FEU PRACTICE QUESTIONS (LE1) Flashcards
ANATOMY,PHYSIOLOGY,HX AND BASIC EYE EXAM, RED EYE
A 25-year-old male was seen at the OPD complaining of hyperacute purulent conjunctivitis. Gram stain of his eye discharge would show this result:
Select one:
a. Pleomorphic rod
b. Dumbbell-shaped diplococci
c. Gram (+) cocci in clusters
d. Gram (-) diplococci
d. Gram (-) diplococci
Rationalization:
* Pleomorphic rod: This refers to bacteria that can vary in shape. It’s not typically associated with hyperacute purulent conjunctivitis.
* Dumbbell-shaped diplococci: This description doesn’t correspond to a known common bacterial shape associated with conjunctivitis.
* Gram (+) cocci in clusters: This typically describes Staphylococcus species (Bacterial Conjunctivitis)
* Gram (-) diplococci: This typically describes Neisseria gonorrhoeae, which is a common cause of hyperacute purulent conjunctivitis.
On VA testing, the patient was unable to read even the first line of the Snellen chart with his left eye despite moving him closer to a distance of 1 meter. What should you do next?
Select one:
a. Repeat VA testing using pinhole
b. Instruct the patient to count your extended fingers at a distance of less than 1 meter
c. Shine your penlight on his left eye to check for pupillary light reflex
d. Replace the Snellen Chart since it is possible that the patient is not familiar with the figures
b. Instruct the patient to count your extended fingers at a distance of less than 1 meter
1 meter = 3 feet
Rationalization:
- Repeat VA testing using pinhole: This helps determine if the decreased vision is due to a refractive error. If the patient cannot see the chart even at 1 meter, it’s unlikely that pinhole testing will yield useful results at this stage.
- Instruct the patient to count your extended fingers at a distance of less than 1 meter: This is a standard practice for assessing very low vision. If the patient cannot see the largest optotype on the Snellen chart at 1 meter, the next step is usually to check if the patient can see hand movements or count fingers.
- Shine your penlight on his left eye to check for pupillary light reflex: This is useful for checking the function of the optic nerve and pathway but does not assess visual acuity.
- Replace the Snellen Chart since it is possible that the patient is not familiar with the figures: This would be considered only if there was a clear indication that the patient cannot recognize the letters, which is unlikely in this context.
Which of the following is in systematic order in observing your fundus?
Select one:
a. Macula, retinal background, retinal vessels, optic media, optic disc
b. Optic media, macula, optic disc, retinal vessels, retinal background
c. Optic media, optic disc, retinal vessels, retinal background, macula
d. Optic disc, optic media, retinal vessels, retinal background, macula
c. Optic media, optic disc, retinal vessels, retinal background, macula
Rationalization:
- The systematic order typically begins with the optic disc, then the retinal vessels, retinal background, and finally the macula.
Which type of age-related cataracts causes myopic shift?
Select one:
a. Diabetic cataract
b. Nuclear sclerosis
c. Posterior subcapsular
d. Cortical
b. Nuclear sclerosis
Rationalization:
- Diabetic cataract: Related to diabetes, not specifically age-related myopic shift.
- Nuclear sclerosis: This type of cataract often causes a myopic shift due to changes in the lens.
- Posterior subcapsular: Causes glare and difficulty reading but not typically myopic shift.
- Cortical: Causes glare and monocular diplopia but not typically myopic shift.
A post-menopausal patient is complaining of intermittent blurring of vision, OU. She also complains of redness, tearing, and burning sensation in both eyes. Which of the following tests will you perform to help with the diagnosis of dry eye syndrome?
Select one:
a. Corneal sensitivity, corneal and conjunctival staining
b. Seidel’s test, phenylephrine test
c. Tear break-up time, Schirmer’s test
d. Dilated fundus exam, Watzke-Allen test
c. Tear break-up time, Schirmer’s test
Rationalization:
- Corneal sensitivity, corneal and conjunctival staining: Useful for other conditions but not specific for dry eye.
