The Imaging Test That Finds Diabetic Retinopathy Damage Hiding at the Edges of Your Vision
Ultra-Widefield Retinal Imaging for Diabetes at a Glance
The retina is the lining at the back of your eye that senses light. Most eye photos show only its middle. This test shows much more of it.
It is called ultra-widefield imaging. One version takes photos alone. The other adds a yellow dye through a vein in your arm. That second version is called an angiogram (clinical: fluorescein angiography).
One ultra-widefield image can capture up to roughly four fifths of the retina. The seven standard photo fields used in older studies cover only about one third.1
Diabetes can harm the far edges of the retina first. Those edges sit outside your reading vision, so you may feel fine. Wider photos are how that damage gets found.
Being sent for this test is not a sign that you are losing sight. It usually means your doctor wants a fuller map before deciding how closely to watch you.
The gain has been measured. In 218 eyes of 118 people with diabetes, wide-angle dye imaging showed 3.2 times more retinal surface than a simulated seven-field view of the same eyes. It also showed 3.9 times more area with no blood flow (clinical: nonperfusion) and 1.9 times more new fragile vessels (clinical: neovascularization). In 22 of those 218 eyes it found a vessel problem the narrower view missed.2
That is one study of moderate size. Treat the exact multiples as a rough guide. The direction is what matters: more retina in view means more chances to catch a change while it is still quiet.
It cannot tell you what your own eyes will do next year. It maps what is there now. It then sorts you into a higher or lower risk group. That is a group average, not a personal forecast.
It is also not a yearly test for everyone with diabetes. The Academy states that routine dye angiography is not indicated as part of the regular examination of patients with diabetes, and lists it as never indicated to screen a patient with no or minimal retinopathy.3
So if you were offered the dye version, there is a question behind it. Ask what that question is.
What Ultra-Widefield Imaging and Dye Angiography Actually Are
The photo-only version is a color scan taken through your pupil. Nothing enters your body and nothing touches your eye. In many clinics it can be done without drops.
The dye version starts the same way. Then fluorescein goes into an arm vein so the camera can watch blood move through the retina. Dye is what reveals leaking vessels and patches where blood no longer arrives.
The two are not interchangeable. Of the 542 eyes in the Protocol AA study that had gradable images of both kinds, 136 had edge lesions on both the color photos and the dye images, 210 on neither, 85 on color photos only and 111 on dye images only. The investigators concluded that color findings are not interchangeable with dye findings.4
Diabetic damage does not politely start in the center. Small bleeds and ballooned capillaries often appear out toward the edge, where standard photos stop.
About one third of diabetic bleeds sit outside the seven standard fields. So do about one third of ballooned capillaries (clinical: microaneurysms), odd vessel segments (clinical: intraretinal microvascular abnormalities) and new vessels.1
Edge findings do not usually blur your sight. They are the part of the disease you cannot notice yourself.
Here is the practical difference, side by side.
| What differs | Seven standard fields | Ultra-widefield |
|---|---|---|
| Retina captured | Roughly one third | Up to roughly four fifths |
| Number of shots | Several, stitched together | Often one per eye |
| Far edges of retina | Mostly outside the frame | Mostly inside the frame |
Neither view replaces your doctor looking into your eye. Photos add detail and a record to compare against next year.
The dye version answers specific questions. The Academy lists dye angiography as usually indicated to find suspected new vessels that an examination cannot make out, and to look into unexplained vision loss. It lists mapping large areas without blood supply, and sorting out the cause of swelling at the center of the retina, as occasional reasons rather than usual ones.3
In practice that often means eye damage that looks worse than expected, vision that has dropped for no clear reason, or a pending decision about laser or injections. If none of that fits you, color photos alone may be enough. That is a fair thing to ask.
How to Get Ready for the Test
One piece of history matters most: whether you have ever reacted badly to fluorescein dye. In a study of 2,789 dye procedures, about 49 of every 100 people who had reacted before reacted again. Among those whose earlier angiogram had passed without trouble, about 2 of every 100 reacted.5
That is a single older study, so read it as a strong signal rather than a precise odds table. Either way, say it when you book, not on the day.
Also mention asthma, drug allergies, kidney disease, heart problems, and every medicine you take. None of these rules the test out on its own. They change how your team plans the visit.
