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PubMed This is a summary of 17 peer-reviewed journal articles Updated
Ophthalmology

Stages of Retinopathy and Macular Edema

At a Glance

Diabetic retinopathy can progress from mild, moderate, and severe non-proliferative disease to proliferative disease with fragile new blood vessels. Diabetic macular edema can occur at any stage and may blur vision, especially when swelling reaches the center of the macula.

Understanding the specific stage of your diabetic retinopathy is like knowing the “weather report” for your eyes. It tells your medical team how much damage has occurred and how likely you are to face vision changes in the near future. Doctors use a standardized grading system to track these changes, moving from early “silent” stages to more advanced “proliferative” stages [1][2]. It is important to know that each eye can be in a different stage, so always ask about both.

Non-Proliferative Diabetic Retinopathy (NPDR)

Most people with retinopathy are in the non-proliferative stage. This means that while blood vessels are damaged and leaking, the eye has not yet started growing new, abnormal vessels [3]. NPDR is graded into three main levels of severity:

  • Mild NPDR: At this earliest stage, the only signs are tiny, balloon-like swellings in the retina’s smallest blood vessels, called microaneurysms [4]. These are like small “blisters” on the vessel walls.
  • Moderate NPDR: As the disease progresses, more blood vessels show damage. You may have small spots of bleeding within the retina (hemorrhages) or “cotton-wool spots,” which are small white patches where the retina is not getting enough oxygen [5].
  • Severe NPDR: This is a critical warning stage. Many more blood vessels are blocked, depriving large areas of the retina of blood. Doctors look for specific signs like venous beading (vessels that look like a string of beads) and IRMA (intraretinal microvascular abnormalities), which are distorted vessels that act as “shunts” to bypass blocked ones [6][7].

If you have severe NPDR, you have a high risk of moving into the most advanced stage of the disease [7].

Proliferative Diabetic Retinopathy (PDR)

The most advanced stage is proliferative diabetic retinopathy. In this stage, the lack of oxygen in the retina becomes so severe that the eye triggers a survival response [8]. It begins growing brand-new blood vessels, a process called neovascularization [3][8].

While the eye is trying to help itself, these new vessels are a major threat. They are extremely fragile and poorly constructed. They often leak blood into the center of the eye (vitreous hemorrhage) or cause scar tissue to form, which can pull the retina away from the back of the eye (tractional retinal detachment) [9][10].

Diabetic Macular Edema (DME)

While the stages above describe the health of the entire retina, Diabetic Macular Edema (DME) is a specific complication that affects the macula—the tiny, central part of your retina responsible for sharp, straight-ahead vision [11].

DME occurs when damaged blood vessels leak fluid into the macula, causing it to swell or thicken [12]. It is important to know that:

  • It can happen at any stage: You do not have to have advanced PDR to develop DME. It can occur even in the mild or moderate NPDR stages [13][14].
  • It is a leading cause of vision loss: Because the macula is used for reading, driving, and recognizing faces, even a small amount of swelling can cause noticeable blurriness or distortion [8][15].
  • Center-Involving vs. Non-Center-Involving: Your doctor may mention if the swelling is “center-involving.” This means the fluid has reached the very center of the macula (the fovea). Center involvement increases the likelihood of vision being affected, but it does not always require immediate treatment; if your vision is still very good, your doctor may recommend observation instead of immediate injections [16][17].

By identifying exactly which stage you are in and whether DME is present, your care team can tailor a treatment plan designed to protect your sight before it changes [1].

Common questions in this guide

What are the stages of diabetic retinopathy?
Diabetic retinopathy is first classified as non-proliferative disease, which can be mild, moderate, or severe. The most advanced stage is proliferative diabetic retinopathy, when fragile new blood vessels grow. The two eyes can be in different stages.
Can diabetic macular edema happen if retinopathy is mild?
Yes. Diabetic macular edema can occur during mild or moderate non-proliferative retinopathy as well as more advanced disease. It happens when damaged retinal blood vessels leak fluid into the macula, which can cause blurred or distorted central vision.
What does center-involving diabetic macular edema mean?
It means swelling or leaked fluid has reached the fovea, the center of the macula used for sharp vision. Center involvement makes vision more likely to be affected, but a person with very good vision may sometimes be monitored instead of receiving injections right away.
What do IRMA and venous beading mean?
They are warning signs of severe non-proliferative diabetic retinopathy. IRMA refers to abnormal small retinal vessels, while venous beading makes veins look like a string of beads; both reflect reduced blood flow and are linked with a higher risk of progressing to proliferative disease.
Why can each eye have a different diabetic retinopathy stage?
Diabetic retinopathy does not always progress at the same rate in both eyes. Your eye-care clinician should assess and record the stage of each eye separately, along with whether diabetic macular edema is present.
How often should I be screened for diabetic retinopathy?
The appropriate interval depends on the stage in each eye, whether diabetic macular edema is present, and your overall eye findings. Ask your eye-care clinician for a personalized schedule so progression can be detected before it affects vision.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.What specific stage—mild, moderate, or severe—is each of my eyes currently in?
  2. 2.Do I have any signs of IRMA or venous beading, and how do these affect my risk of moving to the proliferative stage?
  3. 3.Do I have macular edema, and if so, is it 'center-involving'?
  4. 4.Given my current stage, how frequently should I be screened to catch any progression before it affects my vision?
  5. 5.If I have center-involving DME but my vision is still 20/20, do we need to start treatment now or can we monitor it closely?

