Communityyp gy ophthalmology · Communityyp gy ophthalmology ตตวอยางัวอย าง ๑) ผ ปู วยต อกระจกท ั้ง๒ข าง สายตามองเห็นแค

Community ophthalmology y p gy

P bli H lth O hth l lPublic Health Ophthalmology

P ti f Bli dPrevention of Blindness

P i Primary eye care

Community eye care


5 questions of blindness

1. What is blindness? DEFINITION

2. How many are blind? MAGNITUDE

3. Why are people blind? ETIOLOGY

4. Why the number increase? TRENDS

5 What can we do ? CONTROL 5. What can we do ? CONTROL


WHO. Classification of visual impairment

Snellen Visual Acuity

Normal 6/6 to 6/18

Visual impairment < 6/18 to 6/60

Severe Visual impairment < 6/60 to 3/60

Blind < 3/60 to N L PBlind < 3/60 to N.L.P.


พรบ. ฟนฟสมรรถภาพคนพการลกษณะความพการ ระดบท สายตา ลานสายตา

( ) ๖/ ๘ ๖/๖ สายตาเลอนลาง (VA) ๑ ๖/๑๘ ถง ๖/๖๐ < ๓๐ ถง ๑๐ องศา

สายตาพการ (VF) ๒ < ๖/๖๐ ถง ๓/๖๐( )

ตาบอดขนท๑ ๓ < ๓/๖๐ ถง ๑/๖๐ < ๑๐ ถง ๕ องศา

ตาบอดขนท๒ ๔ < ๑/๖๐ ถง PL < ๕ องศา

ตาบอดขนท๓ ๕ N L Pตาบอดขนท๓ ๕ N.L.P.


ตวอยาง ตวอยาง

๑) ผปวย ตอกระจกทง๒ขาง สายตามองเหนแคนบนว ทง๒ขาง)

๒) ผปวยตอหนทง๒ขาง มองเหนเฉพาะตรงกลาง VA 20/20 ทง๒

ขาง

ป ไ ๓) ผปวยอบตเหตรถยนต หลงผาตดแลว ตาขวามองไมเหน ตา

ซายปกต

๔) เดกตาขนมวมาตงแตเกด มองไมเหนตวหนงสอเลย


Prevention of BlindnessPrevention of Blindness

situation 50 m Blind in 2000 worldwide

1-2% in the third world

0.31% in Thailand

estimation 180,000


Magnitude of Global Blindness

60

70

40

50

20

30 million

0

10

1975 1984 1990 1995 2000 2020


Distribution of total global blindnessg

America&Europe

rest of Asia

India

China

AfricaAfrica

Community ophthalmology y p gyWorldwide blindness

d good poorBlindness rate 0.1 - 0.4 % 0.5 -1.5 %Major causes AMD. Cataract

Glaucoma GlaucomaGlaucoma GlaucomaDR. Trachoma/scar

C it l di O h i iCongenital disease OnchocerciasisHereditary disease Vit. A deficiency

Location Posterior segment Anterior segment% Avoidable 20% 80%% Avoidable 20% 80%Etiology poorly understand usually well known


Cause of Blindness

developing country preventable/undertreatment

partial developed (0.4-0.65%)

developed complicated/untreatable

Community ophthalmology y p gyCause of worldwide blindness, year 2000

disease blind (million) % trend disease blind (million) % trend# Cataract 25 50 # Glaucoma 8 16# Glaucoma 8 16# DR. 3 6# AMD. 2 4# Corneal scar/Trachoma ? 5 10

Vit. A deficiency ? 0.5 1Onchocerciasis ? 0.5 1Leprosy ? 0.5 1 Refractive error 2 4 Refractive error 2 4 Childhood blindness 1 2Trauma 1 2Trauma 1 2Other 1.5 3


Cause of Blindness in Thailand (1994)( )

Cataract 74.65% Corneal opacity 4.93%

Glaucoma 3.52% Globe disorder 3.52%

Macular degeneration 2.82%

Vascular retinopathy 2.11%


Blindness Survey

Prevalence of Blindness

Most common

Prevalence of cataractSurvey Blindness common

causecataract

1st Survey(1983)

