B. NADPH. These agents are found along the sorbitol pathway. This pathway is important in understanding the breakdown of glucose in the body. One molecule of glucose can either undergo reduction to sorbitol in a low oxygen environment or can be converted directly to fructose 6-phosphate.

D. Epinephrine is derived from Tyrosine. Tyrosine molecules are converted to dopamine which leads to production and release of norepinephrine. Norepinephrine is converted to epinephrine via methyltransferase.

B/D. TCAs function by increasing levels of serotonin, norepinephrine/epinephrine, and anticholinergic activity. These three functions lead to increased sympathetic output.

C. Natamycin is an antifungal that works by inhibiting ergosterol thereby forming pores in cell walls. This leads to cell death. Recall that Natamycin is NOT a macrolide – a drug class that inhibits the 50s subunit of bacterial ribosomes. Penicillins inhibit transpeptidase.

C. Oseltamivir, also known as Tamiflu, is used in the treatment of Influenza. The remaining options are antifungals. Of note, Natamycin is NOT a Macrolide as the name indicates.

B. Loratidine is an example of a second generation antihistamine. To recall, “phen” in the drug name is a clue to determining first generation – exception of promethazine. First generation antihistamines penetrate the blood/barrier more easily than second generation antihistamines. This leads to less side effects such as sedation.

B/C. Recall, “Buy AT 30, CEL at 50”. Aminoglycosides and Tetracyclines act by binding the 30s subunit of bacterial ribosomes and preventing protein synthesis. The other three classes work by binding the 50s subunit.

D. Bacitracin prevents bacterial wall synthesis by inhibiting transfer of peptidoglycan into the growing wall. Oxacillin and Cephalexin inhibit transpeptidase. Gentamicin inhibits bacterial protein synthesis by binding 30s subunits of the bacterial ribosome.

D. If a patient is on Warfarin, it is best to prescribe a Penicillin. Cephalosporins may destroy normal intestinal flora thus altering Vitamin K absorption. This may lead to excessive thinning of the blood in conjunction with Warfarin.

D. Nardil, also known as Phenylzine, is a Monoamine oxidase inhibitor. MAO is an enzyme found in the synaptic cleft that breaks down norepinephrine and serotonin to be taken back up. By inhibiting MAO, norepinephrine and serotonin may remain active in the cleft for longer. When used in combination with Phenylephrine, there is too much sympathetic activity.

A. Simvastatin, also known as Zocor, is one of three cholesterol medications that function by inhibiting HMG-CoA reductase. This enzyme is responsible for production of cholesterol. These medications are first line therapies. Gemfibrozil binds to PPAR-alpha leading to breakdown of VLDL. Cholestyramine binds bile acids in intestines to prevent reabsorption. Isotretinoin is a distractor as it is used in treatment of acne.

D. Furosemide is the only diuretic to affect the ascending loop of Henle. Furosemide functions by inhibiting Na+/2Cl-/K+ co-transporter while also increasing Ca²⁺ secretion. Use of Furosemide may lead to development of hypokalemia and/or nephrotoxicity.

A. Losartan, an Angiotensin II receptor antagonist (ARB) is used to treat hypertension. It does not have any effect on bradykinin activity, thus leaving lungs unaffected for cough. The remaining options are ACE inhibitors which act by preventing formation of angiotensin II through ACE inhibition as well as blocking metabolism of bradykinins causing vasodilation.

A, C: MACI is formed by the anastomosis of the long posterior ciliary and anterior arteries. It is located within the iris stroma and is non-fenestrated.

D. The liver is the only region above that does not drain into the right lymphatic duct.

D. The descending limb of the loop of Henle is permeable to water and impermeable to NaCl. The opposite is true of the ascending limb.

B. In the proximal convoluted tubule, the ATPases drive Na+ out into the interstitial space and K+ in to the proximal convoluted tubule for excretion. Water will follow the Na+

A. Alpha cells within the Islet of Langerhans are responsible for production of glucagon. Beta cells produce insulin and amylin. Delta cells produce somatostatin. F cells produce pancreatic polypeptide.

