SlideShare une entreprise Scribd logo
1  sur  68
INDIRECT OPHTHALMOSCOPY
Presenter : Dr. A. Soundariya
Discussant : Dr. N. Karthika
Chair Person : Dr. V. Rajalingam
History
Monocular indirect ophthalmoscope
Binocular indirect ophthalmoscope
• Optical principle
• Parts of indirect ophthalmoscope
• Lenses
• Technique
• Recording the findings
• Advantages and disadvantages
• Handling the instrument
HISTORY
• Dr. William Cumming
• “ every eye could be made luminous if the axis
from a source of illumination directed towards
a person’s eye and the line of vision of the
observer were coincident”
HISTORY
1850 Hermann von Helmholtz
Direct
ophthalmoscope
1852 Theodor Reute
Monocular
indirect
ophthalmoscope
1861 Marc Antonie Giracid
Tenlon
Binocular
indirect
ophthalmoscope
1946 Charles Louis Schepens
Modern binocular
indirect
ophthalmoscope
Early binocular indirect ophthalmoscope
Charles Schepens
Early source of illumination
Modern binocular indirect ophthalmoscope
Head mounted Spectacle mounted
MONOCULAR INDIRECT
OPHTHALMOSCOPE
Parts of monocular indirect ophthalmoscope
Indications
• Small pupils
• Uncooperative children
• Basic fundus screening
• Intolerance to bright light
Advantages
• Increased field of view
• Erect real image
Disadvantages
• Lack of stereopsis
• Limited illumination
• Fixed magnification
• Fair to good resolution
BINOCULAR INDIRECT
OPHTHALMOSCOPE
• Principle
• The principle of indirect ophthalmoscope is to
make the eye highly myopic by placing a
strong convex lens in front of the patient's eye
• When both the illuminating and reflecting
beam pass through the pupil, that area of
fundus is seen.
ILLUMINATION
ILLUMINATION
ILLUMINATION
ILLUMINATION
ILLUMINATION
IMAGE FORMATION
IMAGE FORMATION
IMAGE FORMATION
IMAGE FORMATION
IMAGE FORMATION
IMAGE FORMATION
IMAGE FORMATION
IMAGE FORMATION
IMAGE FORMATION
IMAGE FORMATION
STEREOPSIS
STEREOPSIS
GULLSTRAND’S PRINCIPLE
• Reflex free ophthalmoscope
GULLSTRAND’S PRINCIPLE
• Reflex free ophthalmoscope
BRIGHTER ILLUMINATION
• Bright and even
• Hazy media
FIELD OF ILLUMINATION
• Depends on pupil size
• Varies with refractive status of patients eye
FIELD OF VIEW
Determined by
• Observer’s pupil size
• Aperture of the condensing lens
FIELD OF VIEW
• The condensing lens is held in front of the
patient’s eye at such a distance that the
patient’s pupil and the observer’s pupil are
conjugate foci.
FIELD OF VIEW
• A reduced image of
the observer’s pupil
is therefore formed
in the subject’s
pupillary plane.
FIELD OF VIEW
• Only those rays of
light which leave the
subject’s eye via the
area of image of the
observer’s pupil can,
after refraction by
condensing lens,
enter the observer’s
pupil and be seen by
him.
FIELD OF VIEW
• Field of view also limited by the aperture or
size of the condensing lens
FIELD OF VIEW
Determined by
• Observer’s pupil size
• Aperture of the condensing lens
MAGNIFICATION
Factors affecting magnification
• Power of the condensing lens
• Viewing distance
• Patient’s refractive error
PARTS OF BINOCULAR INDIRECT
OPHTHALMOSCOPE
Filters
• Yellow filter – reduces intensity of light
• Red free filter – blood, membranes, new
vessels and retinal nerve fibre layer defects
• Blue filter – flourescein angiography
INDIRECT OPHTHALMOSCOPE LENSES
Biconvex aspheric lenses with one surface more
curved than the other.
Functions
• Acts as a condensing lens for the light coming
from illumination system
• Acts as a lens for forming an inverted ,
laterally reversed, real aerial image of retina
• The technique is called indirect because the
fundus is seen through a condensing lens
• The image is formed close to the principle
focus of the lens, between the lens and the
observer
• The power of the condensing lens determines
Retinal magnification
Field of view
Stereopsis
Power of lens
( D )
Magnification Field of view
+ 14 D 3.5 X 35 degree
+ 20 D 2.5 X 45 degree
+ 28D 1.5 X 55 degree
Uses
• 30 D - To obtain panoramic view when detail and
stereopsis are not important and used with small
pupil
• 20 D - most widely used as it provides an
adequate field of view, stereopsis and
magnification
• 14 D – useful for detailed view of macula and
optic disc; for determining elevation of retina in
shallow retinal detachment
TECHNIQUE OF INDIRECT
OPHTHALMOSCOPY
Pupil dilation
• Tropicamide 1 % and
• Phenylephrine 2.5 %
Adjusting the IDO headset
• Adjust the head band
• Adjust the IPD
• Set the light aperture
• Light filter
• Adjust the light intensity
Parts of IDO IPD Adjustment
Positioning the patient
• Patient should lie flat in a reclining chair
• Space to move freely around the head
Choosing the right lens
• Lenses available are + 14D, + 20D , + 28D,
+30D
• +20D lens is commonly used
Minimising lens distortion
• Because of the aspheric nature of lens, we
should hold the lens right side up , to
minimise distortions
Examining the patient
• Explain the procedure to the patient
• Dark room
• Make the patient lie supine
• Instruct to keep both eyes open
• Illuminate the patients pupil area by pointing
the illumination towards patient’s eye
• Interpose the condensing lens in the path of
beam of light
• Slowly move the lens away from the eye until
a clear image of retina is seen
• Examine the fundus by moving around the
patient
• Examiner should stand opposite the clock
hour position to be examined
Proprioception helps to look in different
gazes
Holding the lens
Scleral indentation
• Trantas
• Thimble depressor- Schepens
• Hand held scleral depressor
Technique of holding the depressor
RECORDING THE FINDINGS
Amsler Dubois chart Positioning of chart for drawing
FUNDUS DIAGRAM
ADVANTAGES OF INDIRECT
OPHTHALMOSCOPE
• Larger field of view
• Lesser distortion of retinal image
• Stereoscopic view
• Useful in hazy media
• Can visualize retina anterior to equator
• Vitreous can be examined
• Can be used intraoperatively
DISADVANTAGES OF INDIRECT
OPHTHALMOSCOPE
• High learning curve
• Less magnification
• Difficulty with very small pupils
• More uncomfortable to the patient
• Confusing reversed image
HANDLING
• Wipe the headband and instrument surfaces with
a cloth dampened in mild disinfectant every day
• Clean the lens by using hard contact lens cleaner
and warm water , then dry it with a soft lint - free
cloth
• Sterilise the condensing lens – placing in a cidex
solution for 5 – 10 minutes; can also autoclave
the lens in a steel chamber with perforation for
steam
• Handle the knobs gently
• Start with minimum light
• Rest when the bulb is hot
• Wire discipline
• Recharge the batteries at end of each work
day
• Keep the instrument in its case when not in
use
INDIRECT OPHTHALMOSCOPY ppt

