Flashcards in glaucoma Deck (231):
What are the 3 components of trabecular meshwork
uveal (at iris root), corneoscleral (sheets spanning from scleral spur to scleral sulcus), juxtacanalicular (major site of outflow resistance; next to canal of schlem)
What are the 3 mechanisms that aqueous enters the posterior chamber?
active secretion (via Na-K pumps), ultrafiltration (hydrostatic and oncotic pressures), and diffusion (movement of ions down concentrations gradient
aqueous production is via what kind of cells?
non pigmented ciliary cells
what is the Goldmann Equation of IOP?
IOP=(formation of aqueous-pressure insensitive uveoscleral pathway)/(Pressure sensitive trabecular pathway+episcleral venous pressure)
what are the two pathways of aqueous outflow?
via trabecular meshwork (schlem to episcleral veins) and uveoscleral pathway (root of iris/ciliary body to suprachoroidal space)
POAG risk factors
elevated IOP, African American, FMHx, thin corneas, age, decreased perfusion pressure, ischemic vascular diseases (HTN, DM...etc)
PACG risk factors
women, hyperope, inuit/asian
when is peak IOP during the day
early AM; decreases by half during sleep.
What is the rate of aqueous production
what is the venous outflow path from canal of schlem?
schlemm to episcleral veins to anterior ciliary and superior ophthalmic veins then to cavernous sinus
what happens to cross section of canal of schlemm as IOP increases
cross section decreases as trabecular meshwork expands
uveoscleral drainage decreases with age and glaucoma. What increases uveoscleral drainage?
cycloplegics, adrenergic, prostaglandins.
Miotics decreases uveoscleral outflow
what 4 conditions increase episcleral vein pressure?
cavernous-carotid fistula, cavernous thrombosis, sturge weber, thyroid eye disease
what are factors influencing IOP?
time of day
body position, exercise, HR, BP, respiration
what principle is tonometry based on?
Imbert Fick Priciniple
What is the inbert fick principle?
The pressure in a dry thin walled sphere equals the force necessary to flatten its surface divided by the area of flattening. P=F/A
What is the area that is flattened on Goldman application
3.06 mm diameter of the cornea
too much fluoresceine on Goldmann applanation leads to what falsely high or low pressures
what is CCT
central corneal thickness
whats normal CCT
why are tonopens and pneumatic tonometers (both are Mackay Marg Type tonometers) useful for patients with corneal edema or scars?
because it only interacts with a small area of the cornea
what kind of tonometer is good for Peds?
rebound tonometer because it doesn't require topical anesthesia
How does the Schiotz tonometer work?
It indents the cornea with a known weight to be converted to IOP
what are three ways to clean tonometer prisms?
1:10 bleach, 3% hydrogen peroxide, 70% isopropyl alcohol for 5 mins.
Hyperemia in a patient with glaucoma you should think of what two causes?
elevated IOP or their drops
what are some adverse affects of IOP lowering drops?
follicular reaction, decreased tear production.
What characteristics of a bleb should you look at?
height, size, degree of vascularization, integrity, Seidel test
what are breaks in the decemets membrane secondary to enlargement of the cornea called?
Haabs striae (found in glaucoma patients at times)
Characteristic eye driness from glaucoma meds
what's Van Herrick's method
fast method of estimating angle with thin slit lamp beam
In what situations can blood from episcleral veins enter the canal of schlemm?
whenever episcleral vein pressure is higher than IOP. In hypotony, sturge-weber, cavernous carotid fistula
What are normal vessels that can traverse the angle? how are they usually oriented?
radial iris vessels, ciliary body arterial circle, vertical branches of the anterior ciliary arteries.
Either vertically or radially.
what does PAS stand for? What could you possibly confuse this for at the angle?
peripheral anterior synechiae (more solid sheet like)
Can be confused with normal iris processes (uveal meshwork--which are open and lacy)
what is sampaolesi line?
pigment deposition anterior to Schwalbe's line from pseudo exfoliation syndrome.
what are the names of the two most common gonio grading systems?
