Steffen Hamann, PhD, FEBO, FRCOphth, on optic disc drusen diagnostic overlap and imaging advances

At the 2nd International Glaucoma Symposium held on 31 January 2026 in Mainz, Germany, Steffen Hamann, PhD, FEBO, FRCOphth, presented on optic disc drusen (ODD) in the context of glaucoma—offering a look into the future directions for research while providing an overview of the diagnostic overlap and advances in imaging.

Hamann, a professor at Copenhagen University Hospital–Rigshospitalet in Glostrup, Denmark, spoke with Ophthalmology Times Europe about this topic, during which he noted that ODD clinically resembles glaucoma and true optic disc edema, sharing features like a slowly progressive course, similar prevalence, retinal nerve fiber layer thinning, and glaucoma-like visual field defects—making differential diagnosis a key component of care.

Although, unlike glaucoma, ODD currently has no effective treatment. The key clinical challenge is that ODD can mimic swollen discs, glaucomatous nerve fiber bundle defects, and even ischemic or vein-occlusion–like presentations, so recognizing it prevents misdiagnosis and unnecessary work-up.

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

Ophthalmology Times Europe: Could you summarize why it was so important to speak about drusen at the International Glaucoma Symposium?

Steffen Hamann, PhD, FEBO, FRCOphth: It's very nice to be invited to speak about drusen in a glaucoma symposium because it's kind of an odd man out, but in many ways, it's actually very well placed because optic disc drusen shares a lot of similarities with glaucoma. It's an optic neuropathy; it's slowly progressive; it has more or less the same prevalence; it has retinal nerve fiber layer reduction; and you have the visual field effects, which remind us very much of glaucoma. The major difference between the two conditions is that we don't have any treatment for optic disc drusen, whereas you have a lot of different treatment options for glaucoma.

So why is it important to talk about this in this session? It is because it allows you to kind of elucidate what's not causing the pathology in a given case. For example, if you have a swollen optic disc, this is not necessarily due to a true optic disc edema. It can be due to optic disc drusen. And also, if you have these characteristic nerve-fiber-bundle–like defects and visual field effects, these are not necessarily due to glaucoma—they can be due to optic disc drusen. Also, if you have, for example, an ischemic optic neuropathy or branch retinal vein occlusion, these don’t necessarily have to be caused by vascular conditions; they can be caused by drusen as well. From a clinical perspective, it's very timely to have some focus on the disc drusen, and it's very important to correlate what we know these days about the structure and the anatomy of the disc drusen with the function. And we've learned a lot about this in recent years, so I think it's very appropriate to transmit this knowledge to a glaucoma audience.

Ophthalmology Times Europe: What has the field learned in the past few years regarding optic disc drusen?

We've learned a lot in recent years. It's not the actual disc drusen that mimics the disc edema—it's the appearance of the optic nerve head in the case of disc drusen that mimics the appearance of the true disc edema. And the anatomical reason for this is something that we call PHOMS, which is an abbreviation of peripapillary hyper-reflective ovoid mass-like structure—it's a very long name, that's why we got this shorter name, PHOMS. But this is in common with the 2, and so you cannot use the PHOMS to separate them, but you can use a lot of things that are associated with the PHOMS.

First of all, you do the classical fundoscopy, where you look at the optic disc margin to see if the small vessels disappear, etc, and then you do the OCT not only the pericapillary, so-called circle scan, where we measure the retinal nerve fibrillary thickness, but you also do a dense optic nerve head scan with the enhanced depth imaging enabled, where you can kind of scroll through the optic nerve head and you can get a lot of information, both on the on the PHOMS and the associated findings. If you do this combination with the fundoscopy and the OCT imaging, using a systematic protocol, I think you can get a lot of valuable information that allows you to separate true disc edema from pseudo disc edema.

Ophthalmology Times Europe: How has OCT imaging changed in that time? Have there been drastic improvements to its application?

We have, since 2018, more or less—the past 5 to 10 years—really advanced in imaging using OCT because before you did only the ultrasound. Sometimes it's good with ultrasound because you can get a rapid readout, in a way, but you only capture the big drusen that are very calcified, and with the OCT, you can get all kinds of drusen—the big ones and the small ones and those that are less calcified, those that are superficial, and those that are deep. And, in addition, you can get quantitative information. about the damage that has been made to the efferent visual pathway, and you can correlate that with the functional deficits using the visual fields.

OCT has really advanced our understanding, and currently, we are at a stage where we are developing and refining artificial intelligence algorithms to, first of all, separate pseudo-papilledema from papilledema, but also to understand the functional consequences of having drusen, which ultimately will help us in prognostication in the future.

I think it's very important that OCT starts to be integrated into everyday practice. It is already in our family practices worldwide, but my impression is that it's more or less the standard peripillary scan and the macula scan that's used. The enhanced depth-limiting scan, where you do the systematic scrolling through the optic method, takes us a few minutes to do on each side, and it's a long time, especially in kids, where you have the importance of distinguishing between the true disc edema and the pseudo-edema, which is very difficult because here the PHOMS are much more pronounced when you get old than when you get older.

We have a gap, and it takes a little too long of a time. We need to be more time efficient, and that would be really, really nice if we could get down to something like less than a minute to perform the OCT.

Ophthalmology Times Europe: Where does the field need to go from here? What directions should future research look in?

Future work needs to look very much at OCT angiography, as well, because here we can look at the blood flow, and again, we can get more of a functional dimension in not only the structure—which you get from the OCT—but also the function. We will look more at genetics and look at how to identify people at risk. We want to refine our artificial intelligence algorithms for detection and prognostications.

We also want to develop tools for tracing, and ultimately, that's the major goal: to get to a stage where we can safely treat optic disc drusen because right now, we don't really have anything to treat with.

REFERENCE

1. Hamann S. Optic disc drusen – current clinical perspective. Presented at: 2nd International Glaucoma Symposium; 31 January 2026; Mainz, Germany