D. Apocrine secretion – products secreted in membrane-bound vesicles. Holocrine secretion is when the entire cell that contains the product is secreted. Meibomian glands are an example. The main lacrimal gland secretes via merocrine – products move directly into lumen.

A. Natural Killer cells do not require an antigen presenting cell to attack antigens. NK cells serve as the rapid response team for antigens that have yet to be phagocytosed. The remaining cells are part of a specific immunity response.

D. The hypothalamus is responsible for regulating body temperature, hunger, and sleep. The epithalamus contains the pineal gland which regulates circadian rhythms. The thalamus acts as a relay station for sensory input to different cortical regions. The subthalamus and basal ganglia communicate to control muscle movement.

B: Frontalis muscle is responsible for the look of surprise. The frontalis is activated in cases of ptosis and dermatochalasis to assist with raising eyelids. The corrugator creates the look of concentration. Procerus, think rhinoceros.

B,E: The Greater wing and the Zygomatic bones comprise the lateral wall (Great-Z)

All but C: Recall the mnemonic “the nose SMELs” for medial wall of orbit.

D: Seven – Frontal, Ethmoid, Sphenoid, Lacrimal, Maxilla, Palatine, and Zygomatic

B: Preauricular nodes – the site of palpation in cases of red eye. Medial conjunctival lymphatics travel to the submandibular nodes.

C: The corneal ENDOTHELIUM has the most mitochondria to supply energy to the Na/K pumps that maintain corneal water concentration.

C: Muscle of riolan is the most superficial portion of the orbicularis oculi and is responsible for keeping the eyelid adhered to the globe.

C: Smooth muscle that is innervated by the sympathetic nervous system. Mueller’s muscle provides an extra 2-3mm of lift to the eyelids. Loss of innervation to this muscle will lead to a mild ptosis (i.e. Horners)

E: Palpebral conjunctiva and within caruncle are two sites of mucous production

D. Although inflammation does cause a widening of meibomian ducts, meibum that has become more viscous will block the further secretions. This blockade leads to acinar atrophy, a primary cause of dry eye.

C. Pterygopalatine innervates the lacrimal gland to stimulate aqueous secretion.

D. Anterior border layer is the primary contributor to eye color with trace input from the iris stroma.

B: Fetal nucleus is the only site of Y-sutures. The embryonic nucleus contains the most mature fibers.

C: Innervates the SUPERIOR oblique; all other statements are correct.

E. All of the above are correct. It is important to understand the general pathways innervation travels to the orbit and adnexa. Try to draw out these pathways with blanks that you can fill in and erase later.

C. Plica Semilunaris allows for movement WITHIN the globe. The fornix and caruncle are location and redundant tissue, respectively. Mueller’s is responsible for lifting the eyelid. The muscle of riolan is responsible for keeping the eyelid adhered to the globe.

A, B, D: The lateral rectus is unique in that it is the only nerve innervated by CN VI. Nerve innervation begins in the pons and travels past the precarious skull process which is more susceptible to damage from increased cranial pressure (vs. trauma). Unlike the other extraocular muscles, the lateral rectus has two origins on the annulus of zinn and receives blood supply from only one artery.

B. Recall that torsion is a primary function of obliques; OBliques ABduct (or O’s to the nose); and obliques have opposite roles in supraduction.

B. The CRA has networks within both the Nerve Fiber Layer and the Inner Nuclear Layer. Dot and blot hemes are seen in the OPL as bleeding from INL leaks down layers.

C. The outer nuclear layer in the retina contains all the cell bodies of the photoreceptors.

A: Melanopsin is found in the intrinsically photosensitive ganglion cells. These cells are thought to be regulators of the circadian rhythms found in mammals.

A. Vitamin A is the main component of opsins. Vitamin B can be found in all cells and usually depleted in alcoholics. Vitamin C is important in collagen synthesis, antioxidants, wound healing, bone formation, and many other functions. Vitamin D is supplied by the sun and helps in digestion. Vitamin E is an antioxidant found in vapes that in conjunction with nicotine, can increase the likelihood of developing cancer.

