A. ACTH (adrenocorticotropic hormone). ACTH secretion is diurnal and regulated by corticotropin releasing hormone. This secretion is increased during stress and highest in the morning.

C. Tryptophan is the sole precursor for the synthesis of serotonin. We acquire this amino acid through our diet only.

E. Vitamin C is soluble in water. To recall, “DEAK” are the four fat soluble vitamins.

C. Aspirin use in children leads to the development of Reye’s syndrome – a rapid degenerative brain disease that is marked with confusion, seizures, and multi-organ failure.

A/D. Both Ciprofloxacin and Ofloxacin are second generation Fluoroquinolones. Recall “CO2” for second generation and “Three LEVO clover” for third generation. There are no first generation Fluoroquinolones. This information is important as second generation target Gram Negative bacteria while later generations could be used to target both Negative and Positive.

C. Cephalosporins are safe to use during pregnancy. To recall, “She is not FATS, she is PACking a baby”. FATS are not safe to use during pregnancy and includes: Fluoroquinolones, Aminoglycosides, Tetracyclines, and Sulfonamides. PAC is safe to use and includes: Penicillins, Azithromycin (Macrolides), and Cephalosporins.

B/C. Sumatriptan, a drug commonly used as a therapy for Migraines, functions as an anti-inflammatory and vasoconstrictor. Sumatriptan is an agonist of 5-HT1B and 1D receptors.

C. Bromocriptine, a dopamine agonist, is commonly used in treatment of Parkinsons. Amantadine is also considered a dopamine agonist used to treat Parkinsons.

A. Metformin is the only known DM drug that does not cause hypoglycemia. For this reason, Metformin is considered first line therapy for T2DM.

A. Naloxone, also known as Narcan, is administered to those experiencing an opioid overdose. Narcan acts as an opioid antagonist to reverse effects.

C. Sildenafil, also known as Viagra, functions by inhibiting phosphodiesterase-5 (PDE-5). PDE-5 breaks down cGMP which will lead to weakening of smooth muscle.

B. Zidovudine, also known as Retrovir, inhibits the viral RNA-dependent, DNA polymerase responsible for reverse transcription. RIbavirin is used in treatment of Hepatitis C. Foscarnet is used in treatment of CMV that is not responding to other antivirals. Natamycin is an antifungal.

B. Albuterol is a short acting Beta-2 agonist used as a rescue inhaler for Asthma and COPD. Other short acting agonists include Levalbuterol, Terbutaline, Metaproterenol (no longer used due to excessive cardiovascular effects) and Isoproterenol (nonspecific Beta agonist used in treatment of arrhythmias). Salmeterol is a long acting Beta-2 agonist used in maintenance therapy of the above conditions.

A. Trifluridine, also known as Viroptic, contains Thimerosal – a mercury-based preservative found in drops. The remaining options are oral medications used in treatment of herpes virus.

C. Pyrimethamine is NOT used in treatment of Tuberculosis. It is important to note that Isoniazid and Rifampin can be used in isolation for treatment of Latent TB. Active TB is treated with a combination of the RIPE medications.

B. Opsonization is the process by which complement proteins cover an antigen to initiate the immune system. Opsons alert the immune system to phagocytose the target cell.

D. Optic disc drusen are HYPERreflective on B scan ultrasound.

A. An INO is caused by a lesion of the medial longitudinal fasciculus (MLF). The MLF is responsible for coordinating the conjugate movement of eyes with associated head/neck movements. A lesion to the MLF causes an INO – loss of ipsilateral adduction and a contralateral nystagmus.

B. An optic nerve coloboma is caused by the incomplete closure of the fetal fissure during development. The degree of visual impairment varies depending on severity and location. The defect is most commonly located in the inferior nasal region of the disc.

C. The lesion is most likely located in the temporal lobe. To recall, think “pie in the sky”. If these findings were in the inferior field, it is suggestive of a lesion in the parietal lobe.