Contenu connexe

Tendances

Tangent Screen introduction.
Tangent Screen introduction.Tangent Screen introduction.
Tangent Screen introduction.Ananta poudel
 
Humphrey visual field analyser (HVFA)
Humphrey visual field analyser (HVFA)Humphrey visual field analyser (HVFA)
Humphrey visual field analyser (HVFA)Azizul Islam
 
Indirect Ophthalmoscopy and slit lamp biomicroscopy
Indirect Ophthalmoscopy and slit lamp biomicroscopyIndirect Ophthalmoscopy and slit lamp biomicroscopy
Indirect Ophthalmoscopy and slit lamp biomicroscopyLakshmi Murthy
 
Techniques of tear film evaluation by Raju Kaiti
Techniques of tear film evaluation  by Raju KaitiTechniques of tear film evaluation  by Raju Kaiti
Techniques of tear film evaluation by Raju KaitiRaju Kaiti
 
Maddox rod and double maddox rod
Maddox rod and double maddox rodMaddox rod and double maddox rod
Maddox rod and double maddox rodAnuMusyakhwo7
 
Pentacam analysis
Pentacam analysisPentacam analysis
Pentacam analysisNikhil Rp
 
Specular microscopy
Specular microscopySpecular microscopy
Specular microscopyRuchi sood
 
Lenses in ophthalmology
Lenses in ophthalmologyLenses in ophthalmology
Lenses in ophthalmologyReshma Peter
 
Orthoptics Introduction test
Orthoptics  Introduction testOrthoptics  Introduction test
Orthoptics Introduction testPratyush Dhakal
 
ELEVATION BASED CORNEAL TOPOGRAPHY.pptx
ELEVATION BASED  CORNEAL TOPOGRAPHY.pptxELEVATION BASED  CORNEAL TOPOGRAPHY.pptx
ELEVATION BASED CORNEAL TOPOGRAPHY.pptxBipin Koirala
 
Incomitant strabismus
Incomitant strabismusIncomitant strabismus
Incomitant strabismusSheim Elteb
 
A scan ultrasonography
A scan ultrasonographyA scan ultrasonography
A scan ultrasonographySamuel Ponraj
 

Tendances (20)

Tangent Screen introduction.
Tangent Screen introduction.Tangent Screen introduction.
Tangent Screen introduction.
 
Humphrey visual field analyser (HVFA)
Humphrey visual field analyser (HVFA)Humphrey visual field analyser (HVFA)
Humphrey visual field analyser (HVFA)
 
AS-OCT
AS-OCTAS-OCT
AS-OCT
 
Direct ophthalmoscope
Direct ophthalmoscopeDirect ophthalmoscope
Direct ophthalmoscope
 
Indirect Ophthalmoscopy and slit lamp biomicroscopy
Indirect Ophthalmoscopy and slit lamp biomicroscopyIndirect Ophthalmoscopy and slit lamp biomicroscopy
Indirect Ophthalmoscopy and slit lamp biomicroscopy
 
Techniques of tear film evaluation by Raju Kaiti
Techniques of tear film evaluation  by Raju KaitiTechniques of tear film evaluation  by Raju Kaiti
Techniques of tear film evaluation by Raju Kaiti
 
JCC -Jackson Cross Cylinder
JCC -Jackson Cross CylinderJCC -Jackson Cross Cylinder
JCC -Jackson Cross Cylinder
 
Retinoscopy and its principles
Retinoscopy and its principlesRetinoscopy and its principles
Retinoscopy and its principles
 
