Glaucoma Flashcards
1
Q
Pilocarpine : Mechanism of Action
A
Parasympathomimetic - Pilocarpine directly stimulates cholinergic receptors, acting on a subtype of muscarinic receptor (M3) found on the iris sphincter muscle, causing the muscle to contract and produce miosis. timulates the sphincter pupillae in the iris and the ciliary muscle, resulting in displacement of the scleral spur, opening of the trabecular meshwork and/or Schlemm’s canal, and enhancement of conventional aqueous outflow.
2
Q
Beta-Blockers: MOA
A
Beta-blockers decrease aqueous humor production by the ciliary body and hence reduce IOP.
3
Q
Carbonic Anhydrase Inhibitors
A
Carbonic anhydrase is an enzyme that catalyzes the reaction of H2O and CO2 in equilibrium with H+ and HCO3−. The net effect of the enzyme on aqueous production is to generate bicarbonate ions, which are transported actively across the ciliary epithelial membrane into the posterior chamber (sodium is the primary cation); an osmotic gradient is established. Water passively follows because of the presence of the gradient, which results in aqueous production. Inhibition of this enzyme results in lower IOP because aqueous production is decreased approx 50% or more;aqueous outflow and episcleral venous pressure are affected little or not at all.
4
Q
Alpha-Adrenergic Agonists
A
Apraclonidine decreases aqueous production but is also associated with an increase in outflow facility and a decrease in episcleral venous pressure. Brimonidine is 23 times more alpha-2 selective than apraclonidine and 12 times more selective than clonidine. Its mechanism of action includes a reduction in aqueous formation as well as an increase in uveoscleral outflow
5
Q
Relate Ciliary Body Anatomy to demonstrate the difference between Angle Recession, cyclodialysis and irido-dialysis
A
Angle recession is a separation between the longitudnal and radial muscles of the ciliary body. (you see a wide CB band but otherwise N structures) Cyclodialysis is when the longitudnal muscles separate from the scleral spur and ca cause hypotony and haemorrhage. Irido dialysis is separation of the iris root and the ciliary body.
6
Q
OHTS found 5 significant risk factors that increased the risk of POAG
A
- age
- higher iop
- CDR
- greater pattern standard deviation
- reduced CCT
7
Q
What were the pressure lowering goals of OHTS and CNTGS
A
OHTS: 20% from baseline
CNTGS: 30% from baseline
8
Q
What are the risk factors for steroid responders (5)
A
- known POAG
- family hx
- age
- DM
- myopia
9
Q
DDx of arcuate defects
A
Glaucoma ONH drusen NAION, AAION Myelinated NFL Hemiretinal vein occlusions BRAO Optic nerve colobomas, pit Laser scars to one area of retina
10
Q
DDx of enlarged blind spot
A
ONH drusen Papilledema Diabetic papillitis Hypertensive papillitis Optic neuritis MEWDS/IEBSS Megalopapilla High myopia (PPA)
11
Q
Glaucomatous nerve features
A
High CDR Assymetric CDR Notch Loss of NFL Optic disc hg Bayonetting of vessels Nasalisation of vessels Vertical elongation of the cup Laminar dots (?)