Most clinics do not ask you to fast, which matters when you have diabetes. Ask when you book. If fasting is requested, ask how to handle your diabetes medicines that morning.
Bring your glasses and plan to take contact lenses out. Bring a snack and your glucose meter, because these visits can run long.
Tell your team if you are pregnant or breastfeeding. The Academy notes that fluorescein crosses the placenta and has been found in breast milk for up to 72 hours, and that harm to a fetus from the dye has not been documented.6 That is a conversation to have in advance, not an automatic barrier.
Assume both eyes will be dilated and you will not be driving. Dilating drops leave vision blurry and light painfully bright for several hours.
Bring sunglasses and someone to drive. If you are traveling alone, plan a slower journey home.
Treat the visit as most of a morning or afternoon. Booking a demanding meeting straight afterwards is the most common planning mistake.
What Happens During Ultra-Widefield Imaging
You will usually get drops to widen the pupil, then wait twenty to thirty minutes for them to work.
Color photos come first. You rest your chin on a support, look at a target, and the camera fires a bright flash. It is startling rather than painful, and the afterimage fades in a minute or two.
Nothing touches your eye.
Your own lids and lashes block the very edges this test is trying to see. So the photographer may gently hold your lids open and ask you to look up, down, left and right for extra frames.
It is worth tolerating. In 5,919 eyes of 3,014 patients, lifting the lids raised the visible retinal area by about a tenth before dilation, and by about a further tenth after it. The average number of small bleeds and ballooned capillaries seen per eye rose from 4.8 to 6.8.7
If it gets uncomfortable, say so. A short break costs a minute. A squeezed-shut eye costs the edge of the picture.
For the dye version, a small needle goes into a vein in your arm or hand. The Academy describes the dye as taking about 10 to 15 seconds to travel through the body, in an office test that often takes less than 30 minutes.8
Many people feel a brief warm flush or a metallic taste. Some feel a wave of nausea in the first minute. It usually passes quickly, and telling the photographer means they can pause.
The camera then fires repeatedly for several minutes as the dye fills and drains. A few late pictures are taken around ten minutes later.
Allow two to three hours from arrival to leaving, most of it waiting rather than being photographed. Color photos alone can be much quicker.
Afterwards the dye is still in you and will show. Your skin may look slightly yellow for a few hours, and urine may look orange or dark yellow for up to 24 hours.8
Drinking normally through the day helps you clear it. The color change is expected.
Understanding What the Pictures Show
On color images they count small bleeds and ballooned capillaries. They also note where each one sits. Position matters as much as number.
On dye images they look for two things you cannot see any other way: vessels leaking fluid, and patches of retina where blood is no longer arriving.
The Academy states that wide-angle dye imaging has improved detection of poor blood supply at the edges. That includes new vessels that may not be visible on examination.9 In plain terms, the dye finds trouble your doctor could look straight at and still miss.
When most of the damage sits toward the edge rather than the center, graders call it a predominantly peripheral lesion pattern. Where that pattern shows up turns out to matter.
In the Protocol AA study, retinopathy worsened by two or more steps over four years in about 50 of every 100 eyes with edge lesions on dye images at the start. About 31 of every 100 eyes without them worsened that much. Edge lesions on color photos alone showed no such split, at about 38 of every 100 against about 43 of every 100.10
Read that carefully, because the reassuring half is easy to miss. Even in the higher-risk group, about half of eyes did not worsen by two steps in four years. This is a nudge toward closer follow-up, not a countdown.
The most common change is timing. A higher-risk result usually means being seen sooner, not starting a new treatment that day.
The Academy notes that in Protocol AA, edge lesions found on dye imaging were linked with a greater risk of worsening over four years, independent of the retinopathy grade the eye already had.9 Independent means the finding added information on top of that grade.
Large areas without blood flow, or new vessels, can also open a conversation about laser or injections. That decision depends on far more than one scan.
Wider pictures shift probabilities. They do not settle your outcome, and they cannot say whether you personally will keep your reading vision.
Your blood glucose control, blood pressure, kidney health and how long you have had diabetes still carry more weight over a lifetime than any one set of photographs.
Risks, Side Effects and Cost
For the photo-only version, the effects are the drops and the flash: blurry vision, glare for a few hours, and afterimages that fade. That is the whole list.
