OA Admission Exam cheat sheet

Keratoconus: inferior corneal steepening, Fleischer ring (iron at cone base), Vogt striae (deep stromal stress lines that clear with pressure), Munson sign on downgaze.

Anterior uveitis presents with ciliary flush, consensual photophobia, cells and flare in the anterior chamber; hypopyon indicates severe inflammation and requires urgent referral.

Primary open-angle glaucoma: open angle on gonioscopy, cupping with neuroretinal rim thinning, and progressive RNFL loss; IOP is a risk factor, not a diagnostic criterion.

Acute angle-closure: mid-dilated fixed pupil, corneal edema, IOP often >40 mmHg, shallow anterior chamber; treat with IOP-lowering agents and definitive iridotomy.

Age-related macular degeneration: dry form shows drusen and RPE change; wet form shows choroidal neovascular membrane with subretinal fluid or hemorrhage and warrants urgent retinal evaluation.

Diabetic retinopathy grading: microaneurysms and dot-blot hemorrhages (mild NPDR), then cotton wool spots and venous beading (severe NPDR), then neovascularization (PDR).

Papilledema is bilateral, spares the fovea (enlarged blind spot, preserved acuity), and requires neuroimaging; unilateral disc edema with visual loss suggests optic neuritis or NAION.

Pterygium is a fibrovascular growth crossing the limbus onto cornea; pinguecula is confined to conjunctiva and does not cross the limbus.

Prostaglandin analogs (latanoprost) lower IOP by increasing uveoscleral outflow; adverse effects include iris darkening, eyelash lengthening, and periorbital fat atrophy.

Beta-blockers (timolol) reduce aqueous production; contraindicated in asthma, COPD, and heart block; can mask hypoglycemia symptoms.

Alpha-2 agonists (brimonidine) reduce aqueous production and increase uveoscleral outflow; risk of allergic conjunctivitis and CNS depression in children.

Topical corticosteroids suppress inflammation but raise IOP, delay wound healing, and increase cataract and infection risk; taper after prolonged use.

Cycloplegics: atropine (7-14 days), cyclopentolate (24 hours), tropicamide (4-6 hours); cycloplegia is required for reliable retinoscopy in children.

Mydriatics vs cycloplegics: phenylephrine dilates without cycloplegia; cyclopentolate provides both mydriasis and cycloplegia.

Fluoroquinolones are first-line for bacterial keratitis and conjunctivitis; aminoglycosides carry greater epithelial toxicity.

Pilocarpine causes miosis, induces accommodation, and can precipitate angle-closure in a narrow angle; it is used in acute angle-closure and presbyopia management.

Snellen acuity: 20/20 means the patient resolves a letter at 20 feet that a normal eye resolves at 20 feet; 20/40 means the letter must be 40 feet for a normal eye.

Spherical equivalent = sphere + (cylinder/2); used for contact lens conversion and refractive surgery planning.

Power of a thin lens in diopters = 1/focal length in meters; converging lenses are positive, diverging lenses are negative.

Vertex distance matters for powers beyond ±4 D; moving a lens closer to the eye decreases its effective power for plus lenses and increases it for minus lenses.

Astigmatism correction: cylinder axis is the meridian of no power; the power meridian is 90° from the axis.

Jackson cross-cylinder is used to refine cylinder axis and power; the patient chooses between two images with equal spherical equivalent.

Prism power in diopters = 100 × displacement in cm / distance in meters; used to correct strabismus and measure deviations.

Anisometropia >1 D in children warrants correction to prevent anisometropic amblyopia.

Base curve flatter than corneal curvature (larger radius) loosens lens fit; steeper base curve tightens fit.

Oxygen transmissibility (Dk/t) determines corneal oxygenation; silicone hydrogel lenses have higher Dk/t than conventional hydrogels.

Giant papillary conjunctivitis presents with cobblestone papillae on the upper tarsal conjunctiva and is linked to lens deposits and protein buildup.

Microbial keratitis risk rises with overnight wear, poor hygiene, and extended-wear schedules; Pseudomonas is the most common pathogen.

Rigid gas permeable lenses: apical clearance should be minimal; excessive apical clearance causes corneal edema and steep fit.

Keratoconus fitting: steeper base curve with apical clearance and mid-peripheral bearing; scleral lenses vault the cone and avoid corneal touch.

Hydrogel lens replacement schedules: daily, two-week, and monthly; compliance with replacement reduces deposit-related complications.

Over-refraction on a soft lens: if spherical equivalent changes, adjust lens power; if astigmatism remains, consider toric design.

Cover-uncover test detects tropia; alternate cover test detects phoria by breaking fusion.