- Seidel’s test, phenylephrine test: Seidel’s test is for detecting aqueous humor leakage, phenylephrine test for diagnosing Horner’s syndrome.
- Tear break-up time, Schirmer’s test: Both are standard tests for diagnosing dry eye syndrome.
- Dilated fundus exam, Watzke-Allen test: Used for evaluating the retina, not specific for dry eye.
This structure is triangular in shape with smooth muscle fibers that is responsible for accommodation.
Select one:
a. Ora serrata
b. Lamina cribrosa
c. Ciliary body
d. Lens
c. Ciliary body
Rationalization:
- Ora serrata: The serrated junction between the retina and the ciliary body.
- Lamina cribrosa: A sieve-like structure in the sclera where the optic nerve fibers pass.
- Ciliary body: Contains smooth muscle fibers responsible for changing the shape of the lens (accommodation).
- Lens: Changes shape to focus light but does not contain smooth muscle fibers.
This condition is commonly associated with a viral or bacterial infection. A noted feature is inflamed blood vessels at the scleral area which do not move upon manipulation.
Select one:
a. Scleromalacia perforans
b. Necrotizing scleritis
c. Diffuse scleritis
d. Posterior scleritis
c. Diffuse scleritis
Rationalization:
- Scleromalacia perforans: Thinning of the sclera, typically in rheumatoid arthritis, not commonly associated with infection.
- Necrotizing scleritis: Severe form of scleritis with tissue necrosis.
- Diffuse scleritis: Generalized inflammation of the sclera, often associated with infection.
- Posterior scleritis: Involves the back part of the sclera, less visible on the surface.
What test provides a gross evaluation of the visual fields?
Select one:
a. Perimetry
b. Confrontation test
c. Farnsworth-Munsell 100 Hue Test
d. Pseudochromatic chart
b. Confrontation test
Rationalization:
- Perimetry: Detailed evaluation of visual fields.
- Confrontation test: Simple, gross assessment of visual fields.
- Farnsworth-Munsell 100 Hue Test: Evaluates color vision.
- Pseudochromatic chart: Used for color blindness testing.
This type of scleritis has the poorest prognosis among the following:
Select one:
a. Necrotizing scleritis
b. Diffuse scleritis
c. Nodular scleritis
d. Posterior scleritis
a. Necrotizing scleritis
Rationalization:
- Necrotizing scleritis: Most severe and destructive form, often associated with systemic diseases, and has the poorest prognosis.
- Diffuse scleritis: Generalized inflammation, better prognosis.
- Nodular scleritis: Localized, better prognosis.
- Posterior scleritis: Can be severe but typically not as poor prognosis as necrotizing.
Which part of the optic media has the highest refractive power?
Select one:
a. Aqueous humor
b. Vitreous
c. Cornea
d. Crystalline lens
c. Cornea
Rationalization:
- Aqueous humor: Refractive index is low.
- Vitreous: Refractive index is low.
- Cornea: Has the highest refractive power due to its curvature.
- Crystalline lens: Has significant refractive power but less than the cornea.
A 40-year-old farmer felt foreign body sensation, OD while harvesting corn. This persisted for 3 days. On the 5th day, there was redness and tearing. One week later, a small central white opacity appeared, which he noticed to slowly increase in size in the next few days. You see him 2 weeks after the onset of symptoms with a corneal ulcer 3.5mm in diameter. What is your primary impression?
Select one:
a. Fungal keratitis
b. Moraxella keratitis
c. Neisseria gonorrhea keratitis
d. Acanthamoeba keratitis
a. Fungal keratitis
Rationalization:
- Fungal keratitis: Common in farmers due to trauma with organic matter (e.g., plants), and often presents with a gradually enlarging corneal ulcer.
- Moraxella keratitis: Typically occurs in individuals with compromised immunity or chronic eye diseases, not commonly associated with trauma.
- Neisseria gonorrhea keratitis: Rapidly progressive and severe, usually associated with gonococcal conjunctivitis, not typically seen in this context.
- Acanthamoeba keratitis: Associated with contact lens wearers and exposure to contaminated water, not typically linked to trauma with organic material.
