History taking is the foundation of every clinical encounter in ophthalmology. Before a single test is performed or slit lamp turned on, the COA collects the patient history that guides the entire examination. A thorough, organized history identifies the clinical priorities, flags urgent situations requiring immediate physician evaluation, and provides context that makes all subsequent examination findings meaningful.
The COA exam places significant emphasis on the history and assessment domain because it is a core clinical skill that distinguishes a competent ophthalmic assistant from an untrained one. Knowing what questions to ask, in what order, and how to recognize symptoms that demand urgency is as important as knowing how to operate equipment.
A complete ophthalmic history has seven main components: chief complaint, history of present illness, past medical and ocular history, medications, allergies, family history, and social history. Each component feeds clinical decision-making in a distinct way.
The Seven Components of an Ophthalmic History
Chief Complaint (CC)
The patient's main concern in their own words. Document verbatim. Example: "My right eye has been blurry for a week." Avoid paraphrasing that changes the meaning.
Num: 1
History of Present Illness (HPI)
Detailed characterization of the CC using OLDCARTS or OPQRST. Every symptom deserves systematic exploration of onset, character, duration, severity, modifying factors, and associated symptoms.
Num: 2
Past Medical & Ocular History
Systemic conditions (diabetes, hypertension, autoimmune, HIV), prior eye surgery, trauma, prior eye conditions, hospitalizations, and prior ophthalmology records.
Num: 3
Medications
All ophthalmic drops + all systemic medications + OTC drugs + supplements. List name, dose, frequency, and which eye(s). Identify potential interactions and side effects.
Num: 4
Allergies
Drug, food, and environmental allergies. Document: the specific agent, type of reaction (hives, bronchospasm, anaphylaxis — NOT just "allergic"). Distinguish true allergy from intolerance.
Num: 5
Family History
Glaucoma, AMD, retinal detachment, strabismus, amblyopia, hereditary retinal diseases, corneal dystrophies, and systemic diseases with ocular manifestations in first-degree relatives.
Num: 6
Social History & Review of Systems
Occupation, UV/hazardous material exposure, smoking, contact lens use (type, wear schedule, compliance), driving concerns, sports requiring eye protection, review of ROS relevant to eyes.
Num: 7
OLDCARTS: Characterizing the HPI
OLDCARTS is a mnemonic for the elements needed to fully characterize any presenting symptom. Applied systematically to ophthalmic chief complaints, it produces a rich HPI that helps narrow the differential diagnosis before the examination even begins.
| Letter | Element | Sample Questions for Eye Symptoms | Clinical Significance |
|---|---|---|---|
| O | Onset | When did this start? Did it come on suddenly or gradually? | Sudden onset → vascular or mechanical; gradual → degenerative or refractive |
| L | Location | Which eye — right, left, or both? Central or peripheral vision? Entire field or a spot? | Monocular vs binocular narrows CNS vs ocular causes |
| D | Duration | How long has this been present? Is it constant or does it come and go? | Transient monocular vision loss (amaurosis fugax) → carotid or cardiac emboli |
| C | Character | How would you describe it? Blurred? Distorted? Dark? Curtain? Lines wavy? | Metamorphopsia (distortion) → macular disease; curtain → retinal detachment |
| A | Aggravating factors | Does anything make it worse? Bright light? Reading? End of day? Looking up or down? | Worse in bright light → media opacity; worse in dim light → rod dysfunction |
| R | Relieving factors | Does anything make it better? Does removing your glasses help? | Better without glasses → over-minused prescription |
| T | Timing | Worse in the morning or evening? After reading for a while? | Blur worse after prolonged near work → decompensated exophoria or accommodative insufficiency |
| S | Severity | How much does it affect daily activities? Rate your pain 0–10 if applicable. | Severe pain + photophobia + reduced vision → urgent evaluation |
Common Chief Complaints: Follow-up Questions
Flashes and Floaters
Always a high-priority symptom. Ask: Are the flashes in one eye or both? Do they occur in the dark as well as light? How many new floaters? Was there a sudden increase? Is there a shadow or curtain in the peripheral vision? Any prior retinal detachment or strong family history?
Red Eye
Ask: Is the redness in one eye or both? Is there discharge (watery / mucous / purulent)? Is it painful? Is there photophobia? Is vision affected? Is the patient a contact lens wearer? Recent URI? Exposure to pink eye?
Vision Loss
Ask: One eye or both? Sudden or gradual? Complete or partial? Central or peripheral? Painless or painful? Did it resolve? Any neurological symptoms (headache, diplopia, facial numbness)?
Double Vision (Diplopia)
Ask: One eye or both eyes open (monocular vs binocular)? Horizontal, vertical, or oblique? Does it improve when you cover one eye? Any eyelid drooping or pupil changes? Any headache or head trauma?
Medication Reconciliation
Medication reconciliation in ophthalmology requires collecting both ophthalmic and systemic medications because the interaction between the two is clinically significant and highly tested on the COA exam. A patient's glaucoma drop may be contraindicated with a systemic medication their internist prescribed, or a systemic drug may be causing the ocular symptom that brought the patient in.
