ICT Role in 21st Century Education & its Challenges.pptx
Gonioscopy
1. GONIOSCOPY
MADE BY : SWATI PANARA
FROM : BHARTIMAIYA COLLEGE OF
OPTOMETRY
2nd YEAR 4th SEMESTER
2. INTROUCTION
• THE TERM GONIOSCOPY WAS COINED BY
TRANTAS IN 1907.
• IT IS A CLINICAL TECHNIQUE THAT IS USED TO
EXAMINE STRUCTURE IN THE ANTERIOR
CHAMBER ANGLE.
3. PURPOSE OF GONIOSCOPY
• WHY DO I NEED PERFORM GONIOSCOPY ??
- fundamental part of comprehensive exam.
- done initially for all glaucoma patient and
suspects.
- repeated periodically for patients with angle
closure glaucoma.
4. • WHAT CAN I ACHIEVE WITH GONIOSCOPY ??
- Visualization of anterior chamber angle
- view of the peripheral iris
- differentiation between angle closure ,
occludable and secondary glaucoma.
5. • WHAT SHOULD I LOOK FOR IN GONIOSCOPY ?
- level of iris insertion
- shape and profile of peripheral iris
- estimated width of the angle approach
- degree of trabecular pigmentation
- areas of iridotrabecular apposition
6. PRINCIPLE
• The total internal reflection at the cornea occurs
because the angle of incidence of the rays from the
anterior chamber angle structure is greater than the
critical angle of the cornea – air interface , which is
approximately 46°
8. DIRECT GONIOSCOPY
• It is performed with a steep convex lens which
permits light from the angle to exit the eye
closer to the perpendicular at the lens – air
interface.
• These lenses are used with a operating
microscope.
• Direct gonioscopy is useful but fairly
impractical for routine use.
10. KOEEPE LENS
• It is the most commonly used for diagnostic
direct gonioscopy.
11. HUSKINS BARKAN’S LENS
• It is a prototype surgical goniolens used for
goniotomy.
SWAN JACOB’S LENS
• It is also used for surgical purpose..
SIEBACK GONIOLENS
• It is a tiny goniolens which floats on the
cornea.
12. RICHARDSON – SHAFFER’S LENS
• It is basically a small Koeppe lens used for
infants.
WORTH GONIOLENS
• It anchors to cornea by partial vacuum.
•
13. TECHNIQUE
• Cornea is first anaesthetized with 4%
xylocaine instilled topically.
• Ideal position – patient lying supine with the
examiner sitting on the side of the eye.
• Patient looking up , lower lip of the goniolens
is inserted below the lower lid.
• Patient is asked to look down and upper lip is
placed beneath upper lid.
14.
15. • Now the patient’s head turned towards the
examiner , the nasal lip of goniolens is slightly
raised and normal saline drops are used for
irrigation
• Now gonioscopy is performed with the patient
looking to the ceiling.
16. ADVANTAGE
• Greater flexibility
• Used in goniotomy surgery
• Used in anaesthetized patients as in infants
• Causes lesser distortion of anterior chamber
• angle becomes deep in supine position so it is
easy to see the angle.
• Panoramic view is obtained so one part of
angle could be compared with the other.
17. • Using two lenses , both eyes can be examined
simultaneously.
• Provide a straight view rather than inverted
view.
• Detailed examination of minor structure is
possible.
19. INDIRECT GONIOSCOPY
• Indirect gonioscopy uses mirrors or prism to
over come the problem of total internal
reflection.
• Moreover , it uses the slit lamp’s illumination
and magnification system to its advantage.
22. GOLDMANN THREE MIRROR
GONIOPRISM
• The mirror having inclination of 59° and
domed upper border is used for gonioscopy.
• (1) the mirror inclined at 67° is used to
examine pars plana area of ciliary body.
• (2) the mirror having inclination of 73° is used
to examine ora serrata area of peripheral
fundus.
23.
24. GOLDMANN TWO MIRROR
GONIOPRISM
• Both the mirrors are inclined at 62°
• It need to be rotated once to examine the
whole angle.
• Laser trabeculoplasty
25. GOLDMANN SINGLE MIRROR
GONIOPRISM
• The mirror is inclined at 62°
• It is prototype diagnostic gonioprism.
• It is to be rotated three times to examine the
whole angle.
26. ADVANTAGE OF GOLDMANN
GONIOPRISM
• Easy to use
• Excellent view
• Stabilizes the globe and there for can be used
in argon laser trabeculoplasty.
• Peripheral retina can be seen
• Goldman two mirror gives best In – situ view
of the angle.
27. DISADVANTAGE OF GOLDMANN
GONIOPRISM
• Curvature of lens is more than that of cornea
so a coupling material is required. it blurs
vision and fundus therefore field charting ,
direct and indirect ophthalmoscopy cannot be
done immediately after its use.