B. The uvea is made up of iris, ciliary body, and the choroid.

B: Tenon’s capsule – To remember, consider C.C. TESLA From anterior to posterior: C. epithelium, C. stroma, Tenon’s capsule, Episclera, Scleral proper, Lamina fusca, and Anterior choroid

C. Zonula Occludens/Adherens are responsible for tight barriers. Desmosomes maintain structure integrity. Hemidesmosomes are responsible for connecting cells to their basement membranes. Gap junctions serve a role in small ion transport and cell-cell signalling. Keratocytes are cells responsible for structural integrity of the cornea.

B. The lens zonules begin their course from the pars plana and traverse to the posterior lens capsule to participate in accommodation.

E. All of the above traits are true. To recall, the 4 C’s of side effects: Clots, Cancer, Crystal, Corneal Whorl. Tamoxifen inhibits estradiol thereby reducing estrogen effects in the breast. Patients in remission must remain on this medication for up to 5 years after successful treatment.

C. Cyclobenzaprine, also known as Flexeril, is a muscle relaxant used in treatment of muscle spasms. It works by decreasing somatic motor activity by inhibiting tonic activity of alpha and gamma neurons. Caution as this medication may cause Narrow Angle Glaucoma.

B,C,E: Superior limbic keratoconjunctivitis (SLK) is related to FRICTION. Dry eye, thyroid eye disease, and contact lens hypersensitivity are most commonly associated with SLK.

C. Ligneous conjunctivitis is caused by a systemic plasmin deficiency leading to development of thick mucous membranes. Other conditions associated with PAN include viral, inflammatory systemic, and hyperacute bacterial infections.

B. Klinefelter syndrome is NOT associated with keratoconus. To recall these conditions, use the mnemonic “T-DOME”: Turner Syndrome, Down Syndrome (aka Trisomy 21), Osteogenesis Imperfecta (aka Brittle Bone disease), Marfan Syndrome, and/or Ehlers-Danlos Syndrome. Other lower yield conditions include atopic dermatitis (excessive rubbing) and mitral valve prolapse (can be correlated to Marfan syndrome).

E. Indirect illumination is used to assess non-opaque corneal lesions by focusing oculars adjacent to the beam of light (i.e EMBD). Sclerotic scatter is used to evaluate the clarity of the cornea. Optic section is used to determine depth (i.e. Van Herick, corneal scar). Conical beam is used to assess anterior chamber for cells and flare. Specular reflection is used to assess the corneal endothelial cells (i.e. Fuchs).

A,D,E: A normal result for phenol red thread test is >10mm in 15 secs, Schirmer 1 test is >10mm in 5 minutes, Schirmer 2 testing (with anesthesia) is >5mm in 5 minutes. Tear osmolarity should be greater than 308 mOsm/L. Tear meniscus is measured under a slit lamp and should be greater than 0.2mm. Tear break up time (TBUT) is evaluated under slit lamp and blue light conditions. The tear film should remain intact for up to 10 secs.

A,E: Either the nasociliary branch of the trigeminal (V1) and/or the facial nerve (VII). The nasociliary nerve is responsible for sensory information from the cornea. Corneal regeneration is reduced as there is little feedback from the corneal nerves that indicate damage. Common causes of damage include HSV, DM, LASIK, contact lens overwear, and chronic corneal injury. The facial nerve can also cause NK due to reduced reflex tearing and inability to close the eyelid leading to chronic damage of ocular surface and further damage to VI. The cotton-swab test is used for aid in diagnosis of NK.

B. The minimum number is 400-700 cells/mm². This range is seen in older patients or those diagnosed with Fuchs’ endothelial dystrophy. From birth, the average range is 3,000-4,000. After 80, that number drops to about 1,000-2,00 cells. Recall that endothelial cells do not regenerate.

A,C,D: These conditions lead to development of trabeculitis and iritis that reduces aqueous outflow. This reduction in outflow leads to spikes in IOP as high as the 40s-50s. Sarcoidosis may cause inflammation anywhere in the body. Most often, Sarcoidosis leads to bilateral uveitis and may also include posterior or panuveitis. Toxoplasmosis does not often cause anterior uveitis, rather posterior or panuveitis.

