QUESTIONS
1) Upon entering the cranial cavity, the optic nerve runs:
a. lateral to the internal carotid artery and inferior to the anterior cerebral artery.
b. medial to the internal carotid artery and inferior to the anterior cerebral artery.
c. medial to the internal carotid artery and superior to the anterior cerebral artery.
d. lateral to the internal carotid artery and superior to the anterior cerebral artery.
e. lateral to the internal carotid artery and lateral to the anterior cerebral artery.
1) B. At its intracranial exit from the optic canal, the carotid artery
runs below and temporal to the nerve (i.e. the nerve would be medial to the
carotid) and the proximal anterior cerebral artery runs over the nerve (i.e.
the nerve runs inferior to it).
2) A study was performed that examined whether patients with ARMD and CNVM had evidence of prior laser photocoagulation. Records of all patients with the diagnosis of ARMD and CNVM over the last 5 years were compiled. What type of study is this?
A) Prospective study
B) Retrospective study
C) Longitudinal study
D) Cohort study
2) B. Chart review = retrospective study.
3) What percentage of the ciliary body carbonic anhydrase needs to be inhibited before a significant decrease in aqueous humor production is seen?
A) 10%
B) 45%
C) 75%
D) 99%
3) D. Over 90% of ciliary body carbonic anhydrase needs to be blocked to have an effect.
4) Which one of the following antiglaucoma agents is preferred in mild asthma?
a. Timolol (Timoptic, Betimol)
b. Betaxolol (Betoptic)
c. Carteolol (Ocupress)
d. None of the above
4) B. In mild reactive airway disease (asthma), the selective ß1-adrenergic antagonist, betaxolol, is preferred over the other four currently available FDA-approved nonselective beta-adrenergic antagonists. In moderate to severe asthma, both selective and nonselective beta-adrenergic agents should be avoided.
5) Which of the following four computerized videokeratographic (CVK) maps represents a patient who has undergone radial keratotomy? (The scale is present on the right side of each image, with "cooler" colors [blue] representing flatter curvature areas and "hotter" colors [red] representing steeper curvature areas.)
a. Figure A
b. Figure B
c. Figure C
d. Figure D
5) C. This photos shows 4 areas of flattening right around the RK incisions. A shows central flattening of the cornea as you see after excimer laser treatment for myopic correction in LASIK or PRK. B shows what might be keratoconus.
6) Three years after external beam radiation for unilateral retinoblastoma, a 7-year-old child presents with a cataract in the same eye. The retinoblastoma proved to be radiation-sensitive, with complete regression of the tumor. The remainder of the retina and retinal vasculature appear normal although the cataract obscures the view. The opposite eye is normal and is emmetropic.
Which of the following is the MOST appropriate form of treatment for the cataract?
a. cataract extraction with use of aphakic spectacles
b. cataract extraction with use of an aphakic gas-permeable contact lens
c. cataract extraction with use of an aphakic silicone contact lens
d. cataract extraction with posterior chamber intraocular lens implant placed within the capsular bag
6) D. This is an area that is evolving but the books make it sound like you should put in an IOL in the bag in this age group of kids with unilateral cataract.
7) A 65-year-old patient has developed progressive nuclear sclerosis in both eyes and is having difficulty with reading and near work. Refraction is OD -1.25 -1.50 x 155 = 20/50, and OS -5.50 -2.00 x 25 = 20/40. Six years ago he had radial keratotomies performed in both eyes. Prior to his radial keratotomy (RK), he was -5.00 sphere in the right eye and -5.50 sphere in the left eye. He had four-incision RK in each eye with a goal of emmetropia in the right eye and mild myopia in the left eye for near vision. Two years after his RKs, his right eye was 20/60 uncorrected, and his left eye was 20/200. Refraction was OD +2.50 -1.50 x 135 = 20/30; OS -2.75 -0.50 x 180 = 20/30. His original keratometry was OD 42.50 D/43.00 D; OS 42.50 D/43.00 D. His present keratometry is OD 38.50 D/37.50 D; OS 42.00 D/41.50 D. His axial length measurements are OD 25.71 mm and OS 25.94 mm.
The LEAST acceptable course of action would be to
a. obtain computerized video keratography of both eyes
b. proceed with the cataract surgery utilizing his present keratometry and axial length measurements
c. calculate his true corneal power by subtracting his refractive effect (original spherical equivalent minus two-year post-RK spherical equivalent) from his original keratometry
d. calculate his corneal power by placing a piano contact lens of known curvature on his cornea and refracting over it
7) B. Either C or D would be appropriate for IOL formulation after refractive surgery. Video keratography certainly helps evaluate the cornea and would be helpful to look at. Using present (post refractive surgery) As and Ks would almost certainly leave you with a refractive surprise after surgery and an unhappy patient. If they wanted out of spectacles or contacts before surgery and you leave them -1.50 after cataract surgery they’ll be pissed.
8) Which statement is MOST correct regarding endothelial cell loss and phacoemulsification?
a. In-situ (within the lens capsule) phacoemulsification takes longer than nuclear tilt posterior chamber and anterior chamber phacoemulsification and, therefore, results in greater endothelial cell loss.
b. Scleral incisions have the same cell loss as corneal incisions.
c. In-situ phacoemulsification causes less cell loss than techniques involving emulsification of the nucleus anterior to the plane of the anterior capsule or iris.
d. Superior and temporal clear-corneal incisions have the same average cell loss.