Schaffer and Spaeth
Criteria for angle recession glaucoma diagnosis on gonio?
1. abnormally wide ciliary body band
2. increased prominence of scleral spur
3. torn iris processes
4. marked variation of the ciliary face width and depth in 4 quadrants
what is cyclodialysis?
separation of ciliary body from scleral spur
diameter of anterior optic nerve?
diameter of posterior optic nerve
what are the 3 types of retinal ganglion cells in primates?
M cells (magnocellular neurons)
P cells (Parvocellular neurons)
Bistriated cells (koniocellular neurons)
What are M Cells? what kind of vision does it provide? where does it synapse?
They are large axonal cells of the retinal ganglion layer; responsible for dim changes in luminance--thus motion detection. They synapse on the Magnocellular layer of the lateral geniculate ganglion
What are P cells? where do they synapse? what are their function
They are located in the central retina with small diameter axons with slow conduction velocity. They synapse on the parvocellular layer of the lateral geniculate ganglion. They discern color and details. Best in luminance conditions.
what is the bistriated cells' function?
discerning blue-yellow oppnency. Activated when blue cones are stimulated and suppressed with red-green cones.
what are the 4 layers of anterior optic nerve?
nerve fiber layer--essentially same as RNFL
prelaminar layer--juxtaposed to the peripapillary choroid
laminar layer- juxtaposed to sclera and lamina cribosa
retrolaminar layer-Becomes myelinated and leptomeninges wraps around
how can you visualize the nerve fiber layer?
red free filter (green)
What is lamina cribosa?
structural layer of the optic nerve as it exits the eye along the Laminar portion of the optic nerve. It has extraceullar matrix for support, vessels for nourishment. Fenestrations allow traversing central retinal A and V to pass through
What is ring of Elschnig?
connective tissue ring layer next to the sclera/choroid supporting the optic nerve.
lamina cribosa is thinnest where?
superior and inferiorly
What are the two types of peripapillary atrophy (PPA)? Which is concerning
Alpha (normal and in glaucoma with hyper and hypopigmentation. Beta zone is associated with glaucoma and have atrophic RPE and largest in areas of neuroretinal loss
What is the ganglion cell complex?
Retinal layers including RNFL and ganglion cell layer and inner plexiform layer
What are the two other imaging techniques for RNFL/ONH other than OCT?
Confocal scanning laser ophthalmoscopy, scanning laser polarimetry
Clover leaf VF indicates what
Inattentive patient or malingering
What are the classic VF patterns of glaucomatous change?
Arcuate defect (Bjerrum scotoma), nasal step, paracentral scotoma, altitudinal defect, generalized depression, temporal wedge
What is trend based analysis
looking at all VFs throughout time.
what is event based analysis
looking at VFs against a baseline test
what are ways to measure progression based on Visual fields?
mean deviation, visual field index progression plot
What is FDT perimetry?
Frequency doubling technology perimetry. selectively evaluates M pathway for contrast sensitivity toward motion
What is SWAP?
short wavelength automated perimetry. uses narrow blue-violet stimulus against a bright yellow background to test the koniocellular layers projecting toward lat gen ganglion
What is FDF
flicker defined form perimetry. stimulates M pathway and may be useful for early glaucoma detection.
What is UBM and AS-OCT? what's good about each?
US biomicroscopy and ant seg-OCT. AS OCT has higher resolution. however AS OCT doesn't penetrate sclera well...thus UBM is better for ciliary body structures
How was the normal IOP range determined?
average IOP of 15.5 with +/- 2SD on either side. This is based on European studies
whats the average CCT?
what are the major associations risk factors for POAG?
age, race, family history, CCT, IOP
what is the association of HTN and POAG?
young people are protected against POAG and older are more susceptible
Which study found association of DM with POAG? which showed it's protective against POAG?
Beaver Dam showed DM is associated with POAG. OHTS showed it's protective
what are more obscure conditions associated with POAG?
migraines, thyroid, sleep apnea, HLD, low CSF pressure, corneal hysteresis, Raynaud
what characteristic of a POAG patient puts them at most likelihood of blindness?
visual field loss at the time of diagnosis
what's the technical term for normal tension glaucoma?
