Glaucoma

Normals

• The larger the disk the larger the cupping
• Gaussian distribution of area of nerve heads
• Disc’s with Rx >-5.00 are larger
• Disc’s with Rx >+5.00 are smaller
• Rim narrowest at temporal rim
• Normal disc vertical oval
• Normal cup horizontal oval
• Primary macrocups (physiologic)
• Acquired macrocups

Microdiscs

• More likely to have:
• Optic disc drusen
• Pseudopapilledema
• NA ION

Macrodiscs

Primary

• Constant in size from birth
• Morning Glory disc
• No defects
• Pits

Acquired

• Congenital glaucoma
• High myopia
• Increase in size
• Rim broadest at inferior pole

Nerve fibers

• 800,000 - 1,500,000 normal
• 1,200,000 avg. number fibers
• Normal dropout of 5,500 fibers / year
• Fibers from superior retina in superior of nerve

Retinal ganglion cells

Two pathways

P- Beta cells

90% of cells

Color sensitivity

Response based on wavelength

Predominate in fovea

Smaller soma and dendrites

M cells

Contrast sensitivity

Faster conduction

Flicker

Scotopic vision

Uniform response to all wavelengths

Glaucoma damages the larger fibers first (M cells)

Reduced flicker sensitivity

Reduced photopic achromatic contrast sensitivity

Questions to ask – Is there definite evidence of glaucoma?

Are the nerves asymmetric?

• Is there a reason besides glaucoma for the asymmetry?
• Asymmetrical glaucoma
• Anisometropia
• Myopia
• Disc anomaly
• Coloboma
• Congenital pit
• Hypoplasia
• Morning glory syndrome

Does the nerve indicate an acquired change?

• Focal pallor
• Hemorrhage at rim
• Is it old, new, progressive or non-progressive?
• Notching
• Shift of blood vessels
• Thinning of rim

Age groups

• 0.1 - 0.3 % for age 35-
• 1.0 - 3.0 % for age 65+

Factors:

• Age and race
• High myopia
• High IOP and cupping
• Long term local or topical corticosteroids
• Maternal history
• 5x (15-20x?)
• Migraine headaches?

Race

• Blacks 7x
• 4-16x? open angle glaucoma
• Develop earlier, quicker and harder to manage
• Number one cause of blindness in blacks (#5 in whites)

Sick eyes

• Athrosclerosis 5x
• Diabetes 5x
• Cardiovascular disease
• Smokers
• Carotid stenosis
• Thyroid disease

Signs

Afferent pupillary defect

• Even early nerve dropout effects central nerves

Bayoneting

• Sharply angled vessel as it crosses edge of cup

Blue - yellow color vision defects

CD by contour greater than CD by color suspicious

• Cupping spreading faster than pallor (Other optic atrophy pallor larger than cupping)

Central retinal vein occlusion

• High IOP collapses thin vessel wall
• Blood stasis may lead to collateral’s and shunts

Cupping

• 11% have C/D equal or larger than .5
• Less than 7% have asymmetry of 0.1+
• Normal disc vertical oval. Normal cup is near center of disc and round or slightly vertical oval
• Cup is round because Chorio-scleral canal larger vertically but more fibers from superior and inferior areas
• Shape of cup determined by angle of canal and number of nerves
• Larger the canal the narrower the rim (Same volume of fibers)
• Tilted discs have a non-progressive field defect
• Only 7% of normals have a greater C/D vertical than horizontal
• large disks have large cups and small discs have small cups so normal C/D can range from 0-.8
• Glaucoma shows early C/D changes if small cups and fields may be required to recognize if originally a large C/D

Acquired pit (“Pseudopit”) (APON)

• Usually on temporal inferior disc
• Localized horizontal almond shaped deepening of tissue directly at edge of disc adjacent to mottled peri-pappilary atrophy (Notching is in the cup)

Concentric enlargement

• Rim thins in all areas
• H C/D and V C/D same
• Most common response to high IOP
• May progress and regress
• Most difficult to identify

