Why are some patients less able to adapt to floaters and report persistent symptoms?
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Personality factors are key
Floaters are common and do not cause any issue for the vast majority of people. However, a small subset of patients, often young male patients, can be greatly burdened by them, despite their vitreous and retina looking essentially normal.
In a study at Manchester Royal Eye Hospital, we explored the personality traits of 156 patients who had had vitreous floaters for at least 3 months and sought consultation for treatment. We used the Big Five Inventory (BFI) tool, assessing five personality factors: neuroticism, extraversion, agreeableness, conscientiousness and openness. In addition, we assessed symptoms of depression and anxiety using the Patient Health Questionnaire-9 and the Generalized Anxiety Disorder-7 questionnaire.
The BFI tool was previously used in a sample of 400,000 individuals to assess the psychological makeup of the U.K. population. We used this data as a comparator and found that there was a significantly higher score in the domain of neuroticism, 3.27 in our group vs 2.97 in the general population, as well as a reduced score in the domain of extraversion, 2.97 vs 3.24. These results were not surprising as people with greater neuroticism traits tend to ruminate on their symptoms and may become more obsessive as well as more introverted in their outlook and less able to adapt. Many of the patients I have seen and operated on were greatly burdened with floaters, could not consciously ignore them and had been obsessively ruminating on them for years. Rarely, they could express suicidal ideation solely because of floaters, despite 20/20 vision in both eyes. Following surgical vitrectomy, having been fully informed of the attendant risks, their psychological stress was largely resolved.
As far as the depression and anxiety scores, they were significantly higher in our study population as compared with the normative database in the U.K.
Our paper gives a nice snapshot of the typical psychological profile of this subgroup of patients. When they come for treatment, we must be aware that because of their personality traits, and associated depression and anxiety, if an adverse event occurred as a consequence of surgery, the impact could be greater than in the general population. Nevertheless, vitrectomy for floaters is usually a straightforward procedure and gives these patients a real chance of resolving their symptoms. Limited vitrectomy is controversial because of the risk of later posterior vitreous detachment, which then reestablishes the floaters.
- Reference:
- Senra H, et al. Graefes Arch Clin Exp Ophthalmol. 2024;doi:10.1007/s00417-024-06477-y.
- For more information:
- Niall Patton, MBChB, MD, FRCOphth, of Manchester Royal Eye Hospital, United Kingdom, can be reached at niall.patton@mft.nhs.uk.
Location of floaters matters
There are objective reasons why some patients are deeply and persistently affected by symptoms of floaters.
Location is one of the key factors. As demonstrated in a study by Harmer and co-authors, a floater that is close to the retina produces a greater shadowing effect as compared with a floater located farther away; it can also be more visible to the patient than to the observer because the forward scattering intensity is up to 1 million times greater than the backscattering. If I see a tiny floater close to the retina, I know that this is likely to be extremely bothersome, and I am not surprised if the patient reports debilitating symptoms. I tell this to my patients because it is important for them to have an explanation and be reassured that they are not imagining things, that there is a physical cause for what they are experiencing and that they will not be dismissed just as complainers. This helps them psychologically much more than one can imagine. I explain to them that if you are sitting on the top of the Eiffel Tower, you can hardly see someone who is down on the ground, but you see big and clear those who are standing next to you. In the same way, a tiny floater that moves close to the retina, within the macula, is perceived much larger and clearer than if it is farther away.
People with highly symptomatic floaters are often young because the vitreous is still close to the retina. As we grow older, the vitreous gets more liquid and moves away from the retina. Therefore, these young people eventually will become less symptomatic and maybe stop being bothered by floaters, but this can take up to 30 or 40 years.
Pupil size is another physical factor that comes into play. As shown mathematically in the Harmer study, constricted pupils produce a greater effect, while a larger, more dilated pupil reduces the shadow cast by floaters on the retina. Therefore, the first treatment I offer to young patients is atropine. By keeping the pupil slightly dilated in bright light — outdoors but also when doing screen work or working in bright white lighting conditions — the symptoms are often attenuated. In a study we did some years ago in about 40 patients, this treatment alone worked well in about one-third of cases. The following step is laser vitreolysis. In 2009, I taught myself the technique with the help of the book Laser Treatment of Eye Floaters by John Karickhoff. In 2012, I also did a fellowship with Scott Geller, MD, the inventor of floater laser technology. In the 15 years since, I have gained wide experience with it. This allows me to safely treat most floaters unless they are too close to the retina or lens. If a young patient looks down and then straight and the floater comes from below to the center and then falls down, out of sight, then I can often treat it (in reality, the movement and location of the floater is opposite of what the patient sees). I use the Swiss-made Lasag-Meridian Microruptor II laser, which has excellent optics that allow you to be more precise and not hit the retina. It has an aperture that is about 3.5 times the size of that of the Ellex laser and therefore gives you a much broader view. I do about 1,000 laser treatments for floaters per year, and about 10% are young people. Results are rewarding although not all floaters can be treated. But the complication rate is much lower compared with pars plana vitrectomy (PPV) surgery. If laser is not possible or has not enough effect, PPV can be considered as a backup procedure.
- Reference:
- Harmer SW, et al. Bioelectromagnetics. 2022;doi:10.1002/bem.22386.
- For more information:
- Feike Gerbrandy, MD, of OMC Amstelland, Diemen, The Netherlands, can be reached at info@floaterlaser.nl.
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