Maddox rod and double maddox rod
Maddox rod and double maddox rodMaddox rod and double maddox rod
Maddox rod and double maddox rod
 
Pentacam analysis
Pentacam analysisPentacam analysis
Pentacam analysis
 
Specular microscopy
Specular microscopySpecular microscopy
Specular microscopy
 
Lenses in ophthalmology
Lenses in ophthalmologyLenses in ophthalmology
Lenses in ophthalmology
 
Orthoptics Introduction test
Orthoptics  Introduction testOrthoptics  Introduction test
Orthoptics Introduction test
 
Cover test.pptx
Cover test.pptxCover test.pptx
Cover test.pptx
 
ELEVATION BASED CORNEAL TOPOGRAPHY.pptx
ELEVATION BASED  CORNEAL TOPOGRAPHY.pptxELEVATION BASED  CORNEAL TOPOGRAPHY.pptx
ELEVATION BASED CORNEAL TOPOGRAPHY.pptx
 
Maddox rod n wing
Maddox rod n wingMaddox rod n wing
Maddox rod n wing
 
Incomitant strabismus
Incomitant strabismusIncomitant strabismus
Incomitant strabismus
 
Scheimpflug imaging in ophthalmology
Scheimpflug imaging in ophthalmologyScheimpflug imaging in ophthalmology
Scheimpflug imaging in ophthalmology
 
binocular single vision
binocular single visionbinocular single vision
binocular single vision
 
A scan ultrasonography
A scan ultrasonographyA scan ultrasonography
A scan ultrasonography
 

Similaire à INDIRECT OPHTHALMOSCOPY ppt

Direct & indirect ophthalmoscopy
Direct & indirect ophthalmoscopyDirect & indirect ophthalmoscopy
Direct & indirect ophthalmoscopyDR. ROHIT AGRAWAL
 
Presentation Retina.pptx
Presentation Retina.pptxPresentation Retina.pptx
Presentation Retina.pptxmahendra singh
 
Presentation Retina.pptx
Presentation Retina.pptxPresentation Retina.pptx
Presentation Retina.pptxmahendra singh
 
ppt on direct opthalmoscopy
 ppt on direct opthalmoscopy ppt on direct opthalmoscopy
ppt on direct opthalmoscopymanisaikoduri
 
Indirect ophthalmoscopy and fundus drawing
Indirect ophthalmoscopy and fundus drawingIndirect ophthalmoscopy and fundus drawing
Indirect ophthalmoscopy and fundus drawingSonali Singh
 
Looking deep into retina : indirect ophthalmoscopy and fundus drawing
Looking deep into retina : indirect ophthalmoscopy and fundus drawingLooking deep into retina : indirect ophthalmoscopy and fundus drawing
Looking deep into retina : indirect ophthalmoscopy and fundus drawingPrachir Agarwal
 
Binocular Indirect Ophthalmoscopy
Binocular Indirect OphthalmoscopyBinocular Indirect Ophthalmoscopy
Binocular Indirect Ophthalmoscopyabhishek ghelani
 
ophthalmoscopy.pptx
ophthalmoscopy.pptxophthalmoscopy.pptx
ophthalmoscopy.pptxDivya785180
 
Direct & Indirect Ophthalmoloscope.pdf
Direct & Indirect Ophthalmoloscope.pdfDirect & Indirect Ophthalmoloscope.pdf
Direct & Indirect Ophthalmoloscope.pdfmahendra singh
 
Techniques of fundus
Techniques of fundusTechniques of fundus
Techniques of fundusVinitkumar MJ
 
Slit lamp biomicroscopy
Slit lamp biomicroscopySlit lamp biomicroscopy
Slit lamp biomicroscopyHira Dahal
 
Slit Lamp Biomicroscopy.
Slit Lamp Biomicroscopy.Slit Lamp Biomicroscopy.
Slit Lamp Biomicroscopy.Mystic Dider
 
Bio optos-8-21-2011
Bio optos-8-21-2011Bio optos-8-21-2011
Bio optos-8-21-2011Aali Shree
 

Similaire à INDIRECT OPHTHALMOSCOPY ppt (20)

Direct & indirect ophthalmoscopy
Direct & indirect ophthalmoscopyDirect & indirect ophthalmoscopy
Direct & indirect ophthalmoscopy
 
Indirect Ophthalmoscopy .pptx
Indirect Ophthalmoscopy .pptxIndirect Ophthalmoscopy .pptx
Indirect Ophthalmoscopy .pptx
 
Presentation Retina.pptx
Presentation Retina.pptxPresentation Retina.pptx
Presentation Retina.pptx
 
Presentation Retina.pptx
Presentation Retina.pptxPresentation Retina.pptx
Presentation Retina.pptx
 
Ophthalmoscopy
OphthalmoscopyOphthalmoscopy
Ophthalmoscopy
 
ppt on direct opthalmoscopy
 ppt on direct opthalmoscopy ppt on direct opthalmoscopy
ppt on direct opthalmoscopy
 
Indirect ophthalmoscopy and fundus drawing
Indirect ophthalmoscopy and fundus drawingIndirect ophthalmoscopy and fundus drawing
Indirect ophthalmoscopy and fundus drawing
 
