Myopia- pigment dispersion, open angle glaucoma (?)

Hyperopia- small disc, angle closure glaucoma

• Tuberous sclerosis• Neurofibromatosis• Sturge weber syndrome• TAO

• Juvenile xanthogranuloma• Oculodermal melanocytosis• Axenfeld rieger syndrome• Orbital varices• CCF

RAPDCorectopia, ectropion uveae

• Black adrenochrome deposits• Conjunctival injection• Dec tear production• Foreshortening of the conjunctival

fornices and scarring• Bleb• Episcleral vessel dilation• staphyloma

• Haab striae• PED• Microcystic epithelial edema• Krukenberg spindle• Exfoliation material• KP• Guttae• “ beaten bronze” appearance

• Van Herick method• Iris bombé• Heterochromia• Iris atrophy• Transillumination defects• Neovascularization• LENS– Phacodonesis– PSC

1. diagnostic- identify abnormal angle structures and estimate the width of the AC

2. Surgical- LTP, goniotomyVisualize the anterior chamberEliminates tear- air interfacePrevents total internal reflection

DIRECT GONIOSCOPY

Koeppe, Barkan-Hoskins, Swan Jacob

done under EUA (supine)

may examine eye simultaneously

needs handheld biomicroscope, light

source direct image

INDIRECT GONIOSCOPY

Goldmann, Zeiss, Susman, Possner

clinic setting (sitting) one eye at a time needs slit lamp confusing mirror

image

Goldmann- needs coupling agent Stabilizes the globe Clearest visualization of the AC Useful for LTP

Zeiss, Posner, Sussman- Four- mirror goniolens No need for coupling agent Useful for indentation gonioscopy

Koeppe Useful for fundus exam Useful in patients with nystagmus or

irregular cornea

Angular width of the angle recess peripheral iris contour Insertion of the iris root

Pressure is applied to the cornea aqueous humor forced into AC Appositional closure- (+) force opening Synechial closure- remain closed Partial synechial closure- partially open/

closed

Scleral spur and schwalbe’s line- most consistent

Superior quadrant- narrowest Inferior quadrant- widestPigmentation- most marked in the

inferior angle

Faint red line in the posterior TMEpiscleral venous pressure > IOPHypotonyElevated episcleral venous pressure

IRIS PROCESS

Open and lacy Follows the normal

curve of the angle Structures visible

in the open space b/n processes

PAS

More solid or sheet-like

Composed of iris stroma

Obliterate the angle recess

Increases with ageDarkly pigmented irisPDSPESMalignant melanoma traumaUveitis/inflammationSurgery hyphema

PDS

Uniform pigmentation

Finer pigment

PES

Patchy pigmentation

(+) sampaolesi line

Wide ciliary body band

Increased prominence of the scleral spur

Torn iris process Variation of ciliary

face width and angle depth in different quadrants

Early glaucomatous changes Loss of axons,blood vessels and glial

cells

MECHANICAL THEORY

Direct compression of axonal fibers

Distortion of the LC plates

Interruption of axoplasmic flow

Death of RGC

ISCHEMIC THEORY

Decresed optic nerve perfusion

Intraneural ischemia

DIRECT OPHTHALMOSCOPE

Small pupil Detection of NFL No stereosopic detail

INDIRECT OPHTHALMOSCOPE

Uncooperative patients, media opacity, high myope

Can detect ON cupping but less pronounced with slit lamp method

Magnification- is inadequate

Hruby lens, 60, 78 or 90 D lens Can detect subtle changes in ONH High magnification, excellent

illumination, stereoscopic view Quantitative measurement of the

diameter of the disc▪ 60D= x 1▪ 78D= x 1.1▪ 90D= x 1.3

1. Generalized enlargement of the cup2. Focal enlargement of the cup3. Superficial splinter hemorrhage4. Loss of NFL5. Translucency of the neuroretinal rim6. Developmenmt of vessel overpass7. Asymmetry of cupping b/n patient’s

eyes8. Peripapillary atrophy ( beta zone)

Cup disc ratio Measure vertical and horizontal diameter Large disc- large cup▪ Eg myopia, aging, blacks

N- < 0.3 5% - 0.6 Asymmetry of >0.2 -?