This surgical technique involves removal of the entire lens:
Select one:
a. Phacoemulsification
b. Extracapsular Cataract Extraction
c. Intracapsular Cataract Extraction
d. MSICS
c. Intracapsular Cataract Extraction
Rationalization:
- Phacoemulsification: Modern technique where the lens is emulsified and aspirated, lens capsule remains.
- Extracapsular Cataract Extraction: Lens is removed, but posterior capsule remains intact.
- Intracapsular Cataract Extraction: Entire lens, including the capsule, is removed.
- MSICS (Manual Small Incision Cataract Surgery): A variant of extracapsular extraction, smaller incision.
Which of the following is metabolically active?
Select one:
a. Lens epithelial cells
b. Lens cortex
c. Lens nucleus
d. Anterior lens capsule
a. Lens epithelial cells
Rationalization:
- Lens epithelial cells: Responsible for maintaining lens metabolism and transparency.
- Lens cortex: Less metabolically active, consists of elongated fiber cells.
- Lens nucleus: Central, older, and least metabolically active part of the lens.
- Anterior lens capsule: Protective layer, not metabolically active.
A 3-day-old newborn was brought to the OPD for consultation due to purulent discharge of both eyes. Which of the following statements is NOT true?
Select one:
a. Erythromycin eye ointment is effective for inclusion conjunctivitis
b. This may be caused by Pseudomonas aeruginosa
c. Diagnosis is Ophthalmia Neonatorum
d. The most serious etiology is Neisseria gonorrhea
b. This may be caused by Pseudomonas aeruginosa
Rationalization:
- Erythromycin eye ointment is effective for inclusion conjunctivitis: True, commonly used for Chlamydia trachomatis.
- This may be caused by Pseudomonas aeruginosa: Not typical for Ophthalmia Neonatorum, which is usually caused by Neisseria gonorrhoeae or Chlamydia trachomatis.
- Diagnosis is Ophthalmia Neonatorum: True, the term for neonatal conjunctivitis.
- The most serious etiology is Neisseria gonorrhea: True, can cause severe corneal damage if not treated.
The common definition of a Snellen’s index with a vision of less than 3/200 is:
Select one:
a. Partially seeing
b. Hand movement
c. Travel vision
d. Minimal reading
b. Hand movement
Rationalization:
- Partially seeing: This term usually refers to visual acuity that is better than 3/200 but not normal.
- Hand movement: Describes a very low level of vision where the person can only see hand movements but cannot read any letters on the Snellen chart, which corresponds to visual acuity of less than 3/200.
- Travel vision: Generally refers to vision sufficient for basic mobility and navigation, but not specific to the less than 3/200 criteria.
- Minimal reading: Refers to vision just adequate for reading very large print, which would be better than 3/200.
An elderly patient comes in with redness and unilateral blurring of vision as well as vesicles on the right forehead. On examination, he was found to have a corneal dendrite. The following supports your diagnosis of varicella zoster infection versus herpes simplex infection, EXCEPT?
Select one:
a. Dichotomous branching of dendrites with terminal bulbs
b. Hutchinson’s sign on the tip of the patient’s nose
c. Vesicular lesions on the face respecting the midline
d. Non-dichotomous branching of dendrites without terminal bulbs
a. Dichotomous branching of dendrites with terminal bulbs:
This is a feature of herpes simplex keratitis, not varicella zoster. Herpes simplex virus (HSV) dendrites tend to have dichotomous branching and terminal bulbs.
Other Options Explanation:
- b. Hutchinson’s sign on the tip of the patient’s nose: This is indicative of varicella zoster infection, particularly herpes zoster ophthalmicus. It suggests that the nasociliary branch of the trigeminal nerve is involved.
- c. Vesicular lesions on the face respecting the midline: This is characteristic of herpes zoster (shingles) infection, which follows a dermatomal pattern and does not cross the midline.
- d. Non-dichotomous branching of dendrites without terminal bulbs: This description fits the dendrites seen in varicella zoster virus (VZV) keratitis.