Ophthalmoscopy
OphthalmoscopyOphthalmoscopy
Ophthalmoscopy
 
Looking deep into retina : indirect ophthalmoscopy and fundus drawing
Looking deep into retina : indirect ophthalmoscopy and fundus drawingLooking deep into retina : indirect ophthalmoscopy and fundus drawing
Looking deep into retina : indirect ophthalmoscopy and fundus drawing
 
Binocular Indirect Ophthalmoscopy
Binocular Indirect OphthalmoscopyBinocular Indirect Ophthalmoscopy
Binocular Indirect Ophthalmoscopy
 
ophthalmoscopy.pptx
ophthalmoscopy.pptxophthalmoscopy.pptx
ophthalmoscopy.pptx
 
Direct & Indirect Ophthalmoloscope.pdf
Direct & Indirect Ophthalmoloscope.pdfDirect & Indirect Ophthalmoloscope.pdf
Direct & Indirect Ophthalmoloscope.pdf
 
Presentation mopb.pptx
Presentation mopb.pptxPresentation mopb.pptx
Presentation mopb.pptx
 
Techniques of fundus
Techniques of fundusTechniques of fundus
Techniques of fundus
 
Dark room tests in ophthalmology
Dark room tests in ophthalmologyDark room tests in ophthalmology
Dark room tests in ophthalmology
 
Slit lamp biomicroscopy
Slit lamp biomicroscopySlit lamp biomicroscopy
Slit lamp biomicroscopy
 
Binocular Indirect Ophthalmoscopy
Binocular Indirect OphthalmoscopyBinocular Indirect Ophthalmoscopy
Binocular Indirect Ophthalmoscopy
 
Slit Lamp Biomicroscopy.
Slit Lamp Biomicroscopy.Slit Lamp Biomicroscopy.
Slit Lamp Biomicroscopy.
 
Bio optos-8-21-2011
Bio optos-8-21-2011Bio optos-8-21-2011
Bio optos-8-21-2011
 
Direct ophthalmoscopy
Direct ophthalmoscopyDirect ophthalmoscopy
Direct ophthalmoscopy
 

Dernier

❤️Amritsar Escort Service☎️98151-129OO☎️ Call Girl service in Amritsar☎️ Amri...
❤️Amritsar Escort Service☎️98151-129OO☎️ Call Girl service in Amritsar☎️ Amri...❤️Amritsar Escort Service☎️98151-129OO☎️ Call Girl service in Amritsar☎️ Amri...
❤️Amritsar Escort Service☎️98151-129OO☎️ Call Girl service in Amritsar☎️ Amri...shallyentertainment1
 
❤️ Zirakpur Call Girl Service ☎️9878799926☎️ Call Girl service in Zirakpur ☎...
❤️ Zirakpur Call Girl Service  ☎️9878799926☎️ Call Girl service in Zirakpur ☎...❤️ Zirakpur Call Girl Service  ☎️9878799926☎️ Call Girl service in Zirakpur ☎...
❤️ Zirakpur Call Girl Service ☎️9878799926☎️ Call Girl service in Zirakpur ☎...daljeetkaur2026
 
💸Cash Payment No Advance Call Girls Kolkata 🧿 9332606886 🧿 High Class Call Gi...
💸Cash Payment No Advance Call Girls Kolkata 🧿 9332606886 🧿 High Class Call Gi...💸Cash Payment No Advance Call Girls Kolkata 🧿 9332606886 🧿 High Class Call Gi...
💸Cash Payment No Advance Call Girls Kolkata 🧿 9332606886 🧿 High Class Call Gi...India Call Girls
 
💸Cash Payment No Advance Call Girls Nagpur 🧿 9332606886 🧿 High Class Call Gir...
💸Cash Payment No Advance Call Girls Nagpur 🧿 9332606886 🧿 High Class Call Gir...💸Cash Payment No Advance Call Girls Nagpur 🧿 9332606886 🧿 High Class Call Gir...
💸Cash Payment No Advance Call Girls Nagpur 🧿 9332606886 🧿 High Class Call Gir...India Call Girls
 
👉Bangalore Call Girl Service👉📞 6378878445 👉📞 Just📲 Call Manisha Call Girls Se...
👉Bangalore Call Girl Service👉📞 6378878445 👉📞 Just📲 Call Manisha Call Girls Se...👉Bangalore Call Girl Service👉📞 6378878445 👉📞 Just📲 Call Manisha Call Girls Se...
👉Bangalore Call Girl Service👉📞 6378878445 👉📞 Just📲 Call Manisha Call Girls Se...dharampalsingh2210
 
💞 Safe And Secure Call Girls gaya 🧿 9332606886 🧿 High Class Call Girl Service...
💞 Safe And Secure Call Girls gaya 🧿 9332606886 🧿 High Class Call Girl Service...💞 Safe And Secure Call Girls gaya 🧿 9332606886 🧿 High Class Call Girl Service...
💞 Safe And Secure Call Girls gaya 🧿 9332606886 🧿 High Class Call Girl Service...India Call Girls
 
❤️Chandigarh Escort Service☎️9815457724☎️ Call Girl service in Chandigarh☎️ C...
❤️Chandigarh Escort Service☎️9815457724☎️ Call Girl service in Chandigarh☎️ C...❤️Chandigarh Escort Service☎️9815457724☎️ Call Girl service in Chandigarh☎️ C...
❤️Chandigarh Escort Service☎️9815457724☎️ Call Girl service in Chandigarh☎️ C...Rashmi Entertainment
 
