Looking deep into retina : indirect ophthalmoscopy and fundus drawing
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Transcript of Looking deep into retina : indirect ophthalmoscopy and fundus drawing
LOOKING DEEP DOWN : EXAMINING RETINA
Dr Prachir Agarwal
Moderator : Dr Pradeep Kumar Panigrahi3/6/2013
• Indirect Ophthalmoscopy is essential for a detailed, panoramic and complete examination of the fundus
CR Keeler, A Brief History of the Ophthalmoscope, Optometry in Practice ,Vol 4 (2003) :137-45.
Introduction
1851
Direct Helmholtz
1852
Indirect
Mono-ocular Independent light source
Ruete
1861
Indirect
Binocular Independent light source
Giraud - Teulon
1951
Indirect
BinocularHeadmounted
Integrated, clinically useful
Charles Schepens
Outline
Optical principle of Indirect Ophthalmoscopy
Comparison between different lenses used
Comparison of Direct and Indirect Ophthalmoscope
Advantages & Disadvantages of Indirect Ophthalmoscope
Technique of Indirect Ophthalmoscopy & Scleral Depression
Documentation of findings (THE FUNDUS DRAWING)
Optics of Indirect Ophthalmoscopy
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
If the retina could light up….
Emmetropic eye
Image of retinaon distant surface
GTT 04
Fundamental Principle of the Indirect Ophthalmoscope
Condensing lens
Aerial image of retina
Fundamental Principle ofIndirect Ophthalmoscope
GTT 04
Viewing the aerial image with a magnifier
GTT 04
Image is Real and Inverted
The power of the condensing lens determines:
• Working distance • Magnification• Field of view
Lens Power (D)
Static Field of View*
Magnification
Working Distance from
Cornea+14 22 4.17 72 mm
+20 30 3.25 47 mm
+30 40 1.97 26mm
Comparison with Direct Ophthalmoscopy
Retinal Detachment: Principles and Practice, Third Edition Daniel A. Brinton and C. P. Wilkinson
Advantages of Indirect system
• Image not affected by the patients refractive power
• In children
• In eyes with nystagmus
• Delivery of LASER
• Binocular examination of fundus up-to the periphery.
• Large field of view allow for the panoramic view.
• Better Resolution.
• Use in operating room for cryo/scleral buckling.
• Better view in presence of media opacities.
• Increased illumination .
• Reduced distortion.
An additional advantage is that the doctor is at a distance from the patient.
• Difficult to master.
• Small movements alter significantly the size and
clarity.
• Inverted and reversed image.
• Relative lack of magnification.
Disadvantages
Technique of Indirect ophthalmoscopy
Adjusting the instrument
Positioning of the patient
The examination proper & scleral indentation
The fundus drawing
Adjustment of Eye piece, Head band
IPDIPD knob
Adequately adjusted IPD – at arms length
Adjusting IPD
Aperture setting
Filter knob
Rheostat
Technique
Ideal position of the ophthalmoscope
Axis perpendicular to the visual axis of examiner
The scope not resting on the nose of the examiner
The eyepiece as close to the examiners pupils as possible
Adequately adjusted IPD
IDEAL POSITION
Head flexed
Head Extended
Positioning the patient
• Proprioception helps patient to look in cardinal gazes
• Patient should be urged to keep the other eye open
Examination Proper
Holding the lens
Pivot
Scleral Depression Technique
Holding the depressor
• A – Patient looks down, depressor on margin of sup tarsal plate
• B – Depressor advanced into the orbit as patient looks up but no depression applied as yet
• C – Scleral depression applied gently to area of interest
Scleral Depression technique
Critical in obtaining a binocular (stereoscopic) view
Technique of indirect ophthalmoscopy
Scleral Depression technique
Video Presentation
Fundus drawing-Amsler Dubois chart
Junction of P Plicata &
P Plana
The Ora
The Equator
Fundus drawing
Tips for drawing
Disregard Sup/Inf and Temp/Nasal while drawing
What ever appears closer to the observer in the condensing lens is peripheral (anterior)
Observe the disc and follow a vessel to the periphery
Observe the macula at the end for best patient co-operation
Fundus drawing
Fundus drawing
• Right Eye – Localized RD with HST at 11° clock and Lattice at 1° clock
FUNDUS DRAWINGDraw as you see the lesion in the condensing lens
• Retinal arterioles
• Neovascularization
• Vascular anomalies
• Attached retina
• Vascular tumors
FUNDUS DRAWING – RED SOLID
• Hemorrhages ( Pre and retinal)
• Open interior of retinal breaks (tears, holes)
• Open interior of outer layer holes in retinoschisis
•
FUNDUS DRAWING – RED SOLID
• Open portion of GRT or large dialyses
• Inner portion of CRA
• Inner portion of thin areas of retina
• Open portion of retinal holes in inner layer of retinoschisis
FUNDUS DRAWING- RED CROSSED
• Detached retina
• Retinal veins
• Outlines of retinal breaks
• Outlines of ora serrata
FUNDUS DRAWING – BLUE SOLID
FUNDUS DRAWING – BLUE SOLID
• VR traction tuft
• Outline of lattice
degeneration (inner X)
• Outline of thin area of
Retina
•Inner layer of retinoschisis
•White with or without pressure (label)
•Detached parsplana epithelium anterior to separation of ora serrata
•Rolled edges of retinal tears / inverted flap in GRT (curved lines)
FUNDUS DRAWING – BLUE CROSSLINES
• Cystoid degeneration
• Outline of change in area or folds of detached retina because of shifting fluid
FUNDUS DRAWING BLUE CIRCLE/INTERRUPTED LINES
• Opacities in the media
• Vitreous hemorrhage
• Vitreous membranes
• Hyaloid ring
• IOFB
FUNDUS DRAWING- GREEN SOLID
• Retinal operculum
• Outline of elevated Neovascularisation
• Vitreous Substitute – Silicone Oil, Gas
FUNDUS DRAWING – GREEN SOLID
• Asteroid hyalosis
• Frosting or snowflakes on Retinoschisis or lattice degeneration
FUNDUS DRAWING – GREEN DOTTED
• Uveal tissue
• Pigment beneath detached retina
FUNDUS DRAWING – BROWN SOLID
• Pigment epithelial Detachment
• Choroidal melanomas
• Nevus
• Choroidal detachment
FUNDUS DRAWING- BROWN SOLID
• Edge of buckle beneath detached retina
• Outline of Posterior Staphyloma
FUNDUS DRAWING – BROWN OUTLINE
• I/R, S/R hard exudate
• S/R gliosis
• Deposits in the RPE
FUNDUS DRAWING – YELLOW SOLID
• Post-PHC /cryo retinal edema
• Substance of long & short ciliary N
• Retinoblastoma Yellow – stippled-• Drusen Yellow Crossed• Chorioretinal coloboma
FUNDUS DRAWING- YELLOW SOLID
• Hyperpigmentation as a result of previous Rx with cryo/PHC/Diathermy
• Completely Sheathed vessels
• Pigment within detached retina (Lattice, HST)
FUNDUS DRAWING- BLACK SOLID
• Pigment within choroid or pigment epithelial hyperplasia within attached retina (e.g. RP)
• Pigment demarcation line at margin of attached
and detached retina
FUNDUS DRAWING- BLACK SOLID
• Edge of buckle beneath attached retina
• Outline of CRA
FUNDUS DRAWING – BLACK OUTLINE
Thankyou