Amblyopia: reduced best-corrected acuity in one or both eyes without structural cause; treat with refractive correction, patching, or atropine penalization.

Esotropia: inward deviation; exotropia: outward; hypertropia: upward; hypotropia: downward.

Accommodative esotropia is linked to uncorrected hyperopia; treatment is full plus correction and amblyopia therapy.

Convergence insufficiency: near point of convergence >6 cm, reduced positive fusional vergence, and symptoms with near work; treat with convergence exercises.

Stereopsis testing: Titmus fly, Randot, and TNO; TNO uses random-dot patterns and does not require monocular cues.

Duane syndrome: limited abduction or adduction with globe retraction and palpebral fissure narrowing on adduction.

Congenital nystagmus: horizontal, conjugate, often dampens with convergence; acquired nystagmus may signal neurologic disease.

Diabetes: retinopathy, cataract, and increased risk of infection; tight glycemic control reduces progression.

Hypertension: arteriolar narrowing, AV nicking, flame hemorrhages, cotton wool spots, and papilledema in malignant hypertension.

Marfan syndrome: ectopia lentis (superotemporal lens dislocation), tall stature, aortic root dilation.

Homocystinuria: ectopia lentis (inferonasal dislocation), intellectual disability, and thromboembolism.

Graves disease: proptosis, lid retraction, restrictive myopathy (inferior rectus most common), and optic neuropathy in severe cases.

Sarcoidosis: granulomatous uveitis, conjunctival nodules, and optic nerve involvement; chest imaging and biopsy support diagnosis.

Sickle cell disease: comma-shaped conjunctival vessels and proliferative retinopathy; avoid hypoxia during surgery.

Rheumatoid arthritis: scleritis and peripheral ulcerative keratitis; systemic immunosuppression may be required.

Optic neuritis: unilateral painful vision loss, afferent pupillary defect, and dyschromatopsia; associated with multiple sclerosis.

Afferent pupillary defect (Marcus Gunn): swinging flashlight test shows dilation when light moves to the affected eye.

Third nerve palsy: ptosis, down-and-out eye, and mydriasis if compressive; pupil-sparing suggests ischemic cause.

Sixth nerve palsy: esotropia worse on abduction; consider elevated intracranial pressure and microvascular disease.

Fourth nerve palsy: hypertropia worse on head tilt to the affected side and on downgaze.

Horner syndrome: ptosis, miosis, and anhidrosis; test with apraclonidine and localize along the sympathetic chain.

Cortical visual impairment: normal pupillary responses with reduced vision and normal fundus; common in children with neurologic injury.

Homonymous hemianopia localizes to the contralateral optic radiation or occipital cortex; macular sparing suggests occipital lesion.

Chemical burn: immediate copious irrigation with saline or water for at least 15-30 minutes before any examination; check pH after irrigation.

Open globe: shield the eye, avoid pressure, give antibiotics and tetanus prophylaxis, and refer immediately for surgical repair.

Central retinal artery occlusion: sudden painless monocular vision loss, cherry-red spot, boxcarring; treat as emergency with IOP lowering and systemic workup.

Acute angle-closure: IOP-lowering medications, topical steroids, and laser peripheral iridotomy; avoid mydriatics.

Orbital cellulitis: fever, proptosis, pain with eye movement; requires urgent imaging and IV antibiotics.

Retinal detachment: flashes, floaters, and a curtain-like visual field defect; urgent retinal evaluation for repair.

Hyphema: elevated IOP risk, rebleed risk; restrict activity, treat IOP, and monitor for corneal staining.

Endophthalmitis after surgery: pain, decreased vision, hypopyon; urgent vitreous tap and intravitreal antibiotics.

Informed consent requires disclosure of diagnosis, treatment options, risks, benefits, and alternatives, documented in the record.

HIPAA protects protected health information; disclosures require patient authorization except for treatment, payment, and operations.

CPT coding: 920xx for ophthalmologic services, 992xx for evaluation and management; documentation must support the level billed.

Medicare reimbursement for optometry varies by state and procedure; verify local coverage determinations.

Conflict of interest: disclose financial interests in optical products and avoid inducements that compromise clinical judgment.

Record retention: retain patient records per state law and payer requirements; release records only with proper authorization.

Scope of practice: optometrists diagnose and treat ocular disease per state law; surgical privileges vary by jurisdiction.

Malpractice risk reduction: document informed refusal, follow-up plans, and referral communications.

Red flags for urgent referral: sudden vision loss, severe eye pain, trauma, chemical exposure, and new flashes or floaters.

Penetrating injury: do not remove impaled objects; shield and refer immediately.

