Retinal Camera (Fundus Photography) | CPO & CPOA Exam Prep

Retinal Camera (Fundus Photography) | CPO & CPOA Exam Prep | Opterio

Instruments & EquipmentCPO ExamCPOA Exam

Fundus photography is an increasingly important skill for paraoptometric professionals. Retinal cameras—ranging from traditional dilated systems to modern non-mydriatic widefield cameras—allow documentation of the retina, optic disc, and macula for disease detection, monitoring, and treatment planning. Paraoptometrics who can perform high-quality fundus photography contribute directly to better patient care in diabetic retinopathy, glaucoma, AMD, and other conditions.

Types of Fundus Cameras

Traditional Mydriatic Camera

Best image quality; standard for comprehensive exams

Field: 30°–50° field of view

Dilation: Required (≥3–4 mm pupil)

Non-Mydriatic Camera (NMC)

Faster workflow; ideal for diabetic screening programs; lower quality in some patients

Field: 30°–50° typical

Dilation: Not required (works with 2–3 mm)

Widefield / Ultrawidefield

Captures peripheral retina; important for diabetic retinopathy, RD, and peripheral lesions

Field: 100°–200° field of view

Dilation: Model-dependent (often non-mydriatic)

Confocal Scanning Laser (e.g., Optos)

High peripheral resolution; used with or without dilation; integrated with OCT in some systems

Field: Up to 200° pseudocolor

Dilation: Not required

Performing Fundus Photography: Step by Step

Prepare the Patient

Darken the room to allow natural pupil dilation. If dilation is required, instill dilating drops and wait the appropriate time (typically 20–30 minutes for tropicamide + phenylephrine).

N: 1

Enter Patient Demographics

Log in to the fundus camera software. Enter the patient's name, date of birth, or medical record number. Confirm the correct eye (OD or OS) before capturing.

N: 2

Position the Patient

Patient's chin in chin rest, forehead against bar. Eyes level with the instrument aperture. Ask patient to open their eye wide without squeezing.

N: 3

Select the Scan Protocol

Choose optic disc-centered, macula-centered, or both. Some protocols also include superior, inferior, and nasal fields.

N: 4

Align the Camera

Use the joystick to align the camera to the patient's pupil. On the live display, center the disc or macula as required for the scan type.

N: 5

Focus and Adjust Illumination

Use the focus dial to sharpen vascular detail. Adjust illumination intensity to avoid overexposure (washed-out areas) or underexposure (dark image). Patient should fixate on a specific target.

N: 6

Capture the Image

Instruct patient: "Look straight ahead and try not to blink." Press the capture button. Review immediately—if focus is poor, the vessel edges will be blurry; if exposure is wrong, the image will be too bright or dark.

N: 7

Patient: Look straight ahead and try not to blink.

Save and Label

Confirm images are correctly labeled (patient name, eye, date). Save to the electronic record. Note any quality issues (cataract artifact, poor dilation, patient movement).

N: 8

Clinical Uses of Fundus Photography

Diabetic Retinopathy Screening — Document and grade DR severity; track progression; identify patients requiring referral or treatment
Glaucoma Documentation — Photograph optic disc to document cup-to-disc ratio, rim tissue, disc hemorrhages; baseline for comparison
AMD Monitoring — Document drusen size and location, geographic atrophy extent, neovascular lesion appearance
Hypertensive Retinopathy — Photograph arteriovenous nicking, arteriolar narrowing, flame hemorrhages, and disc edema
Nevus / Tumor Baseline — Photograph choroidal nevi for size documentation and monitoring over time
Optic Disc Documentation — Baseline and annual documentation of disc appearance for glaucoma suspects and established patients
Retinal Detachment Follow-Up — Post-surgical documentation of retinal reattachment
Patient Education — Show patients their own retinal photographs to visualize their condition and motivate compliance

Frequently Asked Questions

What is a fundus camera and what does it photograph?

A fundus camera (also called a retinal camera) is a specialized microscope-camera system designed to photograph the posterior segment of the eye—the fundus. It captures images of the retina, optic disc, macula, retinal vessels, and choroid. Most fundus cameras have a 30°–50° field of view. Widefield cameras can capture 100°–200° with or without dilation. The camera uses a ring-shaped illumination system that enters and exits the pupil through different zones, avoiding corneal reflections. Modern cameras produce high-resolution color images, red-free images, fluorescein angiography images, and can connect to electronic health records.

When is pupil dilation required for fundus photography?

Traditional fundus cameras typically require a pupil of at least 3–4 mm for adequate image quality, making pharmacologic dilation (typically with tropicamide and phenylephrine) necessary for patients with small or poorly dilating pupils. Modern non-mydriatic cameras (also called NMC or non-dilated cameras) can capture images through undilated pupils as small as 2–3 mm using flash illumination that avoids the constriction reflex. Non-mydriatic cameras are widely used for diabetic retinopathy screening programs because they eliminate the need for dilation, reduce chair time, and avoid the 4–6 hours of blurred near vision associated with dilation. However, image quality is generally better with dilation, and undilated wide-angle images may miss peripheral pathology.

What are the standard photographs captured during a fundus photography session?

The standard fundus photo protocol typically includes: (1) Optic disc-centered photograph—centers the camera on the optic nerve head to show the disc, cup, and peripapillary RNFL. (2) Macula-centered photograph—centers the camera on the fovea to show the macula and surrounding retina. (3) Combined field showing both the disc and macula when a single image can capture both (may require a widefield camera). Some protocols also include superior, inferior, nasal, and temporal field photographs for a 7-field ETDRS protocol (used in diabetic retinopathy grading). For each eye, images should be labeled correctly: OD (right) and OS (left).

What makes a fundus photograph high quality and how can paraoptometrics improve image quality?

A high-quality fundus photograph should have: (1) Sharp focus across the entire image—the optic disc and macular vessels should be in crisp focus. (2) Adequate and even illumination—no dark zones at the edges (vignetting) or overexposed areas. (3) No corneal reflex or flash artifact obscuring the image center. (4) Correct centering on the target structure (disc or macula). If quality is poor, paraoptometrics can: ask the patient to fixate on a specific target, instill a lubricating drop to improve tear film, dim the exam room lighting to allow natural pupil dilation, adjust joystick position to minimize corneal reflex, or schedule a dilated appointment if persistent quality issues occur.

How does fundus photography contribute to diabetic eye disease management?

Fundus photography is the primary method for screening and grading diabetic retinopathy. Regular retinal photographs allow: (1) Detection of early non-proliferative diabetic retinopathy (NPDR) including microaneurysms, dot/blot hemorrhages, hard exudates, and cotton-wool spots. (2) Documentation of macular edema risk (clinically significant macular edema requires OCT for confirmation). (3) Detection of high-risk proliferative diabetic retinopathy (PDR) including neovascularization of the disc (NVD) and elsewhere (NVE). (4) Longitudinal comparison—photographs from sequential visits show whether retinopathy is stable, improving (after treatment), or progressing. In many diabetic retinopathy screening programs, paraoptometrics perform the photography and trained graders or AI algorithms analyze the images.

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