1.14% Cataract 47%(1983)

2nd Survey(1987)

0.58% Cataract 73%(1987)

3rd Survey(1994)

0.31% Cataract 74%(1994)

4th Survey(2006)

0.59%(LV = 1 57%)

Cataract 52%(2006) (LV = 1.57%)


Visual impairment

Weighted Prevalence

Estimated total Visual impairment

(%) numbers

Low Vision one eye 2 18% 1 369 362Low Vision one eye 2.18% 1,369,362

Low Vision both eyes 1.57% 987,993

Blindness one eye 1 59% 996 040Blindness one eye 1.59% 996,040

Blindness both eyes 0.59% 369,013

Bli d l i i Blindness one eye, low vision one eye 0.39% 242,562

Total 6.32% 3,964,9706.32% 3,964,970


Cause of Visual Impairment (Blind both Eye)

Di b ti ti thDiabetic retinopathy 2%

Optic atrophy 4%

Age-related macular degeneration

Cataract 52%

degeneration 7%

Glaucoma Refractive errors, Glaucoma 10% uncorrected aphakia

2%


Cause of Visual Impairment (Low vision both eyes)p ( y )

Significant pterygium 3%

Diabetic retinopathy 5%

Age-related macular degeneration

4%

3%

4%

Glaucoma 10%

Cataract 57%

Refractive errors, uncorrected aphakia

14%

Community ophthalmology y p gyIncreasing number of blindness

increase in population

increase in life expectancyp yinadequate eye care service

age year2000 future % increase0-4 years 900 900 00 4 years 900 900 05-19 years 1300 1300 020-64 years 3400 5000 50>64 years 400 800 100ytotal 6000 8000 33


4450

30

40/1

000

1920

prev

alen

ce/

0.8 110

p

0

0-14 15-44 45-59 60+


Primary preventionIncidence 6 million /years

Secondary preventionPrevalence

Secondary prevention

50 million

blind

Sight restoration MortalitySight restoration

1 million / year

Mortality

4 million / yearIncrease of1 million/year

Community ophthalmology Healthy y p gy

Birth controlHealth

Di

Healthy

general populationBirth control

promotionDisease

Prevention

Chronic illness

Impairment

Increase life expectancy

Medical care deathIncrease quality of life

More education

HandicapRehabilitation

More wants

More etc. HandicapRehabilitation


Primary prevention

Promotion of Community Immune

Environmental Health

Health Management


Secondary preventionSecondary prevention

screening criteriascreening criteria

morbidity/mortality prevalence natural Hxy y p

effective Rx benefit of early Rx appropriate test

Community ophthalmology y p gyStrategy approach to control of blindness

primary prevention prevent from occuringp y p p gVitamin A deficiency good nutritionTrachoma good water & sanitationTrachoma good water & sanitationRubella & Measles immunization

secondary prevention prevent loss of vision from diseasesecondary prevention prevent loss of vision from diseaseCataract surgery when vision is decreaseGlaucoma sight prevention; surgical/medicalDiabetic retinopathy sight preserving LASER treatment

tertiary prevention restore vision to a blind personCataract sight restoration in bilateral blinding cataractCorneal scar keratoplastyLow vision service visual rehabilitation


4 groups of blindness community control programsg p y p g 1. Priority&majority highly cost- effective intervention

Cataract & significant refractive error (50-67%)Cataract & significant refractive error (50 67%)2. Focal blinding disease cost-effective, prevention&treatment

Trachoma, Vitamin A deficiency etc (10-15%) Trachoma, Vitamin A deficiency etc (10 15%) Primary health care & community eye worker training

3. Complicated disease effective early treatment (by specialist)3. Complicated disease effective early treatment (by specialist)Glaucoma, Diabetic retinopathy etc (20%)community screening program & referral systemcommunity screening program & referral system