Herpes zoster ophthalmicus: vesicular rash in V1 distribution; treat with antivirals and monitor for keratitis and uveitis.

Bacterial keratitis: contact lens wearer with pain, photophobia, and corneal infiltrate; culture and treat with fortified antibiotics.

Orbital compartment syndrome: proptosis, pain, and vision loss after trauma; emergent lateral canthotomy may be required.

Giant cell arteritis: headache, jaw claudication, and vision loss in older adults; start high-dose steroids immediately and biopsy.

Traumatic hyphema: avoid NSAIDs and aspirin; monitor IOP and rebleed risk.

Ultraviolet keratitis: delayed pain and photophobia after welding or sun exposure; treat with topical antibiotics and cycloplegia.

Billing compliance requires accurate documentation of history, examination, and medical decision-making.

Patient confidentiality: do not discuss cases in public areas or on social media without authorization.

Referral communication should include reason, findings, and requested action; document in the chart.

Informed refusal: document the patient's decision to decline recommended care and the risks discussed.

Professional boundaries: avoid dual relationships and disclose any conflicts of interest.

Insurance verification: confirm eligibility and benefits before services to reduce claim denials.

Emergency preparedness: maintain an emergency kit and protocol for anaphylaxis and ocular trauma.

Continuing education requirements vary by state; track credits for license renewal.

Visual field defects: bitemporal hemianopia localizes to the optic chiasm; homonymous defects localize retrochiasmally.

Pupillary light reflex pathway: retina to optic nerve, chiasm, pretectal nucleus, Edinger-Westphal nucleus, and ciliary ganglion.

Optic neuropathy: pale disc, afferent pupillary defect, and visual field loss; distinguish compressive, ischemic, and inflammatory causes.

Papilledema: bilateral disc swelling from elevated intracranial pressure; urgent neuroimaging and lumbar puncture.

Cortical blindness: normal pupillary reflexes and fundus with vision loss from occipital lesions.

Nystagmus: jerk nystagmus has a fast phase; pendular nystagmus is sinusoidal and often associated with visual loss.

Diplopia: monocular diplopia suggests refractive or media cause; binocular diplopia suggests motility or neurologic cause.

Oculomotor apraxia: difficulty initiating saccades; associated with neurologic disorders in children.

Artificial tears: first-line for dry eye; preservative-free formulations for frequent use or corneal disease.

Topical NSAIDs (ketorolac) reduce pain and inflammation but can cause corneal melting in severe dry eye.

Antihistamines and mast cell stabilizers treat allergic conjunctivitis; combination agents provide faster relief.

Atropine 0.01% is used for myopia control; monitor for photophobia and near blur.

Latanoprost is dosed once nightly; dosing more frequently can reduce efficacy.

Timolol is contraindicated in reactive airway disease; consider brimonidine or dorzolamide instead.

Cyclopentolate 1% provides cycloplegia for refraction in children; avoid in narrow angles.

Topical steroids require monitoring of IOP and corneal status during prolonged use.

Retinoscopy: neutralization occurs when the working distance lens is subtracted from the gross finding.

Fogging technique relaxes accommodation before subjective refraction.

Jackson cross-cylinder: axis refinement first, then power refinement.

Duochrome test: red-green balance helps refine spherical endpoint; red clearer suggests over-minus.

Prism: base direction determines image displacement; base-out induces convergence.

Keratometry measures corneal curvature; average K is about 43-44 D.

A-scan biometry measures axial length for IOL calculation; optical biometry is preferred when possible.

Aniseikonia: unequal image sizes; consider iseikonic lenses when anisometropia is significant.

Soft lens fit: adequate movement, centration, and coverage; steep fit shows tight lens with limbal compression.

Scleral lens fitting: vault the cornea and land on sclera; assess clearance and conjunctival bearing.

Orthokeratology: reverse-geometry lenses flatten central cornea to reduce myopia; risk of microbial keratitis.

Toric soft lens: stabilization by prism ballast or thin zones; assess rotation and axis marking.

Multifocal soft lenses: center-distance or center-near designs; assess add power and near acuity.

Contact lens solution: multipurpose solutions require rubbing and rinsing; hydrogen peroxide systems require neutralization.

Corneal neovascularization: sign of hypoxia; refit with higher Dk/t lens.

Contact lens overwear: corneal edema, SPK, and decreased wearing time; recommend reduced wear schedule.

Hirschberg test: corneal light reflex displaced from pupil center estimates deviation.

Krimsky test: prism placed before the deviated eye to center the reflex.

Amblyopia treatment: patching 2-6 hours per day is as effective as full-time patching for moderate amblyopia.

