Opthobook Pimp Questions

5. What portion of the eyelid do you worry about with lid lacerations?

If the laceration is medial (near the nose) it could involve the tear drainage pathway. These canalicular tears are more complicated to repair.

12. A patient presents late at night with a large rhegmatogenous retinal detachment. The central fovea is also detached. How soon do you need to go to surgery?

If the macula is off, then the macular photoreceptors are already damaged and it may be ok (this is the retina surgeon's call) to schedule repair later when your surgeon is well-rested and you've got your best operating team. However, if the macula is still ON, you want to intervene sooner to make sure the macula STAYS on.

4. What findings would prompt you to take a patient with an orbital floor fracture to surgery?

If the patient has muscle entrapment or significant enophthalmos. Most patients have some degree of EOM restriction from soft-tissue swelling. Entrapment causing reflexive bradycardia would also push you toward surgery.

11. The previous patient admits to "not feeling good" and "it hurts my head to brush my hair on the right side" for the past week, but denies all other symptoms. Should you order any labs? Start any medications?

If you have any suspicion for GCA, you pretty much have to order a ESR and CRP. Start oral prednisone (about 1mg/kg/day) immediately and set up for temporal artery biopsy within a week or so. Steroids won't help much with his lost vision in these cases, but decreases the risk to the other eye, which can be affected within hours to days.

7. What is the best way to test the pressure in an eye with a likely openglobe injury: with slit-lamp applanation or with the hand-held tonopen?

If you suspect open globe, you don't want to be mashing on the eye, so neither of these is correct. This is a trick question ... hahahahaha

6. What location for a retinal detachment would be most amenable to treatment by pneumatic retinopexy? a. inferior rhegamatogenous detachment b. superior tractional retinal detachment c. superior rhegamatogenous detachment d. traumautic macular hole

Answer: This question covers several concepts. Rhegamatogenous detachments are the classic detachment occuring from a break in the retina. A pneumatic retinopexy is the technique of injecting a gas bubble into the eye that floats and tamponades the break. Gas bubbles require careful head-positioning and work best for superior breaks (patients can't stand on their heads for weeks for inferior breaks). The correct answer is therefore (c).

7. What's a chalazion, stye, and hordeolum? How do you treat them?

A chalazion is a non-infectious granulomatous inflammation of a meibomian gland sitting in the tarsal plate (see the anatomy chapter). A stye is like a pimple at the lid margin, usually at the base of an eyelash. A "hordeolum" is a general term that describes an "inflamed gland." It is debatable what this means, so I don't like to use the term "hordeolum" myself but you may run across it.

11. What's the difference between a corneal abrasion and a corneal ulcer?

A corneal ulcer is an abrasion PLUS an infectious infiltrate. Ulcers require antibiotic coverage and possible culturing depending upon the severity, size, and location of the lesion.

1. A patient comes into your office in great distress because their eye looks incredibly red. On exam, you see they have a spot of hemorrhage under the conjunctiva. Is this a problem and should they be worried?

A few drops of blood spread under the conjunctiva looks impressive and can be alarming. Subconjunctival hemorrhage occurs when a conjunctival blood vessel "pops," usually after a valsalva or when bending over. This is generally benign as the blood will go away in a few weeks. If the hemorrhage is recurrent, though, start thinking about bleeding disorders.

7. What's a normal eye pressure? Does a patient with pressure of 14 have glaucoma?

About 10 to 22. While glaucoma is classically associated with high pressure, there is a significant minority of patients with glaucoma who actually have "normal" pressure. Also, pressure fluctuates throughout the day so we typically write down the time in our notes. Some studies have noted higher rates of glaucoma in people with large diurnal shifts in eye-pressure.

2. What's the easiest way to see a corneal abrasion? How often do you need to follow simple, non-infected abrasions?

Abrasions are easiest seen with fluorescein under the slit-lamp microscope, though large abrasions can be detected with only a handlight as the edges of the abrasion create a circular shadow on the iris underneath. You'll want to measure the epithelial defect and see the patient often (sometimes daily), until it heals to make sure they don't become infected.

6. Why do yellow sunglasses make images seem sharper?

All lens systems have chromatic abberation because the different colors of light bend differently. This means that images don't focus perfectly on the retina - the blue component focuses slightly in front of the retina, while the red component slightly behind. Tinted glasses limit the spectrum of color that hits the retina, and makes images appear sharper.

3. What is amblyopia? What causes it?

Amblyopia is poor vision in an eye from disuse at an early age, usually secondary to strabismus or an unrecognized refractive error.

14. The pupillary defect that affects the afferent arm of the pupillary response is the: a. Marcus Gunn pupil b. Argyl Robberson pupil c. Adies pupil d. Horners pupil

Answer: A Marcus Gunn pupil is the classic afferent pupillary defect (APD) that we check with the swinging light test. The Argyl Robberson is the syphilitic pupil that reacts with near vision, but doesn't respond to light. Horners and Adies are disorders of the sympathetic and parasympathetic efferent pupil response. The correct answer is (a).

17. When a patient focuses on near objects, the lens zonules: a. rotate b. contract c. relax d. twist

Answer: The zonules connect to the lens periphery and suspend the lens like a trampoline to the surrounding ciliary muscle. With near vision, the ciliary body contracts like a sphincter, causing the zonules to relax, and the lens to get "rounder." This rounding of the lens increases its refractive ability and allows focusing on near objects. With age, the lens hardens and loses its ability to round out - a process called presbyopia. The correct answer here is (c).

15. Aqueous fluid is produced in which chamber? a. anterior chamber b. vitreous chamber c. posterior chamber d. trabecular chamber

Answer: There are actually three chambers in the eye. Aqueous is produced in the posterior chamber where it flows forward into the anterior chamber and drains through the trabecular meshwork into the canal of Schlemm. The vitreous chamber is the big one in the back that is filled with jelly-like vitreous humor. The correct answer is therefore (c).

8. A glaucoma suspect is found on first visit to have a pressure of 19. Her corneal thickness, however, measures only 450 microns. Do you think her actual eye pressure is HIGHER or LOWER than 19?

Definitely higher. This patient has thin "bicycle-tires corneas" that "feel soft" when measured by the Goldman applanation. This woman's corrected pressure is probably well over 22, increasing her risk for glaucomatous progression.

13. You are considering doxycycline therapy for a patient with blepharitis. What should you warn your patient about this medication?

Doxycycline is not the easiest medication to take

11. What mechanisms do the glaucoma drops use to decrease pressure?

Drops either decrease the amount of aqueous produced at the ciliary body or increase the aqueous outflow from the eye (generally via the uveal-scleral pathway or by direct improvement of trabecular meshwork outflow).

