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Gonioscopy.new
1. Gonioscopy
Dr. N.suneel ,MS
1st year
Dept of ophthalmology
2. Introduction
• Definition:
• Why gonioscopy is underutilized?
• How frequently we should do gonioscopy?
• Indications:
• Contraindications:
3. ANATOMY OF ANGLE OF ANTERIOR CHAMBER
• Structures from posterior to anterior
anterior surface of iris
ciliary band
scleral spur
trabecular meshwork
schwalbe’s line
posterior surface of
cornea
4. principle
• Critical angle .
• Total internal reflection .
• Eliminates corneal-air interface
• Direct and indirect gonioscopy
5. Direct gonioscopy
Koeppe lens Barkan lens
• Prototype diagnostic • Prototype surgical lens
lens
Richard son - shaffer Thorpe lens
• Small koeppe lens • Surgical and diagnostic lens
• For use in children • For operating room
Layden Swan – jacob lens
• For premature infants . • Surgical goniolens for use in
Worst gonio lens children.
6. Indirect gonioscopy
Goldmann Goldmann Modified
single mirror three mirror goldmann
Mirror :62 1 for angle No viscous bridge,
Antereflection
2 for fundus coating for laser
trab
7. Zeiss type
Zeiss four mirror
• Mirror:64
• Require unger/holder
Posner four mirror
• Modified zeiss with
attached handle
Sussman four mirror
• Handheld zeiss type
gonioprism
8. Thorpe four mirror
• Mirror 62
• Require fluid bridge
Ritch trabeculoplasty
• Four gonioscopy mirrors:59:2 ;62:2
• Convex lens over 2
Latina trabeculoplasty
• One mirror for trabeculoplasty
11. Indentation gonioscopy
• By changing amount of
pressure on cornea one
can observe effect on
angle width.
• Appositional vs PAS .
• Platue iris syndrom
• Phacomorphic glaucoma
12. Normal angle landmarks
first find the scleral
spur for rapid orientation
(1) pupil border
(2) peripheral iris
(3) ciliary body band
observe the 6 in order (4) scleral spur
(5) trabecular meshwork
(6) Schwalbe's line
if unable to find , look at
another region
13. Angle width
• Estimated by examining the distance between
schwalbe’s line and nearest part of iris .
• If angle between iris and TM is 20 to 45 deg :wide ,
<20 deg :narrow
• Angle :wide/open/narrow/closed :
irregular narrowing : subacute angle closure glaucoma
dislocation of lens,cycts,
posterior adhesions plus pupillary block
Irregular widening :traumatic recession ,
dislocation of lens,cyclodialysis
14. Pupil &iris
• looking at pupillary border also helpfull for
orientation .
• Dandruff like flekens at pupillary margin :t/o PXF .
• Glaucoma flekens ,post synechiae can be seen in ante surface of lens.
contour
iris Site of insertion
Angulation b/w iris &cornea
Neovascularization , hypoplasia , atrophy , polycoria .
16. Ciliary body band
Very light gray -------------------- N in white race
C
O
Darker gray,traces of brown -- N in dark races
L Darker, slate gray ---------------- melanoma.
O Whitish, cobwebby ------------- tear into muscle
U
R
Scleral white
cleft behind the S spur---------- cyclodailysis
W Narrower --------------hyperopics , PAS ,
I
D
Unusually narrow--- congenital glaucoma
T Wider -------------------myopics, tear into CB
H cyclodialysis
17. Scleral spur
• Grey white line of varying width,this white colour makes it
most helpful landmark for rapid orientation .
Spur all visible ------------------------open angle
Spur hidden---------------------------uveal meshwork
excessively narrow angle
closed angle
synechias
Unusually prominent and white--torn uvealmeshwork,
ciliary muscle torn,
cyclodialysis
18. Uveal meshwork
• Proper identification avoid confusion with PAS and IP .
Homogenous, Network of
transperant gray/brown strands
,glittering of variable amount
,unpigmented
•IP:long slender isolated strands that stands out away
from uveal meshwork
•Greater amount nasally .
19. Trabecular meshwork
• Normal variable :covered by uveal meshwork
blood in schlemn canal
• Charecteristic : filteration area finely granular
translucent with or without pigment.