💸Cash Payment No Advance Call Girls Hyderabad 🧿 9332606886 🧿 High Class Call ...
💸Cash Payment No Advance Call Girls Hyderabad 🧿 9332606886 🧿 High Class Call ...💸Cash Payment No Advance Call Girls Hyderabad 🧿 9332606886 🧿 High Class Call ...
💸Cash Payment No Advance Call Girls Hyderabad 🧿 9332606886 🧿 High Class Call ...India Call Girls
 
💸Cash Payment No Advance Call Girls Pune 🧿 9332606886 🧿 High Class Call Girl ...
💸Cash Payment No Advance Call Girls Pune 🧿 9332606886 🧿 High Class Call Girl ...💸Cash Payment No Advance Call Girls Pune 🧿 9332606886 🧿 High Class Call Girl ...
💸Cash Payment No Advance Call Girls Pune 🧿 9332606886 🧿 High Class Call Girl ...India Call Girls
 
2024 PCP #IMPerative Updates in Rheumatology
2024 PCP #IMPerative Updates in Rheumatology2024 PCP #IMPerative Updates in Rheumatology
2024 PCP #IMPerative Updates in RheumatologySidney Erwin Manahan
 
💞 Safe And Secure Call Girls Coimbatore 🧿 9332606886 🧿 High Class Call Girl S...
💞 Safe And Secure Call Girls Coimbatore 🧿 9332606886 🧿 High Class Call Girl S...💞 Safe And Secure Call Girls Coimbatore 🧿 9332606886 🧿 High Class Call Girl S...
💞 Safe And Secure Call Girls Coimbatore 🧿 9332606886 🧿 High Class Call Girl S...India Call Girls
 
❤️ Call Girls service In Panchkula☎️9815457724☎️ Call Girl service in Panchku...
❤️ Call Girls service In Panchkula☎️9815457724☎️ Call Girl service in Panchku...❤️ Call Girls service In Panchkula☎️9815457724☎️ Call Girl service in Panchku...
❤️ Call Girls service In Panchkula☎️9815457724☎️ Call Girl service in Panchku...Rashmi Entertainment
 
🍑👄Ludhiana Escorts Service☎️98157-77685🍑👄 Call Girl service in Ludhiana☎️Ludh...
🍑👄Ludhiana Escorts Service☎️98157-77685🍑👄 Call Girl service in Ludhiana☎️Ludh...🍑👄Ludhiana Escorts Service☎️98157-77685🍑👄 Call Girl service in Ludhiana☎️Ludh...
🍑👄Ludhiana Escorts Service☎️98157-77685🍑👄 Call Girl service in Ludhiana☎️Ludh...dilpreetentertainmen
 
❤️ Chandigarh Call Girls Service☎️9878799926☎️ Call Girl service in Chandigar...
❤️ Chandigarh Call Girls Service☎️9878799926☎️ Call Girl service in Chandigar...❤️ Chandigarh Call Girls Service☎️9878799926☎️ Call Girl service in Chandigar...
❤️ Chandigarh Call Girls Service☎️9878799926☎️ Call Girl service in Chandigar...daljeetkaur2026
 
💸Cash Payment No Advance Call Girls Kanpur 🧿 9332606886 🧿 High Class Call Gir...
💸Cash Payment No Advance Call Girls Kanpur 🧿 9332606886 🧿 High Class Call Gir...💸Cash Payment No Advance Call Girls Kanpur 🧿 9332606886 🧿 High Class Call Gir...
💸Cash Payment No Advance Call Girls Kanpur 🧿 9332606886 🧿 High Class Call Gir...India Call Girls
 
💞 Safe And Secure Call Girls Mysore 🧿 9332606886 🧿 High Class Call Girl Servi...
💞 Safe And Secure Call Girls Mysore 🧿 9332606886 🧿 High Class Call Girl Servi...💞 Safe And Secure Call Girls Mysore 🧿 9332606886 🧿 High Class Call Girl Servi...
💞 Safe And Secure Call Girls Mysore 🧿 9332606886 🧿 High Class Call Girl Servi...India Call Girls
 
The Events of Cardiac Cycle - Wigger's Diagram
The Events of Cardiac Cycle - Wigger's DiagramThe Events of Cardiac Cycle - Wigger's Diagram
The Events of Cardiac Cycle - Wigger's DiagramMedicoseAcademics
 
💸Cash Payment No Advance Call Girls Surat 🧿 9332606886 🧿 High Class Call Girl...
💸Cash Payment No Advance Call Girls Surat 🧿 9332606886 🧿 High Class Call Girl...💸Cash Payment No Advance Call Girls Surat 🧿 9332606886 🧿 High Class Call Girl...
💸Cash Payment No Advance Call Girls Surat 🧿 9332606886 🧿 High Class Call Girl...India Call Girls
 

Dernier (18)

❤️Amritsar Escort Service☎️98151-129OO☎️ Call Girl service in Amritsar☎️ Amri...
❤️Amritsar Escort Service☎️98151-129OO☎️ Call Girl service in Amritsar☎️ Amri...❤️Amritsar Escort Service☎️98151-129OO☎️ Call Girl service in Amritsar☎️ Amri...
❤️Amritsar Escort Service☎️98151-129OO☎️ Call Girl service in Amritsar☎️ Amri...
 