15. What's the difference between dry and wet age-related macular degeneration?

Dry ARMD is when you have drusen and macular RPE atrophy. Wet ARMD implies choroidal neovascularization that has grown up through Bruch's membrane and bleed into the retina. "Wet" essentially means "bloody" in this instance.

7. You are thinking of starting eyedrops to control the eye pressure in a newly diagnosed glaucoma patient. What medical conditions might you ask about before initiating therapy?

Eyedrops can create pretty impressive systemic side effects as they bypass liver metabolism and are absorbed directly through the nasal mucosa. Be sure to ask your patients about heart problems and asthma before starting a beta-blocker.

9. What are the symptoms of a retinal tear or detachment?

Flashes and floaters are the classic signs. With a large detachment your patient may also notice an area of "dark curtain" or "blurry spot" in their peripheral vision.

12. List risk factors for developing retinopathy or prematurity.

Gestational age less than 32 weeks, birth weight under 1,500 grams, and systemic hypoxia.

9. What systemic and eye findings will you see with shaken baby syndrome?

In the eye, you will see retinal hemorrhages at "all levels of the retinal in all four quadrants of the eye." Schisis cavities (large splits within retina layers) are relatively specific. Other system findings include intracranial hemorrhage, brain edema, and skull-rib-long bone fractures. On exam you might also find bruising on the body trunk and under the armpits. Supposedly, these kids can have a torn frenulum (the piece of tissue under the upper lip that connects the lip to the gumline), but I've never seen this myself.

3. What's the difference between open-angle and closed-angle glaucoma? How about chronic versus acute glaucoma?

Open angle is a common, chronic condition where aqueous drainage is impaired. Closed-angle glaucoma is caused by acute closure of the iridocorneal angle leading to blockage of ALL aqueous drainage - an ophthalmologic emergency that can quickly lead to blindness.

11. What's the difference between a PCO and a PSC cataract?

PCO: posterior capsular opacification. This is an "after cataract" that forms on the back surface of the posterior capsule after successful cataract surgery. This opacity can be cleared with a YAG laser. PSC: posterior subcapsular cataract. This is a cataract that forms on the back portion of the lens. These tend to occur more often in diabetics and those on steroids, and tend to be visually significant because of their posterior position.

1. You have a contact lens wearer with a small corneal abrasion. He is in excruciating pain and requests that you pressure-patch his eye for comfort. Will this speed up healing?

Patching may speed healing by keeping the eye immobile and lubricated - but you should never patch an abrasion that might fester an infection. Thus, you don't patch contact lens wearers as you don't want a pseudomonas infection brewing under that patch

1: What does it mean to have a phakic eye or an aphakic eye?

Phakic means that the patient has their original lens. Pseudophakic means that they have a intraocular lens implant. Aphakic means that their lens was removed, but no replacement lens was placed.

6. How do we treat advanced diabetic retinopathy?

Proliferative diabetic retinopathy is treated with PRP (pan retinal photocoagulation). By ablating the peripheral ischemic retina with a laser, we decrease VEGF production and thus decrease neovascularization.

14. You have a patient who appears to have a shallow anterior chambers and occludable angles. Would you use pilocarpine?

In most cases, yes. Pilocarpine will constrict the pupils -- by flattening the iris you potentially open up the drainage angle next to the trabecular meshwork. Pilocarpine will also decrease pressure in the eye by affecting aqueous production and egress. You probably wouldn't use it long term in patients with occludable angles though, as pilo has a lot of side effects such as headache and blurry vision. Ultimately, anyone with occludable angles needs a laser peripheral iridotomy to equalize the pressure between anterior and posterior chambers.

13. How can diabetes cause acute glaucoma?

Retinal ischemia can produce VEFG. As this molecule floats forward it can cause neovascularization of the iris, forming vascular membranes that cover the trabecular meshwork and clog the drainage angle. This leads to a severe neovascular glaucoma that is hard to manage.

5. When the ciliary body contracts, how does the lens change shape (does it get rounder or flatter)?

The ciliary body is a round, spincter-like muscle, so when it contracts the zonules actually relax, allowing the lens to relax and become rounder. With age, the lens hardens and has a hard time relaxing no matter how hard the ciliary muscle contracts. This aging process is called presbyopia. We're going to review this again in the cataract chapter.

1. What bends light more -- the cornea or the lens? What percentage of the eye's total refractive power does the lens contribute?

The cornea does the majority of the refractive power of the eye, because the air-cornea interface has very different densities. The lens is only important for approximately one third of the overall refractive power of the eye.

9. How does the water content of the cornea differ from the rest of the eye?

The cornea is relatively dehydrated, which helps with clarity. If water gets into the cornea, via a disrupted endothelium or a high pressure gradient from acute glaucoma, the cornea turns hazy and white.

4. A patient is sent to your neurology clinic with a complaint of double vision. Other than trace cataract changes, the exam seems remarkably normal with good extraocular muscle movement. On covering the left eye with your hand, the doubling remains in the right eye. What do you think is causing this diplopia?

The first question you must answer with any case of diplopia is whether the doubling is monocular or binocular. This patient has a monocular diplopia. After grumbling to yourself about this inappropriate neurology referral, you should look for refractive problems in the tear film, cornea, lens, etc.

9. Name the four structures we describe in the retina.

The four structures we examine are: M (macula) V (vessels) P (periphery) D (disk) I use the mnemonic/acronym "MVP" (Most Valuable Player) to help me remember these.

8. What are the signs/symptoms of herpetic keratitis? How do you treat?

The hallmark of herpetic infection is the classic dendritic ulcer. You treat with oral acyclovir and topical antiviral drops such as Viroptic.

4. Where does the retina get its nutrition supply?

The inner two thirds of the retina (inner implies toward the center of the eyeball) gets its nutrition from the retinal vessels. The outer third (which includes the photoreceptors) is nourished by the underlying choroid plexus. A retinal detachment, which separates the retina from the choroid, is particularly dangerous for the photoreceptors. This is especially true for detachments involving the macula as the thin macula gets its blood supply primarily from the underlying choroid.

7. A 35 year old man with bad type-1 diabetes presents with a pressure of 65. His anterior chamber is deep but you find neovascularization everywhere - in the retina and on the iris. What do you think is causing the pressure rise, and how do you treat it?

The pressure is up because of neovascularization of the iris angle with blood vessels clogging up the trabecular drain. You treat neovascularization by PRP lasering the peripheral retina to decrease VEGF production. NVA (neovascularization of the angle) is hard to manage and this patient will probably require a surgical drainage procedure in the near future.