C,D: Stellate KPs are unique to Herpes simplex and Fuch’s iridocyclitis. Other options listed here are also considered granulomatous. However, these conditions present with Koeppe (found at pupillary margin) or Busacca nodules (other locations on iris).

A. Trauma is the number 1 cause of unilateral glaucoma. This is due to damage to the TM when the iris root is affected.

A. An S-shaped ptosis is classically associated with dacryoadenitis – inflammation of the lacrimal gland. Dacryoadenitis can occur acutely or chronically. Acute infections present with S-shaped ptosis, pain, redness, and preauricular lymphadenopathy. Acute infections are often bacterial or viral in nature. Chronic infections have a similar set of signs/symptoms, however, to a much lesser degree. Chronic infections are related to inflammatory disorders such as the other answer choices.

B. Mueller’s muscle is the culprit. Horner’s is known to affect the sympathetic nervous system. Mueller’s muscle is innervated by sympathetic input and acts to lift the eyelid 2-3mm. This is the reason for the mild ptosis in Horner’s patients.

B. A consequence of congenital aberrant degeneration, the motor branches of the trigeminal nerves will simultaneously communicate with the superior division of the oculomotor nerve which controls the levator.

E. Although staph epidermidis is a common cause, Staph Aureus is seen most frequently. H. influenza and N. gonorrhoeae are gram “-” bacteria more common in children’s bacterial eye infections. Moraxella is more common in angular blepharitis.

D. Cholesterol. The condition we are seeing is known as Xanthelasma. The yellow plaques develop over time with elevated cholesterol levels. The patient can be referred for excision/cryotherapy after cholesterol levels are brought back to normal levels.

D. H. influenzae is the most common culprit for cellulitis in children. Staph aureus is the most common cause of cellulitis in adults.

C. The correct order is Inferior rectus, Medial rectus, Superior rectus, Lateral rectus, and then the obliques. The mnemonic for this condition is “IM SLO”.

B. Poliosis is the whitening of eyelashes often caused by chronic eye infections. Madarosis describes a loss of eyelashes. Tylosis is thickening of the lid margin. Trichiasis is an inward turned eyelash. Sudoriferous is a term used to describe a cyst.

D. Chemical burns with alkali agents are more dangerous than acidic agents. This list is challenging. First, remove the two acids. Next, we know that fertilizers and pepper spray (PAVA) are both acidic. Calcium hydroxide is not only basic, but also the most common cause of alkali burns.

C. Surface Ectoderm. Embryonic optic vesicles form as an extension of the neural tube. As these approach the surface ectoderm, the lens placide and lens vesicles form. The narrow cleft, aka embryonic fissure, forms in the walls of the optic cup. Hyaloid vessels form the vascular capsule of the lens.

C. Suppression of the left eye. Placing a loose 4BO in front of the right eye causes a small movement of the right eye toward the apex of the prism. Due to yoked muscles movement, the left eye will also move. If the left eye is not suppressing, it should quickly re-fixated to target. If there is NO movement of either eye with lens placement, it is a suppression of the right eye. If the left eye does not refixate after a right eye shift, the left eye is considered suppressed.

E, 4.5 years is roughly when a child should be able to draw and identify a square. Some important shapes to know include: Straight line near the end of 2 years of age, Circle at 3 years, and Triangle near 5 years.

A. Accommodative response is present at birth and reaches maturity at about 3 months of age. It is important to review key ocular motor and visual development milestones.

C. Minus lenses indirectly test NEGATIVE fusional vergence. Adding minus lenses increases accommodation and convergence. In order to maintain images on the fovea,negative fusional vergence is required to overcome the changes. Prisms directly test the direction of their apex.

B. Floppy iris syndrome is an adverse effect of Benign Prostatic Hypertrophy – a condition that causes frequent but poor urination. It is important to remember this medication as Floppy Iris Syndrome can impact cataract surgery. Tamsulosin is considered an Alpha-1 blocker.

