Friedman Anterior segment Flashcards
Pigment Dispersion Syndrome (PDS) demographic
Young, myopic man blurred in exercise Chafing from iris pigment epithelium M>F, young adults, myopic>emmetropic 30-50% develop glaucoma Myopic: increased risk of retinal breaks, lattice degeneration (20%)
Pigment Dispersion Syndrome (PDS) signs and Rx?
Signs?
Krukenberg spindle (cornea)
Scheie stripe (post. capsule)
Zentmayer line (ant hyaloid, zonular fibers)
Concave iris + mid-peripheral slit-like TIDs
Pigment in angle
Wide IOP fluctuations
Treatment? Miotics (minimize iris-zonule touch) LPI unproven ALT good SLT bad (IOP spike; use lower power)
Reverse pupillary block
See in PDS - iris has a concave configuration with contact against the ZONULES.
Iris movement –> pigment liberation from the posterior surface as it rubs against the underlying zonules during normal pupillary movement
Mechanism of Pigment Dispersion Syndrome glaucoma
iris pigment obstructs the TM causing elevated IOP and ON damage
natural course of Pigment Dispersion Syndrome glaucoma
burns itself out once all pigment has been liberated (no more pigment to clog TM and raise IOP)
How to confirm ciliary body tumor (imaging/findings)
Imaging:
Use UBM
Anterior segment OCT
scheimpflug imaging
Findings: lenticular astigmatism and cataract shallow anterior chamber sentinel vessel extrascleral extension
Rx of ciliary body tumor
depending on extent of tumor:
Rx is with surgical excision, chemoRx, XRT or enucleation
DDx for non-granulomatous iritis
idiopathic HLA-B27 Fuchs heterochromic iridocyclitis HSV Posner-Schlossman syndrome Lyme Behcet's disease drugs interstitial nephritis
Work-up for non-granulomatous iritis
HLA-B27 sacroiliac X-ray CBC with diff UA VDRL/RPR and FTA-ABS
Disorders assoc/w/HLA-B27 iritis
PAIR: Psoriatic arthritis (needs to be arthritis, skin finding of psoriasis alone is not enough) Ankylosing spondylitis IBD (inflammatory bowel dz) Reiter's
Whipple’s disease
Whipple’s disease
caused by Tropheryma whipplei, a gram-positive, non-acid-fast, PAS-positive rod (white european men)
Two findings, at least one of which is present in approximately 20 percent of such patients, are considered pathognomonic for Whipple’s disease: oculomasticatory myorhythmia (continuous rhythmic movements of eye convergence with concurrent contractions of the masticatory muscles) and oculo-facial-skeletal myorhythmia.
These abnormalities are almost always accompanied by supranuclear vertical gaze palsy.
Whipple’s disease should be considered in all patients with the four cardinal manifestations (arthralgias, diarrhea, abdominal pain, and weight loss). Suspicion of the diagnosis is more difficult in those patients who do not develop gastrointestinal symptoms. In particular, it should be a consideration in patients with rheumatoid factor-negative migratory polyarthritis that does not respond to immunosuppressive therapy. (See ‘Clinical suspicion’ above.)
Pigmented iris lesion DDx
Nevus Melanocytoma melanoma iris pigment epithelial tumor rarely mtz (usually amelanotic)
Iris pigment epithelial cyst
Iris pigment epithelial cysts are commonly located at the iridociliary junction and are round or oval. When observed by slit-lamp examination, they have a smooth brown surface. Visualization of the tumor can be improved by dilation of the pupil.
Iris pigment epithelial cysts have thin walls and sonolucent contents (as imaged by UBM). It is generally accepted that the high reflectivity of the cyst wall is caused by its epithelial cell lining and that its sonolucent core is consistent with a liquid content.
The iris pigment epithelial cyst seen after dilation of the pupil.
Iridociliary cysts typically displace the iris root anteriorly. This can induce a focal plateau-iris configuration with or without angle-closure. Though single cysts are more common, multiple cysts are found in at least one third of cases. When multiple cysts involve more than 180 degrees of the iris, as it does in 10% of patients, angle-closure glaucoma may develop.
The natural history of iris pigment epithelial cysts is poorly understood. Therefore serial observation is warranted.
Melanocytoma
aka magnocellular nevus (benign proliferation of melanocytes)
Retina - Deeply pigmented tumor with feathery borders
No capsule, causing rapid growth, autoinfarction, and release of cells
Rarely malignant
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Iris melanocytoma is a dark brown to black dome-shaped mass with little to no ectropion and often with a granular “mound of black sand” appearance. Occasionally there is minor seeding into the anterior chamber angle or onto the iris stroma.
How to differentiate iris nevus vs. melanoma:
size (
Test for iris melanoma
Iris FA (nevus has a filigree filling patter that becomes hyerpfluorescent early and leaks late or is angiographically silent vs. malignant melanoma has irregular vessels that fill late)
B-scan or UBM to R/O ciliary body involvement
transillumination
different presentations of iris malignant melanoma
Diffuse
Tapioca
Ring-shaped or localized
+/-Feeder vessels, involve angle structures, cause sectoral cataract, hyphema, IOP, or glaucoma
iris malignant melanoma Rx and Px
Rx: chemotherapy, XRT, complete surgical excision, enculeation depending on extent
Patient may need Rx of increased IOP
Px: good with mortality rate of
PSC cataract associations
V I: age, atopic dermatitis, inflammation T A M: RP, DM I: ionizing radiation, steroid use N
Complications of RBB block
central anesthesia
retrobulbar hemorrhage
globe penetration/perforation
strabismus (IR fibrosis or myotoxicity)
Aspiration Flow Rate
The amount of fluid flowing through the tubing. This is reported in cubic centimeters per minute (cc/min). With a peristaltic pump, flow is determined by the speed of the pump. As flow increases the current in the anterior chamber increases how well particulate matter is attracted to the phaco tip.
What to do to change phaco settings if complications
remove manually or with low-flow phaco settings
>lower the irrigation bottle height
>reduce AFR
>reduce vacuum