2. Why do diabetic patients with oculomotor paralysis have "sparing of their pupil"?

The pupil is typically spared with ischemic third nerve palsies caused by vascular problems. This is because the parasympathetic pupillary fibers run along the surface of the nerve, making them susceptible to aneurysm/tumor compression but resistant to deeper infarction.

8. List the eight structures/areas that we check on the slit-lamp exam.

The slit-lamp exam can be intimidating for the novice student, as there are many structures within the eye that we document within our notes. Working our way from the front to the back of the eyeball, these include: EXT (external structures) LL (lids and lacrimation) CS (conjunctiva and sclera) K (cornea) AC (anterior chamber) I (iris) L (lens) V (vitreous) You may want to check out the first video, "History and Physical" at Ophthobook.com - in the last half of the lecture I show real slit-lamp microscopy videos and work my way through these slit-lamp findings.

12. What does it mean to place a lens "in the sulcus?"

The sulcus is the space between the lens capsule and the back of the iris. If the posterior capsule is torn and can't support the lens, you can often place a lens on TOP of the entire capsule in this potential space.

3. What is the uvea? What eye structures compose it?

The uvea comprises the iris, ciliary body, and the choroid. They are all connected to each other and are histologically similar. Patients can present with a painful "uveitis," an inflammation of the uvea, often secondary to rheumatological/inflammatory conditions like sarcoidosis.

3. When you accommodate (look at near objects) do the zonules relax or tighten?

The zonules relax. With accommodation, the spincter-like ciliary body contracts, the zonules relax, and the lens relaxes and becomes rounder (thus more powerful). You're going to have to think that one out a few times and look at the drawing in this chapter.

8. How many layers are there in the cornea? Can you name them?

There are five: the superficial Epithelium, Bowman's layer, Stroma, Decemet's membrane, and the inner Endothelium.

10. An 84-year-old man was out golfing with his buddies and developed sudden vision loss in his right eye. He has no past ocular history, no medical problems. No complaints of flashes or floaters, just that things "look dimmer" in his right eye. What other questions should you ask about his symptoms?

There are many questions you should ask ... but with any elderly person with vision loss, be sure to ask about the symptoms of temporal arteritis. Specifically, scalp tenderness, jaw claudication, and polymyalgias (muscle aches in the shoulders and arms). This sounds like a central retinal artery occlusion, and in a patient this old you need to rule out life- and visionthreatening causes like GCA (giant cell arteritis).

5. What are some mechanisms in diabetic retinopathy that might lead to decreased vision? What causes the majority of vision loss in diabetic patients?

There are several mechanisms for potential vision loss in these patients, including: Macular edema (probably the leading cause of vision loss) Vitreous hemorrhage Retinal detachment

2. What are the layers of the lens?

There are three layers to the lens. The outer capsule, the inner nucleus, and a middle cortex ... in a configuration like a peanut M&M candy.

6. What is cell and flare?

These are descriptive terms to describe inflammation in the anterior chamber. Flare is protein floating in the aqueous that looks like a projector beam running through a smoky room. Cells are individual cells that look like dust-specks floating through that same projector beam of light.

10. Are eyes with herpetic keratitis more or less sensitive to touch?

These eyes are less sensitive to touch as the virus kills the corneal nerves. When HSV is suspected, we check corneal sensitivity with a cotton swab or a monofilament prior to anesthetic. Eye sensitivity is an important component of the protective blink reflex.

8. Describe the three types of retinal detachment?

These include rhegmatogenous detachments, tractional detachments, and exudative detachments.

8. How often should a patient with a hyphema be seen and why?

These patients need to be seen almost daily for the first week to check for pressure. This is especially important on post-trauma days 3 - 5 as this is when clots begin to retract and rebleed.

11. An elderly patient presents with a brief episode of flashing and now has a single floater that moves with eye movement. A thorough retina exam reveals no detachment or tear, but you observe a small vitreous opacity floating over the optic disk. What has happened?

This again sounds like a PVD. The floater is a Weis ring, a piece of optic disk debris that has pulled off with the vitreous detachment. PVDs are common and usually harmless, though patients should have a thorough exam for retinal tears and be taught the symptoms of retinal detachment.

10. Why can't you see the trabecular meshwork with the slit-lamp microscope?

This area is hard to see because the trabecular drain is tucked in the "angle" formed by the iris and inner cornea. We can't see this area directly because of "total internal reflection" at the cornea-air interface. Gonioscopy allows direct visualization of the trabecular meshwork by interrupting the cornea-air interface with a glass lens.

3. What is the Seidel test?

This is a method to see if a laceration has penetrated completely through the cornea. Basically, you're using fluorescein to look for leaking aqueous fluid.

10. What is a PVD?

This is a posterior vitreous detachment - with aging the vitreous jelly liquefies and contracts. A sudden contraction can cause new floaters. This event is usually harmless, but you should search carefully for retinal tears.

4. What are the risk factors for developing primary open-angle glaucoma?

This is an important list and since I glossed over them in the chapter, here they are again: High intraocular pressure (obviously) Age Family history Race (African American and Hispanics) Suspicious optic nerve appearance (large vertical cupping) Thin central corneal thickness (** remember this one

6. What's the difference between a tropia and a phoria? How can you differentiate this on exam?

This is exactly the kind of question you'll get asked during a pediatric or neuro clinic. A tropia is a deviation that is there ALL the time. A phoria is intermittent, and tends to occur more with fatigue or when one eye is covered. As for how to pick these up: it's hard to describe, so you might want to watch my video lecture at OphthoBook.com to see how this is done. Tropias: cover-uncover test Phorias: cross-cover test

1. What is diabetic retinopathy, and by what mechanism does it occur?

This is retinal bleeding, edema, ischemia, and ultimately neovascularization caused by diabetic damage to the retinal blood vessels.

2. What is a Marcus Gunn pupil?

This is simply an APD (afferent pupillary defect). These usually occur with optic nerve/tract lesions or infarcts.

4. What is "pinholing" a patient?

This is the use of a pinhole to decrease the effects of refractive errors causing visual blurring. When patients significantly improve with the pinhole, they probably need an updated glasses prescription.

10. What is accommodation?

This is when the lens changes shape, allowing the eye to focus on nearobjects. With age, the lens hardens and we gradually lose our ability to accommodate. We'll cover this topic in the optics chapter, but I wanted to bring it up in order to emphasize the need for checking both near and far vision during your exam.

14. What is Schafer's Sign?

This is when you see retinal pigment particles floating in the anterior vitreous chamber behind the lens. This slit-lamp sign increases your suspicion for a tear or detachment.