POAG without elevated IOP
normal tension glaucoma can be split in to which two categories?
Senile sclerotic group-pale sloping neuroretinal rim
Focal ischemic group- deep focal notching of rim
How does VF differ in a NTG pt vs POAG?
NTG tend to be more dense centrally early on
Collaborative NTG Study (CNTGS) found what?
reducing IOP by 30% reduced progression of VF from 35% to 12%... after adjusting for the effect of cataracts
what kind of glaucoma has incisional surgery as first line of treatment?
primary congenital glaucoma
What's the general mechanism of Laser trabeculoplasty surgery?
increase outflow via targeting the trabecular meshwork
How does ALT work?
Thermal damage to trabecular meshwork leading to scarring and release of TNFa, INFb leading to stretching of adjacent areas of trabecular meshwork
How does SLT work?
targets pigmented cells only leading to increased inflammation and trabecular meshwork adjacent to areas targeted.
what are glaucoma suspects?
abnormal nerve appearance OR abnormal fields
pseudo exfoliation syndrome is associated with what gene?
LOXL1; but it's a multifactorial disease.
Classic pattern on exam for pseudo exfoliative syndrome?
- bullseye pattern
- transillumination defect
- Poor pupillary dilation
-weak zonules--phacodonesis, iridodonesis
- Pigment deposition (sampaolesi line) at the angle
- Krukenberg spindles
Intraop (cataract surgery) complications of pseudo exfoliation?
zone dehiscence, lens dislocation, vitreous loss
association of increase risk for progression in pseudoexfoliation syndrome in development of glaucoma was shown in what study?
Early management of glaucoma trial
prognosis of pseudo exfoliative glaucoma vs POAG?
pseudo is worse
What population is pseudoexfoliation syndrome associated with?
Scandinavians (up to 50% of glaucomas)
What are classic exam signs of pigment dispersion syndrome?
- transillumination defect
-pigment deposition (krukenberg spindle and in trabecular meshwork)
Zentamayer ring or scheme stripe is?
deposition of pigment on zoneules and equatorial region of lens in pigment dispersion syndrome.
How is pigmentary dispersion syndrome affected by age.
It may get better given pigment is reduced.
posterior bowing of iris seen in what glaucoma condition
Pigmentary dispersion glaucoma responds well to what?
medical, laser, and trabeculectomy filtering surgery (however caution in young myopes)
How can you distinguish phacoantigenic and phacolytic glaucoma?
phacolytic is nontraumatic/disturbed lens and NO KPs
How can tumors cause glaucoma?
direct angle invaions, angle closure, hemoorhage, NV, inflammation
how to treat retained lens particle glaucoma?
medical therapy to control IOP when the particle resorbs... If cannot be controlled then take it out
Hallmarks of Posner scholssman
High IOP in 40-50s, mild AC reaction, unilateral in middle age person
What is a theoretical cause of Fuch's heterochromic uveitis?
Does fuch's heterochromic uveitis respond to steroids?
Classic findings in Fuch's heterochromic uveitis?
mild inflammation (stellate KPs), elevated IOP, asymptomatic, fine vessels crossing the trabecular meshwork but NO PAS
why are sickle cell patients at an elevated risk of IOP elevation after hyphema?
acidic aqueous induces sickling and traps RBCs in trabeculum. Sickle cell patients' optic nerves also are more prone to damage.
which two patient population with hyphema should you consider early surgical intervention
1. sickle cell as their optic nerves are more susceptible to damage
2. Young children to avoid corneal staining/amblyopia
what's the difference between traumatic hyphema, hemolytic glaucoma, and ghost cell glaucoma
hyphema is layering in AC, hemolytic glaucoma is AC RBCs from vitreous hemorrhage, ghost cells are degenerated hemolytic RBCs
glaucoma is a frequent side effect of PKP. why?
wound distortion of the trabecular meshwork and progressive PAS formation
what's IOP like in most rhegmatogenous RD? What is the issue if it's high? How do you treat this?
