Midterm 1 Flashcards
Glaucoma is the ___ world leading cause of blindness
3rd
Glaucoma is the ___ world leading cause of blindness
3rd
Glaucoma Epidemology
A.A., older, HTN, Hyperlipidemia, diabetes, systemic vascular dz, Raynauds, alchohol/smoking, FHx
Ocular glaucoma risk factor with RE
Myopia (especially greater than 6D)
Visual acuity and glaucoma
Normally only affected late in the dz
Pupils and glaucoma
Affected late in the disease but occur bilaterally so no relative defects
Steamy cornea with perilimbal injection
Acute angle closure glaucoma
Krukenberg spindle
Pigment. May be pigment dispersion glaucoma
Glaucomfleckin
This is opacification of the lens from high IOP.
Normal IOP
10-21 mmhg.
What IOP pressure alone is enough to start tx?
30 mmhg
Normal corneal thickness
555 nm
____ Corneas underestimate IOP
Thin
____ Corneas overestimate IOP
Thick
Corneal thickness at a high risk
Corneal thickness at a lower risk
> 588
Progressive thinning of _____ is pathonogmonic for glaucoma
Neural rim
Disk size of myopes vs. hyperopes
Myopes have a bigger disc.
As C/D reaches ____ glaucoma risk increases
.6
Is asymmetrical optic discs normal?
NO! Any difference of .1 is abnormal
Glaucoma Epidemology
A.A., older, HTN, Hyperlipidemia, diabetes, systemic vascular dz, Raynauds, alchohol/smoking, FHx
Ocular glaucoma risk factor with RE
Myopia (especially greater than 6D)
Visual acuity and glaucoma
Normally only affected late in the dz
Pupils and glaucoma
Affected late in the disease but occur bilaterally so no relative defects
Steamy cornea with perilimbal injection
Acute angle closure glaucoma
Krukenberg spindle
Pigment. May be pigment dispersion glaucoma
Glaucomfleckin
This is opacification of the lens from high IOP.
Normal IOP
10-21 mmhg.
What IOP pressure alone is enough to start tx?
30 mmhg
Normal corneal thickness
555 nm
____ Corneas underestimate IOP
Thin
____ Corneas overestimate IOP
Thick
Corneal thickness at a high risk
Corneal thickness at a lower risk
> 588
Progressive thinning of _____ is pathonogmonic for glaucoma
Neural rim
Disk size of myopes vs. hyperopes
Myopes have a bigger disc.
As C/D reaches ____ glaucoma risk increases
.6
Is asymmetrical optic discs normal?
NO! Any difference of .1 is abnormal
ONH red flags for glaucoma
Vertical elongation or vertical notching.
Rim thinning in glaucoma
Will go temporal–>superior and inferior–>nasal.
Vasculature in glaucoma
Vessel kinking at cup edge, nasal migration of vessels over time. Collateral shunt forming.
___ of individuals with PDS go on to develop glaucoma
30-50% (closer to 35%)
Glaucomatous VF defects
Paracentral scotoma first. Seidel scotoma (not connected to blind spot)–>accurate. Will obey horizontal raph.
PG and PDS epidemilogy
Occurs in younger age 20-40. PDS more common in Caucasians. PDS equal in M and W. PG more common in M. PDS can be inherited as autosomal dominant trait. More often in myopes and those with deep angles.
GDx nerve fiber layer analyzer
Use polarization of NFL. Looks at thickness of NFL.
TSNIT curves
Looks at temporal, superior, nasal, inferior, temporal doing a circle around the NFL. Shows how thickness compares.
Ganglion Cell complex
Measures thickness of 3 innermost layers affected by glaucoma. NFL, GCL, IPL.
Reichert Ocular Response Analyzer
Records to pressure values. The difference is the corneal hysteresis (lower CH in NTG pt)
Color testing in glaucoma
Red cap. Only affects very late
Common Denominator in glaucoma
An acquired, progressive optic neuropathy.
Primary open angle glaucoma
Can be high tension or normal. No associated disorder. The angle is open but aqueous outflow is reduced.