3. This 32 year old overweight woman complains of several months of headaches, nausea, and now double vision. What cranial nerve lesion do you see in this drawing. What other findings might you expect on fundus exam and what other tests might you get?

This looks like a bilateral abducens palsy as the patient can't move either eye laterally. While the majority of abducens palsies occur secondary to ischemic events in diabetics and hypertensives, this etiology seems unlikely in a young patient with bilateral involvement. Her symptoms sound suspicious for pseudotumor cerebri (obese, headaches). You should look for papilledema of the optic nerve, get imaging, and possibly send her to neurology for a lumbar puncture with opening pressure. I'm seeing double

12. A 21 y.o. man presents with a grossly swollen eyelid - a few days before he had a pimple that his girlfriend popped with nail clippers. Since then his eyelid has swollen, with redness, mild warmth and tenderness to touch. What specific findings would make you concerned for deeper involvement.

This patient sounds like he has an infection of the eyelid. The question is whether he has any post-septal involvement (i.e., orbital cellulitis). You need to check for decreased vision, proptosis, chemosis, decreased eye motion, and pain with eye movement. These findings would suggest a dangerous orbital infection with the need for admission, imaging, abscess drainage, etc..

8. A 26 year old woman presents with decreased vision in her left eye that has gotten progressively worse over the past week. The eye seems to ache and the vision worsens with exercise. On exam she is found to have 20/200 vision, trace APD, and markedly decreased color vision in the affected eye. The optic nerve is mildly swollen on that side. What does this patient most likely have?

This patient's age, color vision, and progression are all classic symptoms of optic neuritis. She also describes the classic Uthoff phenomenon of worsening symptoms with increased body-temperature (exercise or shower). Many of these patients describe minor pain with eye-movement; the optic nerve is inflamed and any tugging on the nerve with eye movement is going to irritate it.

1. You have a patient with diplopia. His left eye is turned down and out and his lid is ptotic on that side. What nerve do you suspect and what should you check next?

This sounds like a CN3 palsy, and you should check his pupillary reflex. Pupillary involvement suggests the lesion is from a compressive source such as an aneurysm.

6. What's our favorite diagnosis in the eye-clinic (good for explaining chronically irritated, grainy-feeling eyes with stinging and occasional watering). How do you treat it?

This sounds like blepharitis, which, along with dry eye is probably the most common diagnosis in an eye clinic. You treat blepharitis with artificial tears, warm compresses, and lid scrubs. If this doesn't seem to be working, you can try topical erythromycin or oral doxycycline (don't use in kids or pregnant women).

8. The corneal light reflex appears to be correctly centered (normal Hirschburg), yet the child still looks esotrophic. In fact, the child looks a lot like her mother. What's going on?

This sounds like pseudostrabismus from epicanthal folds. The nasal skin creates the illusion of crossed-eyes as less white sclera can be seen nasally. As babies get older, the nasal bridge becomes prominent and this appearance usually goes away.

2. How many chambers are there in the eyeball?

Three, actually. The anterior chamber sits in front of the iris, the posterior chamber between the iris and the lens, and the vitreous chamber lies behind the lens filling most of the eye.

5. When accommodating to view near objects, does the ciliary body relax or contract? Do the zonules get tighter or looser?

To see close objects, the lens needs to become more powerful and get rounder. To accomplish this, the circular ciliary muscle, which is a spincter muscle, contracts. This releases tension on the zonules and the lens is allowed to become rounder.

5. By what mechanism can a diabetic patient have a temporary refractive error?

Too much glucose will switch the lens metabolism from anaerobic glycolosis to a sorbitol pathway. Sorbitol buildup in the lens creates an osmotic swelling that changes the lens power (the round, swollen lens makes images focus in front of the retina, thus the patient is temporarily near-sighted).

9. What kind of vision loss occurs with glaucoma?

Typically loss of eyesight occurs in the periphery where it is less noticeable. Scotomas (areas of visual field loss) in glaucoma tend to follow certain patterns that start in the mid-periphery. Many patients don't notice visual symptoms until the disease is far progressed. Generally, the central vision is spared until very late stages of glaucoma.

6. Which extraocular muscle doesn't originate at the orbital apex?

Unlike the other muscles, the inferior oblique originates from the orbital floor before inserting on the back of the globe near the macula.

13. What drops are given after a cataract surgery?

Usually an antibiotic, such as ciprofloxacin or vigamox. Also, a steroid is given to decrease inflammation.

3. How are angiogenic molecules involved with diabetic retinas?

VEGF production by areas of ischemic retina leads to neovascularization. These new vessels are harmful as they can cause traction, bleeding, detachments, etc..

5. What's the most common cause of conjunctivitis? How do you treat it?

Viral conjunctivitis, usually caused by adenovirus, is the most common cause of pink eye in the adult. Adenovirus also causes cold symptoms (rhinovirus actually causes the majority of colds) and these patients will often describe concurrent respiratory illness. You treat these patients supportively with cool compresses, Tylenol, and chicken soup. Warn the patient that they are contagious and encourage them to wash their hands, don't share towels, and throw out their makeup.

1. What are the three "vital signs of ophthalmology" that you measure with every patient?

Vision, pupil, and pressure. Some ophthalmologists might say there are five vital signs (adding extraocular movements and confrontational fields.) It's important to check these signs prior to dilation as dilating drops will affect these measurements.

6. A patient accidentially splashes a large amount of bleach-based cleaner in her eye. What should she do?

Wash it out immediately - the faster, the better

5. What do we measure to monitor and follow progression in glaucoma patients?

We generally check three things: pressure, disk changes by photograph, and visual fields. Good stereo slides are difficult to obtain, so many doctors use other imaging modalities like HRT or OCT.

5. When presented with a complaint of "double vision" what is the first thing you should determine?

Whether the doubling is binocular or monocular, as this distinction will completely change your differential. Monocular diplopia is a refractive error while binocular diplopia is a misalignment between the eyes (and a major headache to figure out the cause - see the neuro chapter).

2. What antibiotic would you use for a small corneal ulcer in a contact lens wearer?

While most small ulcers can be treated with erythromycin, you must worry about pseudomonas in contact lens wearers. Treat all CL wearers with ciprofloxacin or moxifloxacin. If the ulcer is large, jump right to fortified antibiotics like vancomycin and tobramycin.

2. What are the retinal signs of diabetic retinopathy. How do they compare to, say, hypertensive retinopathy.

With diabetic retinopathy you typically see a lot of dot-blot hemorrhages, cotton-wool spots, and hard exudates. Hypertension usually has more flame hemorrhages and vascular changes such as arterial-venous nicking and copper/silver wiring.

