Mixed Deck — All Vision and Ophthalmology Topics Flashcards
100 cards from real Vision and Ophthalmology practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 20 Mixed Deck — All Vision and Ophthalmology Topics flashcards as text
A patient who is myopic has a far point located:
Answer: In front of the eye at a finite distance
A myopic eye is too long or too powerful, focusing parallel rays in front of the retina; the far point is at a finite distance in front of the eye.
Irregular astigmatism, unlike regular astigmatism, cannot be fully corrected by:
Answer: Spectacle lenses with cylindrical correction
Irregular astigmatism has principal meridians that are not perpendicular and cannot be fully corrected with spectacle cylindrical lenses; rigid lenses neutralize the irregular surface.
Electroretinography (ERG) measures the electrical response of which cells in the retina?
Answer: Photoreceptors and bipolar cells (a-wave and b-wave)
The full-field ERG records mass electrical responses: the a-wave primarily reflects photoreceptor function and the b-wave reflects bipolar/Müller cell activity.
Selective laser trabeculoplasty (SLT) reduces IOP by:
Answer: Selectively targeting pigmented trabecular cells to improve outflow
SLT uses a 532 nm frequency-doubled Nd:YAG laser to selectively target melanin-containing trabecular cells, triggering a biological response that improves aqueous outflow without coagulative damage.
Dilute pilocarpine 0.1% is used diagnostically for which condition?
Answer: Adie's tonic pupil (supersensitivity denervation response)
Adie's tonic pupil shows denervation supersensitivity to dilute pilocarpine (0.1%), constricting abnormally, while a normal pupil shows minimal response.
A-scan ultrasonography in ophthalmology is primarily used for:
Answer: Measuring axial length for IOL calculations
A-scan ultrasonography measures the axial length of the eye, which is essential for calculating intraocular lens (IOL) power before cataract surgery.
What type of photoreceptors are responsible for color vision in bright light?
Answer: Cones
Cone photoreceptors are concentrated in the fovea and are responsible for color discrimination and high-acuity vision in photopic (bright light) conditions.
Tropicamide eye drops are used to dilate the pupil for fundus examination. What is their mechanism?
Answer: Anticholinergic (muscarinic antagonist)
Tropicamide blocks muscarinic acetylcholine receptors in the iris sphincter and ciliary muscle, causing mydriasis and cycloplegia.
Cocaine eye drops, used in the diagnosis of Horner syndrome, work by:
Answer: Blocking norepinephrine reuptake, causing dilation only if sympathetic innervation is intact
Cocaine blocks presynaptic norepinephrine reuptake; a normal eye dilates (intact sympathetics release NE) while a Horner eye fails to dilate (disrupted sympathetic chain).
Which type of glaucoma is characterized by a sudden painful rise in intraocular pressure with a mid-dilated, fixed pupil?
Answer: Acute angle-closure glaucoma
Acute angle-closure glaucoma presents with sudden severe eye pain, nausea, blurred vision, halos, and a mid-dilated fixed pupil due to abrupt obstruction of aqueous outflow.
Retinitis pigmentosa classically presents with which early visual symptom?
Answer: Night blindness (nyctalopia)
Retinitis pigmentosa first affects rod photoreceptors in the peripheral retina, causing night blindness and progressive peripheral visual field loss.
To minimize the risk of deprivation amblyopia, congenital visually significant cataracts should ideally be removed within:
Answer: The first 6 weeks of life
Visually significant unilateral congenital cataracts should be removed by 6–8 weeks of age to allow normal visual development and prevent severe deprivation amblyopia.
At what age is the visual system most plastic and amblyopia treatment most effective?
Answer: Under 7–8 years
The critical period for visual development closes around age 7–8; treatment is most effective before this window closes.
A patient with herpes zoster ophthalmicus and a lesion on the tip of the nose should be examined for what ocular complication?
Answer: Corneal involvement
The Hutchinson sign (tip-of-nose lesion) indicates involvement of the nasociliary branch of CN V, predicting a high risk of ocular/corneal complications.
Which vitreoretinal surgical technique is used to repair complex retinal detachments with proliferative vitreoretinopathy (PVR)?
Answer: Pars plana vitrectomy with membrane peeling and silicone oil tamponade
Complex retinal detachments with PVR require pars plana vitrectomy to remove the vitreous and peel contractile membranes, followed by silicone oil tamponade for long-term retinal support.
Which class of glaucoma medication is contraindicated in patients with sulfonamide allergy?
Answer: Carbonic anhydrase inhibitors
Carbonic anhydrase inhibitors (dorzolamide, brinzolamide topically; acetazolamide orally) are sulfonamide derivatives and may cause cross-reactivity in sulfonamide-allergic patients.
Retinoblastoma is the most common primary intraocular malignancy in which population?
Answer: Children under 5 years
Retinoblastoma predominantly occurs in young children, typically presenting before age 5, and is the most common primary intraocular tumor in childhood.
Optic neuritis presenting in a young adult is most strongly associated with which systemic disease?
Answer: Multiple sclerosis
Optic neuritis, especially retrobulbar neuritis with pain on eye movement, is a common demyelinating event and may be the first presentation of multiple sclerosis.
Normal intraocular pressure (IOP) in adults ranges from approximately:
Answer: 10–21 mmHg
Normal IOP is generally considered to be between 10 and 21 mmHg, with values above 21 mmHg considered elevated.
Which structure controls the diameter of the pupil by constricting it?
Answer: Sphincter pupillae
The sphincter pupillae muscle, innervated by parasympathetic fibers via CN III, constricts the pupil (miosis).