A,C,E: Note the sizes above. Bowman’s is about 10um and Descemet’s begins at 5um and increases to about 15um with age.

A: The palpebral portion of the orbicularis oculi is responsible for spontaneous and reflex blinking. Voluntary blinking also includes the orbital portion of the orbicularis oculi

D: The Scleral Spur is the origin of the longitudinal muscle fibers. The muscle inserts into the anterior choroid.

E. Anterior iris epithelium – the rest of the options are composed of connective tissue

C: The sclera is thinnest at recti muscle insertions with a thickness of about 0.3mm. The thickest is the posterior pole at about 1mm.

A/C/D. The three medications that may cause aplastic anemia include: Acetazolamide, Methazolamide, and Chloramphenicol. Additionally, Trimethoprim, Pyrimethamine and Methotrexate may also cause aplastic anemia.

C. Topiramate is clinically indicated for treatment of epilepsy to prevent seizures. It is important to know this medication as it may lead to blurred vision, diplopia, and nystagmus. More severe adverse effects include choroidal swelling leading to a myopic shift and acute angle closure glaucoma.

D. Chlamydia is the leading cause of ophthalmia neonatorum in the US. HSV and gonorrhea may also lead to development of this condition.

C. Along with Arlt’s lines other common findings in Trachoma include both follicular and papillary reactions of the palpebral conjunctiva, PAN, and potential SEIs. Dennie’s line are extra creases in adnexal skin in Atopic Dermatitis. Scheie’s line describes pigment in pigment dispersion syndrome. Stocker’s line represents the leading of a pterygium.The Hudson-Stahli line is iron deposition within the cornea that normally occurs with age.

A. Cobblestone papillae are found on the UPPER palpebral conjunctiva. VKC is a form of seasonal allergies that most often affects young males. These young males present with complaints of intense itching and photophobia. Slit lamp examination reveals cobblestone papillae of the upper lid, trantas dots with gelatinous masses at the limbus, and redness of the eye. In extreme cases, epithelial keratitis leads to thinning and eventual ulceration of cornea – a shield ulcer.

A. Macular dystrophy is the only corneal dystrophy that is autosomal recessive. The rest of the options are autosomal dominant.

D. The fine yellow-white rings of crystals in Schnyder’s are composed of cholesterol. Macular Dystrophy presents with multiple gray-white opacities composed of mucopolysaccharides. Granular Dystrophy presents with snowflake granules composed of hyaline. Lattice Dystrophy presents with lattice-like branches of amyloid. Calcium is associated with Band K, which affects Bowman’s layer.

A: Toxoplasmosis is the most common cause of posterior uveitis. Toxoplasmosis presents with unilateral vitritis in presence of a yellow-white retinal lesion near an old inactive scar. When looking within the eye, findings appear as “headlights in the fog”. Other conditions listed also lead to development of posterior uveitis.

B. Histoplasmosis does NOT cause vitritis. This is one major distinguishing factor when comparing to toxoplasmosis. Histoplasmosis is a fungal infection that is common to the Ohio-Mississippi River Valley.

B. The greatest threat to the patient’s vision is a CRAO. Elevated IOP leads to reversal of blood flow due to the change in perfusion pressure. Ischemic damage from CRAO is irreversible.

E. Cortical cataracts have been associated with hyperopic shifts in vision. Cerulean cataracts are congenital and present as small, blue-green opacities that rarely affect vision. Nuclear sclerosis is the most common aging cataract and most often leads to a myopic shift as the lens swells. Rosette cataracts are caused by trauma. PSC cataracts lead to reduced vision at distance and near, worse while reading with constricted pupils.

C. 1 mm of axial length corresponds to about 3 diopters. This emphasizes the importance of accurate A scan measurements prior to surgery.

A: Involutional, or aging, is the most common cause of entropion (an inward turning of the eyelid). Other causes include mechanical (tumor), cicatricial (trachoma, Stevens-Johnson, chemical burns), or congenital.