Questions For You

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References

References (17)
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    Evidence-based Danish guidelines for screening of diabetic retinopathy.

    Grauslund J, Andersen N, Andresen J, et al.

    Acta ophthalmologica 2018; (96(8)):763-769 doi:10.1111/aos.13936.

    PMID: 30311394
  2. 2

    Clinical Course and Risk Factors of Diabetic Retinopathy in Patients with Type 2 Diabetes Mellitus in Korea.

    Yun JS, Lim TS, Cha SA, et al.

    Diabetes & metabolism journal 2016; (40(6)):482-493 doi:10.4093/dmj.2016.40.6.482.

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    Current and Emerging Pharmacologic Therapies for Diabetic Retinopathy.

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    Pharmacotherapy 2026; (46(3)):e70119 doi:10.1002/phar.70119.

    PMID: 41693076
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    Laser Treatment Modalities for Diabetic Retinopathy.

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    Cureus 2022; (14(10)):e30024 doi:10.7759/cureus.30024.

    PMID: 36348830
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    Comparing diabetic retinopathy lesions in scanning laser ophthalmoscopy and colour fundus photography.

    Nghiem AZ, Nderitu P, Lukic M, et al.

    Acta ophthalmologica 2019; (97(8)):e1035-e1040 doi:10.1111/aos.14106.

    PMID: 31286663
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    Venous beading in two or more quadrants might not be a sensitive grading criterion for severe nonproliferative diabetic retinopathy.

    Chen L, Zhang X, Wen F

    Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie 2018; (256(6)):1059-1065 doi:10.1007/s00417-018-3971-3.

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    The United Kingdom Diabetic Retinopathy Electronic Medical Record Users Group: Report 3: Baseline Retinopathy and Clinical Features Predict Progression of Diabetic Retinopathy.

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    American journal of ophthalmology 2017; (180()):64-71 doi:10.1016/j.ajo.2017.05.020.

    PMID: 28572062
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    Diabetic Retinopathy: An Overview of Treatments.

    Mounirou BAM, Adam ND, Yakoura AKH, et al.

    Indian journal of endocrinology and metabolism 2022; (26(2)):111-118 doi:10.4103/ijem.ijem_480_21.

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    A Deep Learning Segmentation Model for Detection of Active Proliferative Diabetic Retinopathy.

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    Ophthalmology and therapy 2025; (14(5)):1053-1063 doi:10.1007/s40123-025-01127-w.

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    Epidemiology of Treated Diabetes Ocular Complications in France 2008-2018-The LANDSCAPE French Nationwide Study.

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    Pharmaceutics 2022; (14(11)) doi:10.3390/pharmaceutics14112330.

    PMID: 36365148
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    Multimodal imaging in diabetic retinopathy and macular edema: An update about biomarkers.

    Parravano M, Cennamo G, Di Antonio L, et al.

    Survey of ophthalmology 2024; (69(6)):893-904 doi:10.1016/j.survophthal.2024.06.006.

    PMID: 38942124
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    [OPTICAL COHERENCE TOMOGRAPHY CHARACTERISTICS OF DIABETIC MACULAR OEDEMA].

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    Characterization of central-involved diabetic macular edema using OCT and OCTA.

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    Optical Coherence Tomography-Based Prevalence of Diabetic Macular Edema and its Associated Risk Factors in Urban South India: A Population-Based Study.

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    Comparison of Prevalence of Diabetic Macular Edema Based on Monocular Fundus Photography vs Optical Coherence Tomography.

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This page explains diabetic retinopathy stages and diabetic macular edema for informational purposes only and does not constitute medical advice. Your eye-care clinician can interpret your findings and recommend appropriate screening or treatment.

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