Secondary glaucoma
Caused by a variety of ocular and systemic disorders. Can be open or closed. Inherited or acquired and bilateral or unilateral
Developmental glaucoma
Due to abnormalities of the anterior chamber angle. Abnormalities occurring during gestation. Most forms are secondary type glaucoma or chronic.
Most common form of adult glaucoma
Open angle glaucoma. No obstruction by iris root
Psudoexfoliation material
Fibrilogranular material of a protein nature and it is amyloidlike. Is possibly secondary to disturbances in the biosynthesis of basement membranes in epithelial cells. Iris pigment epithelium, ciliary epithelium, and peripheral anterior lens epithelium are thought to create. Has a wide distribution throughout the body.
What two glaucoma workups can you not bill on the same day?
OCT and Fundus photos. Bring them back.
Pigment glaucoma and pigment dispersion syndrome
Occurs by pigment from iris depositing on anterior segment structures. Pigment in TM.
Is the ciliary body normally pigmented?
YES
Pig. disperion syndrome vs. Pigmentary glaucoma
Pigmentary glaucoma has pigment accumulation in TM resulting in ocular HTN WITH optic neuropathy. PDS does NOT have optic neuropathy.
Types of PDS
- Classic 2. Long anterior zonule associated PDS (Long zonules inserted onto central lens capsule may cause mechanical disruption of pigment epithelium at the pupillary ruff and central iris. This leads to pigment dispersion)
___ of individuals with PDS go on to develop glaucoma
30-50%
Pathophysiology of PDS
- Pigment release from iris pigment epithelium
- Mechanical disruption-radial folds of iris pigment epithelium against lens capsule or zonular fibers. Occur in middle of iris. Think that a reverse pupillary block (between iris and lens) results in iris bowing back and making concave lips
PG and PDS epidemilogy
Occurs in younger age 20-40. PDS more common in Caucasians.
IS PDS and PG bilateral?
Yes. Can be asymmetrical though (the more myopic eye will be affected more)
Symptoms of PG or PDS
Asymptomatic or intermitten or rapid IOP elevation causing Pain, corneal edema, intermittent blurry vision, halos around lights.
PG or PDS and exercise
Often have symptoms after working out. Working our liberates more pigment. Can also occur with pupil dilation.
Classic triad with PG
- Kruckenberg spindle (can happen with other dz)
- Iris transillumination defects
- Pigment deposition in the TM (homogenous and even). May see Sampaolesi’s line (pigmented schwalbe’s line)
- Zentmeyer ring or Scheie’s line (pigment accumulation at the zonular attachment of the lens)
Kruckenberg spindle
Vertical pigment accumulation in the endothelium
Less common signs of PG
Pigment on anterior iris, pigmentation of the lens zones and lens capsule. Also commonly find concavity of the mid peripheral iris.
What conditions are PG and PDS pt at a higher risk for?
Retinal detachment (6-7%) and lattice degeneration.
Tx and Mgmt for PG
Topical beta-adrenergic antagonist, alpha2 adrenergic agonistic, CAI, Prostaglandin analogues, Miotics, Laser peripheral iridotomy (may eliminate bowing) or Argon laster trabeculoplasty.
Pseudoexfoliative glaucoma vs. pseduoexfoliation syndrome.
Syndrome (PXE/PXS) is anterior segment changes without increased intraocular pressure and/or glaucomatous VF and optic nerve changes.
PXS/PXE characteristics
Characterized by gray-white flakes of granular material depositing through the surfaces of the anterior chamber structures. Associated with secondary open-angle glaucoma. It is a common ocular manifestion of a systemic disease.
Psudoexfoliation material
Fibrilogranular material of a protein nature and it is amyloidlike. Is possibly secondary to disturbances in the biosynthesis of basement membranes in epithelial cells. Iris pigment epithelium, ciliary epithelium, and peripheral anterior lens epithelium are thought to create.
PEX and kruckenberg
Can also cause kruckenberg. Do not automatically assume PDG.
Pseudoexfoliative glaucoma
Occurs when the material is carried to the TM.