E. Canaliculitis is most often caused by Actinomyces israelii. First signs include a pouting puncta, epiphora, and sulfur granular discharge.

D. Demodex folliculorum and D. brevis are the most common mites found on the human eye lash. Phthirus and pediculus are parasites that are contagious and easily spread. If seen in children it is a red flag! Molluscum, a DNA pox virus, is a viral infection of the skin common in children and immunocompromised patients.

B. Cavernous hemangioma is the most common benign orbital tumor in adults. Cavernous hemangiomas develop slowly and lead to unilateral proptosis. Capillary hemangiomas are the most common benign orbital tumor in CHILDREN.

B. Involutional. The most common cause of ectropion is a laxity of the muscles needed to adhere the lid to the globe that develops with age. Congenital and Cicatricial are quite rare in occurrence. Paralytic ectropion is caused by Bell’s Palsy.

A,B,D: Telangiectasia is a critical finding in Coat’s, BCC, and ocular rosacea. Although these may begin to appear as we age, it is important to rule out these conditions on assessment. Molluscum appears as an umbilicated nodule without telangiectasia.

D. Osteogenesis imperfecta is not correlated with angioid streaks. Recall PEPSI as the most common causes of angioid streaks. Pseudoxanthoma elasticum, Ehlers-Danlos syndrome, Paget’s Disease, Sickle-cell disease, and idiopathic.

C. Presence of a halo is a positive sign and will steer diagnosis towards benign. To recall, remember the phrase “To Find Small Ocular Melanomas, Use Helpful Hints Daily”: Thickness (elevation >2mm), Fluid (subretinal), Symptoms, Orange pigment (lipofuscin), Margins are irregular, Ultrasound Hollowness, Halo absence, Drusen present.

B,C,E: RP, Gyrate atrophy, and choroideremia lead to complaints of poor night vision (nyctalopia). Night blindness is a consequence of damage to the rod photoreceptors in the retina. It is important to note that nyctalopia is not limited to these three conditions.

A. Limbal blanching indicates that the chemical burn has resulted in ischemia. Although the remaining options are of major importance, limbal blanching has the most long term consequences on the health of the eye.

B. It is imperative you DO NOT perform gonio or scleral depression until at least 1 month post-injury to avoid rebleeds. The most common cause of a hyphema is trauma so be sure to assess for iris sphincter tears, iridodialysis, rosette cataracts, lens subluxation, and other common traumatic findings.

A. The vestibulo-ocular reflex has the shortest latency of all eye movements with a latency of 15msec. The purpose of the VOR is to stabilize the retinal image as the head moves so it must occur quickly.

B. The minus lens test is the only option that does not measure accuracy but instead measures amplitude.

D. Latent hyperopia (refractive error that is correctable with accommodation) is +3.00 D. Manifest hyperopia (refractive error that is present in subjective refraction) is +4.00 D.

C. Absolute hyperopia (hyperopia that cannot be neutralized with accommodation alone) is +3.00 D; the difference between the two values. Facultative hyperopia (amount of hyperopia neutralized by accommodation) is +2.00D; the total accommodative ability.

B. Maxwell’s spot, as well as visuoscopy and Hidinger’s brush, are used to measure eccentric fixation. 4 BO test is used for ocular alignment, such as in microstrabismus syndrome. Bagolini lenses are used for ARC. W4D is used for sensory status.

D. Wold Sentence Copy is an example of a VMI test. The Beery VMI is another example. Piaget and Gardner, as well as Standing Angels in the Snow, are examples of tests of visual spatial skills. Visual analysis encompasses 6 sub-categories focused on analyzing images of different complexities.

B. According to Piaget, object permanence indicates the beginning of the pre-operational stage (2-7 years). There are four stages: sensorimotor (0-2 years), pre-operational (2-7 years), concrete operations (7-12), and formal operations (12 years and older). Object permanence is the knowledge that an object still exists even if it is not in the same room.

