also฀encourages฀the฀progression฀of฀the฀disease,฀and฀the฀effective- ness฀of฀radiotherapy฀and฀of฀glucocorticoids฀is฀reduced฀ [170] .

7.2.4 Macular Degeneration

Age-related฀macular฀degeneration฀causes฀blindness฀in฀thousands฀of฀patients,฀particularly฀in฀ the฀USA,฀and฀the฀medical฀treatment฀options฀are฀limited฀at฀best฀ [171] . It฀is฀therefore฀understandable฀that฀several฀studies฀have฀attempted฀to฀establish฀an฀asso- ciation฀with฀cigarette฀smoking.฀One฀meta-analysis฀assessed฀data฀from฀three฀studies฀con- ducted฀ in฀ 14,752฀ patients฀ with฀ age-related฀ macular฀ degeneration.฀ Since฀ the฀ population฀ originated฀from฀three฀continents,฀there฀were฀geographical฀differences฀but฀no฀gender฀differ- ences฀in฀disease฀prevalence฀ [172] .฀This฀study฀also฀clearly฀showed฀the฀harmful฀effects฀of฀ smoking฀in฀terms฀of฀the฀development฀of฀macular฀degeneration฀ [172] . The฀risk฀for฀macular฀degeneration฀has฀been฀shown฀to฀be฀associated฀with฀cigarette฀smok- ing฀ and฀ raised฀ serum฀ cholesterol฀ levels฀ [173] .฀ Compared฀ with฀ ex-smokers฀ or฀ never-฀ smokers,฀ the฀ relative฀ odds฀ for฀ age-related฀ macular฀ degeneration฀ in฀ females฀ who฀ were฀ current฀smokers฀has฀been฀reported฀as฀2.50฀95฀CI:฀1.01–6.20;฀for฀males฀it฀was฀3.29฀ 95฀CI:฀1.03–10.50.฀In฀both฀cases,฀the฀exudative฀form฀predominated฀ [174] .฀Macular฀ pigment฀density฀in฀smokers฀was฀substantially฀reduced฀compared฀with฀that฀in฀non-smokers฀ 0.16฀vs.฀0.34;฀p฀฀0.0001;฀an฀inverse฀correlation฀was฀identiied฀between฀macular฀pigment฀ density฀and฀pack-years฀of฀smoking฀ [175] .฀Investigations฀in฀6,174฀persons,฀55฀years฀and฀ older,฀have฀also฀shown฀that,฀compared฀with฀non-smokers,฀the฀risk฀for฀age-related฀macular฀ degeneration฀is฀increased฀6.6-fold฀in฀current฀smokers฀10฀pack-years฀of฀smoking฀and฀ 3.2-fold฀ in฀ ex-smokers.฀ Arteriosclerotic฀ changes฀ did฀ not฀ alter฀ the฀ association฀ between฀ smoking฀and฀macular฀degeneration฀ [176] .฀Among฀women฀who฀currently฀smoked฀the฀rela- tive฀risk฀for฀macular฀degeneration฀was฀2.4฀compared฀with฀women฀who฀had฀never฀smoked฀ [177] ,฀although฀the฀association฀was฀less฀strong฀than฀in฀men฀ [178] .฀It฀should฀be฀emphasised฀ that฀the฀risk฀for฀macular฀degeneration฀increases฀dramatically฀above฀a฀consumption฀of฀20฀ cigarettesday฀ [179] ฀ and฀ that฀ neovascularisation฀ has฀ been฀ detected฀ in฀ addition฀ [180] .฀ Recently,฀smoking฀has฀also฀been฀reported฀to฀be฀associated฀with฀hereditary฀optic฀neuropa- thy,฀a฀rare฀disease฀with฀higher฀penetrance฀in฀men฀than฀in฀women฀ [181] .