4. Blinding disease no effective prevention&treatmentaged related macular degeneration, retinitis pigmentosaaged e ated acu a dege e at o , et t s p g e tosa

congenital ocular abnormalities


Blinding eye diseases

CATARACT TRACHOMA

GLAUCOMA

DIABETIC RETINOPATHY

ONCOCERCIASIS

VITAMIN A DEFICIENCYDIABETIC RETINOPATHY VITAMIN A DEFICIENCY

Occur everywhereaffect individual

Focal diseaseaffect communityaffect individual

affect mainly adultrequires surgery

affect communitystart in children

requires medicinerequires surgeryneed an eye doctor

equ es ed c edoes not requires an eye doctor

HOSPITAL BASE COMMUNITY BASE

Community ophthalmology Primary eye care in the communityScreening

Simple Medication y p gy

P i h it l Health voluntierScreening

Simple Medication

Primary care hospital

Midlevel health personel

Health voluntierScreening

Simple Medication

& treatment

Case refer Academic support

Midl l h lth Seconary care hospital

OphthalmologistSimple Surgery

Research

Midlevel health

personelOphthalmologist

Case refer Academic support

Research

Tertiary care hospital

pp

Complicated Surgery

ResearchSubspecialty Ophthamologist Resident Research

Policy setting

Community ophthalmology Comprehensive Eye Carey p gyComprehensive Eye Care

Provincial Hospital Planning &Provincial Hospital Eye Unit

Planning &

Management Curative Services

Community Hospital

P i C U iPrimary Care Unit

Community Prevention & Promotion

Dec 08 Phnom Penh 17

Community ophthalmology y p gy1998 ประชากร จกษแพทย อตราสวน

กทม./ปรมณฑล 8,619,340 290 29,722

ภาคกลาง 8 928 252 82 108 882ภาคกลาง 8,928,252 82 108,882

ภาคตะวนออก 4,180,837 34 122,966

ใ ภาคใต 8,696,590 49 177,481

ภาคเหนอ 10,048,976 53 189,603ภาคเหนอ 10,048,976 53 189,603

ภาคอสาน 21,404,751 60 356,746

Community ophthalmology Distribution of ophthamologist in Thailandy p gySurvey in 2007 63m population 803 ophthalmologist

area ophthalmologist ratio

gov pri total

Bangkok 244 129 373 1:15171

Central 93 18 111 1:101691

Eastern 42 9 51 1:73230Eastern 42 9 51 1:73230

Southern 66 12 78 1:98124

Northern 70 9 79 1:136781

Northeastern 91 10 101 1:211169

Total 606 187 793 1:78711

Community ophthalmology y p gyBlind person years, four major condition

diti ti t d N d ti bli d condition estimated No ave. duration blind person yearscataract 25 x 5 = 125 1glaucoma 8 x 8 = 64 3DR 3 x 5 = 15 4child blindness 1.5 x 50 = 75 2

20

25

100

120

140

5

10

15

40

60

80

0

5

cataract glaucoma DR child blindness0

20

cataract glaucoma DR child blindness

Community ophthalmology y p gy6 step of problem solving paradigm

1. Define the problem

2 Measure the magnitude2. Measure the magnitude

3. Define the key determinationy

4. Decision of intervention

5. Set policy

6. Implement/evaluation

Community ophthalmology y p gyKey determination

Biological factor

genetic, age, microbiology, diseasegenetic, age, microbiology, disease

Social/culture/behavior

knowledge, fear, life style

Environment/occupationEnvironment/occupation

geographic, manpower, barrier

Community ophthalmology y p gyHealth system evaluation

Equity/Equality

Quality Quality

Efficiency

Social acceptance

Relevant

Important things are not visible to the eye.p g y

By a Fox (in “Little Prince”)

All the lonely people, y p p ,where do they come from?

All the lonely people, where do they belong?where do they belong?

“Eleanor Rigby”

( I can ) change the world( I can ) change the world.