A. 10 pd BI. As we are calculating the prism necessary for exophoria, it is recommended to use Sheard’s Criterion. The equation is Prism = ⅔ Phoria – ⅓ Compensating Fusional Vergence. In this case, the phoria is 18Δ and the compensating fusional vergence (positive fusional vergence for exophoric patients) is the blur point of the BO measurement. To alleviate phoria we expect to move images to the fovea. Therefore the 10Δ will be BI. Remember this is total and NOT per eye.

B. Accommodative esotropia is the most likely diagnosis at this time. There are a few pieces of information that are key. First, the infant is demonstrating an eye turn some of the time. This means there is either a stimulus to the eye turn or it may be a decompensated phoria. The second piece of evidence is the orthophoric position with +3.00D lenses. This indicates that when accommodation demand is low, the eye turn is not present (or reduced).

C. The calculated AC/A is 3.6. The equation of note is AC/A = PD(cm) + WD(m)[Phoria @ N – Phoria @ D]. When plugging in values, Exo is considered “-” and Eso is considered “+”. Therefore, AC/A = 6.4 + .4(-8-(-1)) = 3.6. CAREFUL that PD is in centimeters.

C. To the LEFT. Recall COWS – cold = opposite, warm = same. As we know nystagmus is named by the fast phase (not the slow fixation period). Thus, since the nystagmus is in the same direction with warm water, we know it is to the left.

D. Crossed diplopia. Recall that the right eye sees the red dots and the left eye sees the green dots. If the red dots were located to the right of the green, that is considered uncrossed (or ESO) diplopia. Red dots above or below the green are indicative of a hypertropia. A patient reporting only one set of lights indicates suppression of either eye. A report of 4 dots is what we hope for.

D. Sherrington’s Law states that reciprocal muscles in the SAME eye will both be innervated to provide stability of eye position and gaez. Hering’s law states that yoked muscles in both eyes will receive equal innervation. Donder’s and Listing’s refer to unique orientations of the eye in space and how the eye achieves these positions.

B. End-point nystagmus is noted in extreme position of gaze. It is not noted at other times. Caloric nystagmus refers to the use of warm or cold water to induce eye movement. Optokinetic is related to viewing fast moving or rotating objects as the eye attempts to fixate a target. Rotational refers to rotation of the individual’s body. Latent refers to nystagmus that appears when one eye is occluded.

A/B/C. Topamax, Carbonic Anhydrase Inhibitors, and Pilocarpine are all known to carry the risk of myopic shift.

A. Acetylcysteine, also known as Mucomyst, functions by breaking disulfide bonds. This medication is also used in treatment of severe dry eye disease and corneal burns.

E. Naloxone is not known to cause PTC (otherwise known as Idiopathic Intracranial Hypertension). To recall, “SCANT” or “CATS-N”: Synthroid, Contraceptives, Accutane, Nalidixic Acid (in kids), Tetracyclines”

B. Macugen is an anti-neoplastic agent that prevents angiogenesis through inhibition of VEGF. PEDF has the opposite effect and is required to be in the proper balance of concentration as VEGF.

D. The greatest threat to vision with chronic use of Plaquenil is Bull’s Eye Maculopathy.The mechanism of action is similar to that of steroids. Standard of care (DFE within 1 year of initiation of drug therapy) is as above, exception being a 24-2 for patients of Asian descent.

B. Minocycline may cause a blue sclera. Other causes of a blue sclera include Scleromalacia Perforans, chronic topical steroid use, and thin scleras in newborn infants.

A. Dilation withOUT cycloplegia. Phenylephrine is an adrenergic agonist that causes dilation with no effect on ciliary muscles. When used to differentiate, vessels will become blanched with episcleritis. With diagnosis of Horner’s Syndrome, it helps determine if lesion is pre- or post ganglionic. 10% Phenyl is used to break old or severe PAS.