In the management of fungal keratitis, which of the following is contraindicated?
Select one:
a. Corneal keratectomy for better penetration of topical anti-fungal medication
b. Topical antibiotic drops to cover for possible concomitant bacterial infection
c. Corneal scraping for gram stain, Giemsa staining, and culture studies
d. Topical steroid antibiotic drops to cover for inflammation, chemosis, and possible secondary bacterial infection
d. Topical steroid antibiotic drops to cover for inflammation, chemosis, and possible secondary bacterial infection
Rationalization:
- Corneal keratectomy for better penetration of topical anti-fungal medication: This can be beneficial.
- Topical antibiotic drops to cover for possible concomitant bacterial infection: Common practice.
- Corneal scraping for gram stain, Giemsa staining, and culture studies: Standard diagnostic procedure.
- Topical steroid antibiotic drops to cover for inflammation, chemosis, and possible secondary bacterial infection: Steroids are contraindicated in fungal keratitis as they can exacerbate the infection.
Which of the following is correctly matched?
Select one:
a. cc - without correction
b. OU - both eyes
c. OD - left eye
d. sc - with correction (corrective glasses)
b. OU - both eyes
Rationalization:
- cc - without correction: Incorrect, it means “with correction”.
- OU - both eyes: Correct, OU stands for “oculus uterque”.
- OD - left eye: Incorrect, OD stands for “oculus dexter” (right eye).
- sc - with correction (corrective glasses): Incorrect, it means “without correction”.
Multiple, elevated, polygonal hyperemic mounds with a central fibrovascular core characterize this conjunctival inflammatory response of lymphocytes and plasma cells.
Select one:
a. Follicular response
b. Phlyctenular response
c. Ligneous response
d. Papillary response
d. Papillary response
Rationalization:
- Follicular response: Typically seen in viral and chlamydial infections, not characterized by a central fibrovascular core.
- Phlyctenular response: A localized nodular response, often related to hypersensitivity.
- Ligneous response: Rare and involves the formation of wood-like pseudomembranes.
- Papillary response: Characterized by multiple, elevated, polygonal hyperemic mounds with a central fibrovascular core, seen in allergic conjunctivitis.
Infection or inflammation of the cornea is generally called keratitis. This may affect all layers of the cornea. The layers of the cornea from innermost to outermost are the following:
Select one:
a. Epithelium, Bowman’s, stroma, Descemet’s, endothelium
b. Endothelium, Descemet’s, stroma, Bowman’s, epithelium
c. Endothelium, Descemet’s, Bowman’s, stroma, epithelium
d. Epithelium, Bowman’s, stroma, Descemet’s, endothelium
b. Endothelium, Descemet’s, stroma, Bowman’s, epithelium
Question 21
In performing direct fundoscopy, at what angle do you come closer to the patient’s line of sight?
Select one:
a. About 15 degrees temporally
b. About 25 degrees nasally
c. About 15 degrees nasally
d. About 25 degrees temporally
a. About 15 degrees temporally
Rationalization:
* About 15 degrees temporally: This is the correct angle to view the optic disc directly in direct fundoscopy.
* About 25 degrees nasally: Not typically used for direct visualization of the optic disc.
* About 15 degrees nasally: Incorrect angle for direct fundoscopy.
* About 25 degrees temporally: This angle is too wide for direct fundoscopy.
Question 22
A patient came in for a consult due to blurring of vision. While taking the visual acuity, the patient was unable to see the largest letter on the Snellen chart at 20 feet. What will be your next step to obtain the visual acuity?
Select one:
a. Use penlight to determine if the patient can correctly detect the direction of the light source
b. Ask the patient to count fingers at 3 feet
c. Bring the patient closer to the chart until he/she is able to read the 20/200 line.
d. Determine if the patient can distinguish the presence or absence of Hand Movement (HM)
c. Bring the patient closer to the chart until he/she is able to read the 20/200 line.
Rationalization:
* Use penlight to determine if the patient can correctly detect the direction of the light source: This is a method to check light perception, not visual acuity.
