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Gonioscopy
- 1. GONIOSCOPY DR RUBINA SHAKYA FIRSTYEAR RESIDENT
- 2. OUTLINES History Principle Types Anatomy of angle structures Classification, Interpretation Pathological findings Sterilization
- 3. HISTORY TRANTAS (1907) oFirst to examine angle in the keratoglobus eye and introduced the term GONIOSCOPY SALSMANN (1914) o Introduced the goniolens to observe the angle GOLDMANN (1938) o Introduced the gonioprism BARKAN o Established the use of Gonioscopy in management of Glaucoma
- 4. Introduction Gonioscopy - biomicroscopicexamination of the anterior chamber angle of the eye
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- 8. METHODS OF GONIOSCOPY 1.Direct gonioscopy 2. Indirect gonioscopy -Without indentation -With indentation
- 9. DIRECT GONIOSCOPY Anteriorcurve of goniolens is such that the critical angle is not reached and the light rays are refracted at contact lens-air surface Provide a direct view of the angle They do not require a slit lamp & are used with in supine position
- 10. TECHNIQUE OF DIRECTGONIOSCOPY Patient lies supine with examiner sitting on the side of the eye to be examined After topical anesthesia, goniolens is positioned on the cornea, using balanced salt solution or methyl cellulose Examiner holds the goniolens in one hand and the light source in other and scans the anterior chamber angle by shifting his or her position until all 360 degrees have been studied
- 11. Goniolenses (Direct) Diagnostic lens: -Koeppe (several sizes) Surgical lens : - Barkan - Swan-Jacob
- 12. Indirect gonioscopy Twotypes :- 1. Non indentation 2. Indentation
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- 15. Gonioprisms (Non indentation) Surface is slightly larger than cornea & require a coupling gel Goldmann single mirror Goldmann-3 mirror Allen-Thorpe
- 16. Goldmann mirrors contd… GOLDMANNSINGLE MIRROR GOLDMANN 3 MIRROR
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- 20. Micropulse laser trabeculoplasty(MLT) lens
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- 23. Gonioprisms (indentation) Zeissfour mirror Sussman four mirror Posner four mirror
- 24. Gonioprisms contd… Zeiss fourmirror All 4 mirrors inclined at 64 degrees for gonioscopy
- 25. Gonioprisms contd… Sussman fourmirror - Similar to Zeiss but with no handle
- 26. GONIOPRISMS contd… Posner goniolens Similarto Zeiss-goniolens but made of plastic with a fixed handle
- 27. DIRECT vs INDIRECT FeaturesDIRECT INDIRECT View Panoramic view of iridocorneal angle with ability to adjust view by examiner Segmental Eyes Both eyes can be examined simultaneously One eye at a time Coupling (viscous) material Not required Required Image Direct view as for surgery Mirror image seen Indentation Cannot be done Can be done
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- 29. • Visible inthe AC as a result of iris insertion into ciliary body • Width depends on level of iris insertion • Color: Grey to dark brown Ciliary Body Band (CBB)
- 30. Ciliary body bandcontd… WIDE CBB Narrow or absent CBB Physiological Pathological Hypermetropia Myopia Aphakia Angle recession (blunt trauma) Cyclodialysis Anterior insertion of iris
- 31. Scleral spur • Isthe most anterior projection of the sclera • Attached to – ciliary body- posteriorly – corneo-scleral meshwork- anteriorly • Color : prominent white line
- 32. Trabecular Meshwork (TM) •Pigmented band anterior to scleral spur • A sieve like structure at the angle of anterior chamber • Has 3 components: 1. Uveal meshwork 2. Corneoscleral meshwork 3. Juxtacanalicular meshwork
- 33. 1. Uveal meshwork -Innermost portion - Intertrabecular spaces are larger 2. Corneoscleral meshwork - Lies external to uveal meshwork - Thickest portion - Intertrabecular spaces are smaller 3. Juxtacanalicular meshwork - Outer part of trabeculum - Links corneoscleral meshwork with endothelium of inner wall of canal of schlemm - Has narrow intercellular spaces
- 34. Trabecular Meshwork contd.. •At birth no pigment • With age: faint to dark brown • Pigment deposition : homogeneous or irregular.