C. Timolol may mask the signs of HYPOglycemia in Diabetic patients. Timolol is also known to mask signs and symptoms of hypothyroidism as well as increasing symptoms of muscle weakness in patients with myasthenia gravis. Long term drift describes an increase of IOP after chronic use of Timolol. Short term escape is an initial lowering of IOP before no longer having an effect. D describes the “crossover” effect.

B. Of the options, Scopolamine has the longest mydriatic effect. Recall, ASH CiTy for length of cycloplegia and mydriasis with the cholinergic antagonists.

C. Beta blockers reduce IOP by decreasing aqueous production. Cholinergic agonist (i.e.Pilocarpine) affects IOP by increasing corneoscleral outflow. Alpha agonists both decrease aqueous production and increase uveoscleral outflow. CAIs decrease aqueous production. PGs increase uveoscleral outflow.

A/D. Alpha 1 and Beta 2 receptors in the eye are the targets for topical glaucoma meds. B1 receptors are located in the heart. Alpha 2 are located in the brain and peripheral nerves.

C/D: CAIs are known for several side effects. The most important to note include: metabolic acidosis, aplastic anemia, myopia shifts, bone marrow suppression, and depression. Other SE include metallic taste, tingling of limbs, thrombocytopenia, ED, and anorexia.

A/B/D. PG analogs, alpha agonists, and pilocarpine (a direct cholinergic agonist) all lower IOP by increasing aqueous outflow.

D. Muro 128 is used to reduce corneal edema in conditions such as Fuch’s. The remaining conditions can lead to ulceration of cornea with use of Muro 128.

C. Rifampin, a drug used in the treatment of Tuberculosis, is known to cause orange-pink discoloration of tears and urine.

C. The glycocalyx is found on the APICAL portion of the microvilli of the cornea. The glycocalyx is responsible for keeping the mucin layer adhered to the corneal surface.

D. The image is displaced 9 cm to the left. The equation for this example is PrismPower = image displacement (in cm)/distance to screen (in m). This is why the answer is in centimeters. Next, we note that a prism moves images towards its apex. When the base is positioned to the right, the image moves to the left.

A. The entrance pupil is defined as the image of the aperture stop formed by all lenses in front of it. The exit pupil is the image of the aperture stop formed by all lenses behind it. An entrance port is the image of the field stop formed by all lenses in front of it. The image of the field stop formed by lenses behind it is known as the exit port.

B. -4.08 D. You must first determine r by using the equation [Fair = -12.00 D = (1.50 – 1) / r]. You determine that r = -0.0417m. Using the new equation [Fwater = (1.50 – 1.33) / -0.0417m].

D. Purkinje image IV is the only image that is real and inverted. The remaining three are virtual and upright.

D. The power in the 180 meridian is -1.00. On an optical cross, +2.00DS falls on the 90 meridian. Subtract the astigmatic difference of -3.00 to find the resulting -1.00DS.

C. The power of the thin, Crown glass lens (n = 1.523) is -13.08 D. First draw a picture of this image (should look like two “C”s). First find F1 = (n2 – n1)/r, then F2 with the same equation. Done correctly will result in F1 = +13.075 D; F2 = -26.15 D; F = F1 + F2 → F = 13.075 + (-26.15) = -13.075 D.

D. The correct answer is +1.00 -3.00 x 090. Although cylinder lines are cleared at -2.00 D, the difference between both meridians is the DC of the prescription.

A,C,D: There are two definitions within the ANSI Z87.1 Safety Standard for Impact: high mass impact and high velocity impact. High mass impact is the drop ball test. This test requires a pointed projectile that weighs 500g dropped from 50 inches. The high velocity impact is assessed using a 0.25 inch diameter steel ball fired at 150 feet per second.