* Ask the patient to count fingers at 3 feet: This is used if the patient cannot see any letters on the chart even when moved closer.
* Bring the patient closer to the chart until he/she is able to read the 20/200 line: Correct procedure to determine the visual acuity when the patient cannot see the chart at 20 feet.
* Determine if the patient can distinguish the presence or absence of Hand Movement (HM): This is used when vision is extremely poor and closer methods have failed.
Question 23
Which of the following is TRUE regarding conjunctivitis?
Select one:
a. Perennial: Allergic conjunctivitis
b. Chronic: Viral conjunctivitis
c. Acute: Gonococcal conjunctivitis
d. Hyperacute: Chlamydial conjunctivitis
a. Perennial: Allergic conjunctivitis
Rationalization:
* Perennial: Allergic conjunctivitis: True, perennial allergic conjunctivitis occurs year-round due to allergens such as dust mites.
* Chronic: Viral conjunctivitis: Viral conjunctivitis is usually acute, not chronic.
* Acute: Gonococcal conjunctivitis: Gonococcal conjunctivitis is hyperacute, not acute.
* Hyperacute: Chlamydial conjunctivitis: Chlamydial conjunctivitis is chronic or subacute, not hyperacute.
Question 24
Which of the following is true regarding diabetic cataracts?
Select one:
a. It is usually unilateral.
b. Diabetics develop cataracts later than non-diabetics.
c. Glucose is converted to sorbitol by aldose oxidase in the lens.
d. It can be treated with LASIK surgery.
c. Glucose is converted to sorbitol by aldose reductase in the lens.
Rationalization:
* It is usually unilateral: Diabetic cataracts are typically bilateral.
* Diabetics develop cataracts later than non-diabetics: Diabetics develop cataracts earlier than non-diabetics.
* Glucose is converted to sorbitol by aldose reductase in the lens: True, sorbitol accumulation leads to osmotic stress and cataract formation.
* It can be treated with LASIK surgery: LASIK is for refractive errors, not for treating cataracts.
Question 25
Which of the following conditions can cause ectopia lentis?
Select one:
a. Error of refraction
b. Diabetes mellitus
c. Trauma
d. Hypertension
c. Trauma
Rationalization:
* Error of refraction: Does not cause lens dislocation.
* Diabetes mellitus: Not typically associated with lens dislocation.
* Trauma: A common cause of ectopia lentis (dislocation of the lens).
* Hypertension: Not associated with lens dislocation.
Question 26
A 30-year-old male patient complained of loss of vision in his left eye after he sustained head trauma. Which part of the optic nerve is most susceptible to trauma?
Select one:
a. Intracanalicular
b. Intracranial
c. Intraorbital
d. Intraocular
a. Intracanalicular
Rationalization:
* Intracanalicular: This part of the optic nerve, located within the bony canal, is most susceptible to trauma due to its rigid surroundings.
* Intracranial: Located within the skull, less likely to be directly affected by trauma.
* Intraorbital: Although susceptible, it has more room for movement within the orbit.
* Intraocular: This part is protected within the eye.
Question 27
This is a lens-induced ocular disease secondary to intumescent cataract.
Select one:
a. Phacodonesis
b. Phacomorphic glaucoma
c. Phacolytic glaucoma
d. Phacoantigenic glaucoma
b. Phacomorphic glaucoma
Rationalization:
* Phacodonesis: Refers to lens tremulousness or instability, not specifically related to intumescent cataracts.
* Phacomorphic glaucoma: Occurs when an intumescent (swollen) cataract causes secondary angle-closure glaucoma.
* Phacolytic glaucoma: Caused by leakage of lens proteins from a hypermature cataract, leading to an inflammatory response and glaucoma.
* Phacoantigenic glaucoma: An immune response to lens proteins following surgery or trauma.
Question 28
Which of the following conditions causes secondary angle closure glaucoma?
Select one:
a. Microspherophakia
b. Mittendorf dot
c. Aniridia
d. Lens coloboma
a. Microspherophakia
Rationalization:
* Microspherophakia: A condition where the lens is abnormally small and spherical, leading to angle closure glaucoma.
