3. INTRODUCTION
• Ophthalmoscopy is a technique done to assess
the state of fundus and detect the opacities of
ocular media.
• Ophthalmoscope is the instrument used.
• Invented by Babbage in 1848.
• Reinvented by Von Helmholtz in 1850.
4. 3 METHODS
1. Distant Direct Ophthalmoscopy
2. Direct Ophthalmoscopy
3. Indirect Ophthalmoscopy
6. DISTANT DIRECT OPHTHALMOSCOPY
• It is a routine test done before Direct
Ophthalmoscopy.
• It is performed with self-illuminated
ophthalmoscope or a simple plain mirror with
hole in centre.
7. PROCEDURE
• The light is thrown into the patients eye,
sitting in a semi-dark room, from a distance of
20-25 cm.
• The features of the red glow in the pupillary
area are noted..
8. APPLICATIONS
i. To diagnose opacities in the refractive media
ii. To differentiate between mole and hole of
iris
iii. To recognize detached retina or tumour
arising from the fundus
10. PRINCIPLE
• Modern direct ophthalmoscope works on the
principle of glass plate ophthalmoscope
introduced by Helmholtz.
11. OPTICS
• A convergent beam of light is reflected into
patient’s pupil.
• The emergent rays from any point on the
patient’s fundus reach the observer’s retina
through the viewing hole in the ophthalmoscope.
• The emergent rays from the patient’s eye are
parallel and brought to focus on the retina of the
emmetropic observer when accomodation is
relaxed.
13. TECHNIQUE
• Direct ophthalmoscopy should be performed
in a semi-dark room.
• Patient is seated at a height that is
comfortable for the examiner.
• Patient is asked to look at a fixation target.
• Patients right eye should be examined by the
observer’s right eye and left with the left.
14. TECHNIQUE
• The examiner should reflect beam of light
from the ophthalmoscope into patient’s pupil.
• Once the red reflex is seen, the examiner
should move as close to the patient’s eye as
possible.
• Once the retina is focussed, details should be
examined.
15. EXAMINATION
• Examination involves
1. Inspection of the ocular media at a distance
2. Examination of the anterior segment
3. Examination of the posterior segment
• Optic nerve head, the retinal vessels, the fundus
background and macular area are examined and
then peripheral fundus is examined by
instructing the patient to look upward for
superior fundus, downward for inferior fundus…
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20. INDIRECT OPHTHALMOSCOPY
• It was introduced by Nagel in 1864.
• It is a popular method for examining of
posterior segment.
22. THE MONOCULAR INDIRECT
OPHTHALMOSCOPY
• The direct ophthalmoscope is held at arm’s
length from the patient’s eye and a
condensing lens is placed in the light path in
front of the patient’s eye.
• The examiner holds the ophthalmoscope in
the dominant hand and the condensing lens in
the non dominant hand.
23. MONOCULAR INDIRECT
OPHTHALMOSCOPY
• The examiner remains seated before the
patient 1 metre away, and throws the light
into patient’s eyes.
• Keeping the eye on the red reflex, he
interposes the condensing lens(about +13D) in
the path of the beam of light close up to the
patient’s eye, and slowly moves the lens from
the eye towards himself until the image of the
retina is seen clearly.
24. THE AMERICAN OPTICAL MONOCULAR
INDIRECT OPHTHALMOSCOPE
• It offers a compact 5x monocular indirect
ophthalmoscope that incorporates an
inverting lens system, so the examiner views
an upright, rather than an inverted image.
26. PRINCIPLE
• To make the eye high myopic by placing a
strong convex lens in front of the patient’s
eyes so that the emergent rays from an area
of the fundus are brought to focus as a real
inverted image between the lens and the
observer’s eye.
28. OPTICS
• Binocularity is achieved by reducing the
observer’s interpupillary distance(IPD) to
approximately 15mm by prisms/mirrors.
29. CHARACTERISTICS OF THE IMAGE
• The image formed in indirect ophthalmoscope
is real, inverted and magnified.
• Magnification of image depends upon the
dioptric power of the convex lens, position of
the lens in relation to the eyeball and
refractive state of the eyeball.
• About 5 times magnification is obtained with a
+13D lens.
30. TECHNIQUE
• Dilate the eyes with proparacaine and
tropicamide.
• Patient is made to lie in supine position and
instructed to keep both eyes open.
• The examiner throws the light into the patient’s
eye from an arm’s distance (with the self-
illuminated ophthalmoscope).
• Binocular ophthalmoscope with head band or
that mounted on the spectacle frame is
employed.
31. TECHNIQUE
• The condensing lens should be held so that the
convex surface faces the examiner.
• The fundus examination in begun.
• The examiner slightly tilts the condensing lens
close to the patient’s eye, he or she brings the
condensing lens away from the patient until the
patient’s pupil entirely fills the lens.
• Using +20D lens, the examiner should be about
14 to 16 inches from the condensing lens.
32. EXAMINATION
• The examiner instructs the patient to look
upward while viewing the superior fundus and
downward for inferior fundus… as in
monocular indirect ophthalmoscopy.
• The only difference is that the portion of the
fundus seen is reversed and inverted.
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35. ADVANTAGES
• Larger field of retina is visible.
• Lesser distortion of the image of the retina.
• Easy visualization of the retina anterior to the
equator, where most retinal holes and
degenerations exist.
• Gives 3-dimensional stereoscopic view of the
retina with considerable depth of focus.
• Useful in hazy media because of its bright light
and optical property.
36. DISADVANTAGES
• Magnification is lesser.
• It is impossible with very small pupils.
• Patient is usually more uncomfortable with the
intense light of indirect ophthalmoscope and
scleral indentation.
• Needs extensive practice both in technique and
interpretation.
• Reflex sneezing can occur on exposure to bright
light.
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39. REFERENCE
• THEORY AND PRACTICE OF OPTICS AND
REFRACTION
– A.K. KHURANA
• PRIMARY CARE OPTOMETRY
– THEODORE P GROSVENOR