E. Clapton

Community ophthalmology y p gyproblem solving paradigm for blinding cataract

1. Define the problem What is blinding cataract?

2. Measure the magnitude How many blinding catract 2. Measure the magnitude How many blinding catract are there in Thailand?

3. Define the key determination What is the risk?

4. Decision of intervention What will we do?

5. Set policy How will we support it?

6. Implement/evaluation How does it work?

Community ophthalmology y p gyBlinding cataract

DefinitionDefinition

Blinding 10/200 g

Cataract lens opacity must R/O other cause of blindness

Magnitude

prevalence (backlock)

incidenceincidence

Community ophthalmology y p gyKey determination for cataract

Biological factor

age, disease(DM), trauma, congenitalage, disease(DM), trauma, congenital

Social/culture/behavior

knowledge, attitude, life style, socioeconomic

Environment/occupationEnvironment/occupation

geographic, manpower, barrier, health system

Community ophthalmology y p gyCataract Decision of intervention

Screening of casesScreening of cases

community base/hospital base

health voluntier/health personel

R f l Referal system

routine/fast tract

Operation

satelite hospital/provincial hospital

routine/campaignroutine/campaign

ECCE/PE with IOL

Community ophthalmology y p gyCataract Decision of intervention

Education Education

mass media

patient

i i ltraining personel

Follow up

Ophthalmologist requirement ?

Community ophthalmology y p gyStrategies for finding the cataract blind

1. Wait for patients

Surgical camp2. Surgical camp in community

Screening clinic3. Screening clinic in community

4 S d i l t llit h it l Satellite hospital

4. Secondary surgical satellite hospital

Community based referral

5. CBR case detection in community

Community ophthalmology y p gyCataract policy setting

Target settingTarget settingwaiting timeblinding cataract operation rateblinding cataract operation rate

Supportdoctor fee per case private/governmentequipmentIOLmanpower Ophthalmologist, nurse, personel, etc.p p g , , p ,complication managementspecial supporting group ?special supporting group ?


Cataract program implement & evaluationRegistration/report

waiting timeblinding cataract operation rateregister of blindnessg

Quality assurancegood health care systemgood health care systemaudit

O h ffOther effectother health care systempersonel


Ophthalmic screening (general)p g (g )

asymtomatic early/late damageasymtomatic early/late damage

central/peripheral visioncentral/peripheral vision

monocular/binocularmonocular/binocular

l o w / h i g h r i s k a g el o w / h i g h r i s k a g e


Ophthalmic screening (special purpose)p g ( p p p )

student human rightstudent human right

driver/pilot safetydriver/pilot safety

worker efficiencyworker efficiency

etcetc.


Normal visual developmentintermittent fixation at birth

nearby face fixation 2-3 month

smooth follow near movement 3 month

full accomodation 3-4 month

onset of stereopsis 3-5 month

well distant fixation 6 month

subjective VA test 3 year

adult-type VA test 5-6 year


VA for 6 month children

C enteringg

S teadyS teady

M aintainM aintain




High risk children High risk adultg g

prematurity RD, severe ocular trauma prematurity RD, severe ocular trauma

family Hx family Hxfamily Hx family Hx

intrauterine infection one eye, age > 65intrauterine infection one eye, age > 65

systemic disease systemic diseasesystemic disease systemic disease


มค ๒๕๔๗ มการตดเชอตาแดงในneonatal

ward ทานจะทาอยางไร


๒๕๓๓ หยอด formalin ลงในตาเดกแรกเกด

๒๕๔๘ หยอด silver nitrate แลวมsevere ๒๕๔๘ หยอด silver nitrate แลวมsevere

reaction & corneal scar

How do we do to solve this problem?p


Ophthalmia Neonatorum

cause GC / Chlamydia /Chemical / Herpes simplex

prophylacis 1% Silver nitrate (solution)

1% Tetracyclin / 0.5% Erythromycin (ointment)