* Mittendorf dot: A remnant of the hyaloid artery on the posterior lens capsule, not associated with glaucoma.
* Aniridia: Absence of the iris, can lead to various issues but not specifically secondary angle closure glaucoma.
* Lens coloboma: A congenital defect of the lens, not typically causing angle closure glaucoma.
Question 29
Non-specific conjunctival response more obvious on the upper tarsal conjunctiva presenting as a fine mosaic pattern of dilated telangiectatic blood vessels.
Select one:
a. Papillary conjunctivitis
b. Follicular conjunctivitis
c. Hemorrhagic conjunctivitis
d. Membranous conjunctivitis
a. Papillary conjunctivitis
Rationalization:
* Papillary conjunctivitis: Characterized by a fine mosaic pattern of dilated telangiectatic blood vessels on the upper tarsal conjunctiva.
* Follicular conjunctivitis: Characterized by lymphoid follicles on the conjunctiva, not a fine mosaic pattern.
* Hemorrhagic conjunctivitis: Characterized by subconjunctival hemorrhages.
* Membranous conjunctivitis: Characterized by the formation of membranes or pseudomembranes on the conjunctiva.
Question 30
What is the major function of the lens?
Select one:
a. Main refractive media
b. Acts as a diaphragm
c. Refraction
d. Highest diopter power
c. Refraction
Rationalization:
* Main refractive media: While the lens does contribute to refraction, the cornea is the main refractive medium.
* Acts as a diaphragm: This is the function of the iris.
* Refraction: The lens primarily helps to focus light onto the retina.
* Highest diopter power: The cornea has the highest diopter power, not the lens.
Question 31
Which of the following is a component of pupil examination?
Select one:
a. Assessment of reaction to light
b. Assessment of involuntary eye movement
c. Assessment of pressure
d. Assessment of extraocular movement
a. Assessment of reaction to light
Rationalization:
* Assessment of reaction to light: This is a key part of the pupil examination to check for direct and consensual light reflex.
* Assessment of involuntary eye movement: This relates to nystagmus, not specifically to pupil examination.
* Assessment of pressure: This is related to intraocular pressure, typically assessed in glaucoma exams.
* Assessment of extraocular movement: This is related to eye movement testing, not specifically pupil examination.
Question 32
Which of the following statements is/are TRUE of Visual Acuity (VA) Testing?
Select one or more:
a. VA testing should be done after manipulation of the eye
b. VA testing is the fundamental element of the basic eye examination
c. VA testing is only for patients over 35 years of age
d. VA testing is used to assess the function of peripheral retina
b. VA testing is the fundamental element of the basic eye examination
Rationalization:
* VA testing should be done after manipulation of the eye: Incorrect. VA testing should be done before any manipulation to get an accurate baseline measurement.
* VA testing is the fundamental element of the basic eye examination: Correct. It is a primary assessment to determine the clarity or sharpness of vision.
* VA testing is only for patients over 35 years of age: Incorrect. VA testing is performed on patients of all ages.
* VA testing is used to assess the function of peripheral retina: Incorrect. VA testing primarily assesses central vision, not peripheral retinal function.
Question 33
What structure is visible as dark blue/gray scleral patches among patients with recurrent scleritis?
Select one:
a. Retina
b. Uvea
c. Blood vessels
d. Vitreous
b. Uvea
Rationalization:
* Retina: Not visible as dark blue/gray patches in scleritis.
* Uvea: The underlying uvea can appear as dark blue/gray patches when the sclera thins in scleritis.
* Blood vessels: Not typically described as dark blue/gray patches in this context.
* Vitreous: Not visible as dark blue/gray patches in scleritis.
Question 34
In EOM testing, you note that the patient is unable to abduct his left eye. Movement was full on all positions of gaze for the right eye. This would imply weakness of which muscle in his left eye:
Select one:
a. Medial rectus
b. Lateral rectus
c. Superior rectus
d. Inferior rectus
b. Lateral rectus
Rationalization:
* Medial rectus: Responsible for adduction (moving the eye inward), not abduction.