A/B/C: These three medications may cause retinal pigmentary changes. When it comes to pigmentary changes throughout the eye, the drug class Phenothiazines (antipsychotics) are infamous for this adverse effect. From pigment on endothelium to the retina, the “-Azines” affect all regions of the eye.

C. Chronic corticosteroid use leads to development of posterior SUBCAPSULAR cataracts. PCO develops after a PCIOL has been in an eye for a period of time. The remaining options are correct facts.

B. Loteprednol is considered the safest steroid for prescribing. Unfortunately, many cases of inflammation are severe and require stronger prescription steroids. In these cases, it is important to educate patients about proper use and follow up schedules to avoid rebound inflammation.

E. Cromolyn Sodium is classified as a mast cell stabilizer. The remaining options are NSAIDs. Recall that “-fenac” and “-rolac” help identify generic equivalents.

E. Voltaren is not known to cause Whorl Keratopathy (aka Verticillata). Recall, CHAI-T when asked about verticillata. Do not forget, Fabry’s Disease may also lead to this finding.

B. Abnormal renal function can cause an increased risk of developing side effects related to chronic use. To recall: treatment duration greater than 5 years, abnormal renal function, high body fat percentage, over 60 years of age, and/or liver disease can increase risk of BEM.

A. Optivar is the only allergy eye drop listed here that is a combination of H1 inhibition and stabilization of mast cells. Mast cells stabilizers work by preventing Ca2+ from binding mast cells. Calcium serves to initiate degranulation of mast cells leading to allergy symptoms. Recall, BEZPOP for combination antihistamines.

B. Emadine is considered only an antihistamine with no mast cell stabilizer action. The remaining choices all work by preventing mast cell degranulation by preventing binding of Ca²⁺.

C. Ototoxicity is not considered a side effect of Tetracyclines. Tetracyclines function by inhibiting protein synthesis through binding of 30s subunits of bacterial ribosomes.

B. Use of Pilocarpine may cause a MYOPIC shift. Other side effects include: brow aches, headaches, miosis, cataracts, retinal detachment, and secondary angle closure.

C. Phenylephrine is an adrenergic agonists that acts only on ⍺1. Brimonidine is highly selective for ⍺2 and Apraclonidine acts on ⍺2 receptors with limited ⍺1 activity. Naphazoline and Tetrahydrolozine are non-specific alpha receptor agonists.

C. Adie’s Tonic Pupil. Since the iris sphincter is desensitized in Adie’s, it will respond to even a low concentration of pilocarpine. Recall that ADie’s is an Acutely Dilated pupil normally found in young females.

E. Grave’s disease is not considered a contraindication for PG use. The remaining options describe conditions associated with inflammation. Recall that PGs are produced naturally in response to inflammation in the body.

C. EDTA is a Calcium ion chelating agent that can be used in treatment of Gout and Band Keratopathy. BAK is infamous for causing SPK with the benefit of increased corneal penetration. Thimerosal is considered very toxic as it contains mercury. SP is found in artificial tears/ointment and is considered less toxic.

C. All topical anesthetics are considered esters for their shorter duration and ability to be metabolized locally. Amides have a longer duration and are metabolized by the LIVER.

A,B,C. All of these options will influence pars plicata to produce more aqueous humor. Build up of H+ in pigmented epithelium leads to reversal of bicarbonate ion movement, thus halting aqueous production. A similar mechanism can be seen with increased intracellular Cl- ions.

C. Active secretion is responsible for 80-90% of aqueous humor production. A small portion of aqueous is produced through diffusion and ultrafiltration. Hydration and holocrine are both distractors.

D. Glycocalyx, which is secreted by the epithelial cells, allows adherence of the mucus layer. Goblet cells secrete mucins which make up the mucus layer.

B. The long ciliary nerves of the cornea are branches of the ophthalmic division of the trigeminal nerves (CN V). The nerves enter into the cornea and traverse about ⅔ of the distance before moving anteriorly. These nerves loes myelin sheath about 1.5mm into the cornea.

D. The adrenal gland does not have a ganglion synapse with the ganglionic fibers of the spinal column. Rather, it receives a signal to release epinephrine directly into the bloodstream.

