References References
Diagnosis and therapy of the glaucomaDiagnosis and therapy of the glaucoma
77
thth
edition Becker-Shaffer’s edition Becker-Shaffer’s
Duane’s clinical ophthalmology CD ROM 2005Duane’s clinical ophthalmology CD ROM 2005
Sheilds’ Text book of glaucoma 5Sheilds’ Text book of glaucoma 5
thth
edition edition
AAO 2005-2006 section 10 GlaucomaAAO 2005-2006 section 10 Glaucoma
Presentation layoutPresentation layout
IntroductionIntroduction
Optics of gonioscopyOptics of gonioscopy
Methods of gonioscopyMethods of gonioscopy
DirectDirect
IndirectIndirect
Interpretation Interpretation
Normal Normal
Abnormal Abnormal
Gonioscopy refers to the techniques used for Gonioscopy refers to the techniques used for
viewing the anterior chamber angle of the eye for viewing the anterior chamber angle of the eye for
evaluation, management and classification of evaluation, management and classification of
normal and abnormal angle structures.normal and abnormal angle structures.
Term was coined by Trantas, who in 1907 Term was coined by Trantas, who in 1907
visualized the angle in an eye with keratoglobus by visualized the angle in an eye with keratoglobus by
indenting the limbus.indenting the limbus.
(Gonio:Angle, Scopy: Examination)(Gonio:Angle, Scopy: Examination)
Salzmann in 1944 determined visualization of Salzmann in 1944 determined visualization of
anterior chamber angles is impossible without anterior chamber angles is impossible without
special optical instrument due to total internal special optical instrument due to total internal
reflection and design his own lensreflection and design his own lens
Troncoso ,Koeppe, Goldmann modified Troncoso ,Koeppe, Goldmann modified
gonioscopic techniquegonioscopic technique
Snell’s LawSnell’s Law
Total internal reflectionTotal internal reflection
Indication Indication
Suspected angle-closure diseaseSuspected angle-closure disease
Any sign of angle-closure disease Any sign of angle-closure disease
(glaucomflecken, iritis, iris atrophy)(glaucomflecken, iritis, iris atrophy)
Family member with angle-closure diseaseFamily member with angle-closure disease
Positive van HerickPositive van Herick
History of any type of glaucoma, field loss, or disc History of any type of glaucoma, field loss, or disc
damagedamage
Elevated IOPElevated IOP
Pigment dispersion syndromePigment dispersion syndrome
Ocular blunt trauma or history of foreign body Ocular blunt trauma or history of foreign body
Pseudoexfoliation syndromePseudoexfoliation syndrome
Retinal vascular occlusionRetinal vascular occlusion
History of ocular tumorHistory of ocular tumor
Unexplained hypotony to look for a cyclodialysis Unexplained hypotony to look for a cyclodialysis
cleftcleft
CONTRAINDICATIONSCONTRAINDICATIONS
Patients with known recurrent corneal erosion Patients with known recurrent corneal erosion
Patients with corneal abrasions Patients with corneal abrasions
Patients with keratopathy (i.e., bullous, band, Patients with keratopathy (i.e., bullous, band,
punctate, etc.) punctate, etc.)
Perforating eye injuries Perforating eye injuries
Gonioscopic method Gonioscopic method
Indirect methodIndirect method
Goldmann lens--- surface is slightly larger than the cornea Goldmann lens--- surface is slightly larger than the cornea
and that require gonioscopic gel and that require gonioscopic gel
Zeiss four mirror lens---surface is smaller than the cornea and Zeiss four mirror lens---surface is smaller than the cornea and
that use the patient’s tear film as a coupling agentthat use the patient’s tear film as a coupling agent
Posner four mirror, Sussmann four mirror, Thorpe four Posner four mirror, Sussmann four mirror, Thorpe four
mirror mirror
Direct methodDirect method
Koeppe lens--- surface is quite large ,that use saline as a Koeppe lens--- surface is quite large ,that use saline as a
coupling agent ,and the patient should be in supinecoupling agent ,and the patient should be in supine
Swan Jacob, Barkan, Richardson-Shaffer Swan Jacob, Barkan, Richardson-Shaffer
Direct gonioscopyDirect gonioscopy
The Koeppe lens is an example The Koeppe lens is an example
of a direct goniolens.of a direct goniolens.