IOP is usually low. High IOP can be seen with Schwartz Syndrome given outer segment photoreceptor migration to AC and decreases aqueous outflow.
Retina reattachment to treat
What is Schwartz syndrome
migration of outer segment photoreceptors to AC and decreasing aqueous outflow thereby increasing IOP
what are risk factors for corticosteroid induced glaucoma? 6
POAG, first degree relative with POAG, young age <6 years, connective tissues disease, Type 1 DM, myopia
CIGTS trial. Purpose? Results/big points?
collective initial glaucoma tx study
Purpose: medical vs filtering surgery for initial treatment of POAG
Results: surgery lowered IOP more, but progression were about the same long run. Worse baseline VF and surgery resulted in less progression
OHTS trial. purpose? results/big points
ocular hen study
purpose: efficacy and safety of topical antihypertensives in ocular HTN.
topical were effective preventing onset of POAG.
5 year risk of OAG risks were: older, CDR/morphology, higher pattern standard deviation, baseline IOP. CCT.
EMGT trial. purpose and big points
early manifest glaucoma trial
Purpose: effectiveness of IOP lowering with new, early OAG
Results: no tx progressed more than tx.. risk factors for progression --age, high IOP, pseudo exfoliation, more advanced field loss, bilateral glaucoma
primary angle closure suspect (PACS) definition
vs primary angle closure (PAC) vs Primary angle closure glaucoma (PACG)
iridotrabecular contact >180deg no trabecular/optic nerve damage.
iridotrabecular contact with IOP elevation or PAS, no optic nerve damage
iridotrabecular contact AND optic neuropathy
population most susceptible to angle closure glaucoma
Asian females (inuits the highest)
name some secondary causes of angle closure glaucoma?
NVG, intumescent lens. lax zonules--marfans/pseudoexfoliation, chronic uveitis, corneal endothelial migration, epithelial ingrowth, posterior mass
most common cause of angle closure?
anterior chamber depth of less that what depth is prone to PAC
biometric parameters predisposing to PAC?
short AL, shallow AC (2.5mm), thick lens, small K diameter
which gene is associated with PACG?
general risk factors for PACG?
female, Asian, biometric measures, FMHx, hyperopes
when should you definitely do an LPI for an anatomical narrow angle patient?
appositional closure, PAS, increased segmental trabecular meshwork pigmentation, hx of previous angle closure, high risk factors
eye pain, blurry vision, halos, HA
high IOP, mid dilated pupil, K edema, shallow AC
strategies to break an PAC attack.
miotics cholinergic (with care, this may worsen some types without pupillary block), beta blockers, alpha2 agonists, prostaglandins, carbonic anhydrase inhib, globe compression with gonio, LPI
lowered IOP after an acute angle closure attack doesn't necessarily mean angle is open...why?
ciliary body ischemia may lead to decreased aqueous production leading to lowered IOP...therefore you need to gonio to make sure anle is open
what is subacute angle closure
also called intermittent angle closure... angle closes now and then and resolves --esp while sleeping (miosis). Pt has intermit HA, IOP elevation, eye pain
what is chronic angle closure glaucoma? how do you treat it?
slow progression of PAS at angle. can be confused with POAG. must do LPI
what is double hump sign
how to treat plateau iris?
LPI, lensectomy, iridoplasty
treatment phacomorphic glaucoma?
cataract surgery vs LPI then cataract surgery
iris bombe treatment
LPI 180 degrees apart. then lensectomy
Why does pseudophakic, aphakic, and AC IOL angle closure occur?
vitreous pushes forward to these interphases
what is capsular block?
fluid or visco enters capsular bag and pushes IOL forward narrowing the angle.
NVG occurs mostly with which conditions?
DR, CRVO, BRVO, ocular ischemic syndrome
NVG and ICE both can cause ectropion uvea and PAS in the angle. what feature distinguishes them?
in NVG PAS ends at the Schwalbe line. ICE extens to corneal endothelium.
what conditions causes NVI that's not associated with retinal ischemia?