12
Q
Systemic associations with drusen
A
Autosomal dominant
PXE
Sickle cell
13
Q
DDx of glaucomatous nerve
A
Physiologic cupping
Tilted discs
Anything that causes nerve damage... Glaucoma (open or closed) Optic neuropathies compression toxic/metabolic vascular insults
14
Q
Disc hg ddx
A
Glaucoma (esp NTG) Hemorrhagic PVD Papilledema NAION AAION Diabetes HTN Valsalva
15
Q
Thickest rim
A
I>S>N>T
16
Q
Most suspectible to glaucoma (parts of the rim)
A
I>S>T>N
17
Q
Angle most open
A
Inferior
18
Q
Angle most pigmented
A
Inferior
19
Q
Deep AC in who
A
Myopes
Young
Male
(basically everyone who gets PDS)
20
Q
Shallow AC in who
A
Old
female
hyperopes
Eskimo/Asians
21
Q
Steroid responder risks (5)
A
POAG Family history Age Myopia DM
22
Q
CDN guidelines for suspect, early, mod, and adv glaucoma (dx and management)
A
Class; CDR; VF; Tmax you want; lower by
Suspect; — ; — ; 24; 20%
Mild; 10deg from fixation; 20; 25%
Moderate; 10 deg from fixation; 17; 30%
Severe: >0.9, within 10 deg of fixation; 14; 30%
23
Q
Dose of MMC for trab
A
0.01% for 2 min (in real life this varies but this is a reasonable exam answer)
24
Q
Two types of VF testing
A
Static (Humphrey or Goldmann)
Kinetic (Goldmann)
25
DDx of hyphema in adult
```
Trauma
Bleeding diathesis
Leukemia
Ocular surgery
Fuch's
Other NVI/NVA
UGH
```
26
PXF cataract risks
```
Poor dilation
Stiff pupil
Zonular weakness
Increased risk of phacodynesis and vitreous loss
Capsular fragility
Lower endothelial cell count
Unstable IOP post-op (spikes)
Post-op inflammation
```
27
Findings in PXF
```
Poor dilation
Ring of pigment on anterior lens capsule
PXF material on pupil margin
Pupil margin TID
Pigmented angle
Sampolessi line
```
28
Membrane over angle
ICE
Epithelial ingrowth
PAS (uveitis, bad ALT, chronic ACG)
NVI
29
ICE clinical variants
Chandler - mostly cornea
Iris nevus - membrane on iris tents up normal stroma to look like nevi (not actually nevi)
Essential iris atrophy (correctopia/polycoria)
30
3 lytic glaucomas
Lytic = macrophages clog up TM with junk
Phacolytic - lens particles
Hemolytic - RBC from hyphema
Melanomalytic - pigmented melanocytes (or something) from melanoma cells floating around
31
Secondary glaucomas after IOL implantation
UGH
Pupil block angle closure
Secondary pigmentary glaucoma
32
Pigmented TM in who
```
Pigmented people
Older people
PXF
PDS
Melanomas
```
33
IOP formula
IOP = F/C + EVP
34
Types of tonometry
Indentation - Schiotz
Applanation - tonopen, Goldmann, Perkins, pneumotonometer (don't let this last one throw you - unless they say AIR PUFF, it's still a contact tonometer)
Non-contact - air puff
35
Glaucoma with pigment
```
PXF
PDS
Pigmented people with open angles
Pigment on endothelium from old inflammation, cataract surgery, trauma, hyphema
ICE
Melanoma
```
36
Intermittent ACG findings
```
Hx of intermittent ACG
+/-Normal IOP
PAS
Glaucomflecken
Signs of glaucmatous damage to ON
```
37
Risk of ACG in the fellow eye after AACG
75%. So always do prophylactic LPI
38
Segmental iris atrophy
```
Cataract surgery
Trauma
HSV, EBV, CMV, VZV
ICE syndrome
Axenfeld reiger
PPMD
```
39
Iridodenesis
Separation of iris from CB
Usually result of trauma or surgery
Rx with coloured CL or surgically re-insert
40
Causes of ectropion uveae
```
ICE
Axenfeld reiger
Uveitis
PPMD
NF-1
Epithelial downgrowth
NVG
uveitis
```
41
How do you tell epithelial ingrowth vs fibrous downgrowth
Epithelial ingrowth turns white with YAG
42
Lens induced glaucomas
Phacomorphic - angle closure with pupil block
Phacolytic - lens particles leak through intact capsule. Minimal inflammation, but macrophages ingest the particles and obstruct. NO KP.
Phacoanaphylactic - broken capsule. Maybe after surgery. Some books call this the same as lens particle glaucoma. LOTS OF INFLAMMATION with KP's.
Lens particle - basically the same thing. Maybe it's more after cataract surgery with some lens left behind.
UGH - from IOL
Dislocated lens (if dislocates anteriorly, causes ACG)
Same with microspherophakia causing ACG
43
Cyclodialysis def'n and treatment
Separation of CB from SS
Result of either trauma or surgery
Gonio to confirm
Rx with cycloplegics, most will close on their own in 6/52
Cause hypotony in the meantime, +/- spike when its closing
44
Risks for OHTN progression
```
Age
High IOP
High CDR
High pattern standard deviation
Low CCT
```
45
CCT definition in OHTS
588 = thick
46
RF for OAG
```
Age
High IOP
Family history
Race
Other: HTN, DM, Myope, migraines?