It is placed directly on the cornea It is placed directly on the cornea
along with lubricating fluid, to along with lubricating fluid, to
avoid damaging its surface.avoid damaging its surface.
The index of refraction of a The index of refraction of a
Koeppe lens is approximately 1.4, Koeppe lens is approximately 1.4,
almost exactly that of the almost exactly that of the
cornea(1.37). cornea(1.37).
The incident ray travels through the goniolens The incident ray travels through the goniolens
practically unaltered practically unaltered
The ray escapes because the angle of incidence The ray escapes because the angle of incidence
at the new Koeppe air boundary is now less than at the new Koeppe air boundary is now less than
the critical angle.the critical angle.
Unfortunately it requires the patient to be lying Unfortunately it requires the patient to be lying
down, and so it cannot be so easily used with an down, and so it cannot be so easily used with an
ordinary slit lampordinary slit lamp
Examination of a supine patient using Koeppe gonioscopy
Swan Jacob surgical goniolensSwan Jacob surgical goniolens
Indirect gonioscopyIndirect gonioscopy
Goldmann goniolens:Goldmann goniolens: this utilises this utilises
mirrors to reflect the light from the mirrors to reflect the light from the
iridocorneal angle into the direction of the iridocorneal angle into the direction of the
observer observer
While the view obtained is smaller than While the view obtained is smaller than
that of the Koeppe goniolens, it can be that of the Koeppe goniolens, it can be
used with the patient sitting upright used with the patient sitting upright
position position
Zeiss indirect goniolens:Zeiss indirect goniolens:
Similar to the Goldmann, but employs prisms in the Similar to the Goldmann, but employs prisms in the
place of mirrors.place of mirrors.
Its four symmetrical prisms allow visualisation of the Its four symmetrical prisms allow visualisation of the
iridocorneal angle in four quadrants of the eye iridocorneal angle in four quadrants of the eye
simultaneously, and works well with a slit lampsimultaneously, and works well with a slit lamp
Does not require lubricating fluid, only the patient's tear Does not require lubricating fluid, only the patient's tear
film - allows for indentation gonioscopyfilm - allows for indentation gonioscopy
Indentation GonioscopyIndentation Gonioscopy
Essential in distinguishing appositional angle closure from synechial Essential in distinguishing appositional angle closure from synechial
angle closure.angle closure.
Done with goniolenses that have contact diameters smaller than the Done with goniolenses that have contact diameters smaller than the
corneal diameter.E.g. Ziess, Posner and Sussman lenses.corneal diameter.E.g. Ziess, Posner and Sussman lenses.
Lens is placed centrally on the cornea and pushed posterior, so that Lens is placed centrally on the cornea and pushed posterior, so that
aqueous is pushed into the angle which will deepen the appositionally aqueous is pushed into the angle which will deepen the appositionally
closed angle.closed angle.
Angles having synechial closure either open with Angles having synechial closure either open with
indentation, or partially open with synechiae being indentation, or partially open with synechiae being
tethered to the cornea or trabecular meshwork.tethered to the cornea or trabecular meshwork.
Also helpful in diagnosing iridodialysis, cyclodialysis Also helpful in diagnosing iridodialysis, cyclodialysis
and foreign bodies in the angle.and foreign bodies in the angle.
