Eye Floaters: When They’re a Medical Emergency

For which symptoms should you not wait for a routine appointment?

Flashes of light, a large number of black dots/a shower of soot, and a curtain-like shadow in your vision are alarm signals that something is wrong with the retina. In these cases, an emergency visit to an ophthalmologist is indicated — on Sundays or public holidays, this means going to the ophthalmological emergency service.

Who is particularly at risk: do nearsightedness, previous eye surgery, or a family history play a role?

Yes, there are patients with a higher risk of vitreous detachment and retinal detachment. These include people who are nearsighted. In these individuals, the vitreous tends to shrink earlier and the retina is usually thinner, meaning that when the vitreous detaches it can cause retinal holes or tears and a retinal detachment. Patients who have undergone eye surgery, patients with a positive family history, and patients who have experienced trauma to the eye — for example, from a tennis ball or a champagne cork — are also at higher risk.

Prevention, Diagnosis, and Treatment: What Really Helps

Is there anything you can do yourself to prevent retinal detachment?

Absolutely. I discuss the increased risk with nearsighted patients and recommend regular retinal check-ups, as well as after surgery on the eye — even at a young age following refractive procedures. I also think it is important to exercise a certain level of caution during sports, when opening corked bottles, and when doing DIY work.

If the first symptoms of a vitreous detachment or retinal defect appear, it makes sense not to wait. Unfortunately, many patients still come to the practice too late, and the retina has already detached.

What exactly do you examine when someone comes to you with spots that have appeared suddenly in their visual field?

In general, I always examine the entire eye — as well as the fellow eye — using a slit lamp, which is a specialized microscope. This is followed by funduscopy, meaning an examination of the fundus of the eye using a lens with the pupil dilated by drops. This allows the entire retina, including the peripheral areas, to be visualized.

A wide-field photograph of the retina and a Spectralis OCT (optical coherence tomography) of the central retina are also very helpful. The vitreous and retina are examined for signs of detachment. In the vitreous, these may include flecks or "flies" or what is known as a Martegiani ring; in the retina, they may include bleeding, holes, or even a detachment of the retina.

Laser treatments are offered for bothersome floaters, but there are also reports of risks. How do you assess these procedures, and what alternatives are available?

Laser vitreolysis for vitreous floaters can be a worthwhile option. What matters is the nature of the floater — whether it is clearly defined or more of a streaky change across the various levels of the vitreous — and the degree of distress it causes the patient. If they have found the floaters very limiting and disruptive for more than six months, then laser treatment may be appropriate.

In phakic patients — that is, patients who have not yet had cataract surgery — the laser can damage the lens to the point where it becomes cloudy. In addition, multiple laser sessions are usually required. I always conduct a risk-benefit analysis with my patients.

If the distress is extreme and the floaters are very dense and central and have persisted over a long period of time, a vitrectomy — that is, the surgical removal of the vitreous — can be discussed after the most careful risk-benefit analysis. There are also dietary supplements containing micronutrients that are intended to prevent further clumping of the collagen fibers and restore the balance within the vitreous.