❤️ Zirakpur Call Girl Service ☎️9878799926☎️ Call Girl service in Zirakpur ☎...
❤️ Zirakpur Call Girl Service  ☎️9878799926☎️ Call Girl service in Zirakpur ☎...❤️ Zirakpur Call Girl Service  ☎️9878799926☎️ Call Girl service in Zirakpur ☎...
❤️ Zirakpur Call Girl Service ☎️9878799926☎️ Call Girl service in Zirakpur ☎...
 
💸Cash Payment No Advance Call Girls Kolkata 🧿 9332606886 🧿 High Class Call Gi...
💸Cash Payment No Advance Call Girls Kolkata 🧿 9332606886 🧿 High Class Call Gi...💸Cash Payment No Advance Call Girls Kolkata 🧿 9332606886 🧿 High Class Call Gi...
💸Cash Payment No Advance Call Girls Kolkata 🧿 9332606886 🧿 High Class Call Gi...
 
💸Cash Payment No Advance Call Girls Nagpur 🧿 9332606886 🧿 High Class Call Gir...
💸Cash Payment No Advance Call Girls Nagpur 🧿 9332606886 🧿 High Class Call Gir...💸Cash Payment No Advance Call Girls Nagpur 🧿 9332606886 🧿 High Class Call Gir...
💸Cash Payment No Advance Call Girls Nagpur 🧿 9332606886 🧿 High Class Call Gir...
 
👉Bangalore Call Girl Service👉📞 6378878445 👉📞 Just📲 Call Manisha Call Girls Se...
👉Bangalore Call Girl Service👉📞 6378878445 👉📞 Just📲 Call Manisha Call Girls Se...👉Bangalore Call Girl Service👉📞 6378878445 👉📞 Just📲 Call Manisha Call Girls Se...
👉Bangalore Call Girl Service👉📞 6378878445 👉📞 Just📲 Call Manisha Call Girls Se...
 
💞 Safe And Secure Call Girls gaya 🧿 9332606886 🧿 High Class Call Girl Service...
💞 Safe And Secure Call Girls gaya 🧿 9332606886 🧿 High Class Call Girl Service...💞 Safe And Secure Call Girls gaya 🧿 9332606886 🧿 High Class Call Girl Service...
💞 Safe And Secure Call Girls gaya 🧿 9332606886 🧿 High Class Call Girl Service...
 
❤️Chandigarh Escort Service☎️9815457724☎️ Call Girl service in Chandigarh☎️ C...
❤️Chandigarh Escort Service☎️9815457724☎️ Call Girl service in Chandigarh☎️ C...❤️Chandigarh Escort Service☎️9815457724☎️ Call Girl service in Chandigarh☎️ C...
❤️Chandigarh Escort Service☎️9815457724☎️ Call Girl service in Chandigarh☎️ C...
 
💸Cash Payment No Advance Call Girls Hyderabad 🧿 9332606886 🧿 High Class Call ...
💸Cash Payment No Advance Call Girls Hyderabad 🧿 9332606886 🧿 High Class Call ...💸Cash Payment No Advance Call Girls Hyderabad 🧿 9332606886 🧿 High Class Call ...
💸Cash Payment No Advance Call Girls Hyderabad 🧿 9332606886 🧿 High Class Call ...
 
💸Cash Payment No Advance Call Girls Pune 🧿 9332606886 🧿 High Class Call Girl ...
💸Cash Payment No Advance Call Girls Pune 🧿 9332606886 🧿 High Class Call Girl ...💸Cash Payment No Advance Call Girls Pune 🧿 9332606886 🧿 High Class Call Girl ...
💸Cash Payment No Advance Call Girls Pune 🧿 9332606886 🧿 High Class Call Girl ...
 
2024 PCP #IMPerative Updates in Rheumatology
2024 PCP #IMPerative Updates in Rheumatology2024 PCP #IMPerative Updates in Rheumatology
2024 PCP #IMPerative Updates in Rheumatology
 
💞 Safe And Secure Call Girls Coimbatore 🧿 9332606886 🧿 High Class Call Girl S...
💞 Safe And Secure Call Girls Coimbatore 🧿 9332606886 🧿 High Class Call Girl S...💞 Safe And Secure Call Girls Coimbatore 🧿 9332606886 🧿 High Class Call Girl S...
💞 Safe And Secure Call Girls Coimbatore 🧿 9332606886 🧿 High Class Call Girl S...
 
❤️ Call Girls service In Panchkula☎️9815457724☎️ Call Girl service in Panchku...
❤️ Call Girls service In Panchkula☎️9815457724☎️ Call Girl service in Panchku...❤️ Call Girls service In Panchkula☎️9815457724☎️ Call Girl service in Panchku...
❤️ Call Girls service In Panchkula☎️9815457724☎️ Call Girl service in Panchku...
 
🍑👄Ludhiana Escorts Service☎️98157-77685🍑👄 Call Girl service in Ludhiana☎️Ludh...
🍑👄Ludhiana Escorts Service☎️98157-77685🍑👄 Call Girl service in Ludhiana☎️Ludh...🍑👄Ludhiana Escorts Service☎️98157-77685🍑👄 Call Girl service in Ludhiana☎️Ludh...
🍑👄Ludhiana Escorts Service☎️98157-77685🍑👄 Call Girl service in Ludhiana☎️Ludh...
 