Providone iodine (solution)Providone iodine (solution)

ceftriaxone 125mg Erythromycin base 50mg/kg/day x14 day



Amblyopiay p

refractive error / strabismus /other refractive error / strabismus /other

1-4 % in population occlusion therapy

preschool age 4-6 year

visual screening VA / stereopsis



Amblyopic treatment


Xerophthalmia

Vitamin A deficiency

dry eye /corneal perforation Measle

nutrition breast feeding immunization

vitamin A supplement ? regular/ periodic


Keratomalacia bitot’s spotKeratomalacia bitot s spot


Trachoma

chlamydial infection

poor environment/water supply

superimpose bacterial infection flies

i i i i / i / lid ulcer trichiasis / entropian corneal ulcer/ scar


Trachoma

Rx ineffective, long course, complication, cost

topical tetracyclin / erythromycin bid x 5d/m x 6 month

aim severity population control

surgical correction of entropian



Retinopathy of Prematurityp y y

prematurity / oxygen therapy

vasoconstriction neovascularization traction RD

retrolental fibroplasia

high risk grouphigh risk group

BW < 1500 gm GA < 32 week oxygen Rx > 4 hour


Retinopathy of Prematurity

dilated fundus examination as soon as possible

Threshold ROP stage 3 plus >3 hour cont. / 8 hour sum.

Cryotherapy / laser treatment retinal surgery

follow up look for high myopic astigmatism glaucomafollow up look for high myopic astigmatism, glaucoma

amblyopic treatmentamblyopic treatment


ROP

1 2

3 4 3 4


ROP


Glaucoma ocular hypertension

increase IOP normal tension glaucoma

optic nerve damage physiologic large cupping

visual field defect

POAG PACG SOAG SACG


GlaucomaGlaucoma

Screening testScreening test

IOP Schiotz / applanation tonometry

optic nerve cupping non - stereopsis / stereopsis

visual field confrontation / Goldman perimetry / CTVF


Glaucoma

High risk group

> 40 year old DM, thyroid

HT IHD hi h iHT, IHD high myopia

family history of POAG y s o y o O G

angle recess glaucoma steroid induced glaucoma


normal





Goldman ‘s perimetry


CTVF


Retinal vascular diseaseRetinal vascular disease

Diabetic retinopathy Diabetic retinopathy

DM type1 5year after Dx

DM type2 at time of Dx

annually dilated fundus examination till Dx of DR


Diabetic retinopathy

lif ti / lif tinon - proliferative / proliferative

clinical significant macular edema ( CSME ) ?clinical significant macular edema ( CSME ) ?

LASER Rx PMP PRP vitrectomyy



CSMECSME


Aged macular degenerationAged macular degeneration

central scotoma blur vision metamorphopsiacentral scotoma blur vision metamorphopsia

non - exudative / exudative

screening test Amsler’s grid nutritional support?

LASER Rx stop smoking




Ocular trauma

workplace recreation/sport home transportation

protective device environment law individual

screening test



Disorder change in anatomy/physiology of an organ systemorgan system

Impairment functional change in organ system

Disability skill / ability of the individual

Handicap the societal/economic consequence of a disabilitydisability


• the organ the person

disorder impairment disability handicapanatomical change functional change skill /ability social /economico c c ge u c o c ge s / b y soc /eco o c

inflammation visual acuity reading extraeffort

atrophy visaul field daily living dependence

scar color vision mobility


Disorder Impairment Disability Handicap

Medical/surgicalintervention

Visual aidsadapted equipment

Social interventiontrainingintervention adapted equipment training

counselingeducationeducation


Visual rehabilitation

medical visual aid orientation/mobility trainingy g

educational blind/low vision special schoolp

social behavior, recreation, sex etc , ,

occupational p


Visual field orientation / mobilityVisual field orientation / mobility

51-70 degree normal 31-50 degree normal, use more scanning 11-30 degree near-normal, constant scanning 11 30 degree near normal, constant scanning

6 -10 degree slower, require scanning & cane3 - 5 degree use cane for detection ,vision for

identification less unreliable, use blind mobility skill NLP no visual orientation NLP no visual orientation