PXG prevelance
.6% in 52-64
5% in 75-85 year olds. Predominate disorder of the elderly (60-80). Most studies more common in W. Men more likely to develop glaucoma. Common in scandinavians.
____ of patients with PXS develop glaucoma afte 10 years
15%
Psuedoexfoliation begins most commonly as a ____ conditions
Monocular. Increases bilaterally with age
What conditions is Pseudoexfoliation linked with?
Alzhimers, senile dementia, stroke, TIA, heart disease, hearing loss, higher homocystein levels (risk for cardiovascular dz)
Clinical features of Pseudoexfoliation on the lens
- Grey-white deposits on anterior lens in a bull’s eye pattern
- Three identifiable zones with dilation. Central translucent zone, intermediate clear zone, peripheral granular zone. Clear zone due to rubbing (can cause PDS)
Pseudoexfoliation of the iris and pupil
Pseudoexfoliative material seen at the pupillary border. Pupillary ruff defects are seen. Iris transillumination shows a moth eaten pattern at the peripupillary and sphincter regions of the iris.
Lens subluxation and Pseudoexfoliation
PXM found on the CB and zonules early in the process. Resulting in degernation and lens sublaxation in 10-15%
Cataracts and PXS
33% of cat. pt. also had PXS.
Cornea and PXS
May see flakes or clumps on the endothelium (may have a kruckneberg spindle). Decreased endothelium cell count.
Classifications of angle closure glaucoma
Classified based on anatomical structure of force causing the iris apposition to the TM.
- Pupillary block
- Plataeu iris (level of CB)
- Phacomorphic glaucoma (level of lens)
- Malignant glaucoma (forces posterior to the lens)
Pigment and PXS
Will have increased pigment in the angle. Less dense than in PDS and more spotty.
Medical TX for PXG
Frequently more resistant to medical treatment. Topical beta-adrenergic antagonists, alpha2 adrenergic agonists, CAI, prostaglandin analogues, miotics
Surgical TX for PXG
Argon laster trabeculoplasty (earlier in tx), selective laster trabeculoplasty (repeatable), surgical trabeculectomy, combined surgery.
Diet and PXG
Pt. has increased homocystein concentration. The use of B-12 and folic acid supplements to decrease hyperhomocysteinemia in pt.
Neovascular Glaucoma
Increased IOP due to angle closure from fibrovascular membrane formation obstructing aqueous outflow. Can lead to glaucoma from a secondary open or closed angle mechanism.
Key to neovascular glaucoma tx
early detection
Pathophysiology of Neovascular glaucoma
Usually due to retinal hypoxia or ischemia. Hypoxic retina produces an angiogenic factor that stimulates neovasculerization. New blood vessels on iris (rubeosis iridies or NVI). VEGF.
Most common cause of neovascular glaucoma
CRVO (36%) Ischemic most common.
Other causes of neovascular glaucoma
Diabetic retinopathy (32%), Carotid artery disease (13%)
Disorders that predispose patients to neovascular glaucoma
CRAO (18%), Uveitis, long standing retinal detachment, intraocular tumors, carotid cavernous fistula.
Early phase signs of neovascular glaucoma
Small vessels at the pupillary margin are the earliest sign.
Middle phase of neovascular glaucoma
The angle becomes involved. Neovascularization toward the angle. Fibrovascular membrane can grow with NVA and obstructing the TM. Hyphema may occur.
Late Phase Neovascular glaucoma
Fibrovascular membrane in the AC contracts producing peripheral anterior synechia (PAS) Begins in one quadrant but can go 360
Clinical features of neovascular glaucoma
Cells and flare may be present due to vascular proliferation. Early in disease IOP is often normal. Contraction of the membrane pulls the peripheral iris over the TM resulting in acute angle closure
TX of neovascular glaucoma
Need early dx. Treat underlying disease. Topical steroid to treat inflammation. Anti-VEGF therapy. Control IOP. Panretinal photocogulation is a first line therapy. Panretinal cryotherapy is an alternative to PRP in eyes that have cloudy media and in eyes for which PRP failed. Can use anti-VEGF with PRP. Filtering surgery in neovascular glaucoma is used to prevent pressure-induced injury and to improve vascular perfusion.