Indentation gonioscopy
Differentiates ‘appositional’ from ‘synechial’ angle closure
Press Zeiss lens posteriorly
against cornea
Aqueous is forced into
periphery of anterior chamber
• Part of angle is forced open
During indentation
• Complete angle closure
Before indentation
The gonioscopy processThe gonioscopy process
Briefly explaining the procedure to the patient Briefly explaining the procedure to the patient
Cleaning and sterilising the front (curved) Cleaning and sterilising the front (curved)
surface of the goniolens surface of the goniolens
Applying lubricating fluid to the front surface if Applying lubricating fluid to the front surface if
appropriate appropriate
Anaesthetising the patient's cornea with topical Anaesthetising the patient's cornea with topical
anaesthetic anaesthetic
Preparing the slit lamp for viewing through the Preparing the slit lamp for viewing through the
goniolens goniolens
Gently moving the patient's eyelids away from the Gently moving the patient's eyelids away from the
cornea cornea
Slowly applying the goniolens to the ocular surfaceSlowly applying the goniolens to the ocular surface
Fine-tuning the slit lamp to optimise the view Fine-tuning the slit lamp to optimise the view
Interpreting the gonioscopic image Interpreting the gonioscopic image
Moving the goniolens to view each section of the Moving the goniolens to view each section of the
iridocorneal angle iridocorneal angle
Cleaning the instruments and irrigating the patient's Cleaning the instruments and irrigating the patient's
eyeseyes
Gonioscopic procedureGonioscopic procedure
Angle structures
(1) pupil border; (2) peripheral
iris; (3) ciliary body band; (4)
scleral spur; (5) trabecular
meshwork; and (6) Schwalbe's
line.
Pupil and IrisPupil and Iris
Glaukomflecken and posterior synechiaeGlaukomflecken and posterior synechiae
Dandruff like particlesDandruff like particles
If posterior chamber pathology such as tumors, If posterior chamber pathology such as tumors,
suspected, the pupil should dilated and gonioscopy suspected, the pupil should dilated and gonioscopy
repeated. repeated.
NeovascularizationNeovascularization
Iris configurationIris configuration
Myopes –concaveMyopes –concave
Hyperopes –convexHyperopes –convex
Abnormal convexity (pupillary block)Abnormal convexity (pupillary block)
Abnormal concavity (pigment dispersion)Abnormal concavity (pigment dispersion)
Abnormal last roll (Plateau iris)Abnormal last roll (Plateau iris)
Ciliary Body BandCiliary Body Band
The band is usually tan, gray, or dark brown, The band is usually tan, gray, or dark brown,
pigmented and typically narrow in hyperopes pigmented and typically narrow in hyperopes
and wide in myopes. and wide in myopes.
In angle recession they are broadly exposedIn angle recession they are broadly exposed
The root of the iris normally inserts onto the The root of the iris normally inserts onto the
ciliary body band. ciliary body band.
If the iris inserts directly into the scleral spur, If the iris inserts directly into the scleral spur,
the ciliary body band is not seen easily.the ciliary body band is not seen easily.
Angle blood vesselsAngle blood vessels
The normal angle has three types of vessels:The normal angle has three types of vessels:
(1) circular ciliary body band vessels(1) circular ciliary body band vessels
(2) radial iris vessels(2) radial iris vessels
(3) radial ciliary body band vessels(3) radial ciliary body band vessels
If angle vessel that bridges the scleral spur is seen, it is probably If angle vessel that bridges the scleral spur is seen, it is probably
abnormal.abnormal.
Scleral spurScleral spur
Posterior border of TMPosterior border of TM
Attachment of ciliary bodyAttachment of ciliary body
Insertion of longitudinal muscles of ciliary bodyInsertion of longitudinal muscles of ciliary body
May be obscured by:May be obscured by:
Iris processIris process
Iris bombeIris bombe
PASPAS
PigmentsPigments
Trabecular MeshworkTrabecular Meshwork
Extends from the scleral spur to Schwalbe's line Extends from the scleral spur to Schwalbe's line
Pigment in the meshwork usually accumulates in the Pigment in the meshwork usually accumulates in the
posterior division posterior division
Posterior meshwork is the favored location for Posterior meshwork is the favored location for
trabeculoplasty. trabeculoplasty.
