OEBC OSCE Component flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Sudden painless monocular vision loss

Suggests retinal artery occlusion, retinal detachment or vitreous haemorrhage; requires same-day ophthalmological referral plus vascular risk assessment including blood pressure and carotid evaluation.

Amaurosis fugax

Transient monocular visual loss lasting seconds to minutes, often described as a curtain descending; it indicates embolic carotid or cardiac disease and warrants urgent vascular workup.

Hydroxychloroquine retinal toxicity screening

Risk rises above five milligrams per kilogram per day or after five years of use; baseline examination then annual screening with visual fields and OCT, because damage may progress after the drug is stopped.

Teach-back method

Confirming patient understanding by asking them to restate instructions in their own words; it improves recall and exposes gaps better than asking whether they understand.

Open-ended question in history

Invites the patient to describe the problem in their own words, for example asking what brings them in; this yields richer and more accurate information than leading closed questions.

Van Herick grading

Estimates anterior chamber angle width by comparing peripheral chamber depth with corneal thickness; grade two or less, meaning a quarter of corneal thickness or shallower, prompts gonioscopy.

Goldmann applanation dial reading

Dial reading multiplied by ten gives intraocular pressure in millimetres of mercury, since one gram of applied force corresponds to one millimetre of mercury; verify calibration before use.

Shaffer gonioscopy grading

Grades angle width from zero, closed with no structures visible, to four, wide with ciliary body seen; grades zero and one indicate an occludable angle needing management.

ISNT rule

In a healthy disc the neuroretinal rim is widest inferiorly, then superiorly, nasally and temporally; violation of this order, especially inferior rim thinning, raises suspicion of glaucoma.

Cup-to-disc asymmetry

A difference of 0.2 or more between fellow eyes, or an absolute cup-to-disc ratio above 0.6, is suspicious for glaucoma and warrants visual field testing and optic nerve imaging.

Sclerotic scatter illumination

A broad slit beam is offset from the cornea so light travels within the stroma by total internal reflection, highlighting oedema, scars and foreign bodies against a dark background.

LogMAR to Snellen conversion

LogMAR equals minus log base ten of decimal acuity; 0.0 corresponds to 6/6 or 20/20, 0.3 to 6/12 or 20/40, and 1.0 to 6/60 or 20/200.

Retinoscopy working distance correction

Subtract the dioptric equivalent of the working distance from the neutralization result; 50 centimetres requires minus 2.00 dioptres and 67 centimetres requires minus 1.50 dioptres.

Jackson cross cylinder axis check

The handle is aligned with the correcting cylinder axis; flipping the lens presents two alternative axes and the patient chooses the clearer view, guiding rotation of the axis.

Duochrome test interpretation

Red-green balance check at the end of monocular refraction; if the red target is clearer add minus power, if the green target is clearer add plus, keeping the eye slightly fogged.

Hofstetter amplitude of accommodation

Expected amplitude in dioptres: minimum 15 minus 0.25 times age, average 18.5 minus 0.3 times age, maximum 25 minus 0.4 times age.

Pinhole test purpose

A pinhole improves acuity when vision loss is refractive by reducing blur circles; no improvement suggests media opacity or retinal and neural disease requiring ocular health assessment.

Hirschberg test estimation

A corneal light reflex displaced about one millimetre from the pupil centre corresponds to roughly seven degrees, or twelve to fifteen prism dioptres, of deviation.

AC/A heterophoria formula

AC/A equals interpupillary distance in centimetres plus the near minus distance phoria difference divided by the near fixation demand in dioptres; normal values are 4 to 6 to 1.

Worth four-dot interpretation

Four lights indicates fusion, two red lights mean the left eye is suppressed, three green mean the right eye is suppressed, and five indicate diplopia; test at distance and near.

Bruckner red reflex test

Compares the red reflex of both eyes simultaneously; asymmetry suggests strabismus, uncorrected refractive error or media opacity such as cataract or retinoblastoma and requires referral.

Amblyopia patching dose

Two to six hours of daily occlusion of the better eye is as effective as longer patching for moderate amblyopia; atropine penalization of the better eye is an alternative.

Tear break-up time

Measured after fluorescein instillation; ten seconds or more is normal, while under five seconds indicates an unstable tear film and predicts poor contact lens tolerance.

Contact lens acute red eye

Presents with waking pain, redness and photophobia after overnight or tight lens wear; remove the lens, manage conservatively, and differentiate from microbial keratitis.

Giant papillary conjunctivitis signs

Upper tarsal papillae over one millimetre with itching, mucus and reduced lens tolerance; managed by refitting, frequent lens replacement and mast cell stabilizers.

Orthokeratology mechanism

Overnight rigid gas permeable lenses flatten the central cornea and steepen the mid-periphery, temporarily reducing myopia; typical approved correction range is one to six dioptres.

Acanthamoeba risk factors

Exposure to tap water, swimming or showering in lenses, or homemade saline; presents with severe pain out of proportion to signs and a ring infiltrate, requiring urgent referral.

Informed consent elements

Disclosure of risks, benefits and alternatives, confirmed patient capacity, voluntariness and documentation; required before dilation, procedures or release of records to third parties.

Mandatory reporting duty

A statutory obligation to report suspected child abuse, specified communicable diseases and drivers medically unfit to drive; confidentiality yields to these legal duties.

Duty to refer

When findings exceed your competence or available equipment, arrange timely referral with a written summary of history, findings and urgency rather than continuing unsupported management.

Clinical error disclosure

After an error, disclose promptly and honestly to the patient, document the discussion and file an incident report; an apology is not an admission of liability in most jurisdictions.

Chaperone use

Offer a chaperone for examinations of a sensitive nature, document any refusal, and arrange the room so privacy is maintained while protecting both patient and clinician.