```
47
RF for AACG
```
Female
Age
Previous ACG
Race - inuit or asian
Hyperopic
Nanophthalmos
Family history
```
48
RF for NTG
```
Female
Disc hg
migraine
vasospasm/raynauds
smoking
```
49
DDx of NTG
IOP is high, but you're not measuring it:
- uncalibrated equipment
- low CCT
- corneal edema
IOP is high sometimes but you're missing it:
- diurnal fluctuations
- intermittent ACG
- Posner Schlossman episodes
IOP was high before but its ok now:
- burned out OAG (PDS, PXF)
- old AACG
It's not glaucoma at all:
- ONH drusen
- old optic neuritis, NAION, AION, etc
- compressive lesion (do a CT - nerve to chiasm)
- infiltrative lesion of the nerve (sarcoid, TB, lyme, etc)
Only if you've ruled all that out can you call it NTG.
50
Acute IOP rise ddx
After laser (LPI, SLT, etc)
After surgery (retianed visco, retained lens particles)
Inflammatory (HSV, CMV, Posner Schlossman, Fuch's)
Steroid responder
After hyphema
AACG
51
Characteristics of plateau iris and treatment
Deep central AC, shallow periphery
Flat iris
Bunched up iris in angle
No change in configuration despite LPI
Rx:
- always make sure they have an LPI first
- Argon iridoplasty to pull the iris out of the angle
- miotics
52
DDX of increased EVP
AV malformation: CCF, SWS, orbital varix
Lesion compressing SOV: thyroid, tumor, orbital vein thrombosis, cavernous sinus thrombosis, SVC syndrome
Idiopathic: posture (lying down), familial EVP
53
DDx of blood in Schlemm's
High EVP (AV issues, something compressing SOV)
Hypotony (inflammation, hypotony, following trab)
Normal with compression gonioscopy (occludes episcleral veins)
54
DDx of axenfeld-reiger
```
ICE
Aniridia
Isolated posterior embryotoxin (N in 15%?)
Peter's anomaly
Ectopia lentis et pupillae (no glaucoma)
```
55
Systemic findings in axenfeld reiger
Microdontia
| Redundant peri-umbilical skin
56
Schabel's optic atrophy def'n and ddx
Hyaluronic acid infiltation of the nerve (stains with colloidal iron, alcian blue)
either from end-stage glaucoma or ischemic optic neuropathy (NAION, AION, etc)
57
Posterior pushing mechanisms of ACG
```
Choroidal effusions
Vitreous overfill from gas
Ciliary body mass
Supra-choroidal hemorrhage
Malignant glaucoma
Contraction of retro-lental tissue (ROP, PHPV)
```
58
DDx of NVI/NVA
```
Fuch's heterochromic iridocyclitis
DM, radiation retinopathy, OIS
CRVO, BRVO, CRAO
RB!!! Always think RB
ROP/FEVR/Eales
Sickle cell
```
59
Types of ONH analysers
Surface topography - HRT
| Cross section - OCT
60
Types of setons
Valved (Ahmed)
| Non-valved (Baerveldt, Molteno)
61
Pilocarpine for ACG - what types of ACG?
Really just for pupil block or plateau iris
Everything else you dilate (malignant, CACG, NVG, cyclodialysis)
Also, pilo won't work in IOP > 40 because iris muscle is ischemic. Need to lower IOP first
62
Malignant glaucoma risks
```
Hyperopia
Female
Nanophthalmos
Previous ACG
Recent surgery (5d)
```
63
Malignant glaucoma rx
Always do an LPI first to resolve any component of pupil block
Dilate
Decrease IOP with aq suppressants or hyperosmotics
If pseudophake/aphake, can YAG anterior hyaloid face
If phakic, need vitrectomy
64
Injuries with anterior segment trauma
```
Conj laceration
Scleral perforation
Corneal perforation
Hyphema
Traumatic iritis
Traumatic mydriasis
Angle recession
Cyclodialysis
Iridodialysis
PVD
RT, GRT
RD
Retinal dialysis
```
65
Nanophthalmos - what do you get in the eye and how do you treat
- Large lens - gives phacomorphic ACG. LPI. Can dilate to pull the lens back a bit.