• Abnormalities: execessive pigmentation
inflammatory exudates
blood vessels
synechias
loss of normal textures
traumatic rupture
Congenital abnormalities : posterior embryotoxon (reiger)
iridocorneal malformations
20. Schwalbe’line
• Translucent white ledge that projects slightly in AC
• Corneal parallelepiped of tha slitlamp beam comes together
at this point .
• Sampaolesi ‘s line and posterior embryotoxon
21. Vessels in angle
Radial vessels in iris
Normal Sea serpent type circumferrential vessel on CB
Short and strait vessels seen on CB
Erratic course,branch and arborised on
Abnormal vessels to angle wall ,stands out as solid cords ,
may pull the iris to TM
Congenitally
Congenital glaucoma,axenfield’s syndrom
abnormal vessels
22. IRIS PROCESSES PAS
• Thread like fibers of uveal • Adherence of iris to angle
tissue structures
• Thin Network of strands, • Solid and broad
porus
• Structures behind seen • Structures behind unseen
• Height : usually SS • Height : varies
• Peripheral iris tissue wrap • Peripheral iris tissue butts
around angle recess flat against TM
• Blood vessel -ve • Blood vessel +/_
• Pigmentation - /+ ve • Pigmentation +
23. •Should be differentiated from uveal meshwork
•More on inferiorly and nasally.
•Dens band whole circumference:EXF
PDS,
Pigmentation in angle pig.glaucoma
•Scattered ,lower parts:previous
SX,inflammation,
hyphema
•Black fine ,coarse balls:old blood
Fresh blood :bright red ,
Blood in angle old blood : black particals and balls
Organised clot :synechial filling of angle
•Particles ,inflammatory exudates and foreign bodies
24. Recording gonio findings
• Simple discriptive words are more helpful than using
numericals .
• Three features :post most structure
pigmentation
iris pattern
• Any abnormalities should be noted
25. Grading of chamber angle
Scheie grading shaffer system spaeth system
• Scheie system: most posterior structure visible.
• Shaffer’s system : assess geometric angle width in 4 grades .
angle potential for occlusion.
• Spaeth system : three dimentional structure of angle -
-level of iris insertion and peripheral iris configuration.
26. Shaffer’ s system
• records the angle in degrees of arc subtended by the inner
surface of the trabecular meshwork and the anterior surface
of iris, about one-third of the distance from its periphery.
• assigns a numerical grade to each angle with associated
anatomical description, the angle width in degrees and
implied clinical interpretation.
20
10
25-35
35-45
27. Grading of Angle width
Shaffer’s system
Angle grade Degrees Numeric grade Clinical Interpetation
wide open 30 -45 3-4 closure impossible
Narrow angle 20 2 closure possible
(moderate)
Narrow angle 10 1 closure possible
(extreme) eventually
slit angle <10 s portions appear
closed
Closed angle 0 closure present
28. Spaeth classification
• A complex grading system that captures detailed three
dimensional information in coded form .
• High correlation with UBM and biometric gonioscopy.
• Interobserver variability - minimal .
• Addresses : 1.site of iris insertion .
2.angle width.
3.config of peripheral iris.
4.trabecular meshwork pigmentation.
5.presence/absence of abnormalities.
• Grading is made at four cardinal points of angle .
29. Difficulties and artifacts
• Koeppe lens --- narrow the angle
• Zeiss lens ----- widen the angle by indentation
• Ideal pressure of gonioscopy.
• Dimlight provacaton test:
• Coreal edema : lower IOP ,
oral/topicalhyperosmotics
epithelial debridment
• Cornea guttata : pebbled ,shagreen appearance
against white sclera,,
easier with gonio than slitlamp
30. miscellaneous
• Biometric gonioscopy
• Retroillumination:
• Alternatives for angle assessment :
UBM
Scheimpflug imaging
ophthalmic endoscopy.
• Immobile pt: four mirror + direct ophthalmoscope .
31. History of gonioscopy
• first person to examine the angle- Trantas .
• Contact lens on cornea –saltzman
• Later modified by koeppe
• Congestive glaucoma was due to closer of angle:
Otto Barkan (1936)
• Simplified view of angle:goldmann (1938)
32. summary
• Essential tool in management of glaucoma.
• Routein gonioscopy can prevent cosiderable
number of glaucoma associated blindness.
• Advent of handy goniolens
• know normal, variations in normal to find
abnormals in angle easily.