7.2.5 Glaucoma

In฀a฀comparison฀of฀83฀patients฀with฀deinite฀glaucoma,฀121฀suspected฀cases฀and฀237฀healthy฀ controls,฀the฀risk฀for฀glaucoma฀was฀found฀to฀be฀increased฀in฀current฀smokers฀OR฀com- pared฀with฀non-smokers฀=฀2.9;฀CI:฀1.3–6.6.฀However,฀this฀increased฀risk฀was฀smaller฀than฀ that฀accounted฀for฀by฀untreated฀hypertension฀OR฀=฀5.8;฀CI:฀2.2–15฀ [182] .฀Suggestive฀ associations฀were฀also฀found฀with฀family฀history฀of฀glaucoma,฀deinite฀or฀borderline฀diabe- tes฀and฀myopia.฀The฀vascular฀effects฀of฀nicotine฀were฀studied฀in฀a฀comparison฀of฀11฀glau- coma฀patients฀and฀8฀controls:฀although฀low฀velocities฀were฀slightly฀reduced,฀no฀signiicant฀ differences฀were฀detected฀ [183] . Bonovas฀et฀al.฀performed฀a฀detailed฀meta-analysis฀of฀studies฀published฀in฀peer-reviewed฀ literature฀on฀the฀role฀of฀cigarette฀smoking฀as฀a฀risk฀factor฀for฀primary฀open-angle฀glau- coma฀POAG.฀They฀analysed฀seven฀studies฀and฀reported฀summary฀odds฀ratios฀from฀a฀ ixed-effects฀model฀which฀were฀1.37฀95฀CI:฀1.00–1.87฀for฀current฀smokers฀and฀1.03฀ 95฀CI:฀0.77–1.38฀for฀past฀smokers.฀The฀authors฀concluded฀that฀current฀smokers฀are฀at฀ signiicantly฀ increased฀ risk฀ of฀ developing฀ POAG.฀ Efforts฀ should฀ be฀ directed฀ towards฀ ฀augmenting฀the฀campaign฀against฀smoking฀by฀adding฀the฀increased฀risk฀of฀POAG฀to฀the฀ better-known฀arguments฀against฀smoking฀ [184] .

7.2.6 Strabismus

A฀multicentre฀case-control฀study฀was฀conducted฀in฀377฀children฀born฀to฀mothers฀who฀ smoked.฀Examination฀of฀these฀children฀revealed฀that฀cigarette฀smoking฀was฀associated฀ with฀an฀increased฀risk฀for฀esotropia฀OR฀compared฀with฀controls฀=฀1.8;฀95฀CI:฀1.1–2.8฀ but฀not฀for฀exotropia.฀The฀association฀of฀maternal฀smoking฀throughout฀pregnancy฀and฀ esotropia฀ was฀ strongest฀ for฀ children฀ who฀ weighed฀ less฀ than฀ 2,500฀ g฀ OR฀ =฀ 8.2;฀ CI:฀ 1.1–62.7฀or฀3,500฀g฀or฀more฀at฀birth฀OR฀=฀5.6;฀CI:฀2.1–15.4.฀The฀risk฀was฀increased฀ when฀the฀mother฀also฀smoked฀after฀pregnancy฀in฀the฀presence฀of฀the฀child฀ [185] .

7.2.7 Ocular Tumours

While฀it฀is฀uncertain฀whether฀any฀causal฀relationship฀exists฀at฀all,฀an฀association฀has฀been฀ reported฀between฀cigarette฀smoking฀and฀basal฀cell฀carcinoma฀of฀the฀eyelids฀in฀women฀but฀ not฀ in฀ men฀ OR฀ =฀ 2.87฀ vs.฀ 1.30;฀ not฀ statistically฀ signiicant฀ [186] .฀ The฀ question฀ as฀ to฀ whether฀uveal฀melanomas฀are฀encouraged฀by฀smoking฀remains฀to฀be฀clariied.฀However,฀no฀ differences฀were฀reported฀between฀non-smokers฀and฀smokers฀in฀terms฀of฀progression฀within฀ 3฀years฀following฀irradiation฀ [187] .