- Thick sclera - get uveal effusions. Can do sclerectomies
- Malignant glaucoma - LPI, dilate, YAG hyaloid/vitrectomy
- Can also get high EVP from outflow obstruction through thick sclera - aq suppressants
66
Why cycloplege in uveitis
Reduces pain
Reduces PS
Reduces PAS by deepening the AC
Stabilise blood-aq barrier
67
Deadly effects of atropine
Red as a beet, dry as bone, mad as hatter, hot as hades, blind as a bat
```
Red - vasodilation, flushing, tachycardia
Dry - dry eyes, dry mouth, constipation
Mad - delerium
Hot - fever
Blind - cycloplegia
```
Rx with acetylcholinesterase inhibitor - e.g. physostigmine
68
Side effects of phospholine iodide
Iris cysts and ASC cataracts
69
Side effects of b-blockers
ASTHMA AND DECREASED HR/heart block
| - always ask about asthma and check HR before giving BB
70
Side effects of brimonidine (and C/I)
NEVER GIVE TO CHILDREN - causes respiratory distress/apnoea, CNS depression, hypotension
Adult s/e:
- allergy
- increased HR
- HTN
- vasodilation/flushing
71
Side effects of CAI (and C/I)
Know this cold.
- SJS
- metallic taste
- tingling in hands/feet
- APLASTIC ANEMIA
- renal failure
- metabolic acidosis
- renal stones
- SICKLE CELL CRISIS
Don't give to sickle cell ppl or kidney failure
72
Cloudy cornea infant ddx
G-STUMPED
73
Congenital ocular anomalies with assoc glaucoma
Anterior segment anomalies:
- ICE
- axenfeld reiger
- aniridia
- nanophthalmos, high hyperopia
- microspherophakia
Cornea:
- sclerocornea, megalocornea
Retina:
- PHPV, ROP
Systemic things:
- Lowe's (cataract + glaucoma)
- Rubella (cataract OR glaucoma, never both)
74
Schwartz syndrome
Photoreceptor OS's from old RD clog the TM and cause glaucoma. Resolves after RD repaired.
75
Hemosiderotic glaucoma
Hemosiderin from hyphema/vit hx clog TM
76
Thymoxamine - whats it used for
Causes pupil constriction without shifting iris-lens diaphragm forward. So you can see the effect of un-bunching iris from the angle without changing the position.
Helps you decide if prophylactic LPI would actually be helpful
(never actually used, i don't think)
77
Photophobia/tearing child
Glaucoma
Lid/eyelash malposition
Corneal irritation, trauma, abrasion, infection
Dacryocystitis, congenital NLDO, canalliculitis, etc
78
Congenital glaucoma triad and signs
Tearing, blepharospam, photophobia
```
enlarged K diam
cloud K
Haab striae (horizontal)
high IOP
high CDR
increasing myopia
```
79
Definition of congenital vs infantile vs juvenile glaucoma
```
Congenital = 0-3 mos
Infantile = 3 mos - 3 years
Juvenile = 3 yrs+
```
80
Descemet tears - diff types
Forceps trauma - vertical
Haab striae (glaucoma) - horizontal
Vogt's striae (KC) - concentric to cone
Hydrops, PBK
81
Options for painful blind eye
Always do yearly B-scan to rule out mass if there's no view
- atropine/PF
- cyclophotocoagulation
- retro-bulbar alcohol or chlorpromazine
- enucleation/evisceration
82
GA effects on IOP measurement
Ketamine and succinylcholine increase IOP
(KISS of high IOP)
Others lower it
83
Glaucoma surgery in kids - when to do what
Medical management is just temporizing in kids. Start with CAI. Never give brimonidine.