8) C. In situ phaco
means “in the bag” and that keeps the phaco energy
the farthest away from the endothelium.
It doesn’t take longer than nuclear tilt; that technique requires
manipulation of the nucleus where with in situ you just get on it and go. Scleral incisions, clear corneal
incisions…doesn’t make a big difference in endothelial cell counts as much as
the irrigation during surgery, manipulation of nuclear fragments in the AC, and
phaco power—how much, how long and where it is (AC vs in the bag).
9) Identify the INCORRECT answer.
Whipple's disease:
A. may begin in the eye with corneal infiltrates.
B. is usually diagnosed by colonic biopsy.
C. affecting the brain causes gradual dementia, supranuclear ophthalmoplegia, and ocular myoclonic movements.
D. is associated with periodic acid-Schiff-positive material in many organs.
E. is caused by rodlike bacteria.
9) B. This question blows. Whipples affects the small bowel, not the colon so a colonic biopsy won’t help you. It’s a rod-shaped bacillus called tropheryma whippelii.
10) Identify the INCORRECT statement.
A. Pyrimethamine is safe for use in pregnant women.
B. Treatment of active toxoplasmosis should be continued for at least 1 year.
C. Any active toxoplasmic lesion should be treated in an immunocompromised host.
D. Pyrimethamine is often contraindicated for use in an immunocompromised host.
E. Zidovudine action is often antagonistic to that of pyrimethamine.
10) A. Pyrimethamine,
like other folic acid antagonists, can cause teratogenic
effects on developing fetuses.
11) Aging of the crystalline lens results in all the following EXCEPT:
A. accumulation of high molecular weight aggregates.
B. partial degradation of polypeptides.
C. loss of sulfhydryl groups.
D. increased solubility.
E. nonenzymatic glycation.
11) D. Over time, lens proteins become water
insoluble and aggregate to form large particles that scatter light, creating
lens opacities.
All of the following are possible causes for this condition EXCEPT:
A) alcohol-tobacco amblyopia
B) Leber's hereditary optic neuropathy
C) macular toxoplasmosis
D) bilateral occipital infarcts
12) C. It would be unusual for you to have bilateral macular toxoplasmosis that was so symmetrical and bilateral. This is classic central field defect as you could expect to see with the other conditions listed.
13) Regarding the previous question: You suspect Leber's hereditary optic neuropathy. What would be the best test to confirm your suspicion?
A) MRI scan of brain
B) Lumbar puncture
C) Serum electrophoresis
D) DNA analysis
13) D. Leber’s is transmitted via mitochondrial DNA. The 11778 mutation is the most common, 14484 has the highest chance of visual recovery.
14) Regarding the previous questions: Which fundus finding would be MOST suggestive of Leber's?
A) Sectoral optic atrophy
B) Optic nerve drusen
C) Hyperemic optic nerve with telangiectatic capillaries
D) Papilledema and a macular star
14) C. Classis fundus in Leber’s: hyperemic, elevated optic disc with thickening of
peripapillary retina (“pseudoedema”) and
peripapillary telangiectasia, and tortuosity of the medium sized arterioles.
15) Regarding the previous questions: What percentage of his children will also be affected?
A) 40%
B) None
C) 100%
D) 16%
15) B. Leber’s
is transmitted by mitochondrial DNA which comes from the mom, so HIS kids won’t
get it from him.
16) Which of the following conditions is MORE commonly seen in boys than in girls?
a. congenital third-nerve palsy.
b. Duane's syndrome.
c. congenital sixth nerve palsy.
d. congenital oculomotor apraxia.
e. Möbius' syndrome.
16) D. No sex predilection exists
for congenital third or sixth nerve palsies.
Duane’s is more common in girls than boys.
17) Systemic disorders associated with angioid streaks include:
1. Paget's disease of bone.
2. pseudoxanthoma elasticum.
3. Ehlers-Danlos syndrome.
4. high myopia.
a. 1, 2, and 3.
b. 1 and 3.
c. 2 and 4.
d. 4 only.
e. 1, 2, 3, and 4.
17) A. Think of
the PEPSI mnemonic. High myopia is associated with angioid
streaks but it’s not a systemic disorder.
18) Abnormalities in retinal physiology felt to be important in the early stages of diabetic retinopathy include:
1. impaired photopigment recycling and metabolism.
2. impaired autoregulation of retinal blood flow.
3. impaired retrograde axoplasmic transport.
4. breakdown in the blood-retinal barrier.
a. 1, 2, and 3.
b. 1 and 3.
c. 2 and 4.
d. 4 only.
e. 1, 2, 3, and 4.
18) C. There’s not a photoreceptor
recycling issue with DM and the blood-retina barrier doesn’t typically break
down.
19) Which method of closure of penetrating keratoplasty (PK) causes the GREATEST amount of irregular astigmatism (prior to suture removal):
a. interrupted.
b. single running.
c. double running.
d. combined interrupted plus single running.
e. combined interrupted plus double running.
19) A. Running sutures in theory
distribute the tension more evenly and thus induce less astigmatism. In real
life, it depends on the surgeon a little bit.
20. The major cause of mortality in patients with embolic central retinal artery occlusion (CRAO) is massive cerebral infarction.
- True
- False
20. B. The major cause of
mortality in patients with CRAO is cardiac disease, although stroke is another
major problem with these patients.