Anterior Segment Flashcards
What common ophthalmic disorder can Amicar (aminocaproic acid) be used to treat?
Hyphema. Amicar is used to treat acute bleeding.
What is the difference between an 8-ball hyphema and a total hyphema?
8-Ball Hyphema: blood has clotted and is black or purple in color (deoxygenated blood); this is an indication for washout
Total Hyphema: bright red blood (indicates good aqueous circulation); wash out indicated if persistent for >5d
When is the greatest risk for recurrent hemorrhage in hyphema?
2-5 days
Which glaucoma meds should be avoided in sickle-cell patients who have a hyphema? (three)
- ) CAIs
- ) alpha-agonists/epinephrine
- ) hyperosmotics
All can lead to sickling; beta-blockers are safe to use
Name the location of tear:
- ) Iridodialysis
- ) Angle Recession
- ) Cyclodialysis
- ) Iridodialysis: iris root from ciliary body
- ) Angle Recession: longitudinal and ciliary muscles
- ) Cyclodialysis: ciliary body from scleral spur
Cyclodialysis allows aqueous to flow into the suprachoroidal space and can induce hypotony. What medication can be used to treat this?
Atropine. Laser or surgical repair are also treatments.
What is the difference between penetration and perforation when referring to an open globe
Penetration: entrance wound only
Perforation: entrance + exit wound
List four things that increase the risk of post-traumatic of endophthalmitis.
- retained FB
- delayed surgery (>24h)
- rural setting (soil contamination)
- lens disruption
What is the most common organism that causes post-traumatic endophthalmitis?
Staph. aureus
What causes chalcosis?
intraocular copper
List how chalcosis affects each of the following:
Cornea:
AC:
Iris:
Lens:
Retina:
ERG:
Chalcosis
Cornea: Kayser-Fleisher ring
AC: mild inflammation
Iris: green and sluggish
Lens: sunflower cataract
Retina: degeneration
ERG: decrease amplitude (suppressed by Cu ions)
In what layer of the cornea is Cu deposited in a Kayser-Fleisher ring?
Descemet’s membrane
List eight causes of hyperchromic iris.
Hyperchromic iris:
- ocular/oculodermal melanocytosis (C)
- iris pigment epithelial hamartoma (C)
- iris nevus/iris melanoma (A)
- ICE syndrome (A)
- rubeosis (A)
- siderosis (A)
- hemosiderosis (A)
- prostoglandins (A)
(C=congenital; A=aquired)
Name 9 causes of a hypochromic iris
Hypochromic iris:
- Horner’s syndrome (C+A)
- Waardenburg’s syndrome (C)
- Hirschprung’s disease (C)
- Parry-Romberg hemifacial atrophy (C)
- Fuchs’ heterochromic iridocyclitis (A)
- iris atrophy (A)
- metastatic carcinoma (A)
- juvenile xanthogranuloma
What other ocular conditions are associated with Pigment Dispersion Syndrome?
Myopia and Lattice Dystrophy
List nine common things in the DDx of NVI (rubeosis iridis).
DDx of rubeosis iridis:
- PDR
- CRVO
- CRAO
- Carotid occlusive disease
- Sickle cell retinopathy
- anterior segment ischemia
- tumor
- uveitis
- chronic RD
What are three different variations of Iridocorneal Endothelial (ICE) Syndrome?
ICE Syndrome Variants:
1.) Chandler Syndrome: primarily only corneal findings
2.) Iris Nevus (Cogan-Reese) syndrome: multiple pedunculated/pigmented iris lesions (bunching of iris cells by the endothelial membrane)
3.) Essential iris atrophy: extensive iris pathology
ICE syndrome can affect many structures, but what structure is primarily affected in all variations?
Corneal Endothelium. ICE Syndrome occurs when the corneal endothelium acts more like an epithelium and migrates across the TM.
What demographic of patient is ICE Syndrome classically seen in?
Middle-aged women; typically a unilateral disease
What is a pathognomonic gonioscopy finding in ICE Syndrome?
High PAS
PAS that extends beyond Schwabe’s line; PAS from other etiologies should NEVER extend onto corneal endothelium i.e. past Schwabe’s line)
What iris pathology is seen here?
Iridoschisis
separation of the iris stroma
Name all three iris inflammatory nodules and their locations.
Iris Inflammatory Nodules:
- ) Berlin: angle
- ) Busacca: body of iris
- ) Koeppe: Pupillary margin
(alphabetical order starting at the _A_ngle. because you always start with _A_)
What technique can be used on slit lamp exam to differentiate a solid iris tumor from an iris cyst?
Transillumination
Name two variations of melanocytosis** that affect the eye.
Melanocytosis:
- ) Congenital ocular: unilateral diffuse iris nevi
- ) Oculodermal (nevus of Ota): ocular + periborbital skin
Name this iris lesion. What is the risk of melanoma?
Melanocytoma
this is a form of an iris nevus. 5% risk of progression to melanoma
List four risk factors of metastatic spread of malignant melanoma of the iris.
Risk Factors of mets of malignant melanoma of iris:
- ) TM involvement
- ) glacuoma
- ) older age
- ) poorly differentiated margins
What iris lesions are shown here? What systemic disease are they associated with?