- goniotomy - needs clear K
- trabeculotomy - don't need clear K
- trabeculectomy - if the others fail
84
6 reasons to do an LPI
- acute ACG
- prophylactic if other eye has ACG
- occludable angles
- malignant glaucoma
- plateau iris
- if silicone oil in an aphakic eye (do it inferiorly. SO rises so a superior one will get plugged with SO)
- with ACIOL
85
Define false positive
Patient presses the button when there is no stimulus provided
Max acceptable = 30%
86
Define false negative
Patient doesn't press the button despite it being suprathreshold and in the same area as where they previously saw it
Max acceptable = 30%
87
Define fixation loss (2 ways)
1. There's a pupil tracker on most machines that follows where the patients eye is moving
2. Patient sees a spot that's in the blind spot that was already mapped out
Max acceptable = 1/3
88
What is short term fluctuation on VF
10 points are re-tested 2x each
It measures the difference in brightness that the patient responds to
Can reflect inattention or advanced dz
89
What is MD on visual field
Average of the deviation of all the patient's spots from age-matched control. Measure of the total drop in VF (could be due to glaucoma or cataract/etc)
90
What is PSD on visual field
Measure of the standard deviation of the difference in the patient vs age-matched control. An estimate of the depression in the hill of vision
91
How would a scotoma look if BCVA is
Wider and deeper
92
What happens to the VF if pupil
Globally depressed
93
How do you define a scotoma on VF
Area of vision >3 degrees that is depressed >6 db
Or 1 pt on Humphrey > 10 db depressed
or 2 adj points > 5 db each
94
What is the definition of legal blindness
BCVA in the BETTER eye
95
what doubles in FDT
It's basically a bunch of wide stripes that they flicker really fast in different areas of the VF
So it's high temporal frequency, low spatial frequency
What doubles is the temporal frequency
96
What cells do FDT preferrentially test for
M cells (may be affected first in glaucoma so it may be more sensitive as a screening tool than humphrey)
97
What are the 4 types of VF testing algorithms
Acronym - STER (like a STER-case that we know is used in VF testing)
1. Threshold: staircase of up 4 db, then down 2 db until it reverses again
2. Supra threshold: screening test that shows bright spots higher than threshold. Only picks up severe defects as a screening tool.
3. Efficient threshold: estimates threshold for age-matched and tests those first. Subsequent spots up/down based on what was seen. Only one reversal @ each spot (=SITA)
4. Threshold-related: Threshold determined for a few points then hill of vision determined from those. Then shows 6 db brighter at all spots than threshold - i.e. again just a screening tool for mod/adv dz.
98
How do you classify ACG
Primary or secondry, pupil block or not
Primary pupil block: AACG
Primary non pupil block: chronic ACG, plateau iris
Secondary pupil block: phacomorphic, PS, bombe, lens dislocation/microspherophakia, IOL pupil block
Secondary non-pupil block:
- Anterior pulling: PAS, NVG, ICE, PPMD, epithelial downgrowth
- Posterior pushing: choroid (effusion or anterior rotation), vitreous pressure (silicone oil, gas, tumors, aq misdirection), retro-lental membranes (ROP, PHPV)
99
What did GLT show
L = laser, T = timolol
Laser (ALT) vs drops as first line therapy. Both are ok.
100
What did CIGTS show
T = timolol, S = surgery
For initial glaucoma, is medical therapy better or surgery?
Surgery was worse initially but both had equal Va and IOP control and VF changes at 5 years
101
What did EMGT show
T = timolol (vs nothing)
Is lowering IOP even helpful for glaucoma?
Used timolol +/- ALT needed
Answer is yes, obviously.
53% progressed (62% with no rx, 45% with rx)
102
What did AGIS show
S = surgery
This was primarly a surgical trial looking at ALT vs trab in advanced glaucoma that had failed medical therapy.
Results based on race:
- Blacks: ALT is better initially (because they scar a lot - think keloids - so trab is not going to be good)
- Whites: trab is better initially
ALT failure assoc with young age, high IOP
Trab failure: young age, higher IOP, DM, post-op complications (IOP, inflammation, etc)
103
What did TVT show
Looked at people with glaucoma who either had prev cataract or prev trab surgery
Randomized to get a trab (with MMC) or tube as the next step
Both groups did well. Therefore, tubes can be used earlier than previously thought.
104
What did OHTS show
Inclusion: IOP 24-32, normal field, normal nerve
Lowering IOP by 20% reduces progression from 9.5% to 4.5% over 5 years
Risks for progression:
- age
- lower cct (
105
What did NTGS show
Lowering IOP by 30% is helpful in reducing progression
Risks of progression:
- female
- disc hg
- migraine
106
What are the laser settings for ALT
```
Argon
Spot size 50um
Power 400 mw
Time 0.1 s
50 spots x 180 deg
```
107
What are the laser settings for SLT
YAG laser on SLT setting
400 um size
power - start at 0.6-0.9 mJ, want champagne bubbles on some shots
50 spots / 180 deg
108
What are the laser settings for iridoplasty
Argon
500 um size
400 mw power
0.5 - 1.0 seconds (whoa, long)
```
Think of iridoplasty as 10x argon...