B. You can increase the seg height by any of the following: narrow the pads, move pads down, increase vertex distance, reduce pantoscopic tilt, or shrink the bridge. Consider the opposite in cases where the seg height appears too high.

B. Polycarbonate has the lowest Abbe value of all these options. Abbe value is inversely proportional to the level of chromatic aberrations. In other words, the higher the Abbe value, a lower amount of chromatic aberrations will be induced.

C. The true power is +7.47 D. To solve, first determine r using the clock reading: [Flc = +6.00 D = (1.53 – 1) / r; r = +0.08833m. Now solve for true with Flens = (1.66 – 1) / r = 0.66/0.08833 = +7.47 D)

B. An increase in lens diameter will allow for better lid attachment. Flattening the base curve, decreasing center thickness to reduce weight, or changing to minus carrier design can help with lid attachment.

B. First, calculate the BC of the DxCL → 337.5/7.67 = 44.00 D. The equation for lacrimal lake is LL = BC – K. In the 180 meridian, 44.00 – 44.50 = -0.50 D. In the 90 meridian, 44.00 – 43.00 = +1.00 D. Therefore, LL = +1.00 -1.50 x 090.

D. Using the LARS rule, the answer is -1.00 -1.00 x 085. The mark has rotated clockwise, or Left, so will need to add the 10 degrees to an axis. Most forget that we adjust the axis of the original subjective refraction rather than the diagnostic lens. Therefore, 85 is the new axis.

C. A hyperope wearing glasses will have the highest demand. A hyperope will have increased accommodative demand to overcome the prescription. When comparing, plus specs vs contact lenses, plus power spectacles require more convergence.

C. -1.00 x 090. The equation of note is RA = SRcyl – Kcyl. We know that SRcyl = -0.50 x 180. Using the K values, we determine the corneal cyl is -1.50 x 180. Solving for RA = (-0.50 x 180( – (-1.50 x 180) = +1.00 x 180 or -1.00 x 090

C. A back surface toric is appropriate as the information supports the “123” rule. The “1” is the residual astigmatism. The “2” is double the RA and represents corneal astigmatism. The “3” is double that of the corneal astigmatism and represents the vertex refraction (be sure to adjust the refraction before deciding which lens.

A. Warpage occurs on AND off the eye. Flexure only occurs ON the eye. Higher Dk lenses have more chance of flexure.

A. +6.00. Recall Kestenbaum’s Rule when determining initial ADD power. In this case, BCVA is 20/120. Therefore starting ADD is 120/20 = +6.00 D.

C. Feq = +14.00 DS. To calculate, recall the equation Feq = F1 + F2 – cF1F2. As there is no separation in the equation, we simply calculate F1 + F2.

D. This patient has Ankylosing Spondylitis – an inflammatory condition that causes sacroiliitis in young males that improves with exercise. AS is the most common cause of acute, unilateral anterior nongranulomatous uveitis. You can recall the UCRAP conditions as the most common causes of acute, unilateral anterior nongranulomatous uveitis and for their association with HLA-B27. The last option refers to sarcoidosis – causes chronic, bilateral granulomatous anterior uveitis.

D. Rheumatoid arthritis is not expected in Primary Sjogren’s syndrome. Primary Sjogren’s syndrome is defined as dry eye, dry mouth, and presence of autoantibodies. To diagnosis Secondary Sjogren’s, a patient must present with all the previous findings AND an autoimmune disease such as RA, SLE, and other connective tissues diseases.

C. Myasthenia gravis is caused by antibodies that target acetylcholine receptors. This condition leads to reduced muscle innervation over the course of a day leading to symptoms worse at night. Ocular findings include ptosis and diplopia. Recall the ice pack test and tensilon (Edrophonium) test.

D. Hyperthyroidism is characterized by elevated levels of T3/T4 hormones and low levels of TSH. This condition is caused by constant thyroid stimulation leading to increased production of T3/T4. Elevated levels of T3/T4 inhibits the production of TSH by the thyroid gland leading to decreased levels of TSH.