Cupping changes

• Normally impossible to diagnose glaucoma with one exam
• Change is the most important sign
• Pit always indicates glaucoma unless proved otherwise
• Alternate fixation shift evaluation

End stage atrophy

• Disc edge undermined (Bean pot)

Focal notching

• Usually inferior temporal or superior temporal
• Due to local ischemia
• Leads to bayoneting as vessel’s undermined
• Leads to focal peripapillary atrophy where notch reaches rim edge
• Produce wedge shaped scotomas approaching fixation

Generalized deepening of cup

• Saucerization (Concentric enlargement)
• Bowing back of entire disc
• Leads to any type of field defect

Temporal unfolding

• Enlargement primarily to temporal area - Nasal resisting
• Cups up, down and temporally so VC/D > HC/D
• Due to elevated IOP
• Large even area of atrophy and increased cupping

Field defects

• Nerve changes usually precede field changes
• 50% nerve loss is possible before field loss
• Paracentral superior scotoma often first defect 80%
• Nasal step above or below horizontal 18%
• Temporal constriction above or below horizontal 6%
• Overall depression

IOP

• 33%-50% of Glaucomas have normal IOP
• IOP screening may miss 30-50% of glaucoma’s
• 90% of elevated IOP do not develop damage
• Diurinal fluctuation #1 indicator
• IOP usually increases in sleep Highest in AM (>7mm)
• Only 10% of ocular hypertensives develop glaucoma
• Significant number of normal IOP’s develop damage
• 3 mm differential in IOP
• Prior use of miotics (Pilo) may show increase in IOP on dilation
• Phenylephrine and Cyclopentolate release pigment cells that may plug trabecular meshwork IOP may increase 1 1/2 hours later Tropicamide no response

• Effect of dilation with peripheral iridectomy
• Phenylephrine does not increase IOP
• Cyclopentolate increases IOP
• Post-dilation increase in IOP may indicate tendency to glaucoma

Laminar dots

• More visible because less fibers (35% of normals have visible lamina)
• Round holes become more horizontal slits in glaucoma

Nasal displacement of vessel’s

• Always with large cups and may not indicate glaucoma

Pallor

• Pallor due to loss of axons and capillaries

Para-papillary atrophy

• In glaucoma atrophy is larger than normal and more likely greatest in zone beta
• May proceed optic nerve damage??
• May be an indicator of susceptibility to high IOP

Retinal nerve fiber defects

• An early change that precedes field loss
• Nerve fiber dropout seen with green filter
• Small linear hemorrhages
• Temporal contrast sensitivity changes
• Vascular loops at disc indicating venous stasis

Physiology

• Vascular theory
• Reduced vascular flow through the lamina
• Mechanical theory
• Choking of axons at lamina
• Retinal ganglion theory
• Nerve fiber bundle densest at inferior temporal arcade

Differential

• Anterior ischemic optic atrophy AION
• Due to temporal arteritis
• Swollen disc with decreased acuity and hemorrhages
• Later cupping
• Acute vision loss
• Usually not marked cupping
• Central retinal artery occlusion

Herdofamilial optic atrophy

• Megapapilla

Morning glory disc

• Large excavated disc
• Central core of white or gray glial cells
• Surrounded by elevated subretinal tissue of variable pigmentation
• Vessels straightened
• Usually unilateral and myopic

Optic disc coloboma

• Usually inferior
• Visual acuity variable
• Vessel’s enter at margin

Optic disc drusen

• Bumpy disc

Optic disc pit

• Congenital (Gray or black)
• Acquired (White)

Peripapillary staphyloma

Tilted discs

• Fuchs coloboma
• 1-2% population
• 75% bilateral
• Superior temporal field defect that crosses midline
• 75% have mild visual acuity reduction
• Nasal elevation of disc
• Temporal scleral crescent

• Cup appears to extend to temporal edge (No rim)

Closed angle

Van Herick angle estimation

• 60 degrees at limbus
• Grade 1 chamber < 1/4 cornea thickness
• Grade 2 chamber = 1/4 cornea thickness
• Grade 3 chamber = 1/4 - 1/2 cornea thickness
• Grade 4 chamber > cornea thickness

