The document summarizes the history and development of the ophthalmoscope, from its early crude prototype invented by Hermann von Helmholtz in 1850 to the modern version. It describes the key components and functioning of the modern ophthalmoscope, including its light source, lenses of varying diopters, and use for examining the interior structures of the eye such as the retina, optic disc, macula, and blood vessels. It also outlines the normal findings upon ophthalmoscopic examination and some common pathological conditions that can be observed, such as papilledema, pseudopapilledema, optic atrophy, and retinal abnormalities.

2. Why is it important ?

3. Hermann von
Helmholtz
In 1850, invented
the
ophthalmoscope .
Hermann
constructed a
crude instrument
made of
cardboard, glue
and glass plates
from a microscope.

4. The modern
ophthalmoscope:
Here light source
from the batteries
is reflected at 90o
using a mirror
placed in the head
portion at 45o
angle. The
examiner looks
through a hole in
the mirror that is
through the light.

5. The modern
ophthalmoscope:
The modern
ophthalmoscope is
compact,efficient
as well as durable.
It consists of a
body and head.
The body lodges
the batteries and a
rheostat for
adjusting the
intensity of light.

6. The head of the
ophthalmoscope:
The head consists
of a window for
viewing the retina,
and one for
viewing the lens
numbers and a
wheel for changing
them. Lens
numbers are
marked in black
(positive) & red
(negative)

7. The structure of
the head piece:
The head portion
contains a series of
lenses ranging
from 1 to 30
diopter which can
be selected by
turning a side
wheel & the red or
black coded
diopter can be read
out through a
window

8. 14 diopter 10 diopter 7 diopter 0 diopter -2 diopter
Choosing the appropriate lens:
The structures closer to the ophthalmoscope are best seen
using positive lenses, which are labeled with black letters. The
retina comes into focus at the 0 diopter, the cup at 2 red.

9. procedure
 Ideally should be examined in a dark room.
 Ask the patient to fix stare at an object.
 Turn on scope and set dial at 0.
 Right with right
 Begin at arms length,should see red reflex.
 Move close until optic disc is visible.
 Turn dial until disc is in focus - +/-

10. Examination- what to observe
 Media-opacity
 Optic disc – size,shape,margins,colour,cup- disc ratio
 Macula – haemorrhage.,edema,hard exudates
 Retinal blood vessels-
narrowing,tortuosity,sheathing,vascular pulsation
 General background-
hamorrhage,exudates,pigmentary
changes,vascularisation

11. The Normal Retina:
Fundus
examination
reveals the optic
disc in the center
and the
physiological cup
inside it. The
vessels are seen
emerging from the
cup region and
diverging out of
the disc
peripherally

12. Schematic view of
the retina:
The retina as seen
by
ophthalmoscope
can have the optic
disc, the macula
and the fovea. The
retinal vessels are
seen emerging
from the optic
disc, the arteries
and the veins.

13. The optic disc and
the optic cup:
These are seen, a
little to the
temporal side of
the center of the
visible retina. The
disc has clear
margins and a pink
color which is
lighter than the
surrounding
retina, the cup is
paler.

14. The fovea
centralis:
It is the slightly
more pink area
seen about two
disc spaces
temporal to the
disc margin. This
is the area which
comes into focus
when vision is
focused and it
contains only the
cones.

15. Why is the normal optic nerve pink?
 Axons surrounded by glial columns
 carry blood vessels -> red
 Nerve fibers are translucent
 Light rays are carried like fiberoptics
 rays that escape assume the pink color of the
surrounding columns
Quigley and Anderson , Am J Ophthalmol 83:709-717, 1977a

16. PAPILLOEDEMA-pathophysiology
 Raised ICP pressure on optic nerves impaired
axoplasmic flow axonal edema impaired
venous return from retina engorged capillary
and retinal veins-splinter and flame shaped h’ge
CWS- elevation of disc.

20. Other causes of disc edema
 Optic neuritis
 AION
 CRVO
 Compression of optic nerve in the orbit
 LHON
 Diabetic papillopathy
 Optic nerve infiltration.

22. Pseudopapilloedema
 Disc colour is normal
 Retinal blood vessel obscured.
 Venous pulsations present
 Disc has a lumpy app.
 Blurring of margins irregular.
 Seen in optic nerve drusen/myelinated nerve fibre

23. Psudopapilledema True Papilledema
Disc vessels obscured Disc margin vessels clear
Elevation of peripapillary Elevation confined to the
NFL disc
Small cupless disc Loss of cup late
Anamolous disc vessels (tri-, Normal vessels
quadrifurcation)
No hemorrhage or exudates NFL hemorrhage, cotton
wool spots, exudate

25. Pathology of Pallor
Pink Nerve -> Axonal damage -> Pallor
 Axons die
 Remaining astrocytes are opaque
 Rearrange at right angles to entering light
 Surround blood vessels
 Reflect light

27. OPTIC ATROPHY
PRIMARY SECONDARY
 Appears denovo or after  Destruction of ganglion
toxic,metabolic,nutrition cells secondary to deg.
al,compressive or Or inflamm. lesions of
glaucomatous insult choroid or retina.
 Chalky white  Yellow waxy
 Edges are sharply  Not sharp
outlined  Vessels attenuated
 Recession of disc  Choriortinitis,RP
 Retinal vessels normal