- 35. Corneal Wedge • Whena thin slit of light hits the irido-corneal angle at an angle of 10⁰-15⁰, two light reflections are seen from: – External corneal surfaces – Internal corneal surfaces (Schwalbe’s line)
- 36. Schwalbe’s Line • Junctionbetween anterior chamber angle structures and cornea where the descement’s membrane terminates • Fine ridge anterior to TM • Identified by a small built up of pigment
- 37. Sampaolesi’s line • Pigmentscattered around and on Schwalbe’s line
- 38. Gonioscopic classification 1. Scheiesystem: Most posterior structure visible 2. Shaffer’s system : Assess geometric angle width in 4 grades angle potential for occlusion 3. Spaeth system : Three dimensional structure of angle Level of iris insertion, angular width, peripheral iris configuration and TM pigmentation
- 39. GRADE STRUCTURE SEENPROBABILITY 0 CBB Seen No angle closure I CBB Narrow No angle closure II CBB not seen, SS Seen Rarely closure possible III Posterior TM Not seen Closure likely IV Schwalbe’s Line not seen Gonioscopicaly closed Scheie System
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- 41. Spaeth System • Levelof iris insertion • Angular width • Iris configuration • Pigmentation of posterior trabecular meshwork
- 42. Spaeth System Step1: Site of iris insertion A - Anterior to trabecular meshwork (i.e., Schwalbe’s line) B - Behind Schwalbe’s line (i.e., at level of trabecular meshwork) C - Centered at the level of the scleral spur D - Deep to the scleral spur (i.e., anterior ciliary body) E - Extremely deep in the ciliary body
- 43. Spaeth System Step2: Angle width • As with the Shaffer system • Geometric angle estimated at the perceived intersection of the imaginary tangents formed by the peripheral third of the iris and the inner wall of the corneo- scleral junction
- 44. Spaeth System • Step3: Configuration of peripheral iris Four iris configurations, indicated by the first letter of their description • B - ‘bows 1 to 4 plus’ (usually indicative of optically- appearing closure, altering with indentation) • P -‘plateau’ • F - ‘f lat approach’: the commonest iris appearance • C - ‘concave’ as in posteriorly bowed iris
- 45. Spaeth System Step4: Trabecular meshwork pigmentation • Minimal or no pigment is graded 1 • Dense pigment deposition is indicated as grade 4 • 2-3 in between Example: E40c, 4 + TMP
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- 50. Possible affects oftrauma on angle Angle Recession Cyclodialysis Intraocular foreign body Blood clots
- 51. Angle recession (arrows)following blunt ocular trauma
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- 53. Foreign body inangle of AC
- 54. • Hyphaema •Iridodialysis
- 55. Specific angle characteristics •Fuchs heterochromic iridocyclitis • Pseudoexfoliation syndrome • Pigment dispersion syndrome • Plateau iris • Elevated episcleral venous pressure
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- 59. Plateau iris S -shaped configuration of iris
- 60. Blood in schlemm’scanal
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- 63. Golden brown discolorationseen in Wilson’s disease
- 64. • Iris melanoma• Iris nevus
- 65. Clinical uses ofGonioscopy DIAGNOSTIC Classification of glaucoma To identify plateau iris To look for abnormal angle pigmentation, pseudoexfoliation, angle recession, cyclodialysis, foreign body, neoplasm, copper deposition, blood in schlemm’s canal
- 66. Clinical uses ofGonioscopy THERAPEUTIC Laser trabeculoplasty Goniotomy/ Gonioplasty Peripheral laser iridotomy Reopening of blocked trabeculectomy opening Laser of suture around tube of glaucoma drainage devices Indentation gonioscopy to break an attack of acute ACG
- 67. Contraindications Globe rupture Recent history of hyphema Ocular surface infections like Herpes simplex; Epidemic kerato-conjunctivitis Epithelial basement membrane dystrophy
- 68. Limitations Contact investigation-> patient discomfort Conjunctival infection Slit lamp illumination - pupil constriction -> opens up the angle Wide inter observer variations Indentation -> corneal folds, distorted view of angle structures, epithelial injury Cannot be performed in painful inflamed eyes Difficult to perform in cases of acute glaucoma where eyes are painful, congested and have oedematous cornea Mydriatics obscure angle by bunching up iris therefore not possible in such cases
- 69. Sterilization & Disinfection Soakingthe lens for 5-10 min in 2 % of Sodium Hypochlorite Rinsing with sterile saline Air drying
Editor's Notes