Accommodative convergence/accommodation (AC/A) ratio: normal is 4-6 prism diopters per diopter.

Intermittent exotropia: treat with over-minus lenses, patching, or surgery depending on control.

Vertical deviations: assess with Parks-Bielschowsky three-step test for superior oblique palsy.

Fusional vergence: positive fusional vergence for convergence; negative for divergence.

Stereopsis: normal is 40-60 seconds of arc; reduced stereopsis suggests amblyopia or strabismus.

Thyroid eye disease: proptosis, lid retraction, and restrictive myopathy; smoking worsens the disease.

Multiple sclerosis: optic neuritis, internuclear ophthalmoplegia, and nystagmus.

Giant cell arteritis: anterior ischemic optic neuropathy, cotton wool spots, and choroidal ischemia.

Lupus: keratoconjunctivitis sicca, retinal vasculitis, and cotton wool spots.

Behcet disease: recurrent uveitis with hypopyon and oral/genital ulcers.

Syphilis: uveitis, interstitial keratitis, and Argyll Robertson pupil.

Tuberculosis: granulomatous uveitis and choroidal tubercles.

Lyme disease: uveitis, optic neuritis, and cranial nerve palsy.

Coding: use modifiers when multiple procedures are performed on the same day.

Documentation: record visual acuity, IOP, and fundus findings for each visit.

Referral: send a copy of the report to the referring provider.

Patient education: document discussion of risks and benefits.

Billing: verify insurance benefits before scheduling elective procedures.

Compliance: follow state and federal regulations for prescribing controlled substances.

Emergency protocol: maintain an emergency kit and contact list.

Professionalism: maintain confidentiality and respect patient autonomy.

Chemical injury: irrigate immediately and check pH; refer urgently.

Open globe: shield and avoid pressure; give antibiotics and tetanus prophylaxis.

CRAO: sudden vision loss; lower IOP and obtain systemic workup.

Acute angle-closure: lower IOP and perform laser iridotomy.

Orbital cellulitis: urgent imaging and IV antibiotics.

Retinal detachment: urgent repair; flashes and floaters are warning signs.

Hyphema: monitor IOP and restrict activity.

Endophthalmitis: urgent vitreous tap and intravitreal antibiotics.

Optic neuritis: painful vision loss with afferent pupillary defect.

Third nerve palsy: ptosis, down-and-out eye, and mydriasis if compressive.

Sixth nerve palsy: esotropia worse on abduction.

Fourth nerve palsy: hypertropia worse on head tilt to the affected side.

Horner syndrome: ptosis, miosis, and anhidrosis.

Cortical visual impairment: normal pupillary responses and fundus.

Homonymous hemianopia: contralateral optic radiation or occipital lesion.

Papilledema: bilateral disc swelling from elevated intracranial pressure.

Keratoconus: inferior steepening, Fleischer ring, Vogt striae, and Munson sign.

Anterior uveitis: ciliary flush, consensual photophobia, and cells/flare.

POAG: open angle, cupping, and progressive RNFL loss.

Acute angle-closure: mid-dilated pupil, corneal edema, and high IOP.

AMD: drusen and RPE change (dry); subretinal fluid or hemorrhage (wet).

Diabetic retinopathy: microaneurysms, cotton wool spots, and neovascularization.

Papilledema: bilateral, spares fovea, and requires neuroimaging.

Pterygium crosses the limbus; pinguecula does not.

Prostaglandin analogs increase uveoscleral outflow; side effects include iris darkening and eyelash lengthening.

Beta-blockers reduce aqueous production; contraindicated in asthma and heart block.

Alpha-2 agonists reduce aqueous production and increase uveoscleral outflow; risk of allergic conjunctivitis.

Topical steroids raise IOP and increase cataract and infection risk.

Cycloplegics: atropine (7-14 days), cyclopentolate (24 hours), tropicamide (4-6 hours).

Phenylephrine dilates without cycloplegia.

Fluoroquinolones are first-line for bacterial keratitis.

Pilocarpine causes miosis and can precipitate angle-closure.

Snellen 20/20: patient resolves at 20 feet what a normal eye resolves at 20 feet.

Spherical equivalent = sphere + (cylinder/2).

Lens power in diopters = 1/focal length in meters.

Vertex distance matters beyond ±4 D.

Cylinder axis is the meridian of no power.

Jackson cross-cylinder refines axis and power.

Prism power in diopters = 100 × displacement in cm / distance in meters.

Anisometropia >1 D in children warrants correction.

Flatter base curve loosens fit; steeper base curve tightens fit.

Silicone hydrogel lenses have higher Dk/t than conventional hydrogels.