Anterior chamber risks

• Pigment or kruckenberg spindle
• Iris transillumination defects
• Capsule exfoliation
• Neovascularization
• Fuchs endothelial dystrophy
• Anterior cleavage
• Corneal edema

Low-tension glaucoma

• May be forms of anterior ischemic optic neuropathy
• Usually focal damage
• Unknown if lowering IOP helps

Congenital glaucoma

• Normal infants C/D 0.3
• Cupping reversible

---

Anaridia

• Congenital absence of iris

Atrophies, Iris

• Essential iris atrophy
• 30-40 yr. old females
• Through and through monocular iris holes and pupil distortion

Fuch's heterochromic cyclitis

• 30 -40 year olds
• Low grade uveitis and depigmentation of iris
• Heterochromia

Pigment dispersion syndrome

• Multiple wedge defects

Pupillary ruff atrophy

• Aging

Coloboma

• Keyhole pupil

Configurations

Corectopia

• Irregular pupil

Iris bombe

• Bowed forward from synechia

Plateau Iris

• Anterior insertion of iris and deep chamber
• Increased risk of closure

Polycoria

• Multiple pupils

Cysts

Iridodenesis

• Shaky iris

Iridodialysis

• Torn iris

Persistent pupillary membrane

• Iris threads

Hyphema

• Red blood cells following trauma
• High risk glaucoma

Isolated focal defects

• Due to surgery or laser

Pigmentation’s

• Albinism
• Heterochromia

Pseudoexfoliation syndrome

• 60+
• Bilateral
• Pigment on pupil
• Glaucoma

• Age 20-50 type “A” personality
• By Race:
• Blacks Sarcoid (10X)
• Caucasians Ankylosing spondylitis, Reiters syndrome
• Mediterreans Bechets
• Orientals Vogt-Koyanagi-Harada

• Less than 6 weeks
• Deep boring pain in eyes
• Photophobia
• Tearing but no discharge
• Visual acuity variable but hazy
• Limbal flush
• Corneal edema

• Fine kp
• Mutton fat kp
• Pigmented kp (Kruchenberg, Arlts)
• Cells
• White blood cells or rarely red blood cells
• Specks floating
• 0-1+ Trace flare by bilateral comparison
• 1-2+ Obvious presence by comparison
• 2-3+ Hazy
• 3-4+ Plasmoid aqueous, thick, cloudy aqueous

• Protein
• Milky haze
• 0-1+ 1-5 cells in 60 sec
• 1-2+ 5-10 in beam at once
• 2-3+ Cells scattered throughout beam
• 3-4+ Dense cells in beam

• White blood cells

Anterior

• Peripheral
• Cornea to iris
• Rare

Posterior

• Central
• Corneal margin to lens

 

Atrophy

• Transillumination defects

Busacca nodule

• Whitish yellow
• Always granulomatous

Granuloma

• Fleshy vascularized mass

Hyphema

IOP

• Usually ~5 mm lower than other eye in early stage then increase later

Koeppe nodule

• Round pigment at pupil margin

• Pigment on lens
• May go to posterior sub-capsular cataracts PSCC

• Usually miotic
• May be corectopia
• Swelling
• Vitreous

• Henkind test
• Light to contralateral eye should cause pain inipsilateral

• 6 weeks or less
• Responds to therapy in 6 weeks
• 2 or less times ( 3 probably chronic)
• Unilateral
• Bilateral or alternating is probably chronic
• No systemic problem

• Chronic nongranulomatous uveitis
• Endogenous
• Infection
• Simplex
• Zoster
• Rubeola

• Pars planitis
• Fuchs heterochromic iridocyclitis
• Recurrent unilateral uveitis
• Loss of iris pigment
• Glaucoma

• Reiters
• Post chlamydial arthritis
• Conjunctivitis
• Anterior uveitis

• Recurrent iritis
• Mucous membrane ulcers of mouth and genitals
• CNS and joint disorders
• Age 18-40 2:1 male
• Japanese and mediterranean
• Peripheral occlusive vasculitis
• Young adults
• Recurrent oral and genital ulcers

