Basic opthalmoscopy findings - presentation at www.eyenirvaan.com

1. BASIC
OPHTHALMOSCOPY
FINDINGS
Isha Dave B.Sc (Hons), M.C Optom (UK)
Practicing Optometrist and Educator
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2. The Normal Fundus
• Definition of Fundus:
– The interior of the globe as seen with an
opthalmoscope
– Limit is the orra serrata
– Direct ophthalmoscopy allows
visualisation of approx 60-70% of fundus
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4. Fundus Background
• What colour is the
retina????
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5. Fundus Background
• Orange/red background comes from:
– Light directly reflected from choroidal blood
vessels
– Light reflected from sclera and transmitted through
choroidal blood vessels
• Amount of light reflected depends on:
– Degree of pigmentation of retina
– Degree of pigmentation of choroid
• Most fundus layers are transparent and do
not contribute to appearance of fundus
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6. Types of fundus
1. Dark/Negroid
2. Medium/Caucasian
3. Light/Blonde
4. Tesselated
5. Albinotic
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7. 1. Dark/Negroid
• Heavily pigmented
RPE
• Heavily pigmented
choroid
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8. 2. Medium/Caucasian
• Normally
pigmented RPE
• Normally
pigmented choroid
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9. 3. Light/Blonde
• Lightly pigmented RPE
• Lightly pigmented choroid
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10. 4. Tessilated
• Lightly pigmented
RPE
• Normal/heavily
pigmented choroid
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11. 5. Albinotic
• Virtually no pigment
in RPE or choroid
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12. Why are some fundi more
pigmented than others?
• Age
• Race
• Hereditary
• Metabolism
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13. Optic Disc
• Definition:
– The ophthalmoscopic view of the optic nerve head
• Features:
– Size
– Shape
– Colour (NRR)
– Margins
– Cupping
– Vessels
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15. Optic Disc Cupping
• No detectable cup in 15% of eyes
• Can be measured by recording vertical
C/D ratio
• >0.2 difference between the eyes is
suspicious of glaucoma
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16. Optic Disc Vessels
• Central Retinal Artery
– Becomes and arteriole
after branching
• Central Retinal Vein
– Becomes a venule after
branching
• Cilio-retinal arteries
– Not branches of CRA,
derived from blood
vessels supplying the
choroid
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17. Optic Disc surroundings
• Elschnig’s scleral
ring
– RPE and choroid
stop short of the
disc
• Choroidal crescent
– RPE stops short of
the disc
• Peri-peripheral
pigment

18. Retinal Blood Vessels
• Two layers of capillaries:
– Superficial network in nerve fibre layer
– Deep network at junction of inner nuclear and
outer plexiform layer
– No capillaries at the fovea
• Walls of BVs are transparent
• Linear light reflex notable feature of arterioles
• Purpose of vessels
• Ocular vessel health reflects health of
circulation throughout body

19. A/V and V/A crossing
phenomena
• Generally arterioles
cross venules
• Venule dips to avoid
arteriole
• Disease induced
changes are most
noticeable at the
crossings
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20. Vessel Calibre
• Pathological changes cause arteriole
narrowing or venule thickening
• A/V ratio good indication of patholgy
– Normal = 2/3

21. Macula
• Macula is 1.5 to 2 disc
diameters temporal to
optic disc
• Horizontally oval
• Roughly same size as
the optic disc
• Foveal reflex
– Bright spot of light at
centre of macula
– Only real landmark on
healthy macula

22. Peripheral Retina

23. Peripheral Retina
• Peripheral retinal lesions:
– Size (in mm or DD)
– Location
– Shape
– Colour
– Flat/raised??
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24. Direct Vs. Indirect
Opthalmoscopy
• Direct
– Good magnification
– Good for macular
assessment
– V. useful is
assessment of media
opacities
– Real image – right
way up!
– Light and portable
• Indirect
– Stereopsis!!
– Good FOV
– Good for optic disc
and peripheral retina
assessment
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25. THANK YOU
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