C. A patient diagnosed with T1DM should have a dilated fundus exam within 5 years of diagnosis. Patients diagnosed with T2DM are recommended to have a DFE upon diagnosis.

A. Heat intolerance is not associated with Hypothyroidism (low amounts of sympathetic innervation). Rather, the classic symptoms include COLD intolerance, weight gain, decreased appetite, weakness and lethargy.

B. Wernicke-Korsakoff Syndrome is caused by a deficiency of Vitamin B1 (thiamine). This condition is seen most commonly in alcoholics.

C. Fabry’s disease is associated with development of verticillata, also known as whorl or vortex keratopathy. Several medications (recall CHAI-T) as well as the condition sphingolipidoses can cause verticillata as well.

A,B,D: The classic triad of Neurofibromatosis 1 includes cafe au lait spots, neurofibromas, and iris Lisch nodules. It is important to examine a patient for these signs in the presence of at least one of these findings. Other findings may include optic nerve gliomas and congenital glaucoma.

C. The above most accurately describes Leber’s hereditary optic neuropathy – transmitted through maternal inheritance. A single AA base substitution can describe many conditions including, but not limited to, Sickle Cell anemia. Abnormal collagen synthesis may lead to changes in vision due to corneal malformation and weakness of lamina cribrosa. Neither Trisomy 21 (Down Syndrome) nor Turner Syndrome (absent X) are known to cause these findings.

B. Contact dermatitis is an example of a Type IV hypersensitivity reaction, also referred to as delayed or cell-mediated hypersensitivity. T-lymphocytes are the primary immune response in this type of reaction. Type I hypersensitivity uses IgE. Type II hypersensitivity is the more common IgM/IgG response. Type III hypersensitivity utilizes antigen/antibody complexes.

B. Pseudodendritic keratitis is a complication of Herpes Zoster Virus. One would expect to find dendritic keratitis in HSV. Dendrites appear as branching areas of staining on the cornea with terminal end bulbs. Use of Rose Bengal or Lissamine Green staining is important in this diagnosis. Recall that HSV can lead to development of follicles.

B. Between the CCB and the SCG. A lesion of the sympathetic pathway leads to development of Horner’s syndrome. These lesions can be defined by one of three regions: preganglionic central, preganglionic, and postganglionic. See answer choices for description.

B. Dementia is not a classic sign of Parkinson’s. To recall the signs, think of the mnemonic TRAP – Tremor at rest, Rigidity, Akinesia, and Postural instability.

A. Age is the most highly associated risk factor for hypertension. The remaining options are also risk factors.

C. An aneurysm is the most likely cause of this CN3 palsy. The fixed, dilated pupil is indicative of a compressive CN 3 palsy. As the pupillary fibers course along the outside of cranial nerve 3, any growth, lesion, or pressure on the outside of the nerve will prevent the pupil from constricting. Vascular diseases affect the nerve from the inside and spare the pupillary fibers. HSV is more often correlated with Bell’s Palsy.

D. Cluster headaches are characterized by periods of attacks that occur for several weeks before going into remission. These headaches most commonly affect males between the ages of 30 and 50 years. These headaches can be accompanied with red eyes, nasal congestion, and transient or permanent Horner’s syndrome.

B. A tumor that causes compression of both the posterior and middle cerebral arteries is most likely to cause a macula-only homonymous hemianopsia. The macular center of the occipital lobe is superficial and fed by both arteries. Vascular events often only damage one of the sources, thus leading to macular sparing homonymous hemianopsia.

D. Rods take about 30-40 minutes for complete dark adaptation. Cones take about 5-10 minutes for light adaptation.

C. The low frequency cut off is due to lateral inhibition in the retina. Lateral inhibition is produced by the interneurons: horizontal and amacrine cells. The high frequency cut off is due to optical aberrations and photoreceptor spacing.