10. How much of the lens is removed in typical cataract surgery?

With eye surgery, we create a hole in the anterior capsule and suck out the inner nucleus and cortex. The outer capsule is left behind to serve as a pocket to put the new implant into.

2. A child has a cataract operation and a lens implant is inserted. A month after surgery the child sees 20/20 on the distance Snellen chart. Will this child need glasses when he returns to school?

Yes, the child needs reading glasses. An implanted plastic lens can't accommodate (change shape) with near reading, necessitating a +3 lens or bifocal for close-up vision.

7. An Asian American woman brings in her new baby. She is concerned because her friends think her baby's eyes look "crooked." Casual inspection shows a healthy 12-month old baby who appears mildly esotrophic (cross-eyed). How would you measure ocular alignment in this child?

You can check the corneal light reflex with a penlight.

5. You suspect a baby of having strabismus, but because of the baby's age you aren't able to measure eye deviation with your prism set. How can you estimate the amount of eye deviation?

You can do this by measuring the corneal light reflex in relation to the underlying pupil (Hirschburg test). For every millimeter of light deviation, you have approximately 15 diopters of strabismic deviation.

3. Can you patch an eye to promote healing and comfort? Are there situations where you'd avoid patching?

You can patch an eye with an epithelial defect as patching makes the eye feel better and may speed up surface healing by decreasing exposure. However, you definitely don't want to patch the eye if there is any chance of infection. Thus, you shouldn't patch anyone with bacterial infiltrate, contact lens, or trauma by "dirty material" such as from vegetable matter, animals, or dirt.

13. What kind of surgeries can we perform to relieve retinal detachments?

You can perform a vitrectomy to clean out the inside of the eye and relieve retinal traction. While in there you can also reappose the retina. You can also perform a scleral buckle or a pneumatic retinopexy.

16. What kind of travel restrictions would you tell a patient who has a pneumatic retinopexy?

You don't want these patients to fly. A decrease in ambient pressure causes gases to expand. If this happens in the eye it could explode

9. An African American presents with hyphema after trauma. What additional workup might you consider? Are there any medications you would avoid?

You may consider getting basic coagulation labs and a sickle prep. Avoid CAIs as these promote acidosis and can worsen sickling of blood in the anterior chamber and worsen glaucoma.

9. What measurements must you have to calculate a lens implant power?

You need to know the cornea curvature (because the cornea performs the majority of the eye's refractive power) and the length of the eye.

12. What retinal findings do you see with glaucoma?

You see increased cupping of the optic disk, usually in a vertical pattern that goes against the ISNT rule. You can sometimes see hemorrhages at the disk and "undermining" of the blood vessels as they exit the disk.

3. How do you perform the swinging light test?

You shine a light back and forth between the pupils. You should see "constriction-constriction-constriction-constriction" as you flip-flop between the eyes. If you see constriction-dilation-constriction-dilation, then something's wrong (you've discovered an APD).

9. You suspect a patient of having a herpetic corneal infection, based on the shape of her epithelial defect, and you are concerned about corneal scarring. Can you use a steroid to decrease inflammation and the resulting scarring?

You should NEVER use a steroid drop in herpetic disease if there is still an epithelial defect, as this will cause the virus infection to worsen and develop into a terrible "geographic ulcer." You use topical antivirals like Viroptic and oral acyclovir and wait until the epithelium has healed before considering steroids to decrease scarring.

7. A patient with diplopia is finally diagnosed with myasthenia gravis after a positive ice-pack test and a positive acetylcholine receptor antibody test. What else should you work up this patient for.

You should check for a thymoma, which is highly associated with MG. Also, check their thyroid level as 20% of myasthenia patients also have Grave's disease.

4. How do you treat amblyopia?

You treat by "penalizing" the good eye. Using a patch over the good eye forces the amblyopic lazy eye to work. Also, you need to treat any underlying cause of the amblyopia such as anisometropia.

7. Which full-thickness eyelid laceration is more dangerous - medial or lateral lacerations? Why?

You worry about the canalicular tear-drainage system involvement with medial lacerations. You want to repair this system as soon as possible, to avoid chronic epiphora.

6. You are giving a tensilon test to a suspected myasthenia gravis patient and he collapses. What do you do?

Your patient may have a reaction to the anticholinersterase such as bradycardia or asystole. You should have a crash-cart handy and administer atropine. Hopefully, this scenario never happens to you. In this day and age, few ophthalmologists perform the tensilon test, reserving this for neurology (who more often perform EMG studies).

7. A mother brings in her two-year old child because she is concerned that her baby is cross-eyed. Which of the following is an inappropriate statement: a. the baby may maintain 20/20 vision b. the esotropia could lead to permanent vision loss c. the esotropia might be corrected with glasses alone d. surgical treatment should be delayed until adolescence

Answer: Answer (d) is the inappropriate statement. Esotropia (cross-eyed) is a common finding in the pediatric clinic. There are many causes, and one of them is poor vision in one eye. Spectacle vision can help anisometropic eyes fuse images properly and correct the alignment problem. This condition should be treated promptly, via spectacle correction, and possibly patching the strong eye to avoid amblyopia - if the crossing doesn't correct with these measures, then you proceed to surgical options. A child may maintain good vision in each eye if he/she learns to cross-fixate (switch eye dominance depending upon what direction the child is looking). There is no point in waiting until adolescence - you want to avoid an amblyopic eye and give the child a chance to develop good stereopsis at an early age.

8. Which of the following is the biggest risk factor for primary open angle glaucoma? a. Asian ancestry b. smaller diurnal pressure IOP changes c. thin corneas d. large optic disks

Answer: Asians are more likely to develop acute angle-closure glaucoma, not POAG. Everyone has diurnal eye pressure changes, and there is some evidence that glaucomatous patients have larger shifts in their pressure throughout the day. Large optic disks aren't concerning, though large cupping of a disk could indicate nerve fiber loss from glaucoma. Thin corneas ARE associated with glaucoma, as shown by the famous OHTS clinical trial. We measure every new glaucoma patient's corneal thickness with a small ultrasound pachymeter. The correct answer is (c).

28. What antibiotic would you use in a newborn with suspected chlamydial conjunctivitis? a. Ciprofloxacin drops b. Erythromycin drops c. Oral Doxycyline d. Erythromycin drops and oral erythromycin

Answer: Chlamydia is one cause of conjunctivitis you should suspect in the newborn. Treatment involves topical drops such as erythromycin and systemic coverage because of concurrent respiratory infections these kids can develop (chlamydia infects mucous membranes and can cause pneumonitis). You don't use doxy in children (especially under the age of eight). Fluoroquinolones might work, but we don't use them in children because of theoretical bone suppression. The correct answer is (d).

