Gonioscopy is a technique used to examine the anterior chamber angle of the eye. It can be performed directly using a thick contact lens, or indirectly using lenses with mirrors. Direct gonioscopy allows for a panoramic view but is more difficult to learn, while indirect gonioscopy using Goldmann lenses provides better magnification and visibility of details. Gonioscopy is used to evaluate structures like the trabecular meshwork and diagnose conditions affecting the anterior chamber angle like narrow angle glaucoma.

1. GONIOSCOPY
Jemima S Hubert
Ms Jemima S Hubert, DAIO 1

2. Definition:
Gonioscopy is a clinical technique used to examine
structures in the anterior chamber angle.
Trantas, using limbal indentation in an eye with keratoglobus
in 1907, first visualized the anterior chamber angle in a living
eye and coined the term gonioscopy.
Ms Jemima S Hubert, DAIO 2

3. The normal angle of
the eye is not
visible, due to total
internal reflection of
light emanating
from the angle.
Ms Jemima S Hubert, DAIO 3

4. •Rays of light reflected from structures in the
angle,
•Strike the air-tear interface at an angle
greater than the critical angle
•Therefore, totally internally reflected.
Ms Jemima S Hubert, DAIO 4

5. Direct Gonioscopy:
•First method of gonioscope – used a very
thick contact lens
•The anterior curve of the goniolens is
such that the critical angle is not reached
Ms Jemima S Hubert, DAIO 5

6. •light rays are refracted at the contact lens-
air interface
•This allows examiner to directly see the angle
structures.
•This is called as “direct gonioscopy” and
•The lens is called as Koeppe Lens.
Ms Jemima S Hubert, DAIO 6

7. Eg
• Koeppe,
• Shaffer,
• Layden,
• Barkan,
• Thorpe,
• Swan Jacob
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8. •Examiner uses a small, portable binocular
microscope and
•A focal illuminator
Ms Jemima S Hubert, DAIO 8

9. Advantages:
•Minimal patient cooperation required
•Any quadrant can be measured.
•An erect and panoramic view.
•Can be performed on both eyes
simultaneously.
Ms Jemima S Hubert, DAIO 9

10. Disadvantages:
•Difficulty of learning technique.
•Instrumentation expensive and difficult to
obtain.
•Less magnification
•Also need for the patient to be supine.
Ms Jemima S Hubert, DAIO 10

11. •Uses:
•Surgical goniolenses used at the time of angle
surgery, e.g. goniotomy, and
•for Gonioscopy in infants for diagnostic
purposes.
Ms Jemima S Hubert, DAIO 11

12. Indirect Gonioscopy
•The light rays are reflected by a mirror/ prism
in the contact lens and
•leave the lens at nearly a right angle to the
contact lens- air interface.
Ms Jemima S Hubert, DAIO 12

13. •Eg:
•Goldmann single, and three mirror lenses,
•Zeiss four mirror lenses,
•Posner and Susmann four mirror lenses,
•Thorpe four mirror,
•Ritch trabeculoplasty lens
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14. Ms Jemima S Hubert, DAIO 14

15. •Goldmann single mirror- mirror inclined at
62 degree for gonioscopy.
•Central well- dia of 12 mm, post radius of
curvature of 7.38 mm
•Goldmann three mirror- 59 degrees
•Zeiss four mirror- all four mirrors inclined
at 64 degree.
Ms Jemima S Hubert, DAIO 15

16. Goldmann lens
•Ease in learning technique and less
expensive.
• Greater visibility of detail than with
the Koeppe technique because of
higher magnification.
Ms Jemima S Hubert, DAIO 16

17. •Better for detection of details such as
subtle neovascularization
•Stability of lens over cornea better.
•Disadvantages: Cannot perform
dynamic, or indentation Gonioscopy.
Ms Jemima S Hubert, DAIO 17

18. Four mirror lenses- Zeiss type:
•Allows quick evaluation of angle
structures.
• No coupling solution necessary.
• Enables differentiation between
•appositional (reversible) and
•synechial angle closure
Ms Jemima S Hubert, DAIO 18

19. •Disadvantages:
• Mastery of proper technique requires skill and
practice.
• Tendency to underestimate the narrowness of the
angle; it is difficult to avoid inadvertently applying
pressure to the central cornea,
• thus artificially widening the angle.
Ms Jemima S Hubert, DAIO 19