Community ophthalmology y p gymobility training

t li i i 3/200 ith 50 d VFtraveling vision 3/200 with > 50 degree VF< 20 degree VF orientation problem < 20 degree VF orientation problem

1) sight guide2) long cane3) dog guide4) electronic mobility device4) electronic mobility device

Community ophthalmology y p gyการนาทางคนตาบอด

๑) ผนาทาง หบแขนขางลาตว งอขอศอกเลกนอย๒) ผตาม ใชมอจบทเหนอขอศอก หางผนา๑/๒กาว๒) ผตาม ใชมอจบทเหนอขอศอก หางผนา๑/๒กาว๓) ผนาทาง เดนพอใหผตาม สามารถเดนตามทนได ๔) ผนาทาง ขยบขอศอกไปดานหลง เพอเปนสญญาณวา ทางแคบลง มปร ต วา ทางแคบลง มประต

๕) ผนาทาง คอยบอกวามสงสงเกตทสาคญ อยทใด๕) ผนาทาง คอยบอกวามสงสงเกตทสาคญ อยทใด๖) เมอจะปลอยใหผตามอยตามลาพง ควรไวทตดเกาอหรอ กาแพง


Cane

long cane foot to 1 1/2 inch above sternum bottomcontact feed back scanningno forewarning of overhead obstaclesno forewarning of overhead obstacleswhite cane sign of visual impairmentg p


dog guide

extensive training maturity & intelligence 18 60 d h lth d h i d age 18 -60, good health, good hearing and no

residual visionGerman shepherd, Golden/Labrador retriever and Boxer

F l d f d Female dogs are preferred.


Low vision care

1) diagnosis2) di l & i l t t t2) medical & surgical treatment3) analysis of visual function3) ys s o v su u c o4) problem discussion 5) low vision examination6) h i l 6) psychosocial assessment7) provision of a range of equipment7) provision of a range of equipment

Community ophthalmology y p gylow vision care

8) d ti & i t ti f ti l d i8) recommendation & instruction of optical device9) prescription9) prescription10) dispensing11) patient education12) vision & other rehabilitation service13) access to available funding sources13) access to available funding sources14) continuing eye care15) training & continuous education


Range of VA reading ability general ability

20/12 - 20/25 normal normal c reserve

20/30 - 20/60 shorter distance normal s reserve

20/80 - 20/160 near - normal near normal require aids 20/80 - 20/160 near - normal near normal require aids

20/200 -20/400 slower than normal slower than normal

20/500 -20/1000 limited reading some task c aids

20/1250 20/2500 li bl f k b i20/1250 -20/2500 unreliable few task, use substitute

NLP not possible no task p


adaptive low vision device

1) relative size device) i /i i i 2) light/illumination control

3) posture/positioning device3) posture/positioning device4) writing /communication device5) medical assistive device6) mobility assistive device7) sensory substitution device7) sensory substitution device

Community ophthalmology y p gysensory substitution device

A dit b tit tAuditory substitutetalking book/device, computer program etc.talking book/device, computer program etc.

Tactile substituteBraille, Nonbraille

Vision substituteneural prosthesisneural prosthesis

Community ophthalmology y p gyBraille

6 raised dot 3 high / 2 wide6 raised dot 3 high / 2 widegrade 1 letterggrade 2 contraction/abbreviated word grade 3 personal note taking

b tt l i i hildbetter learning in children100 word/ min but talking book 175 word/min100 word/ min but talking book 175 word/min


Optical aids

Hand-held magnifiers Stand magnifiersIll i t d ifi R di lIlluminated magnifiers Reading glassesLoupes and visors Reading telescopes oupes d v so s e d g e escopes Telescopes Video magnifiersPrisms Reverse telescopes


Hand - held magnifiers

inexpensive / familiar / easy to use

normal working distance

i imust be held steadily at an exact distance

limited viewing field make slow readinglimited viewing field make slow reading



Stand magnifiers

stand hold the lens steadily at fixed / proper distance

i i i fuse with reading glasses to obtain best focusotherwise same as Hand - held magnifiers otherwise same as Hand held magnifiers


