advantages of indirect ophthalmoscopy, optical principle, fundus drawing

1. Dr Prachir Agarwal
Moderator : Dr Pradeep Kumar Panigrahi
3/6/2013

2. • 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 Binocular
Headmounted
Integrated, clinically useful Charles Schepens

3. 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)

4. 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

5. If the retina could light up….
Emmetropic
eye
Image of retina
on distant surface
GTT 04
Fundamental Principle of the
Indirect Ophthalmoscope

6. Condensing lens
Aerial image of retina
Fundamental Principle of
Indirect Ophthalmoscope
GTT 04

7. Viewing the aerial image with a magnifier
GTT 04

8. Image is Real and Inverted

9. 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

10. Comparison with Direct Ophthalmoscopy
Retinal Detachment: Principles and Practice, Third Edition Daniel A. Brinton and C. P. Wilkinson

11. 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.

12. • 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.

13. • Difficult to master.
• Small movements alter significantly the size and clarity.
• Inverted and reversed image.
• Relative lack of magnification.
Disadvantages

14. Technique of Indirect ophthalmoscopy
 Adjusting the instrument
 Positioning of the patient
 The examination proper & scleral indentation
 The fundus drawing

15. Adjustment of Eye piece, Head band

16. IPD
IPD knob

17. Adequately adjusted IPD – at arms length
Adjusting IPD

18. Aperture setting

19. Filter knob

20. Rheostat

21. 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

22. IDEAL
POSITION
Head flexed
Head Extended
Positioning the patient

23. • Proprioception
helps patient to look
in cardinal gazes
• Patient should be
urged to keep the
other eye open
Examination Proper

24. Holding the lens
Pivot

25. Scleral Depression Technique
 Holding the depressor

26. • 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

27. Critical in obtaining a binocular (stereoscopic) view
Technique of indirect ophthalmoscopy

28. Scleral Depression technique

29. Video Presentation

30. Fundus drawing-Amsler Dubois chart
Junction of
P Plicata &
P Plana
The Ora
The Equator

31. Fundus drawing

32.  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

33. Fundus drawing
• Right Eye – Localized RD with HST at 11 clock and Lattice at 1 clock

34. FUNDUS DRAWING
Draw as you see the lesion in the
condensing lens

35. • Retinal arterioles
• Neovascularization
• Vascular anomalies
• Attached retina
• Vascular tumors
FUNDUS DRAWING – RED SOLID

36. • Hemorrhages
( Pre and retinal)
• Open interior of
retinal breaks
(tears, holes)
• Open interior of
outer layer holes in
retinoschisis
•
FUNDUS DRAWING – RED SOLID

37. • 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

38. • Detached retina
• Retinal veins
• Outlines of retinal
breaks
• Outlines of ora
serrata
FUNDUS DRAWING – BLUE SOLID

39. FUNDUS DRAWING – BLUE SOLID
• VR traction tuft
• Outline of lattice
degeneration (inner X)
• Outline of thin area of
Retina

40. •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

41. • Cystoid degeneration
• Outline of change in
area or folds of
detached retina
because of shifting
fluid
FUNDUS DRAWING
BLUE CIRCLE/INTERRUPTED LINES

42. • Opacities in the media
• Vitreous hemorrhage
• Vitreous membranes
• Hyaloid ring
• IOFB
FUNDUS DRAWING- GREEN SOLID

43. • Retinal operculum
• Outline of elevated
Neovascularisation
• Vitreous Substitute –
Silicone Oil, Gas
FUNDUS DRAWING – GREEN SOLID

44. • Asteroid hyalosis
• Frosting or
snowflakes on
Retinoschisis or
lattice degeneration
FUNDUS DRAWING – GREEN DOTTED

45. • Uveal tissue
• Pigment beneath
detached retina
FUNDUS DRAWING – BROWN SOLID

46. • Pigment epithelial
Detachment
• Choroidal
melanomas
• Nevus
• Choroidal
detachment
FUNDUS DRAWING- BROWN SOLID

47. • Edge of buckle
beneath detached
retina
• Outline of
Posterior
Staphyloma
FUNDUS DRAWING – BROWN OUTLINE

48. • I/R, S/R hard
exudate
• S/R gliosis
• Deposits in the
RPE
FUNDUS DRAWING – YELLOW SOLID

49. • Post-PHC /cryo
retinal edema
• Substance of long
& short ciliary N
• Retinoblastoma
Yellow – stippled-
• Drusen
Yellow Crossed
• Chorioretinal
coloboma
FUNDUS DRAWING- YELLOW SOLID

50. • Hyperpigmentation as a
result of previous Rx
with cryo/PHC/Diathermy
• Completely Sheathed
vessels
• Pigment within detached
retina (Lattice, HST)
FUNDUS DRAWING- BLACK SOLID

51. • 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

52. • Edge of buckle
beneath attached
retina
• Outline of CRA
FUNDUS DRAWING – BLACK OUTLINE