Last step tx for neovascular glaucoma
Cyclodestruction, retrobulbar alcohol injection or enucleation.
Angle closure glaucoma cause
Caused by iris apposition to the TM due to abnormal relationships of the anterior segment structures. No aqueous reaches the TM.
Symptoms and signs to diagnose angle closure glaucoma
2 symptoms (ocular pain, N&V, history of intermittent blurring with halos) and must have 3 signs (IOP greater than 21, Conj injection, corneal epithelial edema, mid-dilated non-reactive pupil, shallow chamber in presence of occlusion)
Pupillary block AACG
Rapid increae in IOP. Triggered with mid-dilation. May occur in people with or without predisposing ocular char. Most attacks occur during the evening. Can also occur in the movies (dark and pupil dilates). Adherence between the back of the iris and the front of the lens, prevents aqueous to pass forward, increased in IOP behind the iris creates an Iris Bombe, the peripheral iris is pushed forward to adhere to the cornea or TM.
Risk factors of AACG
Females, hyperopes (shallower eye), caucasian, asian, positive family history, increased risk with age (until cataract surgery), increased lens thickness.
Enviormental stimulus causing AACG
Entering a dark room, mental and emotional stress, fatigue, trauma, respiratory infections
Features of AACG
Gonioscopy shows a 360 closed angle, possible peripheral anterior synechiae, possible posterior synechiae, glacomflecken. Iris torsion, patchy iris atrophy, disc edema, possible optic atrophy.
Dark room provocative test
Dilate or put in a dark room and see if angle closes.
AACG without pupillary block (plateau iris)
Plateau iris occurs. Caused by large ant. positiond ciliary processes. Pushes peripheral iris forward. Obstruction of aqueous outflow due to position of the ciliary processes against the TM crowding the angle. Last iris roll will be bunched and forced against the TM on pupil dilation.
Plateau Iris Epidemiology
Accounts for more than 50% of young pts with recurrent angle closure. Tends to occur in young patients and females. Suspect if narrow angle persists.
TX for plateau iris
Laser peripheral iridotomy is the first tx. Some patients have plateau iris syndrome (occluded angle even with LPI) Treat these patient with laser iridoplasty (laser burns at the peripheral iris to shrink the iris and pull it from the angle) May need to use conventional surgery to keep IOP down (tube shunt)
Phacomorphic glaucoma
Due to lens swelling.
Malignant glaucoma
Due to virtual pressure. Angle closure due to posterior forces pushing the lens iris diaphragm forward.
Glaucoma treatment flow
Medical–>laser treatment (laster trabeculoplastey–>surgery (filtration/bleb/trabeculectomy)
Theories of glaucoma damage
Direct mechanical theory (ocular pressure blocks axoplasmic flow) Ischemic theory (ocular pressure blocks circulation to n) Apoptosis (programmed cel death mediators involved. Genetic predisposition)
Main glaucoma tx mechanisms
Reduce aqueous production,
Increase aqueous outflow,
Neuroprotections.
Drugs that reduce aqueous protection
Adrenergic antagonists (beta blockers), CAI (Amide)
Beta blockers
Beta 1-the heart
Beta 2-the lungs
Used to be the drug of choice.
olol
Betaxolol
The only Beta 1 selective. May be more safe. Won’t affect patients with asthma. May have neuroprotection.
Dosing with beta blockers
Normal dosing is BID.
Carteolol
Does not cross the BBB as much as the other drugs.
CAI
Inhibits Carbonic anhydrase E in ciliary epithelium from produced aqueous. Rarely used by itself. Amide.
Systemic CAI
Acetazolamide, methazolamide, dichlorphenamide. use in 911 situation. Use with above 40.
CAI SE
Bitter taste, sulfa allergies, HA, nausa, tinnitus. Don’t use with such. Avoid with sulfa allergy, sick cell, blood dyscrasias, corneal surgery patient, or corneal endo cell disease.