Notching or narrowing of the rim Inferior and superior temporal poles

Linear red streak on or near the discUsually located inferotemporallyMay clear over weeks to months–

localized notching of rim and VF lossNTG more likely to have hgesPrognostic sign for development or

progression of VF loss

Red- free illumination N- plush, refractile appearanceThinning, less visibleDiffuse > focal

• Tissue between the cup and border• Orange or pink• ISNT rule• More translucent in glaucoma

Alpha zone- irregular hyper and hypopigmentation of

the RPE Temporal crescent seen in myopia Seen in normal subjects

Beta zone Choriocapillaries and RPE loss Choroidal vesels and sclera visible- white appearance More common in glaucoma patients

Nasalization of vesselsLaminar dot signBayonetingBaring of circumlinear vesselsNarrowing of peripapillary retinal

veseelsPale and excavated cup in advanced

stages

Confocal scanning laser ophthalmoscopy

Scanning laser polarimetryOptical coherence tomography

Measures differential light sensitivity or the ability of the subject to distinguish a stimulus light from background illumination

Assess the visual field1. Identify abnormal visual field2. Quantitative assessment of normal or

abnormal fields to guide follow- up care

1. short wavelength automated perimetry- blue- yellow perimetry

2. Frequency- doubling technology- uses a low spatial frequency sinusoidal grating undergoing rapid phase reversal flicker Simulates M cells

3. Visually evoked cortical potentials and electroretinography- assess RGC function

KINETIC

Moving stimulus of fixed intensity and size

Simple confrontation, tangent screen, Lister perimeter, Goldmann perimeter

manual

STATIC

Non moving stimuli of varying intensity

Henson, Octopus, Humphrey

automated

Traquair’s Island of vision Island of sight surrounded by sea of

darkness

Nasal= 60Superior= 60 Inferior= 70Temporal= 90Blind spot= 10- 20 temporally

Almost always localizedRespects the horizontal meridianBegins nasal to the blind spot almost always detectable within the

central 30Structural loss precedes VF loss50% RNFL loss before VF defect

develops

Generalized depressionParacentral scotomaarcuate-/Bjerrum scotomaNasal stepAltitudinal defectTemporal wedge

Relative or absolute visual loss within 10 of fixation

10- 20 from fixation

Relative depression of one horizontal hemifield compared with the other

Near complete loss of the superior or inferior VF

Advanced GON

1. Fixation2. Stimulus luminance3. Size of stimulus4. Presentation time5. Patient refraction6. Pupil size7. Wavelength of background and

stimulus

Numerical- threshold for all points checked

Grey scale- decreasing sensitivity is represented by

darker tones Each change in grey scale tone is

equivalent to 5 dBTotal deviation-

deviation of the patient’s result from age matched controls

Pattern deviation Adjusted for any generalized depression

in the overall fieldProbability values

P indicates the significance of the defects

< 5%, < 2%, < 1%, and < 0.5% The lower the P- greater clinical

significance

Fixation losses- indicate steadiness of gaze during the

testFalse positives-

detected when a stimulus is accompanied by a sound

Trigger happy patients Grey scale print out appears pale > 33%- unreliable

False negatives- detected by presenting a stimulus much

brighter than threshold at a location where sensitivity has already been recorded

Indicates inattention or tiredness May also be an indicator of disease severity Grey scale print out has a clover- leaf shape > 33% unreliable

Mean deviation- measure of overall field loss

Pattern standard deviation- measure of focal loss or variability within the field taking into account any generalized depression in the hill of vision

Miosis- decreases threshold sensitivity in the peripheral field and increases variability in the central field

Lens opacitiesUncorrected refractive errorLens rimPtosis Inadequate retinal adaptation

1. Optic disc less cupped than expected for the degree of VF loss

2. Pallor> cupping3. Progression of VF loss is excessive4. Pattern of VF loss is uncharacteristic

for glaucoma5. Location of VF loss does not

correspond to the location of cupping or thinning of neural rim