The dye version adds nausea. The Academy reports nausea as the most common reaction, in about 3 to 15 of every 100 patients, with hives in about 5 of every 1,000.6
A study of 2,789 procedures recorded a reaction of some kind after about 5 of every 100. Nausea followed about 3 of every 100 and vomiting about 1 of every 100. There was no case of severe allergic collapse, heart attack, fluid on the lungs or seizure.5 A briefly sore arm is common and settles on its own.
Serious reactions to fluorescein happen. They are rare enough to be worth stating precisely rather than vaguely. Across 78 published reports from 1961 to 2017, severe reactions occurred in roughly 4 to 59 of every 10,000 procedures. Deaths were reported at about 1 in every 100,000 to 220,000.11
Those figures cover several decades and many settings, so they describe the shape of the risk rather than your clinic. The same review found the one established way to lower risk is checking whether you have reacted to the dye before. That is why the question gets asked twice.
The Academy states that every angiography site should have an emergency care plan and a clear protocol for handling complications.6 You are having this test in a room set up for the rare bad minute.
Both versions are usually billed as diagnostic imaging rather than as part of a routine eye exam. Your share can differ from your usual copay, so ask the billing office beforehand.
Ultra-widefield cameras are not in every practice. If yours does not have one, ask whether the question your doctor is chasing really needs one. Travel is a real barrier, so say so rather than quietly skipping the test. There is often a nearer site.
When to Call Your Eye Doctor
Most people go home with nothing worse than blur and yellow urine. A few symptoms are worth a same-day call to the clinic that did your test.
- A rash, widespread itching or hives after you leave.
- Wheezing, throat tightness or trouble breathing, which needs urgent care rather than a call.
- Growing pain, swelling, hardness or blistering at the injection site in your arm.
- Severe eye pain, or vision getting worse rather than clearing as the drops wear off.
- Feeling faint, or vomiting that will not settle hours later.
None of these is likely, and each has a clear response. Save the clinic's number in your phone before you go.
Separately from the test, some changes in diabetic eyes need quick attention. A shower of new floaters, a dark curtain moving across your sight, sudden loss of vision in one eye, or flashing lights all belong in that group.
These can signal bleeding inside the eye or a retina pulling away. Both are handled far better early than late. Call your eye clinic the same day and say what you saw and when it started.
Blurring that comes and goes with your blood sugar is a different thing. Mention it at your next visit rather than treating it as an emergency.
Imaging is one moment in a longer schedule. The schedule follows how much damage you already have. The Academy advises an eye exam about every 12 months when there is no damage, or mild damage with no swelling at the center of the retina. It advises about every 6 to 12 months for moderate damage. It advises about every 3 to 4 months for severe damage, and for early stages of the growing-vessel form (clinical: proliferative diabetic retinopathy). It advises about every 2 to 4 months for the high-risk growing-vessel form.12
Those gaps assume there is no swelling at the center of the retina. Swelling there, or growing vessels needing treatment, shortens them. Your own gap may also be shorter if your imaging showed edge findings, or if your diabetes control has changed. Ask for your next date before you leave.
Common Questions About Ultra-Widefield Retinal Imaging
No. Nothing touches your eye for the photo-only version. The camera works through your pupil from a short distance away. The bright flash is the least pleasant part, and it leaves an afterimage for a minute or so. If you are also having dye, the needle in your arm feels like a blood test. Tell the photographer if the lid holding gets uncomfortable, because they can pause.
Often photos are enough. Color ultra-widefield images can grade your retinopathy and document change over time. Dye is added when your team needs to see blood flow itself, for example to find suspected new vessels, map areas with no blood supply, or explain vision loss the photos do not account for. Ask which of those questions the dye is meant to answer for your eyes.
Color ultra-widefield images can often be taken without drops. That is one reason screening programs use them. Drops still help, because they widen the view and sharpen the edges of the picture. For the dye version, expect drops. Assume you will be dilated unless your clinic says otherwise, and arrange your ride on that basis.
Two explanations are common, and only one is bad news. Retinopathy does progress, so a real change may have happened. But if last year used narrower photos, the finding may have been outside the frame rather than absent. In one screening program, edge findings pointed to a more severe level of retinopathy in about 7 of every 100 affected eyes.13 Ask which applies to you.
