2° Glaucomas - Pre/Post TM Outflow Obstruction

Pretrabecular Outflow Obstruction Glaucomas are described as a group of secondary glaucomas in which:

Iris or other tissue obstructs the angle to prevent aqueous from reaching the TM

Why is it important to see if pupil block is present in Pretrabecular Outflow Obstruction Glaucomas

this well effect tx

Secondary pupil block occurs when:

the iris becomes adherent at the pupillary margin to the lens and restricts aqueous flow forward

(T/F) Iris Bombe shallows the entire anterior chamber

FALSE

shallows the anterior chamber peripherally but usually remains deep centrally

What 2 things may cause raised IOP to persist after an attack of pupil block

- Large areas of PAS formed during the attack

- TM became damaged

List 3 possible causes of secondary angle closure WITH pupil block

- Posterior synechiae

- occlusion of pupil by implant or vitreous gel in aphakic eyes

- forward lens movement or swelling of cataractous lens

Pupil block secondary to inflammation in the anterior segment is due to (low/high) grade or (acute/chronic) iritis

low grade

acute

Describe the mechanism behind how inflammation in the anterior segment may cause pupil block

- Low grade or acute iritis

- Producing posterior synechiae

- Occludes pupillary aperture

(iris bombe possible)

image slide 7

Modern cataract surgery (does/does not) produce a lot of inflammation, which gives (low/high) risk of iris bombe

does not

low risk

(but still may happen)

In aphakic eyes, synechiae may form between ________ and ___________

iris and vitreous gel

image slide 8

List 3 causes of Forward Movement of Anterior Lens Surface that may result in secondary angle closure with pupil block

- Anterior dislocation/subluxed lens

(image slide 9)

- Traumatic lens dislocation

(image slide 11)

- Age related growth

(image slide 10)

List 4 possible causes of secondary angle closure WITHOUT pupil block

- post seg changes that push the lens and iris diaphrahm forwards

- ant seg changes causing loss of AC depth -> iris trab contact -> synechial closure

- small eyes

- cellular proliferation within the angle -> iris trab adhesions

List 5 potential post seg changes that could result in angle closure w/o pupil blcok

- Tumors

- Choroidal effusion

- Posterior scleritis

- Scleral buckles

- "Malignant Glaucoma"

What is "Malignant Glaucoma"

ciliolenticular block or aqueous misdirection syndrome

there is obstruction to forward flow of aqueous humor in the presence of a shallow anterior chamber or misdirection of aqueous into the posterior segment with pooling in the vitreous gel

What drug class must be avoided when treating Malignant Glaucoma

miotics

_________ glaucoma is one of the most complex and difficult of all the glaucomas to treat, and it can progress to permanent blindness without prompt intervention

Malignant

Exact underlying pathophysiology of Malignant Glacuoma is poorly understood - However, it is clear that which 4 structures are all involved

- iris

- ciliary processes

- lens

- vitreous area

Malignant Glaucoma occurs in __-__% of eyes undergoing surgery for angle closure glaucoma

2-4%

When does Malignant Glaucoma occur

may occur at any time during the postoperative period of surgery, but most cases occur shortly after incisional surgery

(T/F) Pupillary block is present in Malignant Glaucoma

FALSE

not pupil block BUT...

lens iris diaphragm moves forward and occludes the angle

(T/F) Uveitic eyes can develop PAS even if its angle is not narrow

TRUE

image slide 17

List 3 congential conditions that cause pt to have abnormally small eyes that put them at risk of angle closure w/o pupil block

- congenital high hyperopia

- nanophthalmos

- congenital syphilis

Describe the pathophysiology behind nanophthalmos and angle closure

the eye itself is abnormally small with an axial length of less than 20mm, but the lens is normal size so it compresses the internal ocular structures to close the angle

List the 3 different cell types may be responsible for abnormal cellular proliferation that causes angle closure

- neo membrane

(NVG)

- endothelium

(Iridocorneal endothelial syndromes/ ICE)

- epithelium

(epithelialization of the anterior chamber)

_____________ is the most common type of cellular proliferation causing angle occlusion

NVG

Which 6 pt populations do you most frequently see NVG in

(most common)

- DM pt

- eyes with CRVO

(others)

- OIS

- RD

- intraocular tumors

- radiation retinopathy

What is the stimulus of NVG

retinal hypoxia and release of VEGF

NVG progresses through the growth of a _____________________ on the anterior surface of the iris and the iridocorneal angle of AC

fibrovascular membrane

(may start off as just blocking, but then eventually contract and cause secondary angle closure)

