Citicoline has a legitimate history in eye research, most of it in glaucoma, where the proposed mechanism is neuroprotection of retinal ganglion cells. Diabetic retinopathy is a newer and separate line of work, and it rests on a reframing of the disease: retinopathy has historically been treated as a microvascular problem, but there is growing evidence that neurodegeneration of the retina begins early, potentially before visible vascular damage. That reframing is what opened the door to testing a neuroprotective compound. The research that followed is genuinely interesting. It also has one feature that almost never survives into supplement marketing, and it changes everything about how the results apply.
Nothing here constitutes medical advice. Citicoline has not been approved by the FDA to diagnose, treat, cure, or prevent diabetic retinopathy or any other condition. Diabetic eye disease is progressive and sight-threatening, and it requires ongoing management by an ophthalmologist alongside diabetes care.
Key Takeaways
- The diabetic retinopathy studies used citicoline eye drops combined with vitamin B12, applied three times daily, not oral citicoline capsules or powder [1][2].
- Because the drops also contained vitamin B12, the studies cannot separate citicoline’s contribution from B12’s [1][2].
- A 3-year randomized, double-masked pilot in 20 patients with type 1 diabetes and mild non-proliferative retinopathy found the placebo group deteriorated on retinal function and structure while the treated group did not [1].
- A companion 36-month analysis found macular electrophysiological responses increased in treated eyes and significantly decreased in placebo eyes [2].
- A 2025 observational report of reduced hard exudates involved only 4 patients, was not statistically analyzed, and its authors say it needs confirmation in larger prospective studies [3].
- No published trial has tested whether oral citicoline does anything for diabetic retinopathy.
The Route of Administration Is the Whole Story
This point is worth stating before anything else, because it determines whether the rest of the evidence is relevant to a supplement buyer at all. In both of the pilot studies, one eye of each patient in the treated group received citicoline and vitamin B12 eye drops, dosed as one drop three times daily, while one eye of each patient in a separate placebo group received drops containing hypromellose [1][2]. The 2025 observational report likewise used citicoline eye drops three times a day [3].
Topical delivery to the eye and oral delivery to the gut are not interchangeable. A drop places the compound directly onto ocular tissue. An oral capsule is absorbed, metabolized into choline and cytidine, distributed systemically, and then has to cross the blood-retinal barrier at whatever concentration survives that journey. There is no published work establishing that oral citicoline reproduces the retinal exposure achieved by drops, and the retinopathy studies were not designed to answer that question. So a study showing a benefit from drops is not evidence for a benefit from capsules, and treating it as such is the single most common error in how this literature gets summarized.
The second confound is compositional. The drops used in both pilot studies contained citicoline and vitamin B12 [1][2]. Vitamin B12 has its own neurological relevance. With no citicoline-only arm, the design cannot attribute the result to either ingredient individually.
What the Three-Year Pilot Found
The core study was a prospective, randomized, double-masked pilot in 20 patients with type 1 diabetes showing mild signs of non-proliferative diabetic retinopathy, split evenly into a treated group and a placebo group, followed for three years with frequency doubling technology perimetry, spectral domain OCT, OCT angiography, and adaptive optics imaging at baseline and at 12, 24, and 36 months [1].
The way the result is framed matters. The placebo group showed significant deterioration: reduced 10-2 FDT mean sensitivity, increased inner nuclear layer thickness, decreased outer plexiform layer thickness, and decreased foveal vessel density. The treated group showed no such significant changes. The authors’ conclusion was that the treated patients achieved stabilization or a decreased rate of functional impairment, neuroretinal degeneration, and microvascular damage [1].
In other words, the finding is mostly about the treated eyes not getting worse over three years while the untreated eyes did. For a progressive disease, that is a meaningful kind of result, and arguably a more realistic goal than reversal. It is worth being precise about it rather than upgrading it to improvement.
The Electrophysiology Companion Study
A companion analysis of the same patient population followed macular function specifically, using multifocal electroretinogram recordings at baseline and 36 months. Eighteen eyes completed the study, ten placebo and eight treated [2].
Here the direction was more than stabilization. Response amplitude density increased significantly in the treated eyes across every ring measured, while in placebo eyes it decreased significantly over the same period. Aggregated across the central ten degrees, treated eyes went from about 21.6 to about 26.9 nV/degree squared, while placebo eyes fell from about 21.0 to about 16.2 [2]. The authors concluded that the treated patients achieved an improvement in macular bioelectrical responses while the placebo patients showed worsening macular function [2].