Fuch's heterochromic uveitis., pseudoexfoliation, iris melanoma
what is Schwabe's line
where descemet meets trabecular meshwork
what is posterior embryotoxon
thin gray arcuate line marking anteriorly displaced schwalbes line
what are some contraindications for incisional filtering surgery?
conj scarring/surgery, active scleritis/uveitis, active anterior segment NV
whats the definitive treatment for NVI
What are the triads of ICE syndrome.
iris atrophy, angle closure, corneal edema
patient population of ICE syndrome
middle age, women, unilateral
What are the three clinical variants of ICE syndrome?
Essential progressive iris atrophy, Cogan-Reese syndrome, Chandler syndrome
What is unique about PAS formed in ICE syndrome?
high PAS reaching pass schwalbe's line
what is essential progressive iris atrophy?
clinical variant of ICE syndrome characterized by extreme iris atrophy: heterochromia, corectopia, ectropion uveal,, iris stromal atrophy, holes
What is Chandler syndrome
ICE variant characterized by corneal edema and angle closure mostly with minimal iris atrophy
What is Cogan Reese syndrome?
ICE variant characterized by tan pedunculate nodules on iris surface
what is the percentage of patients with ICE who develop glaucoma?
two conditions with beaten bronze endothelium appearance?
Treatment for ICE? medical? surgical?
targeting K edema and ACG. Hypertonic topicals, aqueous suppressant, prostaglandins. Filtering surgery is good. YAG can be used if endothelial cells grow over filtering fistula
what is malignant glaucoma?
AKA aqueous misdirection or ciliary block. mostly postop with sudden onset pain/IOP, diffusely shallowing of the AC--AVOID miotics
what's the definitive treatment for malignant glaucoma? what about in the interim prior to definitve tx.
vitrectomy with anterior hyaloidozonulectomy and deepening the AC.
-can do topicals, YAG to disrupt anterior vitreous in pseudophakics, and Argon photocoagulation of ciliary processes in the interim
How do you confirm a diagnosis of epithelial ingrowth?
argon laser produces white burns on epithelium
define nanophthalmos. other features?
axial length <20mm. small cornea, lens is relatively large compared to eye, thick sclera (impede vortex veins drainage)
surgical risks of nanophthalmic eyes
choroidal effusion, nonrhegmatogenous RD, angle closure
what can topiramate cause? how to treat?
bilateral sudden onset angle closure and myopic shift. usually bilateral. Stop topiramate and get IOP down
what are meds that can cause secondary acute angle closure?
topiramate, Bactrim, acetazolamide/methazolamide,
what should you think of with bilateral angle closure and myopic shift.
what are the 4 categories of primary pediatric glaucomas?
1. congenital open angle glaucoma
2. juvenile open angle glaucoma
3. glaucoma due to ocular anomalies
4. glaucoma due to systemic diseases
three classic features of primary congenital glaucoma (PCG?)
high IOP, large cornea, haabs striae
whats the time frame of new born primary congenital glaucoma?
at birth or witin 1 month of age
whats the time frame of late diagnosed primary congenital glaucoma?
up to 2 years of life
what's the time frame of juvenile open angle glaucoma? what's it associated with? general prognosis?
after 2 years of life (4-35 usually) associated with anterior segment abnormalities. px most will end up need trabs and tube shunts.
juvenile open angle glaucoma is associate with what genes?
TIGR, MYOC --both of GLC1A locus
mode of inheritance of primary congenital glaucoma?
sporadic and autosomal rescessive
mode of inheritance of juvenile open angle glaucoma?
genetic association of aniridia?
PAX6, usually autosomal dominant
genetic associations of axenfeld rieger?
genetic associations of Peter's syndrome
PAX6, FOXC1, PITx2, CYP1b1
gender association of primary congenital glaucoma?
good prognostic factors in primary congenital glaucoma?
diagnosis between 3 mo and 1 year
bad px factors in primary congenital glaucoma?
dx at birth or after 1 year, K diameter >14mm
classic presenting triad of congenital glaucoma?
photophobia, blepharospasm, epiphora
why are corneas large in congenital glaucoma?