❤️ Chandigarh Call Girls Service☎️9878799926☎️ Call Girl service in Chandigar...
❤️ Chandigarh Call Girls Service☎️9878799926☎️ Call Girl service in Chandigar...❤️ Chandigarh Call Girls Service☎️9878799926☎️ Call Girl service in Chandigar...
❤️ Chandigarh Call Girls Service☎️9878799926☎️ Call Girl service in Chandigar...
 
💸Cash Payment No Advance Call Girls Kanpur 🧿 9332606886 🧿 High Class Call Gir...
💸Cash Payment No Advance Call Girls Kanpur 🧿 9332606886 🧿 High Class Call Gir...💸Cash Payment No Advance Call Girls Kanpur 🧿 9332606886 🧿 High Class Call Gir...
💸Cash Payment No Advance Call Girls Kanpur 🧿 9332606886 🧿 High Class Call Gir...
 
💞 Safe And Secure Call Girls Mysore 🧿 9332606886 🧿 High Class Call Girl Servi...
💞 Safe And Secure Call Girls Mysore 🧿 9332606886 🧿 High Class Call Girl Servi...💞 Safe And Secure Call Girls Mysore 🧿 9332606886 🧿 High Class Call Girl Servi...
💞 Safe And Secure Call Girls Mysore 🧿 9332606886 🧿 High Class Call Girl Servi...
 
The Events of Cardiac Cycle - Wigger's Diagram
The Events of Cardiac Cycle - Wigger's DiagramThe Events of Cardiac Cycle - Wigger's Diagram
The Events of Cardiac Cycle - Wigger's Diagram
 
💸Cash Payment No Advance Call Girls Surat 🧿 9332606886 🧿 High Class Call Girl...
💸Cash Payment No Advance Call Girls Surat 🧿 9332606886 🧿 High Class Call Girl...💸Cash Payment No Advance Call Girls Surat 🧿 9332606886 🧿 High Class Call Girl...
💸Cash Payment No Advance Call Girls Surat 🧿 9332606886 🧿 High Class Call Girl...
 