• Steroid use may activate herpes
• Chloroquine may cause pigment damage to macula

• Chronic inflammation of joint capsule and lower back pain
• Unilateral anterior uveitis

• 20-30 yr.
• Usually male
• Recurrent gastrointestinal inflammation
• Anterior uveitis

• White females
• Bilateral uveitis and colitis
• Unknown
• Most common
• Exogenous
• Post-surgical
• Trauma
• Sterile inflammation following penetrating foreign body

• Infectious
• TB
• Syphilis
• Leprosy
• Mycotic
• Parasitic

• Sarcoid
• Uveitis
• Chest granulomas
• Vogt-Koyansgi-Harada
• Juvenile xanthrogranuloma

Incidence

• Nuclear 66% of 75 yr. olds
• Cortical 28% of 75 yr. olds
• Posterior sub-capsular 20% of 75 yr. olds

Types

Nuclear sclerosis

• Oxidization of proteins
• UV exposure
• Smoking
• Riboflavin, vitamins C, E, and carotene may retard development
• Progressively cloudy nucleus and fluid vacuoles
• Myopic shift may precede cloudiness (Second sight)
• Often very slowly progressing
• Blue light test
• Amount of decreased blue light penetration vs. white light is a measure of effect on visual acuity
• May produce monocular diplopia

 

Cortical cataract (Cuneiform - wedge shaped)

• Osmotic imbalance leading to areas of fluid dissolved in the fibers
• Peripheral wedge shaped opacities (Fluid filled).
• Usually inferior (Spoking)
• Strong UV association
• No early effect on visual acuity
• Night visual acuity may be decreased (Mydriasis effect)
• If highly hydrated progress rapidly
• Swelling may increase IOP
• As opacities grow towards optic axis visual acuity decreases

Posterior subcapsular cataract

• Epithelial cell proliferation at pole with fluid filled areas within
• Central opacities and vacuoles
• UV association
• Most visually distressing type
• Reduced acuity at reading (Miosis effect)

• UV
• UV-A 315 - 400
• UV-B 290 - 315 nm
• UV-C <290 nm
• Ozone and cornea absorb
• Welders flashburn
• Tetracycline, psoralens and isoretinoin sensitize

Grade 1

• Slight nuclear sclerosis (Yellow)
• 1/4 spoking only
• Central posterior sub-capsular only

Grade 4

• Brown nuclear cataract
• “Oil drop” nuclear ataract
• 360 spoking
• “Cuneiform ” cataract
• Sub-capsular opacities throughout
• “Cupuliform ” cataract

• Potential acuity meter
• If compromised cornea do a cell count
• A Scan to determine power
• Physical

• Pretreat with antibiotics 3-5 days before
• Dilate
• Pretreat with topical antiprostaglandins
• Inhibits reflex miosis to prosiglandin release
• Cardiac monitor
• Barbituates
• Facial nerve block
• Retrobulbar injection of anesthetic to stabilize muscles
• Inject lid to stabilize it
• Reduce IOP digitally or with Honan ball
• Betadine, drape and insert speculum

• Not done if chronic uveitis
• 9mm incision removing anterior capsule
• IOL in bag
• Up to 50% will require a Yag capsulotomy

• Extinct procedure
• 11mm incision
• Entire capsule removed

• 3mm incision, 6mm if implant
• 6 interrupted sutures
• Most common
• Too tight results in with the rule astigmatism
• Too loose results in against the rule astigmatism and wound gap
• Running sutures
• Usually results in against the rule astigmatism
• Non-disolvable 10/0 nylon

• YAG laser
• Almost always clouds over

• General
• 2-3 D cylinder for 6 weeks
• At 6 weeks should be <1.50
• If against the rule astigmatism check wound gapage
• If high with the rule astigmatism cut sutures
• Seidel test for closure
• 2+ flare and cells for 1-2 weeks
• Hyphema not unusual
• Hypopyon refer
• Pseudophakic kp’s precipitate on IOL due to low grade chronic iritis
• Wound itch for 2 weeks

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Last modified: May 1, 2006