Prof. Dr. med. Wolf Lagrèze on OCT's use, limitations, and potential in diagnosis

OCT is a useful tool for ophthalmologists in differential diagnosis and disease progression monitoring, but it does have limitations. Although it can help in the identification of optic nerve diseases and measure swelling, it lacks specific biomarkers that could expand its use in neuro-ophthalmic diseases, making continued intentional collaboration between neurologists and ophthalmologists crucial. Additionally, when combined with artificial intelligence, OCT has shown promise for earlier disease detection, but specificity remains a key factor in avoiding false diagnoses.

Recently, Ophthalmology Times Europe spoke with Prof. Dr. med. Wolf Lagrèze to discuss the role of OCT in neuro-ophthalmology and neurological disorders. At the 2nd International Glaucoma Symposium held on 31 January 2026 in Mainz, Germany, Lagrèze presented on this very topic and thus shared his perspective on OCT’s applications in clinical care.

Below is a transcript of that conversation. It has been edited for clarity.

Ophthalmology Times Europe: How can OCT help clinicians differentiate non-glaucomatous optic neuropathies from glaucomatous damage in everyday practice?

Prof. Dr. med. Wolf Lagrèze: It can, but it is not an exclusive solution. I think, in general, OCT has to be regarded as 1 diagnostic tool, which is part of a spectrum that consists of endoscopy, fundus photography, perimetry, visual acuity, pupillary testing, history taking, etc. It can help with differential diadiagnosis,d it can help in judgment of disease progression, which is, of course, the mainstay in glaucoma.

The differential diagnosis between glaucomatous optic atrophy and optic atrophy caused by other diseases is not that difficult because the glaucomatous optic disc has a specific appearance. Honestly, you don't need an OCT for that. For the differential diagnosis, it is not necessary. So if you are an experienced examiner, you look at the fundus, you take the history, you do what you need to do, and you can clearly come up with a diagnosis without OCT.

Where it helps, for instance, if you have just seen the field and nothing else and you want to know, "Hey, can it be glaucoma, or can it be optic drusen?" It might be very helpful, especially in the enhanced depth mode, as you can look deep into the optic nerve head. All other optic nerve diseases usually go along with some kind of swelling, and of course, you can measure that with OCT, but you can also see it with your ophthalmoscope or the fundus image.

Ophthalmology Times Europe: Which OCT patterns or biomarkers are most useful for identifying optic nerve involvement in neurologic disease?

There is no specific fingerprint for the very common diseases, like Alzheimer or so. There's a lot of very interesting research going on—also including AI—but on a on an individual, single-patient basis, you cannot say, from an OCT, "Oh, it’s very likely multiple sclerosis or early Alzheimer's." That is impossible. However, it is super, super helpful to detect minor degrees of papilledema. That means this swelling is caused by increasing your cranial hypertension. There, it is very useful, but calling it a "fingerprint" or a "biomarker"—I’m very careful with that statement. Of course, we look at certain patterns. We look at the ratio between ganglion cell loss and axonal swelling. We look at which sectors are affected, stuff like that.

Ophthalmology Times Europe: What are the limitations of OCT and neural-ophthalmology, and how should clinicians avoid misinterpretation of findings?

The limitations are, for instance, it gives you a black and white image. Fundus photo or your ophthalmoscope gives you some color information. But on the other hand, OCT these days can also give you information on the microvasculature with OCT-A, of course—that is very interesting.

In the hands of a nonophthalmologist—that is, a neurologist—who has an OCT, you have to be very careful that you do not solely rely on certain parameters. For instance, in the context of MS diagnosis, last year, the McDonald Criteria for multiple sclerosis [diagnosis] have been revised, and now the optic nerve is like a fifth location within the central nervous systems for the proof of spatial dissemination of inflammation in the nervous system. There's the so-called "inter-eye difference" that has been established, which is like 4 microns in the nerve fiber layer and 6 microns in the ganglion cell layer complex. But if you take that perimeter in isolation, it is very dangerous that, for instance, a patient with multiple sclerosis, or optic neuritis, or whatever, can get a false positive or wrong diagnosis of multiple sclerosis if you don't know the refraction of the patient or the history about glaucoma or not glaucoma. I think it is very important for every neurologist to use that tool always in cooperation with an ophthalmologist who is aware of the entire differential diagnostic spectrum—whatever can affect the eye, that is very important. So that is a limitation, and one has to be very careful in several boards of scientists have now written reviews or statements to use that technology with caution.

Ophthalmology Times Europe: Looking ahead to the future, how do you see the role of OCT evolving in the diagnosis and monitoring of neurological disorders affecting the optic nerve?

There are eye diseases like glaucoma, optic disc drusen, or papilitis, but if you focus on neurology, then you look at more general autoimmune diseases—optic neuritis, MOGAD, NMOSD, brain pressure problems, and neurodegeneration—and I think that OCT is a super helpful tool, especially in conjunction with artificial intelligence. Over the last few years, we have really seen amazing potency and findings of AI and imaging of the back of the eye. Usually, they use fundus images, but if you add OCT to it, I think it will open an entirely new era. [It has] its limitations, but of course, AI is super powerful in in dealing with large data sets that nobody else can deal with on an individual basis, and that certainly might help to detect diseases early. However we use it, we have to be very cautious that we are specific. It can be very sensitive, but we need to be specific to protect patients from false diagnoses with severe consequences.

Ophthalmology Times Europe: Is there anything else that you'd like to add?

It is important for neurologists to partner up with a good ophthalmologist to interpret OCT findings in a more comprehensive way, [and] to avoid mistakes. I think that is very important. The other issue is the availability of OCT. Who has it? Who uses it? Maybe you want to place it in an emergency department if you want to judge intracranial pressure—all these things have to be discussed in the future. But I think it's a groundbreaking technology that has been around now for almost 30 years, and it gets better and better every year.

REFERNECE

Lagrèze W. Non-glaucomatous optic neuropathies – OCT in neuro-ophthalmology and neurological diseases. Presented at: 2nd International Glaucoma Symposium; 31 January 2026; Mainz, Germany.