INDIRECT OPHTHALMOSCOPY ppt

Notes de l'éditeur

  1. A front runner in field of ophthalmology 1846
  2. 1851 helmhotz published the optical principles involved Reute – concave mirror with aperture Tenlon – france Earliest source of illumination candle; later lamps incorporated a reflecting mirror behind the candle and a strong convex lens in front to condense the light Reflex free ophthalmoscopy Thornerand Allvor Gullstrand 1911
  3. Intro by reute, it was designed for its use in undilated pupil, Original monocular io used an external light source reflected by a mirror held in front of observer’s eye The monocular indir method allows use of low power lenses (13d) thru which small details are seen larger Since it is monocular stereoscopic exmn not possible
  4. The emergent rays from an area of fundus are brought to focus as a real inverted image between the lens and observer’s eye
  5. Assuming the ptnt eye is emmetropic Parallel ray of light 20 D LENS covex lens Img is formed 5 cm in front of condensing lens
  6. Assuming the ptnt eye is emmetropic Parallel ray of light 20 D LENS covex lens Img is formed 5 cm in front of condensing lens Img is magnified but not as mag as in DO Img is real, inverted, laterally reversed
  7. Emmetropic eye : parallel rays – converge by condensing lens - img fomed in focal plane Myopic eye : emergent rays are converging- further converged by the condensing lens- img formed much closer to the convex lens Hypermetropic eye : emergent rays are diverging- converged by condensing- but img formed beyond the focal plane i.e, farthet from the condensing lens IMAGE FORMATION VARIES WITH REFRACTIVE STATUS
  8. NOW HOW TO VISULAISE THE IMG All we need to do is accomodation- we can see the img clearer If we ( observer ) unable to accommodate, we can use our presbyopic correction glasses/ contact lens IO has incorporated some power in ocular which we can use to focus At 1/3 rd meter : 3D accomodation needed Change of +/- 0.1D in observer’s accomodn accounts for +/- 5D in ptnt’s refrac error Thus, minor changes in examiners accomodation can easily compensate for major refractive error that ptnt may have
  9. For stereoscopic view, we should see with both eye, and also we should adjust the IPD so that both viewing beam fits into the patients pupil Normal IPD is 60 mm, reduced to 15mm by use of prism IDO
  10. Normal IPD is 60 mm, reduced to 15mm by use of prism IDO
  11. Presence of corneal reflection and usual backscattering of light from healthy cornea and lens make the evaluation difficut Gullstrand evaluated the principle . Observation and illumination beam be separated at corneal and lens plane to avoid reflection and scattering for which a DILATED PUPIL IS needed With ptnt and observer pupil conjugate , loss of light is minimized and field of view is maximised
  12. The illuminating beam and viewing beams must be totally separated through cornea , pupillary aperture and lens to avoid reflection, but must coincide on retina to permit viewing
  13. ILLUMINATION is provided by an electric lamp mounted on observers head. Light from this source is rendered convergent by the condensing lens. Thus a convergent beam enters the ptnt’s eye and is brought to a focus within the vitreous by eye’s refractive system. The light then diverges to strike the retina. The illumination is therefore bright and even, as it comes from the real mage of the light source within the ptnt’s eye.
  14. Largest in myopia , smallest in hypermetropia In all refractive states, size of subject’s pupil limits the field of illumination
  15. It is usual to dilate the ptnt’s pupil widely prior to IDO exmn , in order to increase the fied of illumination. It is not practical to dilate the observer’s pupil bcus his VA wud be impaired. This is bcus he wud suffer an increase in aberrations and l/o accomodan, the latter being particularly troublesome for low hypermetrope. Therefore a condensing lens of largest possible aperture is chosen to inc the field of view. THE lens redirects the peripheral rays towards the obsever’s eye
  16. This means that light arising from a point in subject’s pupillary plane is brought to focus by the conden lens in observer’s pupillary plane and vice versa
  17. - Image of a 4mm pupil is approx 0.7 mm
  18. Only those rays which leave the subjects eye via the image of observer pupil and which passes through the condensing lens will be seen by the observer. Therefore , field of view is determined by the observer’s pupil size and the aperture of the condensing lens
  19. It is usual to dilate the ptnt’s pupil widely prior to IDO exmn , in order to increase the fied of illumination. It is not practical to dilate the observer’s pupil bcus his VA wud be impaired. This is bcus he wud suffer an increase in aberrations and l/o accomodan, the latter being particularly troublesome for low hypermetrope. Therefore a condensing lens of largest possible aperture is chosen to inc the field of view. THE lens redirects the peripheral rays towards the obsever’s eye
  20. 1) Magnification is a function of power of the condensing lens to power of the patient’s eye. Eg: emmetropic eye (60 D) , with condensing lens of 20D= 60/20= 3X magnification In a 10 D MYOPE , 70/20 = 3.5X magnification 2) The reference point for designation of magnification is 25cm; if the image is viewed from more than 25cm, the perceived magnification decreases proportionately 3) In myopia , img size increases as the conden lens is moved towards ptnt’s eye, while in hypermetropia the img size inc if lens is moved away from ptnt’s eye
  21. Light sources : halogen light, LED ( much cooler and last longer) Battery – in examiners belt or incorpor in headband itself
  22. Yellow- offers protection to the user because of decreased inten of light entering the ptnts eye and may even offer protectn to ptnts retina or provide comfort to the patient -Red – subtle pigmentary changes
  23. Aspheric lenses – peripheral distortions reduced
  24. Condensing lens is a powerful convex lens
  25. Working dist from cornea 72mm, 47mm & 26mm respectively Stereopsis 1, ¾, ½ Mag= power of eye/power of lens; field= power of lens * 2; stereopsis= mag/4 30D lens has highest magnif DO 15X 12.5 deg 2.5 DD DD 5, 8.5,11
  26. 28D viewing pathology near ors serrata is easier with 28D. It has magnificn of around 2.2 times but offers a larger dynamic field of view of 69 degree
  27. Nowadays lenses are coming with antireflective coating i.e yellow filter within , to reduce blue light ( blue light causes scaterring and glare )
  28. To conduct a good peripheral exmn, the ptnts eye must b well dilated. Use both tropicamide and phenylephrine. Ptns with dark colored iris may need more than one set.
  29. So that scope is secure on your head and height of the beam so you can see a full beam with each eye Set light aperture to the largest spot for a fully dilated pupil, use the smallest aperture for small pupils and intraocular gas Filter – generally we use white light filter. A diffuser can improve the field of view and is softer and more comfortable to the ptnt to allow yourself a clear view while attempting to make the ptnt comfortable
  30. 20 D double aspheric lens has magnificn upto 3 times. Used to evaluate macula and periphery. Dynamic field of view is 60 degree 28D viewing pathology near ors serrata is easier with 28D. It has magnificn of around 2.2 times but offers a larger dynamic field of view of 69 degree
  31. The silver line should be towards the patient , so that the surface with steeper curvature is towards the examiner- to decrease the aberrations Move the lens in and out to focus and refine the view Aspheric – means two different curved surfaces to avoid spherical abertn
  32. Start with lower illumin and slowly incr the illum
  33. Proprioception helps ptnt to look in diff gazes Rest the frree fingers on ptnts cheek or forehead Less convex side towards patnt Gently tilt the lens to avoid disturbing reflexes Held at 5cm from ptnt Distance from the eye = focal length of the lens
  34. Eg: to examine the inf quadrant, we shld stand at head end i.e at 12 o clock and ask the ptnt to look DOWN By asking the ptnt to look in extreme gaze and by using the scleral indenter the whole periphery upto ora can be examined
  35. Schocket scleral depressor, Cotton tip applicator Done with dep placed over lid This helps in making the barely perceptible lesions more prominent, can better appreciate the dif ts color and densities Most sensi part is superonasal quadrant
  36. Should move the dep in a direction opp to that in which examiner wishes to the dep to appear Scl dep shld be rolled gently and tangentially over the surf
  37. Img seen in ido is inverted and laterally reversed The chart is placed upside down i.e 12 o clock of chart placed towards feet so that the img fields can be visually translated directly onto the paper without having to mentally invert them
  38. 1) 10 fold increase in area of retina visible as compared to dir ophthalmoscope 2) 3)With considerable depth perception 4) Bcus of its bright light and optical ppty. As IDO is a larger instrument there is more scope for fitting more powerful light sources 5) Where most retinal holes and degenerations exist 6) Various vitreous abn can be diagnosed 7) Bcus it is used at a distance whch slows to preserve a sterile operative field Laser energy can be delivered thro the ido to effect retinal photocoagln
  39. 1) 2) In comparison with DO 3) 4) Due to intense light and scleral indentation 5 expensive
  40. Make sure the instru is switched off before is kept in case