* Lateral rectus: Responsible for abduction (moving the eye outward), so inability to abduct suggests lateral rectus weakness.
* Superior rectus: Responsible for elevation and some adduction, not abduction.
* Inferior rectus: Responsible for depression and some adduction, not abduction.
Question 35
Which of the following is TRUE of the Tenon’s capsule?
Select one:
a. It is composed of 2 to 5 layers of stratified columnar epithelial cells
b. It is held in place by suspensory ligaments
c. It secretes mucin for the maintenance of the precorneal tear film
d. It is continuous with the extraocular muscles
d. It is continuous with the extraocular muscles
Rationalization:
* It is composed of 2 to 5 layers of stratified columnar epithelial cells: Incorrect. This description does not apply to Tenon’s capsule.
* It is held in place by suspensory ligaments: Incorrect. This refers more to the lens.
* It secretes mucin for the maintenance of the precorneal tear film: Incorrect. This is the function of the goblet cells in the conjunctiva.
* It is continuous with the extraocular muscles: Correct. Tenon’s capsule envelops the extraocular muscles.
Question 36
What type of distance vision chart is used for illiterate or pre-verbal children?
Select one:
a. Bailey-Lovie chart
b. Picture chart
c. ETDRS chart
d. Snellen chart
b. Picture chart
Rationalization:
* Bailey-Lovie chart: Used for assessing visual acuity, but typically not for illiterate or pre-verbal children.
* Picture chart: Correct. Picture charts use recognizable images that children can identify.
* ETDRS chart: Used for research and clinical trials, not specifically designed for children.
* Snellen chart: Standard chart for literate individuals.
Question 37
This photoreceptor is extrafoveal in location and is used for night vision.
Select one:
a. Cones
b. Bipolar
c. Rods
d. Ganglion
c. Rods
Rationalization:
* Cones: Located in the fovea and used for color vision and fine detail.
* Bipolar: These are not photoreceptors; they are intermediate cells in the retina.
* Rods: Correct. Located outside the fovea and responsible for night vision.
* Ganglion: These are not photoreceptors; they transmit visual information from the retina to the brain.
Question 38
The patient was able to read all the letters in Line 6 and 2 letters at Line 7. What is the visual acuity of the patient?
Select one:
a. 20/25 - 2
b. 20/30 + 2
c. 20/25 + 2
d. 20/30 - 2
b. 20/30 + 2
Rationalization:
* 20/25 - 2: Incorrect. This would imply the patient missed 2 letters on the 20/25 line.
* 20/30 + 2: Correct. This means the patient read all the letters on the 20/30 line and 2 letters on the next line (20/25).
* 20/25 + 2: Incorrect. This would imply the patient read all the letters on the 20/25 line and 2 letters on the next line (20/20).
* 20/30 - 2: Incorrect. This would imply the patient missed 2 letters on the 20/30 line.
Question 39
What test provides a more detailed evaluation of the visual field?
Select one:
a. Pseudoisochromatic chart
b. Farnsworth-Munsell 100 hue test
c. Perimetry
d. Confrontation test
c. Perimetry
Rationalization:
* Pseudoisochromatic chart: Used for color vision testing.
* Farnsworth-Munsell 100 hue test: Used for detailed color vision testing.
* Perimetry: Correct. Provides detailed evaluation of the visual field.
* Confrontation test: A basic and gross assessment of the visual field.
Question 40
In cases of microbial keratitis, the etiologic organism is confirmed by:
Select one:
a. Giemsa stain
b. Periodic Acid Schiff stain
c. Gram stain
d. Culture studies
d. Culture studies
Rationalization:
* Giemsa stain: Useful for detecting intracellular organisms, not definitive for all microbial keratitis pathogens.
* Periodic Acid Schiff stain: Used for fungal infections, not comprehensive for all microbial keratitis.
* Gram stain: Useful for initial identification of bacteria but not definitive for all pathogens.
* Culture studies: Correct. The gold standard for identifying the specific causative organism in microbial keratitis.