Systemic Drugs with Ocular Effects
- Hydroxychloroquine (Plaquenil): bull's-eye maculopathy — annual screening
- Amiodarone: corneal verticillata, anterior subcapsular cataracts, optic neuropathy
- Steroids (oral/inhaled): PSC cataracts, IOP elevation
- Rifabutin: uveitis
- Sildenafil (Viagra): transient blue tinge, NAION risk
- Tamsulosin (Flomax): intraoperative floppy iris syndrome (IFIS)
- Ethambutol: optic neuropathy
Ophthalmic Drugs with Systemic Effects
- Timolol: bradycardia, bronchospasm, depression
- Brimonidine: CNS depression in children, drowsiness in adults
- Phenylephrine 10%: hypertension, cardiac events
- Atropine 1%: anticholinergic toxicity especially in children
- Dorzolamide/brinzolamide: systemic CAI effects rare but possible in renal failure
- Topical prostaglandins: systemic absorption minimal; safe for most
Allergy Documentation
Allergy documentation is a safety-critical function. An incompletely documented allergy can lead to a potentially life-threatening drug exposure. The COA must record not just the allergen but the specific reaction type — this determines whether it is a true hypersensitivity reaction (requiring drug avoidance) or a non-immune intolerance (which may or may not require avoidance).
Document: Agent + Reaction Type
Not “allergic to penicillin.” Instead: “Penicillin — anaphylaxis (throat closing, required epinephrine).” Or: “Penicillin — GI intolerance (nausea), no systemic reaction.” The distinction matters enormously for cross-reactivity risk assessment.
Ask About Sulfonamide Allergy
Sulfonamide allergy is relevant in ophthalmology because topical carbonic anhydrase inhibitors (dorzolamide, brinzolamide) contain a sulfonamide moiety. Patients with documented sulfonamide drug allergy may have cross-reactivity. The physician must be alerted before prescribing topical CAIs in these patients.
Ask About Fluorescein Dye and ICG
Before fluorescein angiography, ask about prior FA and any reactions. Ask about iodine allergy (relevant for ICG angiography). Document the answer in the procedure pre-screening notes even if negative — a documented negative screen is part of the safety record.
Documentation Format: SOAP Notes
The SOAP note format is the standard clinical documentation structure used in most outpatient medical settings, including ophthalmology. The COA contribution falls primarily in the Subjective section (history and symptoms) and objective measurements, while the Assessment and Plan are physician responsibilities.
Subjective
CC, HPI (OLDCARTS), PMHx, medications, allergies, family history, social history. The patient's own account of their symptoms and history.
Letter: S
Objective
Measured data: VA, IOP, refraction, slit lamp findings, fundus findings, VF results. What the COA measures and the physician examines.
Letter: O
Assessment
The physician's diagnosis or differential diagnoses based on the subjective and objective data. Not the COA's role to complete.
Letter: A
Plan
Treatment, prescriptions, follow-up plan, patient education, referrals. Physician-authored. COA may document patient education given.
Letter: P
Red Flag Symptoms Requiring Urgent Escalation
Immediately Escalate to the Physician When Any Patient Reports:
- Sudden vision loss (monocular): suspect CRAO, ischemic optic neuropathy — emergent
- Severe eye pain + halos + nausea: acute angle-closure glaucoma — emergent
- Curtain or shadow across vision + new floaters: retinal detachment — same day
- Diplopia + ptosis + dilated pupil: CN III aneurysm — emergent neurology
- Chemical eye exposure: irrigate immediately 20–30 minutes, then emergent care
- Penetrating eye injury: do not irrigate or pressure; shield and emergent care
- Red eye + pain + photophobia in contact lens wearer: corneal ulcer — urgent
- Proptosis + pain + fever: orbital cellulitis — urgent/emergent
Occupational and UV Exposure History
Occupational history provides context that directly affects diagnosis and management. A welder with a red eye after work suggests photokeratitis (UV flash burn), requiring no antibiotics. An agricultural worker with a corneal ulcer suggests possible fungal keratitis, requiring different treatment than bacterial ulcer. A computer user with eye strain suggests accommodative dysfunction or dry eye related to reduced blink rate.
UV Exposure History
Chronic UV exposure is a risk factor for pterygium, pinguecula, cataract, and cortical cataract specifically. Ask about outdoor occupations (construction, farming, fishing, military), recreational UV exposure (skiing, cycling), and whether UV-protective eyewear is consistently worn.
Driving Concerns
Always ask whether the patient drives and whether their vision difficulties affect driving. A patient with visual acuity below the legal driving threshold (varies by state, typically 20/40–20/50 in the better eye) may have a legal obligation for reporting. Document the discussion. Night driving difficulty may indicate early cataract, contrast sensitivity loss, or rod photoreceptor disease.
Practice COA History and Assessment Questions
Opterio includes patient history, symptom recognition, and red flag identification in COA exam practice, with AI-powered explanations that reinforce clinical reasoning.