Illuminated magnifiers

build in lighti S ifieither Hand - held or Stand magnifiers

AC / batteries / rechargeable batteriesAC / batteries / rechargeable batteriesincandescent, halogen, or fluorescent


Reading glasses

leave the hands free i fi f iwidest field of view

very close working distancevery close working distancetraining program


Loupes & Visors

small field of viewsmall field of viewheadgear cumbersome gusually inexpensive can be flipped in or flipped out


Reading telescopedifficult to use high magnification but constrict field /shallow depth of fieldhigh magnification but constrict field /shallow depth of field

arm’s length working distance mounted in lower part of a pair of glasses bioptic telescope mounted in middle part of a pair of glasses easier to usemultifocal turning end / reading capmultifocal turning end / reading cap


Telescope

the only visual aids for distance visionl / bi lmonocular / binocular

Galilean (distance) / Keplerian ( closer)G e (d s ce) / ep e ( c ose )small field of view / must be held very steadilymagnification >8X are not routinely recommended


Monocular telescopeMonocular telescope





Video magnifiersg

small video camera with a zoom closed-up lens connected with a monitor

make the image as large as necessarymake the image as large as necessaryreverse polarity may be more contrast

iexpensive



Aids for visual field loss

Prismsexpand VF awareness in loss side vision

f i / di i ti d t i iconfusing / disorienting, need trainingReverse telescopesReverse telescopes

smaller magnification but larger field

Community ophthalmology y p gyRelative size devices

Large printsharp edgesharp edgeat least 2.7 mm. height letter 18 point typeg p yphigh contrast & good opaque paper

Large print typewriters & computer


Lighting & illumination controlSunlight natural but control problemFluorescent lower contrast but fewer shadow coolerFluorescent lower contrast, but fewer shadow, coolerIncandescent more contrast, more shadow, less scatter

Neodymium sunlight improve reading performanceHalogen UV may be phototoxic, should be caution

Rheostat use to control light sourceRheostat use to control light source


Filter

control glarel t l l di t ticolor neutral gray no color distortion

green very little effect on color perceptiong y p pyellow increase contrast by absorbing scattering

blue light






Occupational healthhealth assessment

) & 1) pre & post employment exam2) exam for hazard exposure2) exam for hazard exposure3) treatment as family doctor4) emergency treatment at workplace


Occupational health

Advisory service1) prevention of occupational disease1) prevention of occupational disease2) forensic medicine3) di l t f k / i t3) medical aspect of work process / environment4) prevention of common non-occupational disease5) t i i fi t id5) training first aid6) plan for major disaster


Eye protection program

1) environment survey

2) vision screening

3) implementation of the program

4) maintenance of the program


Environment surveychemical

identify occupational hazardchemical

physical

control hazard biological

ergonomic

emergency first aid deviceemergency first aid device

accident recordaccident record


advantage of vision screening in industry1) l i f l i bl1) selection of personnel suitable2) identify visual disable transfer/rehabilitation3) improve relationship4) improve visual efficiency increase productivity4) improve visual efficiency increase productivity

reduce accidentreduce visual fatiguing

5) appropriate compensatory claim5) appropriate compensatory claim


Implementation of the program 1) elimination / control of ocular hazard

2) provision of eye protectors) p y p3) hazard zoning with warning sign4) first aid facility4) first aid facility5) lens cleaning station6) safety committee6) safety committee7) education /training


Prevention & control strategy

1) specification 2) substitution

3) segregation 4) local extract ventilation

) )5) dilution ventilation 6) personal hygiene

7) reduce time exposure 8) personal protection7) reduce time exposure 8) personal protection


Safety sign

type prohibition mandatory warning safe condition

meaning STOP MUST CAUTION way to gomeaning STOP MUST CAUTION way to go

symbol






Documents

Communityyp gy ophthalmology · Communityyp gy ophthalmology ตตวอยางัวอย าง ๑) ผ ปู วยต อกระจกท ั้ง๒ข าง สายตามองเห็นแค