Lisch Nodules
Associated with NF-1
They are benign hamartomas of the iris pigment epithelium
What type of tissue is the lens capsule?
Basement Membrane
What is the thinnest part of the lens capsule?
Posterior (4 µm)
The lens capsule is the thickest peripherally (23 µm)
What is seen in this photo and what prior event is it indicative of?
Glaukomflecken
sub-capsular lens epithelium necrosis that occurs after acute IOP elevation. Classically described as “white flecks”
What is the orientation of the Y sutures in the lens?
Anterior: upright Y
Posterior: inverted Y
The zonules connect the lens to what structure?
Pars plicata
What nerves allow for lens accommodation?
Parasympathetics via CN III
PS lead to ciliary mm. contraction –> zonule relaxation –> lens becomes more spherical (von Helmholtz theory)
What type of cataract is seen here? Describe the pathophysiology and a possible side effect.
Morgagnian Cataract
Complete liquefaction of the cortex allows the nucleus to float freely. Secondary phacolytic glaucoma can occur if the liquified cortex leaks through the in-tact capsule and blocks the TM.
What are different causes of a PSC cataract?
Causes of PSC cataract:
- age
- trauma
- steroids
- inflammation
- ionizing radiation
- retinitis pigmentosa
- atopic dermatitis
- Werner’s syndrome (premature aging; genetic)
- Rothmund’s syndrome (skin condition; genetic)
- diabetes
What is the name of this finding?
Vossius ring
typically secondary to blunt force trauma causing IPE onto the lens capsule and secondary pigment deposition.
A patient has an abnormally long handshake and you see the below finding on his exam. Name the finding and systemic disease.
Christmas Tree Cataract seen in Myotonic Dystrophy
(Autosomal Dominant; chromosome 19)
Your patient has the below finding. What treatment should be started for their systemic disease?
This is a (Green) Sunflower Cataract found in Wilson’s Disease. This patient should be started on Penicillamine.
Patients typically have LOW serum ceruloplasmin and LOW serum Cu levels (it’s accumulating in the body, not in the blood)
What type of lens design (Acrylic, Silicone, PMMA) and which type of edge design (square, round) increases the risk of PCO?
- ) PMMA (Acrylic < Silicone PMMA)
- ) Round ( Square Round)
An 18-year old, 6’10” UNC basketball player from Africa presents w/ the finding in the photo. What life-threatening pathology is he at risk for?
Dissecting aortic aneurysm.
Marfan Syndrome: chromosome 15q; defect in fibrillin; 65% of lenses are subluxed Supertemorally.
List seven different ocular manifestations of Marfan Syndrome.
- ) ectopia lentis (superotemporal; see photo)
- ) glaucoma
- ) keratoconus
- ) cornea plana
- ) axial myopia
- ) retinal degeneration (salt and pepper fundus)
- ) retinal detachment (high risk for)
A cognitively delayed 14-year-old presents with bilateral inferonasal ectopia lentis. What life-threatening complication should you consider when planning their surgery?
Increased risk of thromboembolic events ESPECIALLY with general anesthesia.
This patient likely has a cystathionine beta-synthase deficiency (homocystinuria). 80% of these patients have bilateral ectopia lentis by the age of 15.
Name three diet/supplement changes you should recommend to a patient with homocystinuria.
Supplement: cysteine and folate
Restrict: methionine
What leads to glaucoma in Weill-Merchesani Syndrome?
Pupillary Block. Microspherophakia and ectopia lentis increase the risk of this.
Do errors in axial length measurements effect long or short eyes more?
Short (hyperopic) eyes
~0.1mm AL = 0.3D IOL power error; more so for short eyes
What type of refractive shift does silicone oil cause?
Hyperopic Shift
(Increase IOL power selection by 3-3.5D if longterm silicone oil use is anticipated)
Name the structures responsible for this A-scan spike
Cornea (anterior and posterior surfaces)
Name the structures responsible for this A-scan spike
Anterior lens surface
Name the structures responsible for this A-scan spike
Posterior lens surface
Name the structures responsible for this A-scan spike
Retina
Name the structures responsible for this A-scan spike
Sclera
Name the structures responsible for this A-scan spike
Orbital Fat
Post-refractive surgery lens calcs:
What is the “clinical history” formula?
Clinical History Method:
K = preopK + (refraction preop - refraction postop)
Post-refractive surgery lens calcs:
What is the “Contact Lens Method”?
Contact Lens Method:
K = CL base curve + CL power + (refraction w/ CL - refraction w/o CL)
Peristaltic and Scroll pumps are ______-based systems.
Peristaltic and Scroll pumps are flow-based systems.
(Vacuum requires tip occlusion)
Venturi, Diaphragm, and Rotary Vane are ______-based systems.
Venturi, Diaphragm, and Rotary Vane are Vacuum-based systems.
Name three things that can prevent post-occlusion surge:
- ) venting
- ) rigid tubing
- ) microprocessor in pump
(per Seibel manage intra-op surge by first raising the bottle, then decreasing vacuum)
You are experiencing poor followability during quadrant removal; what setting should you change?
Decrease Power
(The phaco tip is pushing the lens material away)
What FA finding differentiates Irvine-Gass Syndrome from other forms of CME (such as DME)?
IGS has late staining of the optic nerve.