24. Oral doxycycline helps blepharitis patients by: a. antibiotic tear secretion b. changing lipid viscosity c. inhibiting cytokine release d. improved lacrimal gland excretion

Answer: Doxycycline changes the lipid viscosity of the meibomian gland secretions, improving oil secretion from the gland into the tear film. This superficial lipid layer is needed to keep the tears from evaporating too quickly. The correct answer is (b).

11. A patient presents after MVA with a fracture of the orbital floor. What would be the indication for surgery in the near future? a. double vision that worsens with upgaze b. chemosis and moderate proptosis c. restricted forced ductions d. decreased extraocular movement

Answer: Floor fractures are very common and these patients always look impressively bad on exam, with marked swelling and subconjunctival bleeding. They can have decreased EOMs and proptosis from this swelling alone, which shouldn't concern you. More worrisome is entrapment of the inferior rectus muscle in the orbital floor - this entrapment can only be determined by forced ductions ... grab the limbus with forceps and tug on the eye to see if movement is restricted. The correct answer is (c).

21. A 32-year-old white man with a history of type-1 diabetes presents to you complaining of decreased vision. He has not seen an eye doctor in years. On exam, you find numerous dot-blot hemorrhages, hard exudates, and several areas of abnormal vasculature in the retina. Pan-retinal photocoagulation might be done in this patient to: a. kill ischemic retina b. tamponade retinal tears c. ablate peripheral blood vessels d. seal off leaking blood vessels

Answer: PRP is performed to kill areas of peripheral ischemic retina. By doing so, less VEGF is produced, leading to cessation and regression of neovascularization. While it is true that we sacrifice some of the peripheral retina with PRP, it is worth it to save important central vision. Lasers can be used to help peg down retinal tears and to help with leaking vessels ... but this is called "focal laser therapy." The correct answer here is (a).

23. A 57-year-old man complains of flashing lights and a shade of darkness over the inferior nasal quadrant in one eye. On exam you find the pressure a little lower on the affected eye and a questionable Schaffer's sign. What condition would lead you to immediate treatment/surgery? a. macula-off rhegmatogenous retinal detachment b. epi-retinal membrane involving the macula c. dense vitreous hemorrhage in the inferior nasal quadrant d. mid-peripheral horseshoe tear with sub-retinal fluid

Answer: Schaffer's sign is when you see pigment behind the lens on slit-lamp exam, and occurs when a tear of the retina allows the underlying pigment to release into the vitreous chamber. A macula-off retinal detachment is unfortunate, but isn't an immediate emergency. It certainly needs to be repaired, but can wait for a few days if necessary, as the damage to the detached macular photoreceptors has already occurred. Epi-retinal membranes are common and aren't an emergency unless actively creating a tractional detachment. Vitreous hemorrhage is not an emergency either, assuming there isn't a detachment behind that blood on your ultrasound. Smaller retinal tears, however, need to be treated early to make sure they don't progress and peel off the macula. The answer is (d).

30. Steroids typically induce what kind of cataract? a. Nuclear sclerotic b. Posterior polar c. Posterior subcapsular d. Cortical

Answer: Steroids and diabetes are classically known to cause posterior subcapsular cataracts on the back surface of the lens. Nuclear sclerotic cataracts are common and usually result from aging, while posterior polar cataracts are often congenital. Cortical cataracts are also common and are rather nonspecific. The correct answer is (c).

18. What is glaucoma? a. retinal damage from high intraocular pressure b. optic nerve death caused by mechanical stretching forces c. ischemic nerve damage from decreased blood perfusion gradients d. none of the above

Answer: The best answer here is probably the last one, as no one really understands the pathogenesis of glaucoma. Ultimately, it involves death of the nerve fibers and it seems associated with high ocular pressure. However, there are plenty of patients out there with glaucoma damage and normal eye pressure, so pressure isn't the "ultimate cause" - but this is certainly the only risk factor that we can treat. There are many mechanical and biochemical theories that explain glaucoma damage, and each has its merits and faults.

25. Put the following retinal layers in order from inside (next to the vitreous) to outside: a. ganglion nerves, photoreceptors, choroid, then sclera on the outside. b. photoreceptors, ganglion nerves, choroid, then sclera on the outside. c. choroid, photoreceptors, ganglion nerves, then sclera on the outside. d. choroid, ganglion nerves, photoreceptors, then sclera on the outside.

Answer: The correct answer is (a). This question illustrates a few important concepts. The first is that the photoreceptor cells lie relatively deep in the retina, such that light has to pass through many layers to reach them. One of these layers is the ganglion nerve layer, comprised of nerve fibers that course along the surface of the retina toward the optic nerve. The choroid is a deeper bed of blood vessels that nourishes the photoreceptors from below, while the sclera is the tough collagen matrix that forms the outer wall of the eye.

26. In the absence of lens accommodation, a myopic eye focuses images: a. in front of the lens b. In front of the retina c. behind the retina d. behind the cornea

Answer: The correct answer is (b). Myopic, or near-sighted eyes, are typically large eyes that focus images in the middle of the eye, in front of the retina within the vitreous chamber. These eyes require a minus concave-shaped lens in their glasses - this effectively weakens the overall refractive power of the eye, allowing images to focus further back on the retina.

1. Which conjunctivitis is least likely to occur bilaterally? a. allergic b. viral c. bacterial d. vernal

Answer: The correct answer is (c) bacterial. Allergies are likely to affect both eyes and present with itching and watering. Vernal is a type of seasonal allergy you see in young boys. Viral conjunctivitis usually starts in one eye, but hops to the other eye as it is very contagious. Bacterial conjunctivitis can occur bilaterally, but of the available choices is most likely to occur in just one eye.

3. Which optic nerve finding is most concerning for glaucomatous damage? a. large disk size b. horizontal cupping c. vertical cupping d. disk tilt

Answer: The correct answer is (c) increased vertical cupping, which would go against the ISNT rule (the Inferior and Superior neural rim is normally the thickest with the Nasal and Temporal thinner). Many patients have large myopic (nearsighted) eyes with resulting large optic disks and disk "tilting" from the angle at which the nerve enters the back of the eye - these are physiologically normal variants and are not concerning for glaucoma.

22. Which of the following is a risk factor for retinal detachment? a. black race b. male sex c. presbyopia d. myopia

Answer: The correct answer is (d) myopia. Myopic (near-sighted) eyes are large eyes with a stretched-out retina that is more likely to tear at the periphery. Neither blacks nor males are at higher risk of RD. Presbyopic lens hardening occurs with age and doesn't have anything to do with the retina.