The important caveat is what was measured. Multifocal ERG is an electrophysiological measure of retinal cell response, not a measure of vision as the patient experiences it. An improvement in signal amplitude is a real biological finding and a reasonable early marker, but it is not the same as a demonstrated change in visual acuity, in progression to sight-threatening disease, or in anything a patient would notice. In eight treated eyes at one center, it is a promising signal awaiting a larger trial.
The 2025 Hard Exudate Report
A 2025 real-life prospective observational study in Croatia enrolled more than 100 patients with non-proliferative diabetic retinopathy from a screening program, prescribed citicoline eye drops, and followed them for a year or longer with color fundus photography. The reported finding is that in four patients with macular hard exudates, applying the drops three times daily for at least six months to a year resulted in reduction or complete disappearance of those exudates [3].
The authors are appropriately restrained about it, describing it as the first study to establish a clinically positive effect of citicoline eye drops on hard exudates while stating directly that the conclusions still need confirmation by statistical analysis of a larger sample and prospective studies with longer follow-up [3]. This is a four-patient observation inside a larger cohort, with no control group and no statistical testing. It is a hypothesis-generating detail, not a result to act on.
What This Evidence Base Does and Does Not Support
Taken together: the neurodegeneration-first model of early diabetic retinopathy is a serious research direction, citicoline plus B12 eye drops produced consistent signals across two analyses of the same 20-patient cohort over three years, and one uncontrolled observational report adds a small further hint. That is a legitimate case for larger, multicenter, longer trials of the eye drops.
It supports essentially nothing about oral citicoline supplements for diabetic eye disease. Every study here is small, from a limited number of centers, in type 1 diabetes with only mild non-proliferative changes, using a combination product delivered topically. There is no evidence that a capsule reproduces any of it. Anyone with diabetes should treat glycemic control, blood pressure management, and regular dilated eye exams as the interventions with actual outcome evidence behind them, and should raise any question about citicoline drops with an ophthalmologist, since the products used in these studies are prescription or pharmacy formulations in the countries where they were studied, not a supplement purchase.
Frequently Asked Questions
Does oral citicoline help diabetic retinopathy?
No published trial has tested oral citicoline for diabetic retinopathy. All of the diabetic retinopathy research described here used citicoline eye drops applied topically three times daily [1][2][3], and topical results do not transfer automatically to oral supplementation.
What did the three-year study actually find?
In 20 patients with type 1 diabetes and mild non-proliferative retinopathy, the placebo eyes showed significant deterioration in retinal function, structure, and foveal vessel density over three years, while the treated eyes did not, which the authors described as stabilization or a decreased rate of damage [1].
Why does it matter that the drops contained vitamin B12?
Because there was no citicoline-only arm, the studies cannot separate citicoline’s contribution from vitamin B12’s [1][2]. The result belongs to the combination product, not to citicoline specifically.
Did any study show vision actually improving?
The 36-month companion study found macular electrophysiological responses increased significantly in treated eyes and decreased in placebo eyes [2]. That is an electroretinogram signal measurement, not a measure of visual acuity or of patient-noticeable vision, and it involved eight treated eyes.
How strong is the hard exudate finding?
Weak on its own. It describes four patients within a larger observational cohort, with no control group and no statistical analysis, and the authors explicitly state it needs confirmation in larger prospective studies [3].
References
- Parravano M, Scarinci F, Parisi V, et al. Citicoline and Vitamin B12 Eye Drops in Type 1 Diabetes: Results of a 3-year Pilot Study Evaluating Morpho-Functional Retinal Changes. Adv Ther (2020). PMID 32180131
- Parisi V, Ziccardi L, Barbano L, et al. Citicoline and Vitamin B12 Eye Drops in Type 1 Diabetes: Results of a 36-Month Pilot Study Evaluating Macular Electrophysiological Changes. Adv Ther (2021). PMID 34091874
- Tomić M, Babić T, Bulum T, Ljubić S, Jukić T. Citicoline May Effectively Reduce Hard Exudates in Diabetic Retinopathy. Biomedicines (2025). PMID 41153644
These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease. This article is for informational purposes only and is not a substitute for professional medical advice. As an Amazon Associate we earn from qualifying purchases.
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease. Content is for informational purposes only and is not medical advice; consult a qualified healthcare provider before starting any supplement. As an Amazon Associate we earn from qualifying purchases.