- #4 Keratoglobus is a rare, noninflammatory corneal ectasia characterized by diffuse protrusion and thinning of the cornea he congenital form is present at birth and is associated with Ehler-Danlos type VI, Leber congenital amaurosis, and the blue sclera syndrome. The acquired form presents in adulthood and may evolve from preexisting cases of pellucid marginal degeneration or keratoconu
- #5 Other means of angle assessment such as anterior segment optical coherence tomography (OCT) and high-frequency ultrasound biomicroscopy (UBM) offer advantages in some aspects of angle analysis. Ac- ant. By back of cornea and post by iris and part of CB, 3 mm in centre, 0.25ml in AC ,0.006 in post chamber
- #6 When light passes from a medium of higher refractive index to one with a lesser index, the angle of refraction (r) is larger than the angle of incidence (i). When r equals 90 degrees, i is said to have attained the critical angle. When i exceeds the critical angle, the light is reflected back into the first medium. When a ray of light travelling form an optically denser medium to an optically rarer medium is incident at an angle greater than the critical angle of the pair of media in contact, the ray is totally reflected back into the denser medium. This phenomenon is called total internal reflection. Angle of anterior chamber cannot be visualized directly through an intact cornea because light emitted from angle structures undergoes total internal reflection
- #7 The normal eye: light from iridocorneal angle is reflected back into eye and thus cannot be seen Goniolens- has same refractive index with that of cornea so eliminates tear film air interface with tear film goniolens interface The direct goniolens: As the index of refraction of lens is similar to that of cornea, light enters lens and is then refracted by lens to enable observer to view angle The indirect goniolens: principle similar to direct lens but, once light has entered lens, it is reflected by a mirror. Critical Angle: Cornea Air Interface~46degree. Light rays from Angle exceeds Critical angle so rays reflected back into AC, preventing direct visualisation of Angle.
- #8 Goniolens eliminates the total internal reflection by replacing the cornea- air interface by a new interface, which has a refractive index greater than that of cornea and tear
- #9 Can be done………………….
- #11 Useful but fairly impractical for routine use 4 percent xylocaine and 0.5 per proparacaine, 0.3% hypromellose
- #12 Swan-Jacob Direct surgical gonioscope, held on cornea with a handle KOEPPE- It is most commonly used for diagnostic direct gonioscopy It is easy to use & provides a panoramic view of the angle
- #15 (A) The Goldmann lens is brought into contact with the inferior sclera. (B) The Goldmann lens tipped up into position. After anaesthetising the cornea, the coupling gel is inserted into the cup of the goniolens as the curvature of the contact lens is steeper than that of cornea goniolens is placed and tipped onto the cornea. Slit-lamp beam is focused on the mirror which shows the inverted angle image.
- #16 A systematic approach is to be followed- nasal-sup-temporal-inf (A) Schematic of indirect gonioscopy mirror, with images viewed 180º reversed but oriented the same right-to-left (e.g., 11 o’clock, 12 o’clock, 1 o’clock positions). (B) Example of indirect gonioscopy, showing location of surgical iridectomy, iris nevus, and neovascular vessels as they appear on the iris and as an image in the gonioscopic mirror.
- #17 Coupling gel- carboxymethyl cellulose, viscous,
- #18 Single – mirror is inclined at 62 deg 3 mirror- 59 deg
- #19 3 mirror lens :59:iridocorneal angle…67:ora serrata…73:equator D or apical mirror : angle examination Other two : peripheral retina Central /equatorial lens : macular examination D shaped mirror should be first placed at 12o’ clock position and eventually rotated thrice to view the other 3 quadra
- #20 Four gonioscopy mirrors; inclined at 62 degrees; requires fluid bridge
- #21 Selective laser trabeculoplasty (SLT) One mirror for Trabeculoplasty
- #22 Argon laser trabeculoplasty (ALT) Ritch trabeculoplasty laser lens is specifically designed to provide goniosocpic vieweing with the addition of plano convex button lenses on the anterior surface to facilitate target magnification and beam spot minification for this filtering procedure. Anterior surface has a high efficiency antirelfective coating to cut energy transmission losses while increasing brightness and contrast of the transmitted image.
- #24 Abraham iridectomy lens is Designed to facilitate full thickness laser iridectomies and protect against superficial corneal burns. The lens consists of a specially modified Goldmann type fundus lens with a small plano-convex button bonded to the anterior surface.