In screening programs it has done well. One national program compared 16,218 eyes imaged with ultra-widefield against 35,052 imaged with standard photos, both without drops. Images that could not be graded fell from about 27 of every 100 eyes to about 3 of every 100. Damage was found in about 24 of every 100 eyes rather than about 12 of every 100.13 Fewer unusable images means fewer repeat visits.
No, and any report that seems to promise an individual outcome is being over-read. The images sort eyes into broad risk groups based on what happened to large numbers of people with similar findings. Even in the higher-risk group in the main study, about half of eyes did not worsen by two steps over four years. Use the result to set your follow-up schedule and your glucose and blood pressure goals.
More Questions About the Dye, the Results and Follow-Up
Fluorescein is a different substance from the iodine-based dye used for x-ray and CT scans, and it is unrelated to shellfish. What matters most is whether you have reacted to fluorescein itself before. A past reaction is the strongest known warning sign of another one.11 Tell your team about all your allergies, including asthma, and let them decide what it means for your visit.
This is a common source of confusion, because the kidney warnings most people have heard about attach to the iodine dye used for CT scans, which is a different substance. Kidney disease is still worth raising. Tell your eye team about it and about any dialysis, because it affects how they plan the visit and how they read your wider diabetes picture. Ask your kidney team as well if you are unsure.
Many retina clinics review the images the same day and talk you through them before you leave. If a reading center grades them, results may take one to two weeks. The report usually names your grade of damage, whether edge lesions are present, and whether there are areas without blood flow, leaking or new vessels. Ask to see the pictures on screen, because edge findings are easier to grasp visually.
There is a scan called OCT angiography that maps blood flow with no injection. The Academy notes that it avoids the needle but cannot show leaking, and that its role in diabetic eye disease is still being worked out.3 It is a useful companion rather than a straight swap. Which one you need depends on the question your doctor is asking.
Bring these to your appointment and write the answers down.
- What question are we answering with this imaging, and would color photos alone answer it?
- Did my images show edge lesions, and were they on the color photos, the dye images, or both?
- Did you see any areas without blood flow, any leakage, or any new vessels?
- Does this result change how often I need to be seen, and what is my next date?
- Given my allergy and medical history, is there anything about the dye I should know?
- What symptoms should make me call you before that next appointment?
- Saudi Journal of Ophthalmology (full text via PubMed Central) (2024). Peripheral retinal lesions in diabetic retinopathy on ultra-widefield imaging.
- Retina (Wessel MM, et al.; PubMed record) (2012). Ultra-wide-field angiography improves the detection and classification of diabetic retinopathy.
- American Academy of Ophthalmology (full guideline PDF) (2025). Diabetic Retinopathy Preferred Practice Pattern: when angiography is and is not indicated.
- American Academy of Ophthalmology, EyeNet Magazine (2023). Predominantly peripheral lesions and DR progression: role of UWF-FA.
- Ophthalmology (Kwiterovich KA, et al.; PubMed record) (1991). Frequency of adverse systemic reactions after fluorescein angiography.
- American Academy of Ophthalmology (guideline page) (2025). Diabetic Retinopathy Preferred Practice Pattern: risks of fluorescein angiography.
- JAMA Ophthalmology (Jacoba CMP, et al.) (2022). Maximizing visible retinal area by manual eyelid lifting when using ultra-widefield imaging.
- American Academy of Ophthalmology, EyeSmart patient education (2024). What is fluorescein angiography?.
- American Academy of Ophthalmology; Ophthalmology 2025 (PubMed record) (2025). Diabetic Retinopathy Preferred Practice Pattern: widefield angiography and Protocol AA.
- Retina Specialist, reporting DRCR Retina Network Protocol AA (2023). Lessons from Protocol AA for ultra-widefield imaging in diabetic retinopathy.
- Survey of Ophthalmology (Kornblau IS, El-Annan JF; PubMed record) (2019). Adverse reactions to fluorescein angiography: a comprehensive review of the literature.
- American Academy of Ophthalmology; Ophthalmology (journal full text) (2025). Diabetic Retinopathy Preferred Practice Pattern: recommended follow-up intervals.
- Ophthalmology (Silva PS, et al.; PubMed record) (2016). Identification of diabetic retinopathy and ungradable image rate with ultrawide field imaging in a national teleophthalmology program.