IOP elevation causes K and scleral stretch up to 3 years old--leading to large K and bulthalmos. Causing K edema and Haab's striae
what origin are trabecular meshwork cells?
what is axenfeld anomaly
posterior embryotoxon with peripheral iris strands
what is Rieger anomaly?
axenfeld anomaly (Posterior embryotoxon) +corectopia, iris atrophy, ectropion uvea
what is axenfeld-Rieger syndrome?
ocular( posterior embryotoxon, corectopia, iris atrophy, glaucoma), dental malformation, maxillary hypoplasia, redundant periumbilical folds, hypospadias, pituitary abnl
eye manifestations of Peter's anomaly
leukoma (stromal, decemet, endothelial abnls), iris strands, aniridia,
systemic manifestation of Peter's anomaly?
cardiac, urogenital, musculoskeletal, ear, palate, spine
Peters anomaly mode of inheritan
sporadic-- both autos dom and rece also exist
what percent of Peters anomaly patients develop glaucoma? What about Axenfeld rieger?
50% for both
why is aniridia associated with glaucoma?
angle closure occurs when rudimentary iris stomp rotates forwards and forms PAS over time
aniridia is associated with what cornea abnl?
limbal stem cell deficiency-->pannus formation
aniridia mode of transmission? associated genes?
autosomal dominant. PAX6, WT1 (wilms tumor)
systemic syndromes associated with aniridia?
Wagr (wilms tumor, aniridia, genitourinary, retardation)-autosomal dom
Gillespie: autos recessive-aniridia, cerebellar ataxia, retardation
sturge weber-- % associated with glaucoma? why glaucoma?
30-70%. increased episcleral venous pressure and malformation of the trabecular meshwork
associations of sturge weber (systemic)
leptomeningeal angioma, choroidal cavernous hemangioma, calcifications, seizures, focal neurologic deficits, cognitive impairement
ocular surgical risk in patients with sturge weber?
choroidal effusion, choroidal hemorrhage
neonate with ectropion uvea-- you should work them up for what?
NF1 ocular findings? systemic findings?
Lisch nodules, optic nerve gliomas, eyelid neurofibromas, glaucoma.
café aulait spots, cutaneous nerofibromas, axillary freckling
aphakic glaucoma risk factors?
cataract surgery within 1st year of life, post op complications, small K diameter
normal corneal diameter in new born and 1 year old?
9.5-10.5 at birth, 11-12 mm at 1 year
anesthesia all lower IOP except for what? and what increases IOP
ketamine incrases IOP
what are the therapies of choice for primary congenital glaucoma?
surgical: goniotomy (for clear corneas) or trabeculotomy (for cloudy corneas)
70-80% success for patients diagnosed 3 mo to 12 mo.
trabeculectomy or tube shunts are reserved for which pediatric patients?
if they have failed two conservative surgeries (goniotomy/trabeculotomy)
what are some complications of cyclodestruction
phthisis bulbi, uveitis, hypotony, RD
what is trabeculotomy?
sclerotomy and then cannulating the canal of schlem 360.
what is goniotomy?
incision at the uveal trabecular meshwork with a gonio lens in place and through a clear corneal incision
trabeculectomy has a low success rate in which patients?2
younger than 2 y/o and aphakic
what are the aqueous suppressing meds?
alpha agonist, beta blocker, carbonic anhydrase
side effects of betablockers?
what are side effects of carbonic anhydrase? who should NOT be given these?
diarrhea, hypokalemia, sickle cell crisis, SJS, aplastic anemia
sulfa allergies, poor renal function
side effect of alpha blockers? contraindications?
crosses BBB, therefore apnea, hypotension, bradycardia, hypothermia, hypotonia, somnolence, follicular conjunctivitis with long term use
contraindicated in children <3
which are the outflow promoters?
alpha agonists, prostaglandins, cholinergics
possible side effect of prostaglandins?
hypertrichosis, trichiasis, conj hyperemia, periocular pigmentation, darkening of iris color, prostaglandin associated periorbitaopathy (sunken in eyes), CME
general rule of thumb with target IOP in glaucoma pts?