same power (400 mw)
10x spot size (500 vs 50)
10x time (1 sec vs 0.1 sec)
```
109
What is total deviation on VF
Map of deviation of each point from an age-matched control
110
What is pattern deviation on VF
Take the total deviation, subtract the 7th BEST point and apply that subtraction to all points
Should remove media opacities or general depressions and help you see the hill of glaucoma defects
111
Gene for PXF
LOXL-1
112
2 types of outflow and relative contributions
Trabecular = 90%
UVS = 10%
(% vary depending on source)
113
What drops have an effect on which outflows
PG's: increase UVS
Alpha ag: increase UVS
Cycloplegics: increase UVS
Miotics: increase TM outflow
114
Greatest site of resistance to outflow
Juxta-canalicular meshwork (part of UVS pathway)
115
Outflow measurement called what
Tonography
116
Outflow rate normally
0.22-0.28 ul/min/mmHg
117
GAT size
3.06 diam
118
Ideal cct for GAT
520 um
119
How to clean GAT
alcohol wipe
or 5 min soak with:
- 70% etoh
- 1:10 bleach
- 3% hydrogen peroxide
120
Schaeffer grading system for narrow angle
```
I = narrow
IV = open
```
121
What supplies ONH
short posterior ciliary arteries
122
NFL supplied by what
recurrent branches from CRA
| everything OPL and forward is from CRA
123
2 theories of glaucoma damage
1. mechanical: compression of NFL axons from high IOP causes damage
2. ischemic: poor blood flow to NFL axons causes them to die
124
% normals with CDR > 0.6
5%
125
% normals with assym CDR > 0.2
1%
126
Hemifield assymetry on VF
compares top half of VF to bottom half
sup is normally 1-2 db less than inferior
(see better inferiorly)
anything different is suspicious
127
Narrow angle provocative tests
Prone-dark test (30-60 min lying prone in the dark)
128
SLT best for who
Pigmented glaucoma and angles
| PXF and PDS
129
PDS - risk of glaucoma
25-50%
130
Who gets PDS
young, myopic, males
131
Compare Fuch's vs Posner Schlossman
Fuch's:
- presents with blurred vision
- fine stellate KP
- min AC rxn
- iris heterochromia
- fine angle vessels that bleed easily
- treat IOP, steroids don't really help
PS:
- mild AC rxn
- no KP
- no heterochromia
- episodic unilateral pain
- rx with steroid (IOP should come down on its own)
132
Sickle cell - how to treat IOP
avoid CAI
| avoid alpha-1 ag (apraclonidine). alpha-2 ok (brimonidine)
133
Abx in kids - whats not ok
Tetracyclines def not ok
134
When do you get ghost cell glaucoma
1-3 months after vit hx
135
How do you treat ACG from microspherophakia
DILATE the pupil (flattens the lens and pulls it back)
136
How to treat fibrous ingrowth/epi downgrowth over the angle
If blocks the angle, treat with meds first
| Can't do laser
137
Rx for topamax induced ACG
dilate the pupil (rotate CB backwards)
138
how to treat glaucoma in pregnancy
```
All drugs class C except brimonidine (class B)
better to do laser first if you can
```
Stop brimonidine once she starts nursing
139
ALT stats
Decreases IOP by 20-25%
80% ppl respond
50% success at 5 years (10% per year drop off)
140
Bleb endopht risks
young age
male
blepharitis
dacryocystitis, NLDO
141
Bleb endopht bugs
Strep pneumo, H flu
142
How to treat bleb endophth
tap and inject + fortified topicals
| EVS PPV results don't really apply. So might do PPV earlier I think?
143
Rate of aq production
2-3 ul/min = 3 ml/day
144
AC vol
250 ul
145
Fluorophytometry is what
Measures rate of aq production
146
Decreased aq production with:
age
sleep (45% less!)
inflammation, surgery, trauma, meds
147
Aq humor compared to plasma
15X more ascorbate (remember this one)
Less protein, less ca, less phosphorous
everything else the same
148
Blood:CB barrier is...
fenestrated
149
CB = what layers
Inner non-pigmented epithelium (equiv to retina - inner and non-pig)
Outer pigmented epithelium (continuous with RPE - think outer, pigmented)