GPC: cobblestone papillae on upper tarsal conjunctiva.

Microbial keratitis risk rises with overnight wear; Pseudomonas is common.

RGP fit: minimal apical clearance.

Keratoconus: steeper base curve with apical clearance; scleral lenses vault the cone.

Replacement schedules: daily, two-week, and monthly.

Over-refraction on soft lens: adjust power or consider toric design.

Cover-uncover test detects tropia; alternate cover test detects phoria.

Amblyopia: reduced acuity without structural cause; treat with correction, patching, or atropine.

Esotropia: inward; exotropia: outward; hypertropia: upward; hypotropia: downward.

Accommodative esotropia: linked to uncorrected hyperopia.

Convergence insufficiency: NPC >6 cm and reduced positive fusional vergence.

TNO uses random-dot patterns and does not require monocular cues.

Duane syndrome: limited abduction/adduction with globe retraction.

Congenital nystagmus: horizontal, conjugate, dampens with convergence.

Diabetes: retinopathy, cataract, and increased infection risk.

Hypertension: arteriolar narrowing, AV nicking, and flame hemorrhages.

Marfan syndrome: ectopia lentis (superotemporal) and aortic root dilation.

Homocystinuria: ectopia lentis (inferonasal) and thromboembolism.

Graves disease: proptosis, lid retraction, and restrictive myopathy.

Sarcoidosis: granulomatous uveitis and conjunctival nodules.

Sickle cell disease: comma-shaped conjunctival vessels and proliferative retinopathy.

Rheumatoid arthritis: scleritis and peripheral ulcerative keratitis.

Optic neuritis: painful vision loss with afferent pupillary defect.

Afferent pupillary defect: swinging flashlight test shows dilation in the affected eye.

Third nerve palsy: ptosis, down-and-out eye, and mydriasis if compressive.

Sixth nerve palsy: esotropia worse on abduction.

Fourth nerve palsy: hypertropia worse on head tilt to the affected side.

Horner syndrome: ptosis, miosis, and anhidrosis.

Cortical visual impairment: normal pupillary responses and fundus.

Homonymous hemianopia: contralateral optic radiation or occipital lesion.

Chemical burn: irrigate for at least 15-30 minutes and check pH.

Open globe: shield, avoid pressure, and refer immediately.

CRAO: sudden painless vision loss with cherry-red spot.

Acute angle-closure: lower IOP and perform laser iridotomy.

Orbital cellulitis: fever, proptosis, and pain with eye movement.

Retinal detachment: flashes, floaters, and a curtain-like defect.

Hyphema: monitor IOP and restrict activity.

Endophthalmitis: urgent vitreous tap and intravitreal antibiotics.

Informed consent requires disclosure of diagnosis, options, risks, benefits, and alternatives.

HIPAA protects PHI; disclosures require authorization except for treatment, payment, and operations.

CPT coding: 920xx for ophthalmologic services, 992xx for evaluation and management.

Medicare reimbursement varies by state and procedure.

Disclose financial interests in optical products.

Retain records per state law and payer requirements.

Scope of practice varies by state.

Document informed refusal and referral communications.

Red flags: sudden vision loss, severe pain, trauma, chemical exposure, and new flashes or floaters.

Penetrating injury: do not remove impaled objects.

Herpes zoster ophthalmicus: vesicular rash in V1 distribution.

Bacterial keratitis: contact lens wearer with pain and corneal infiltrate.

Orbital compartment syndrome: proptosis and vision loss after trauma.

Giant cell arteritis: headache, jaw claudication, and vision loss; start steroids immediately.

Traumatic hyphema: avoid NSAIDs and aspirin.

Ultraviolet keratitis: delayed pain and photophobia after welding.

Billing compliance requires accurate documentation.

Patient confidentiality: do not discuss cases in public areas.

Referral communication should include reason, findings, and requested action.

Informed refusal: document the decision and risks discussed.

Avoid dual relationships and disclose conflicts of interest.

Verify insurance eligibility before services.

Maintain an emergency kit and protocol.

Track continuing education credits for license renewal.

Bitemporal hemianopia localizes to the optic chiasm.

Homonymous defects localize retrochiasmally.

Pupillary pathway: retina, optic nerve, chiasm, pretectal nucleus, Edinger-Westphal nucleus, ciliary ganglion.

Optic neuropathy: pale disc, afferent pupillary defect, and field loss.

Papilledema: bilateral disc swelling from elevated intracranial pressure.

Cortical blindness: normal pupillary reflexes and fundus.

Jerk nystagmus has a fast phase; pendular nystagmus is sinusoidal.

Monocular diplopia suggests refractive or media cause.