22.2 Core Workflows and Decision Points

22.2 Core Workflows and Decision Points

Imaging is a sequence, and the COA exam loves to test where in the sequence an action belongs. Build a mental checklist for each modality and you will answer most workflow items quickly.

Fundus photography workflow

1. Verify the order and the eye to be photographed.
2. Dilate unless a non-mydriatic camera is used; a dilated pupil of roughly 4 mm or more greatly improves field and reduces artifacts.
3. Enter accurate patient data so the image files attach to the correct chart.
4. Align and focus: center the optic disc or the macula per protocol, set working distance, and adjust focus until vessels are crisp.
5. Capture, then review immediately for focus, illumination, and field. Recapture before the patient leaves.

OCT workflow

OCT usually does not require dilation, which is a frequent exam contrast point with FA. Steps: confirm patient and scan protocol (macular cube vs. optic-disc/RNFL), seat the patient with chin and forehead firmly placed, ask the patient to fixate on the internal target, optimize the signal strength/quality index, center the scan, and capture. Reject scans with low signal strength, blink artifacts, motion lines, or segmentation errors where the software mis-draws the retinal layers.

Fluorescein angiography workflow and decision points

FA adds an intravenous dye and timed photography, so safety and timing dominate.

Phase timing is testable. After a brisk antecubital injection, dye reaches the retinal arteries in about 10-15 seconds (the arm-to-retina time). Sequence: choroidal/pre-arterial flush, arterial phase, arteriovenous (capillary) phase, venous phase, and late/recirculation phase at roughly 5-10 minutes that reveals leakage and staining. The photographer fires frames rapidly during early transit, then returns for late frames.

Post-procedure and handoff

After a dye study, remove the IV, confirm the patient is asymptomatic, and counsel on expected yellow skin and urine. Document the dose, lot number, time, and any reaction. Flag any reaction to the supervising clinician. The most error-prone handoffs are mislabeled image files and undocumented adverse reactions, so close the loop in the record every time.

ICG angiography workflow

ICG follows the FA pattern with two key differences. First, screen for iodine allergy and liver disease because indocyanine green is iodine-based and hepatically cleared. Second, the camera must be capable of near-infrared excitation and detection, since ICG fluoresces in the near-infrared to reveal the choroid. ICG is frequently performed together with FA in the same sitting to image both the retinal and choroidal circulations; in that case the photographer captures the FA frames first or runs a combined protocol per the device.

Decision points the exam tests

The workflow yields a short list of high-yield decision points. Memorize the correct branch at each fork:

Documentation closes the workflow

The last step in every imaging workflow is documentation. For dye studies, record the agent, dose, lot number, route, time, and any reaction, and confirm the images are filed to the correct patient and encounter. For OCT and fundus, confirm scan protocol, eye, and signal quality were acceptable. Incomplete documentation is the most common workflow failure tested, because it propagates errors into diagnosis, follow-up comparison, and billing. The defensible answer always closes the loop in the chart.

Sequencing logic the exam rewards

Many workflow items are really sequencing questions in disguise: they show you several correct-sounding steps and ask which comes first or next. Anchor on a fixed order. For any dye study the order is verify (patient, eye, order, consent, allergy history), prepare (dilate, establish IV), baseline (red-free photo for FA), inject and time, capture through the phases, then post-procedure care and documentation. You never inject before consent and allergy screening, you never capture before verifying laterality, and you never let the patient leave before reviewing image quality and removing the IV.

For OCT and fundus the order collapses to verify, position, optimize signal or focus, capture, review, recapture if needed, and document. When a stem offers 'inject the dye' as an early option but you have not yet confirmed consent or screened for allergy, that early-injection choice is the trap. The skill being tested is disciplined ordering under mild time pressure, exactly the situation a working ophthalmic assistant faces in a busy clinic, and the safe sequence protects both the patient and the integrity of the image record.