More pigmented with ageMore pigmented with age
Aqueous flow is through posterior TMAqueous flow is through posterior TM
More pigment inferiorlyMore pigment inferiorly
Schwalbe's LineSchwalbe's Line
Termination of Descemet's membrane and is the most anterior Termination of Descemet's membrane and is the most anterior
angle structure angle structure
Marks the forward limit of the trabecular meshwork Marks the forward limit of the trabecular meshwork
Landmark for identification of TM in narrow anglesLandmark for identification of TM in narrow angles
Pigmented –Sampaolesi’s linePigmented –Sampaolesi’s line
Schlemm's CanalSchlemm's Canal
The canal is located directly anterior to the scleral spur The canal is located directly anterior to the scleral spur
and is normally not seen.and is normally not seen.
However, during gonioscopy, blood may reflux into However, during gonioscopy, blood may reflux into
the canal the canal
Blood in the canal is more common under conditions Blood in the canal is more common under conditions
of elevated episcleral venous pressure( eg Sturge –of elevated episcleral venous pressure( eg Sturge –
Weber syndrome ) ,active uveitis or scleritis Weber syndrome ) ,active uveitis or scleritis
Hypotony may also cause blood to reflux into the canal. Hypotony may also cause blood to reflux into the canal.
Blood in schlemm’s canalBlood in schlemm’s canal
Angle PigmentationAngle Pigmentation
A minimal amount of angle pigment is expected A minimal amount of angle pigment is expected
Excessive may be caused by pigmentary glaucoma, Excessive may be caused by pigmentary glaucoma,
pseudoexfoliation, trauma, uveitis, or tumors. pseudoexfoliation, trauma, uveitis, or tumors.
Excessive trabecular pigment at the 12 o'clock position occurs in Excessive trabecular pigment at the 12 o'clock position occurs in
only 2.5% of individuals and is usually pathologic.only 2.5% of individuals and is usually pathologic.
Grading of chamber anglesGrading of chamber angles
Van HerickVan Herick
Grade 4Grade 4
Grade 3Grade 3
Grade 2Grade 2
Grade 1Grade 1
PAC>CTPAC>CT
PAC=1/4-1/2 CTPAC=1/4-1/2 CT
PAC=1/4 CTPAC=1/4 CT
PAC<1/4 CTPAC<1/4 CT
Angle is wide openAngle is wide open
Angle is narrowAngle is narrow
Angle is dangerously narrowAngle is dangerously narrow
Angle is dangerously narrow or closedAngle is dangerously narrow or closed
Open angleOpen angle
Close angleClose angle
Shaffer grading
• Ciliary body easily visible
Grade 4 (35-45 )
• At least scleral spur visible
Grade 2 (20 )
Grade 3 (25-35 )
Grade 1 (10 )
• Only trabeculum visible
• Only Schwalbe line and perhaps
top of trabeculum visible
• High risk of angle closure
• Iridocorneal contact present
• Apex of corneal wedge not visible
• Angle closure possible but unlikely
• Use indentation gonioscopy
3
2
1
0
4
Grade 0 (0 )
Scheie classificationScheie classification
Spaeth gradingSpaeth grading
Myopic eye with pigment dispersion syndrome Myopic eye with pigment dispersion syndrome
E 40 q/4+TMP= An extremely deeply inserting iris E 40 q/4+TMP= An extremely deeply inserting iris
root ,in a 40 degree angle recess ,with posterior root ,in a 40 degree angle recess ,with posterior
bowing of the peripheral iris and extensive TMPbowing of the peripheral iris and extensive TMP
Gonioscopy flow diagramGonioscopy flow diagram
Closed angleClosed angle
Open angle
Open
angle
Iris melanoma
Neovascularization
Neovascularization
Microhyphema following traumaMicrohyphema following trauma
Foreign bodyForeign body
Foreign bodyForeign body
Note relative deepening of the iris insertionNote relative deepening of the iris insertion
Post traumatic angle recessionPost traumatic angle recession