- #25 Indentation gonioscopy. Pressure on the cornea displaces the iris to widen a narrow or closed anterior chamber angle. This maneuver exposes additional anatomic landmarks and is useful in determining the presence or absence of peripheral anterior synechiae. Synechiae, if present, can sometimes be separated. (A) Without pressure. (B) With pressure. Varying amount of pressure applied to the cornea with a tear coupled indirect contact lens. Examiner observes the effect on angle width. Increased pressure indents the central cornea & displaces fluid into the angle, opening it wider. When iris covers the trabecular meshwork (TM) its easy to mistake: The non-pigmented TM for scleral spur Pigmented Schwalbe’s line for TM Apposition from synechiae Indentation Gonioscopy is particularly useful in these cases Useful when iris surface is convex Done when recognition of angle structures is difficult Performed in all glaucoma cases Differentiates appositional vs synechial closure in pupillary block Measures extent of angle closure Identifies plateau iris config. Identifies lens induced angle closure When iris covers the trabecular meshwork (TM) its easy to mistake: Non-pigmented TM for scleral spur Pigmented Schwalbe’s line for TM Apposition for synechiae Indentation Gonioscopy is particularly useful in these cases. Useful when iris surface is convex Done when recognition of angle structures is difficult Performed in all glaucoma cases Differentiates appositional vs synechial closure in pupillary block Measures extent of angle closure Identifies plateau iris configuration Identifies lens induced angle closure
- #27 Fig….indirect…indentation-It has four identical mirrors angled at 64° which allow examination of the four quadrants without rotation of the lens. -The contact surface of lens has a 9mm diameter
- #29 TOKEL GONIOLENS It is a single mirror goniolens & has got a wider field of view.
- #30 Primary (appositional) angle closure refers to an eye with raised IOP (>21 mm Hg) associated with obstructed filtering trabecular meshwork of more than 180° in the absence of PAS, disc damage, or field changes. On the other hand, primary (synechial) angle closure (PAC) refers to an eye in which portions of the anterior chamber angle are closed permanently by PAS with more than 180° of iridotrabecular contact with or without raised IOP.
- #34 Normal width- 0.5mm,
- #36 Scleral spur might be obscured by * Iris processes * iris bombe * Peripheral anterior synechiae *Pigments
- #37 uveal- innermost meshwork,intertrabecular spaces are large and offer lesser resistance to the passage of aqueous Corneoscleral- lies ext to uveal meshwork, thickest portion, intertrabecular spaces are smaller and provide greater resistance Juxtacanalicular- Outer part of trabeculum, links corneoscleral meshwork with the endothelium of inner wall of canal of schlemm, narrow intercellular space and offers major proportion of resistance to aq. outflow It is considered as 2 portions: Anterior Posterior Anterior - between schwalbe’s line and ant. Edge of schlemm’s cannal Involved in lesser degree of aqueous out flow Posterior – Functional part , primary site of aqueous out flow Appearance of functional TM depends on amount of pigment deposition
- #38 1. 25-75 micron 2. 5-50 3. 2-20
- #40 The point where ext and int corneal surface meet , it is called corneal wedge. marking the anter….ior border of trabecular mes Useful technique to identify the trabecular meshwork Nonpigmented Excessively pigmented hwork…Parallelopiped down at sclero-corneal junction
- #41 Landmark for TM in narrow angle
- #42 particularly inferiorly at 6 o’clock (mirror at 12 o’clock).When an abundance of brown pigment is seen at or anterior to Schwalbe's line, a Sampaolesi line is said to be present.[1][2][3] The presence of a Sampaolesi line can signify pigment dispersion syndrome or pseudoexfoliation syndrome
- #47 The first grading decision assesses the site of the iris insertion, both as it appears functionally (without pressure on the cornea) and as it actually inserts anatomically (after indentation).