>25%, but should be individualized
what are the 6 classes of glaucoma meds?
alpha agonist, beta blocker, carbonic anhydrase, prostaglandin, cholinergics, hyperosmotics
what are the 4 prostaglandins and what's special about each
latanoprost/travoprost: lowers by 25-32%
bimatoprost: lowers by 27-33%
Tafluprost: only preservative free
what's special about betaxolol
it's a beta 1 selective inhibitor. less effective than the nonselectives
pilocarpine is used for what?
plateau iris syndrome, pigmantart glaucoma
serious side effects of hyperosmolars?
CHF, MI, confusion, subdural/subarachnoid hemorrhage. Contraindicated in renal failure
which glaucomas are good for laser trabeculoplasty?
POAG, steroid induced, pseudoexofliation, pigmentary
which glaucomas should not be treated with laser trabeculoplasty?
developmental, inflammatory, NVG, ICE
which is the only category B glaucoma med in pregnancy?
what are the 3 lasers used for laser trabeculoplasty?
argon (ALT), nd;yag (SLT), iodide
what is peripheral iridotomy used for?
primary angle closure, pupillary block, or PAC suspects
contraindications of LPI?
completely flat chamber--avoid K damage
secondary angle closures w/o pupillary block
how do you deal with bleeding during LPI?
push laser lens on the eye to tamponade the bleed. if that doesn't work use argon laser to coagulate it
what is gonioplasty/iridoplasty?
argon laser to the peripheral iris to allow AC to deepen by causing stromal shrinkage. This is done after LPI in angle closure/plateau iris
what are the cyclodestruction techniques
cyclocryotherapy (higher risk of phthisis, hypotony)
when do you do cyclodestruction
poor visual potential, poor candidate for incisional surgery. "painful NLP eye"
methods of treating painful NLP eyes?
retrobulbar alcohol, retrobulbar chlorpromazine, enucleation, transscleral cyclophotocoagulation
what are the contraindications of external cyclodestruction?
what are contraindications of endoscopic cyclophotocoagulation?
external (cryo, transscleral): contraindicated in good vision, NV--> high risk of phthisis
endoscopic CP: contraindicated in blind eyes due to sympathetic ophthalmia risk
what are indications for incisional surgery
uncontrolled IOP, progression of field loss, medication nonadherence
contraindications for trabeculectomy. 3
active uveitis/infection, bad conj/sclera, blind eye
whats the most common cause of vision loss s/p trabeculectomy? what are other causes?
cataract formation. others include macular edema, hypotony maculopathy, "wipe out" loss of vision for no apparent reason, blebitis/endophthalmitis
short term complications of trabeculectomy?
wound leak, hypothyroidism, shallow AC, choroidal effusion/hemorrhage.
long term complications of trabeculectomy
blebitis, endophthalmitis, bleb leak/failure/scaring/over hang, hypotony associated maculopathy, choroidal hemorrhage, eye lid issues, dellens, contact fitting issues
risk factors for bleb related endophthalmitis
chronic bleb leak, blepharitis, conjunctivitis, trauma, nasolacrimal duct obstruction, CL use, male, young
risk factors for bleb failure?
young, African American, aphasia, uveitis, anterior NV, prior cataract surgery, prior failed filtering surgery
name the two nonvalved tube shunts?
name a valved tube shunt
what did the tube vs trabecular study show?
-both were similar in terms of IOP and required medications
-tube was more successful in eyes with prior intraocular surgery
-tubes required fewer additional procedures
indications for tubes?
-CL lens use
contraindications of tube shunts?
poor corneal endothelial function
tube shunt complications?
hypotony, corneal touch, tube obstruction, plate migration, tube erosion, endophthalmitis
which is more likely for leaks? fornix based or limbus based trabeculectomy?
fornix based is more likely to leak bc the incision is at the limbus
when is surgical iridectomy indicated?
when laser iridotomy can't be done-- cloudy cornea, shallow/flat AC, inadequate pt cooperation