C. All but Vitamin B are found in the tear film. Lysozymes serve as bacteriolytic cells. Defensins and IgA serve to detect foreign material and cells. Lactoferrin protects the eye from free radical iron molecules.

D. This CT pattern is indicative of against-the-rule astigmatism. WTR astigmatism is characterized by a bow tie pattern with vertical steepening. Keratoconus would present with inferior steepening. Pellucid marginal degeneration scans are known for a kissing dove or crab claw appearance.

D. Total prism induced is 0.8 BI. First, recall Prentice’s law (Total prism = power of lens x decentration in centimeters). In this example, the answer is 0.8. Next, draw a picture of the lens (two triangles sharing one side). We can see that the patient is looking through the base-in portion of the lens.

D. The lens will need to be moved 2 mm to place the optical center in front of the patient’s eye. Do not forget that TOTAL decentration is 4 mm but each lens only moves half of that. Easy rule of thumb – patient PD < frame PD = move lens in and vice versa

A. This pattern is classic for WTR astigmatism. The opposite pattern of clearance and touch indicates ATR. General clearance or touch is more characteristic of a spherical cornea. You would expect an inferior spot of lens touch.

D. Increased oxygen transmission via silicone as the water content decreases. Increasing water content leads to lower ratio of Silicone to water. Therefore, more water in the lens means less oxygen from tears through the silicone.

C. The minimum amount of clearance is 50 microns. In practice, it is best to aim for 100-150 but 50 microns will still allow for corneal clearance even with blinks.

D. 20/500 is considered Profound low vision. Recall the following pairs: Normal = 20/12 -20/25, Near-Normal = 20/30 to 20/60, Moderate = 20/70 – 20/160, Severe = 20/200 – 20/400, Profound = 20/500 – 20/1000, Near Blindness > 20/2000. Blindness is no perception of light or motion.

C. 5x. Recall the equation Effective magnification = F/4 = 20/4. Standard distance is 25 cm as the standard presbyopic and emmetropic patient needs a +4.00 add for magnification.

B. Kaposi’s sarcoma is a malignant lesion that develops secondary to an active herpes infection in an immunocompromised individual. The remaining options are all opportunistic infections that develop as CD4 cell count declines.

A. SLE is an example of a Type III hypersensitivity reaction – involves ag/ab complexes. SLE most often presents in young women in their teens and twenties. These patients may experience a malar rash, joint pain, and other consequences of inflammation in the body. Blood work will reveal a positive ANA.

C. Folic acid supplementation can significantly reduce the risk of spina bifida in a newborn. Spina bifida is a defective closure of the spinal cord that leads to lower body dysfunction and decreased mental function.

C. Klinfelter syndrome is the only option in this list without evidence of prominent epicanthal folds. Be sure to know other conditions besides Down syndrome and Fetal Alcohol syndrome. Blepharophimosis is an eyelid condition that demonstrates REVERSE epicanthal folds.

D. Behcet’s disease is an inflammatory disease that occurs more commonly in young males of Middle Eastern or Asian descent. It is defined as recurrent mouth, eye and/or genital sores. One must have two of these to receive a formal diagnosis. Behcet’s is associated with acute recurrent hypopyon as well as all forms of uveitis.

A. An ESR of 30 mm/hr is considered normal in a female of this age. This patient suffers from Giant Cell Arteritis. Abnormal GCA results include: elevated ESR, CRP, and platelet count as well as inflammation of the temporal artery noted on biopsy. Recall that elevated ESR in males is greater than their age divided by 2 (> age/2) and in females it is their age plus ten (> (age+10)/2). Elevated CRP is considered greater than 2.45 mg/dL. Elevated platelet count is any value > 400,000.

A. Ricco’s law states that the number of photons is the same for all stimulus sizes that are less than a critical diameter. This varies as stated above. Bloch’s law describes a critical time threshold for stimulation. Ferry-Porter law states the critical flicker frequency with the log of retinal illumination. Granit-Harper law states that the CFF increases as the stimulus area increases.