List the 5 risk factors of NVG

- CRVO

- PDR

- OIS

- Hypoperfusion

- Venous Stasis

ICE syndromes sre more common in (male/female)

females

List the 3 ICE syndromes

- Essential Iris Atrophy

- Chandler's Syndrome

- Iris-Nevus (Cogan-Reese)

ICE syndromes all result from primary disorder of the _______________

corneal endothelium

___________ occurs when there is a loss of cell contact inhibition with corneal endothelial cell proliferation, causing formation of Descemet's like membrane spreading across the angle and the iris surface

ICE syndromes

(T/F) In ICE syndromes, a demarcation line may be seen on the cornea between normal and abnormal endothelium

TRUE

image slide 23

ICE syndromes are tpyically (uni/bi)lateral

unilateral

What is teh typical age of onset of ICE syndromes

4th to 5th decade

Which ICE syndrome is characterized by...

• Unilateral glaucoma

• Corectopia

• Pseudopolycoria

• PAS

• & migration of endothelium onto the iris produces chronic traction at that point and stretching and eventual hole formation

Essential Iris Atrophy

image slide 25

Which ICE syndrome is characterized by...

- Bullous keratopathy

- Corectopia

- Iris atrophy

Chandler's Syndrome

image slide 26

Which ICE syndrome is characterized by...

- Iris atrophy

- More corneal edema

- Anterior surface of the iris is covered by a sheet of Descement membrane like material

- Ectropion uvea

Iris Nevus Syndrome (Cogan-Reese)

The corectopia and iris atrophy is seen (less/more) extensively in Chandler's Syndrome than in Essential Iris Atrophy

less extensive in Chandlers

The iris atrophy is seen (less/more) extensively in Cogan-Reese than in Essential Iris Atrophy

less extensive in Cogan-Reese

What are the 3 tx options to manage the corneal edema seen in ICE syndromes

- hypertonic saline

- banadage CL

- corneal surgery eventually

What IOP lowering drops are used in ICE syndromes and why

aqu. suppressants (ABCs)

no PGAs because the TM is blocked, the angle is closed so there can be no increase in outflow

What are ALT/SLTs not very helpful in ICE syndromes

cant visually access the TM and even if you can see it there is so much debris in the way that you cant access it specifically

Why do filtering blebs often fail in ICE syndrome pt

the endothelial cells that migrate in ICE syndromes will migrate into the bleb and block that passage way as well

What is Epithelialization of the Anterior Chamber

epithelial cells gain entry into the anterior chamber from epithelial downgrowth

they then proliferate inside the eye as a sheet of cyst

image slide 30

The (sheet/cyst) form of Epithelialization of the Anterior Chamber is worse

sheet - just keeps growing and covering more and more

Epithelialization of the Anterior Chamber is a rare but devastating complication of:

ant seg surgery or trauma

(T/F) In Epithelialization of the Anterior Chamber the membrane grows rapidly over the whole cornea

FALSE

rarely grows more than halfway down the cornea but grows rapidly over the iris and AC angle

Prognosis for eyes with Epithelialization of the Anterior Chamber is very (good/poor)

poor

IOP is the balance between....

- inflow of aqueous

- outflow od aqueous

- EVP

List the 2 conditions that can cause a chronically raised EVP

- caroticocavernous fistula

- Sturge Weber Syndrome

Chronically raised EVP is usually caused by shunting of arterial blood to the orbital veins by a ______________

caroticocavernous fistula

A carotid-cavernous fistula is the result of:

abnormal vascular connection between the internal carotid artery (ICA) or external carotid artery (ECA) and the venous channels of the cavernous sinus

Why do we see ophthalmic manifestations of a carotid-cavernous fistula

due to venous drainage of the orbit from the cavernous sinus

Pt experiencing a carotid-cavernous fistula has what 2 presenting signs

- red eye

- raised IOP

(scleral vessels will look engorged and elevated!!)

image slide 37

Glaucoma is more common in Sturge Weber pt when the (lower/upper) lid is involved

upper

About ___% of Sturge Weber pts present with buphthalmos within the first 2 years of life but, there is lifelong risk of glaucoma

50%

Glaucoma presents in ___-___% of patients with Sturge Weber Syndrome

30-70%

A Sturge Weber Syndrome pt Presents with facial and intracranial ____________ of variable degree

angiomas

Why do we see blood in Schlemm's canal in Sturge Weber Syndrome pt (assuming were not pushing too hard on gonio lol)

the normally outwardly directed pressure gradient is reversed by the raised episcleral venous pressure

(T/F) Raised EVP secondary to Sturge Weber Syndrome response poorly to tx

TRUE

List 2 reasons why filtration surgery may be hazardous to perform on Sturge Weber Syndrome pt

- dissection of the scleral flap may be difficult due to hemangiomas

- meticulous hemostasis is required

(surgical technic with minimum blood loss)