4. A young 23-year-old black man presents with a hyphema in the right eye after blunt injury. All of the following are acceptable initial treatments except? a. sleep with the head elevated b. prednisolone steroid eye drops c. cyclopentolate dilating drops d. carbonic anhydrase inhibitor pressure drops

Answer: The correct answer is (d). For patients with hyphema (blood in the eye) advise them to avoid straining and sleep with their heads elevated to allow the blood to settle. Use steroids to decrease the inflammation and a medium-acting cycloplegic to dilate the eye for comfort and to keep the inflamed iris from "sticking" to the underlying lens. If the pressure is high, you can use pressure drops, but we avoid CAIs in African Americans as it induces RBC sickling in sickle-cell patients. You can get a sickle prep if you are suspicious for this disease.

5. A 7-year-old boy presents with a grossly swollen eyelid. His mother can't think of anything that set this off. What finding is most characteristic of a dangerous orbital cellulitis? a. chemosis b. warmth and erythema of the eyelid c. physically taut-feeling eyelid d. proptosis

Answer: The correct answer is (d). With any eyelid cellulitis, you must determine if the infection is pre-septal or post-septal (i.e., orbital cellulitis). While chemosis is certainly seen with orbital infection, a proptotic bulging eye is even more indicative of orbital infection. Other signs include decreased eye-movement, pain with eyemovement, and decreased vision.

27. A man calls the office complaining of eye pain after splashing bleach in his eye. You should instruct him to: a. patch the eye and immediately go to the office b. irrigate the eye for 15 minutes and then go to the office c. immediately apply lubricating ointment and then go to the office d. immediately wash the eye with contact saline solution and go to the office if he notices any change in vision

Answer: The final visual outcome for a chemical burn is going to depend upon how quickly the chemical is washed out of the eye, so have your patient wash out their eye immediately

12. A 64-year-old man presents to you with new onset of "crossed-eyes." His left eye can't move out laterally and he has a chronic mild headache that he attributes to eyestrain. Which of the following is least likely the cause of his condition: a. hypertension b. diabetes c. aneurysm d. increased intracranial pressure

Answer: The most common causes of all the ocular nerve palsies are from vasculitic events secondary to diabetes or hypertension. It sounds like this patient has a CN6 palsy as he can't abduct his eye. With abducens palsy you should always consider increased intracranial pressure. An internal carotid aneurysm could hit the 6th nerve in the cavernous sinus, but you would expect other findings with these cavernous lesions. Aneurysms in general cause more third nerve palsies. Thus, the correct answer is (c).

16. Which orbital bone is most likely to fracture with blunt trauma to the eye? a. zygomatic b. maxillary c. ethmoid d. sphenoid

Answer: The orbital floor, which is formed by the maxillary bone, is the most commonly fractured wall of the orbit. Orbital fat will commonly herniate through this bone and muscle can get stuck if the break acts like a trapdoor. The ethmoidal lamina papyracea is also often broken because it is the thinnest, but this occurs less often because of extensive bolstering. The lateral zygomatic component of the orbit is rarely broken, nor the more posterior sphenoid. The correct answer is (b)

20. Gonioscopy overcomes the concept of: a. angled biomicroscopy b. spherical abberation c. total internal reflection d. specular microscopy

Answer: The trabecular meshwork can't be visualized directly because light coming from this angle bounces off the cornea (technically, the tear film) back into the eye because of Snell's Law and total internal reflection. By placing a hard glass lens onto the eye, the cornea-air interface is broken and light can escape and be seen through the microscope. The correct answer is therefore (c).

10. A woman presents to you complaining of a red, watering eye for the past two days with stinging and some photophobia. Her vision has dropped slightly to 20/30. She has a history of diabetes and is taking drops for glaucoma, but is otherwise healthy. The most likely cause of her redness is: a. angle-closure glaucoma b. viral conjunctivitis c. diabetic retinopathy d. papilledema

Answer: This woman probably has a history of POAG (primary open angle glaucoma) if she is on drops. If she were to have an acute angle closure, her eye would be very painful and the vision would have gotten much worse from corneal edema. Diabetic retinopathy is usually a background finding of leaky vessels in the retina and doesn't create this picture. She merits a full eye exam, but her symptoms are consistent with "pink eye," with viral conjunctivitis being the most common cause in an adult. The correct answer is therefore (b).

13. The abducens nucleus would be most affected by a brainstem lesion at: a. pons b. mid-brain c. medulla d. foramen magnum

Answer: To answer this question you need to know where the 6th nerve nucleus is located. One useful aid is the "4-4 Rule," which states that the bottom four nuclei (CN 12,11,10,9) are in the medulla, while the next four nuclei (CN 8,7,6,5) are in the pons. The correct answer is therefore (a).

19. Which condition would result in an inaccurately high reading with applanation pressure measurement? a. thin cornea b. thick cornea c. edematous cornea d. keratoconus

Answer: We measure pressure by pushing the cornea with a weighted device called an applanation tonometer - a process I compare to kicking a car tire to determine the air pressure. Thick "truck-tire corneas" are going to feel hard when you measure them. Conversely, thin "bicycle-tire" corneas are going to feel softer. Corneal edema also makes the eye feel squishy (giving a falsely low pressure) and patients with keratoconus often have thin corneas. The correct answer here is (b).

2. You're consulted by an intern from the ICU because his ventilated patient, with a head injury, has a fixed and dilated pupil. The intern is concerned for acute glaucoma. What do you tell him? a. find a Tono-Pen and check the pressure b. call his upper-level fellow immediately c. taper the patient's benzos d. increase the PEEP ventilator setting

Answer: Well, you need more history, of course, but any blown pupil in a trauma- ICU should make you think of an uncal-herniation and impending death. Tell him to (b) find his senior resident/fellow/attending immediately and call you back if they still want an eye-consult.

29. You are measuring eye deviation in a child with strabismus. The corneal light reflex is 2mm temporal to the pupil in the right eye. How much deviation would you estimate? a. 10 diopters esotropia b. 20 diopters exotropia c. 30 diopters esotropia d. 40 diopters exotropia

Answer: You can estimate eye alignment using the Hirshburg rule - for every millimeter the corneal light reflection is decentered, equals 15 diopters of deviation. This child has 30 diopters of esotropia, so (c) is the correct answer.