20. •Normal IOP : 10.5 - 20.5 mmHg
•Mean pressure : 15.5+/- 2.57 mmHg.
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21. • Angle structures can be visualized with gonioscope.
• Angle structures plays an important role in aqueous humor
drainage.
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22. •Ciliary body band
•Scleral spur
•Trabecular meshwork
•Schwalbe’s line
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23. Shaffer system:
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24. • 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
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28. Indications for Gonioscopy
•Shallow anterior chamber
•Open or narrow angle glaucoma
•Anterior or posterior uveitis
•Iris or ciliary body mass
•Intumescence of crystalline lens
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29. Indications for Gonioscopy
•Dislocation or subluxation of lens
•Rubeosis iridis
•Central artery or vein occlusion
•Blunt trauma – Angle recession glaucoma
•IOFB
•Any symptoms suggestive of glaucoma
Ms Jemima S Hubert, DAIO 29

30. •Scheie system:
•Grade 0- Entire angle visible as far posterior as a wide
ciliary body band
•Grade I- Last roll of iris obscures part of the ciliary body
•Grade II- Nothing posterior to trabecular meshwork visible
•Grade III- Posterior portion of trabecular meshwork hidden
•Grade IV -No structures posterior to Schwalbe’s line visible
Ms Jemima S Hubert, DAIO 30

31. •Based upon the most posterior structure visible in the angle.
•Caveats: Because this classification system does not deal
with the issue of the angle of approach and, hence,
occludability,
•the scleral spur could be visible for its entire circumference
in an eye with an occludable angle.
Ms Jemima S Hubert, DAIO 31

32. DIRECT
OPHTHALMOSCOPE
JEMIMA S HUBERT
Ms Jemima S Hubert, DAIO 32

33. •Direct Ophthalmoscope(DO)
– used to view
• the retina and
• optic disc
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36. •With accommodation relaxed, if patient
is emmetropic,
•The patients retina will be in sharp focus
to clinician
•If clinician is also emmetropic.
Ms Jemima S Hubert, DAIO 36

37. •If patient or clinician
•Not emmetropic or
•Not relaxing accommodation,
•Compensatory lenses needs to be used
to get a clear image.
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38. •A series of auxillary lenses – built into DO
•To compensate refractive error of
•Patient and
•Clinician
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39. •If examiner is emmetropic
•Patient has +3.00DS,
•Examiner will require +3.00Ds lens to see
clearly.
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40. Uses of DO
•Inspection of ocular media
•Examination of anterior segment of the eye
•Examination of posterior segment of the eye
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41. Inspection of ocular media
•With patient fixating distant target,
•With no lens in peep hole,
•Examiner inspects ocular media at 20 to 25
inches
•Opacities in media like cortical cataract -
detected
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42. Examination of anterior segment of the
eye
•Can be evaluated
•With +8D or +10D in the peephole,
•At a distance of 4 to 5 inches
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43. Examination of posterior segment of
the eye
•Examiner gradually reduces the amount of
lens power
•While focussing on the internal structures of
the eye -
•Lens
•Vitreous
•Retina.
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45. •When retina is seen,
•Optic nerve head
•Retinal vessels and
•Macula
•Should be clearly visible .
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46. •Once optic nerve head is visualised,
• the examiner should follow the blood vessels
•Examining the macula – in the end
•To avoid too much constriction of pupil.
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48. •Peripheral fundus – can be evaluated
•Instruct the patient to look in the direction
corresponding to the portion of fundus to be
examined.
•Eg.
•To examine superior fundus, patient – should
look up
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49. •To get a good field of view,
•Instrument should rest against examiner’s
brow &
•As close as possible to patient’s eye
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50. •Fixation target of the instrument – used to
measure eccentric fixation
•Red free filter – used to view blood vessels
•Slit beam – useful for examining contours
like cup-disc margin
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52. •Patient - seated in a comfortable position
• Ask patient to look at something straight ahead
•Dim light in the room, so patients pupils dilate a
little.
Ms Jemima S Hubert, DAIO 52

53. •Generally viewed without dilation.
•Mydriatic eye drops can be used to dilate the
pupil
•At about 30cm distance with light on eye, locate
red reflex (seen as an orange glow in the pupil)
Ms Jemima S Hubert, DAIO 53

54. •Follow red reflex into the eye
•at 15 degrees lateral to the patients line of vision,
this will get you directly into the optic disc
• If you cannot find the disc, trace any blood vessels
back to it
• Examine vessels in all 4 quadrants of eye (upper
and lower nasal and temporal quadrants)
Ms Jemima S Hubert, DAIO 54

55. •Identify macula – slightly darker pigmented
area,
•2 optic disc widths lateral away from the
optic disc
• Ask patient to look at the light – this will put
the macula in focus.
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56. • DO: 15x magn in emmetrope
• Reduced field of view
Ms Jemima S Hubert, DAIO 56

57. • Reference:
• AAO
• Borish
• Pco
• Cpo
• https://www.youtube.com/watch?v=-iuumsGWo6k
• Direct ophthalmoscope video – but some errors-not accurate
• More points in David Elliots pg 295
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