• It cannot be used for indentation gonioscopy.
• Only one mirror is there for gonioscopy so it
needs to rotated by 360°
28. ALLEN – THROPE GONIOPRISM
• It has got four prisms instead of mirror
and allows examination of the whole angle
without rotating the prisms.
30. ZEISS FOUR MIRROR GONIOPRISM
• Four identical mirrors angled at 64° which
allow examination without rotation of the
lens.
• ADVANTAGE : coupling material not required
• Easy to perform when mastered
• Indentation gonioscopy can be performed
• DISADVANTAGE : difficult to master
• Does not stabilize the globe
31.
32. POSNER LENS
• It is similar to zeiss gonioprism but is made of
plastic instead of glass and also has fixed
rather than detachable handle.
33. TOKEL GONIOPRISM
• It is a single mirror gonioprism and has got a
wider field of view.
• SUSSMAN LENS
• It is also similar to zeiss lens except that it has
no handle.
34.
35. TECHNIQUE
• Eye is anaesthetized with the topical anaesthetic
anent
• Patient who is sitting on the slit lamp is asked to
look down
• The thumb of one hand is used to retract the
upper lid.
• The lower edge of the gonioscope is placed on
the lower lid.
• Slit lamp beam is focused on the mirror that
shows the angle diametrically opposite to it.
36. ADVANTAGE
• Easier to learn.
• Faster to perform.
• Requires less instrumentation and space.
• Slit lamp provides better optics and lighting.
• Indentation gonioscopy can also be done.
• Magnified stereoscopic view of optic disc can
also be obtained.
37. DISADVANTAGE
• Comparison is not possible.
• Limited positioning of light rays.
• Difficult to perform in horizontal meridian.
• Mirror image seen , so confusing.
• Excessive pressure may open or close the
angle artefactually.
38. RECORDING
• Most posterior angle structure observed.
• Angular approach at the recess.
• Iris contour
• Amount of pigment
• to what degree the angle opens with
indentation
• Surgical alteration such as sclerectomy and
peripheral iridotomy.
39.
40. GRADING SYSTEM FOR THE ANGLE OF
ANTERIOR CHAMBER
SCHEIE’S
GRADING
SHAFFER’S
GRADING
RP CENTRE
GONIOSCOPIC
GRADING
Speath
GONIOSCOPIC
GRADING
41. SCHEIE’S GRADING
• Grade 1 narrow = hard to see over iris root
into recess
• Grade 2 narrow = ciliary body band obscured
• Grade 3 narrow = posterior trabeculum
obscured
• Grade 4 narrow = only schwalbe’s line visible.
42. SHAFFER’S GRADING SYSTEM
• Grade 0 —PARTIAL OR COMPLETE
CLOSURE
• Grade I </= 10° angle of approach
• Grade II -20° angle of approach
• Grade III 20°–35° angle of approach
• Grade IV 35°–45° angle of approach
43.
44. RP CENTRE GONIOSCOPIC GRADING
• Grade 0 = no dipping of the beam
• Grade 1 = dipping of the beam
• Grade 2 = schwalbe’s line and anterior one –
third of the trabecular meshwork visualized.
• Grade 3 = middle one – third of trabecular
meshwork visualized.
• Grade 4 = posterior one – third of trabecular
meshwork
• Grade 5 = scleral spur visualized
• Grade 6 = ciliary body band visualized
49. SCHWALBE’S LINE
• Termination of descement’s membrane
• It is marked only by a slight change in colour
from trabecular meshwork or by a faint white
line.
• Important landmark in identifying the
gonioscopic anatomy in confusing angle.
50.
51. TRABECULAR MESHWORK
• It has an anterior non pigmented trabecular
meshwork and posterior pigmented
trabecular meshwork.
52. CILIARY BODY BAND
• It is light grey or dark brown just posterior to
the scleral spur.
53. ROOT OF IRIS
• Iris contour is slightly convex or flat.
• Colour varies in different individuals.
55. CLINICAL USE OF GONIOSCOPY
• Differentiation between primary open angle
glaucoma and primary closure angle glaucoma
• To diagnose and provide a prognosis for the
congenital glaucoma.
• To diagnose secondary glaucoma and unusual
causes of glaucoma.
• For treatment
• To diagnose condition like tumours of anterior
segment , intraocular foreign body.
56. LIMITATION
• Cannot be performed in painful inflamed eyes.
• Difficult to perform in case of acute glaucoma
where eyes are painful.
57. REFERENCE
• CLINICAL PROCEDURE IN PRIMARY EYE CARE –
DAVID B. ELLIOTT
• OPTIC AND REFRACTION – A K KHURANA
• NET
• PURAB SIR’S NOTES
• COMPREHENSIVE OPHTHALMOLOGY – A K
KHURANA
• KANSKI