9. A 27-year-old contact lens wearer presents to the ER complaining of ocular irritation. On exam he has a small 2mm corneal abrasion. You should a. treat with erythromycin ointment b. treat with ciprofloxacin drops c. bandage contact lens for comfort and speed reepitheliazation d. patch the eye and follow-up in 72 hours

Answer: You need to be concerned for pseudomonas infection in any contact lens wearer. Erythromycin is great stuff, but these higher risk patients should get something stronger like a fluoroquinolone (cipro). A bandage contact lens can help with painful abrasions, but I'd avoid one in this patient as the abrasion isn't big, and you typically don't patch ulcers. Patching can also be used to help with lubrication and comfort, but I never patch a potential infection, as bacteria like to grow in dark warm environments. If you decide to patch, you need to see your patient daily to make sure nothing is brewing under that patch. The most appropriate answer is (b).

2. What is the flow-pathway for aqueous fluid? Where is it made, and where does it leave the eye?

Aqueous is first produced by the ciliary body. It then flows forward through the pupil into the anterior chamber. Finally, aqueous drains through the trabecular meshwork and back into the venous system via the Canal of Schlemm.

4. How do we categorize diabetic retinopathy?

As either NPDR (nonproliferative diabetic retinopathy) or PDR (proliferative diabetic retinopathy) depending upon the presence of neovascularization.

10. A pseudophakic (i.e., implanted lens) patient is found to have excellent far vision, but reading is terrible. What's going on?

As we get older, our natural lens hardens and does not change shape very well, making it hard to accommodate and see near objects. This phenomenon is called presbyopia and is a normal finding in people over 40 years of age. A prosthetic lens is not able to change shape at all, so all patients (including small children) with implanted plastic lenses require reading glasses to read.

4. What are the two functions of the ciliary body?

The ciliary body changes lens shape, allowing fine focusing and accommodation. It also produces aqueous fluid that inflates the anterior chamber and nourishes the avascular lens and cornea.

12. A young man complains of complete vision loss (no light perception) in one eye, however, he has no afferent pupil defect. Is this possible? How might you check whether this patient is "faking it?"

Assuming the rest of the eye exam is normal (i.e., the eye isn't filled with blood or other media opacity) this patient should have an afferent pupil defect if he can't see light. There are many tests to check for malingering and factitious disorders: you can try eliciting a reflexive blink by moving your fingers near the eye. One of my favorite techniques is to hold a mirror in front of the eye. A seeing eye will fixate on an object in the mirror. Gentle rocking movements of the mirror will result in a synchronous ocular movement as the eye unconsciously tracks the object in the mirror.

1. Why don't objects like contact lens and eyelashes get stuck behind the eye?

Because the conjunctiva covering the front of the eye loops forward and covers the inside of the eyelids as well.

2. How do you determine the refractive error (glasses prescription) in a pre-verbal child?

By streak-retinoscopy. This is where you flash a light beam across the retina and hold up different lenses in front of the eye until the red-reflex movement is neutralized. Correct for your working distance and you have your prescription.

11. Name three causes for a leukocoric pupil.

Cataract, retinoblastoma, and retinopathy of prematurity.

10. Parents say that a child fell from her crib and hit the floor. Do you think this would cause a fracture and the retinal findings of shaken baby?

Kids are relatively bouncy, but this story COULD account for the skull fracture. However, it takes a LOT of traumatic force to create large retinal hemorrhages -- this story sounds a little fishy. An experienced pediatrician and ophthalmologist needs to examine this child.

8. How can a cataract cause glaucoma?

Many cataracts are large, and this bulk can push the iris forward and predispose to angle closure glaucoma. Also, end-stage cataracts can leak proteins into the aqueous fluid and the resulting inflammatory cells (macrophages) can clog the trabecular meshwork.

5. A patient complains of intermittent double vision that seems to be worse in the evenings. On exam you find a confusing diplopia that doesn't seem to map out to any particular nerve palsy. What else is on your differential as a cause, and what tests might you perform in the office?

Myasthenia gravis and thyroid orbitopathy are both great masqueraders that cause diplopia. Graves patients often have lid retraction and reduced upgaze from inferior rectus muscle restriction. The double vision in myasthenia patients can look like an isolated nerve palsy, a mixture of nerve involvement, or may not fall into any specific nerve combination - a changing palsy is more indicative of a process like MG. You can check for fatiguable ptosis by prolonged upgaze (hold your arm up and see who gets tired first). In addition, you can perform a cold-pack rest test or even a Tensilon test.

1. What is glaucoma? What actually causes damage to the neurons and optic nerve with glaucoma?

Nobody is sure exactly "what glaucoma is" but at its most basic, glaucoma is gradual death of the optic nerve. If anyone asks you for the definitive definition (or if a glaucoma specialist corners you), just say "nobody knows" or "death of the optic nerve." If you say "high pressure" you'll be laughed at (glaucoma specialists are odd ducks). The optic nerve damage arises from pressure, stretching, sheer forces, vascular compromise, or some kind of hormone regulator - we're not sure of the exact mechanism.

7. How soon should a child with a cataract go to surgery?

Soon, as cataracts create a visual deprivation that quickly leads to amblyopia. Some practitioners recommend surgery prior to two months.

13. How soon should a congenital (found at birth) cataract be removed?

Soon, in order to avoid amblyopia. Some recommend removing these early cataracts in the first two months.

1. How is the Bruchner test performed? What will a near-sighted child look like with this exam?

The Bruchner test is a simple method to estimate the refractive error in a child. You look at a child through your direct ophthalmoscope from a distance. Light up the face such that both pupils are lit. Hyperopic children will have superior crescents in their red-reflex, while myopic (near-sighted) children will have inferior crescents.

6. What does corneal thickness have to do with glaucoma (as far as risk for developing glaucoma)?

The OHTS clinical trial showed that people with thin corneas are at higher risk for developing glaucoma, independent of other risk factors. We're not sure why, but it's believed that people with thin corneas are anatomically predisposed to optic nerve damage. We measure corneal thickness using a small ultrasound probe (this is called pachymetry) with all new glaucoma patients.

9. A patient develops optic neuritis. Should you treat with steroids? Would you start with IV or oral steroids? Will the MRI findings of numerous demyelinating lesions change your management? Do you tell the patient that she will develop MS?

The ONTT study has shown that steroids can speed recovery from optic neuritis, but have little effect on long-term visual outcome. Surprisingly, the study also showed that oral prednisone may actually increase reoccurrence of optic neuritis. Therefore, you give IV Solu-Medrol and don't give oral prednisone

4. What are the three kinds of conjunctivitis? How do you differentiate them on history and physical exam?

The cause of a conjunctivitis is not always obvious. Generally you'll see the following classic findings: Viral watery discharge, follicles, enlarged nodes Bacterial mucous discharge, often unilateral Allergic bilateral itching and swelling