- #48 Though some examiners prefer increments of 10°, as with the Shaffer system, and others use increments of 15°
- #50 An extremely deeply inserting iris root, in a 40° angle recess, with posterior bowing of the peripheral iris and extensive TM pigmentation (as might be seen in a myopic eye with pigment dispersion syndrome). E - Extremely deep in the ciliary body C - ‘concave’ as in posteriorly bowed iris
- #51 This is the most clinically useful method of recording gonioscopic findings. Firstly abbreviation for most posteriorly visible structure viz.. Ciliary body(CB), scleral spur(SS), trabecular meshwork(TM), schwalbe’s line(SL) Grading of pigmentation in each quadrant Configuration of the iris Any abnormality in the angle
- #53 Schematic drawing of gonioscopic finding…7 circles…outer 3 -----TrABECULAR MESHWORK…inner 3----level of iris insertion…middle –SS…pupil blak… Advantage- reduce the need for writing down every finding, they also help in better communication of facts between ophthalmologists, make f/u quicker
- #55 ANGLE RECESSION – characterised by widely visible CBB due to tear between longitudinal and circular ciliary muscle fibres CYCLODIALYSIS–disinsertion of ciliary body band from scleral spur, characterised by deep angle & decreased iop ; shows a white band on gonioscopy Intraocular foreign body , blood clots
- #56 ANGLE RECESSION – characterised by widely visible CBB due to tear between longitudinal circular ciliary muscle fibres
- #57 CYCLODIALYSIS–disinsertion of ciliary body band from scleral spur, characterised by deep angle & decreased iop ; shows a white band on gonioscopy
- #59 Iridodialysis, sometimes known as a coredialysis, is a localized separation or tearing away of the iris from its attachment to the ciliary body
- #60 FUCH’S HETEROCHROMATIC IRIDOCYCLITIS:fine fragile vessels.. is a chronic unilateral uveitis appearing with the triad of heterochromia, predisposition to cataract and glaucoma, and keratitic precipitates on the posterior corneal surface PSEUDO EXFOLIATION SYNDROME: it is the common cause of secondary open angle glaucoma and seen after age of 50, patchy TM AND SL hyperpigmentation and Sampaolesi”s line which is an irregular band of pigment running on or ant to SL, PIGMENT DISPERSION SYNDROME: abnormal posterior bowing of iris, TM heavily pigmented , sampaolesi line also seen here PLATEU IRIS: flat configuration iris with peripheral hump mimicking narrow angle.. It is caused by large or anteriorly positioned ciliary processes that push the peripheral iris forward. RAISED EPISCLERAL VENOUS PRESSURE :uniform linear reddish hue (blood in schlemm’s canal),
- #61 FUCH’S HETEROCHROMATIC IRIDOCYCLITIS:fine fragile vessels.. is a chronic unilateral uveitis appearing with the triad of heterochromia, predisposition to cataract and glaucoma, and keratitic precipitates on the posterior corneal surface
- #62 PSEUDO EXFOLIATION SYNDROME: it is the common cause of secondary open angle glaucoma and seen after age of 50, patchy TM AND SL hyperpigmentation and Sampaolesi”s line which is an irregular band of pigment running on or ant to SL,
- #63 PIGMENT DISPERSION SYNDROME: abnormal posterior bowing of iris, TM heavily pigmented , sampaolesi line also seen here
- #64 PLATEU IRIS: flat configuration iris with peripheral hump mimicking narrow angle.. It is caused by large or anteriorly positioned ciliary processes that push the peripheral iris forward,,,,,,,, . It is caused by large or anteriorly positioned ciliary processes that push the peripheral iris forward. The mechanical position of the ciliary processes against the trabecular meshwork crowds the angle and obstructs aqueous outflow.
- #65 Physiological variant Sturge weber syndrome Carotid cavernous fistula and dural shunt Obs of SVC
- #66 is a condition in which there is apposition of the iris to the lens, preventing aqueous from flowing from the posterior to the anterior chamber.
- #68 Kayser-Fleischer rings
- #69 Iris melanoma seen as variably pigmented tumour Iris nevus- lesion appears to seat on the top of the iris without distorting or disrupting the normal iris architecture
- #71 Laser trabeculoplasty – argon laser trabeculoplasty (ALT), micropulse laser trabeculoplasty (MLT), selective laser trabeculoplasty (SLT) Laser trabeculoplasty, both argon laser trabeculoplasty(ALT) and selective laser trabeculoplasty (SLT) types, is used to increase aqueous outflow facility through the trabecular meshwork (TM) in order to lower intraocular pressure (IOP) in cases of ocular hypertension and glaucoma. Gonioplasty aka iridioplasty used in plateau iris
- #72 EBMD- recurrent cornral erosion so not performed
- #74 Helps against transmissible spongiform encephalopathies
- #75 Anterior chamber angle is viewed under following conditions on a Haag-Streit 900 BM slit lamp