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Wednesday / May 22.
HomemicontactBloody Floaters

Bloody Floaters

Professor Nathan Efron’s personal journey of retinopexy, cryopexy, vitrectomy and IOL surgery. Uncomfortable – and occasionally socially awkward – vision problems persist, despite successful laser surgery.

So here is another double entendre for you. Do I mean ‘floaters containing blood’ or ‘damned annoying floaters’? Actually, I mean both. A few months had passed since my last round of laser surgery, and my retinas seemed firmly attached with no more ‘ink in the sky’ events or other visual disturbances … with the exception of bloody floaters!

So exactly what are floaters composed of? I guess this can vary considerably from person to person. In older people who have otherwise healthy eyes, floaters are generally pieces of collagen, pigment cells or other intracellular debris that become more mobile as the vitreous softens and degenerates. Just about everyone has noticed floaters at some point in their lives, but these are typically innocuous.

The floaters I experienced formed as a result of my retinal tears and subsequent bleeding into the eye (i.e. ink in the sky). Although much of that blood would have been reabsorbed, it seems that some blood remnants and other components of the extravascular fluid that entered my eye became trapped in a disorganised and degenerating, partly attached vitreous, leading to a form of floaters that were actually quite profound and annoying. In discussing my floaters over the next few months with fellow eye care practitioners, it seemed that despite my complaints of visual degradation, most were ready to dismiss my floaters as a temporary nuisance that I should adapt to and that would, in any case, dissipate over time.

… despite my complaints of visual degradation, most were ready to dismiss my floaters as a temporary nuisance that… would, in any case, dissipate over time

In fact, neither was the case. For a number of reasons, I would consider the visual impact of my floaters to extend far beyond just being ‘annoying’. They really were visually debilitating. In view of the pivotal role that these floaters were about to play in decisions I would soon be forced to make in relation to my ocular welfare, I will spend some time explaining the true impact of the floaters I was experiencing and why I considered these to be significantly impairing my vision.

Types of Visual Compromise

There were basically two forms of visual interference I experienced with floaters. First, there was the ‘classical’ floater, which I really only noticed when looking at a blank or featureless field, such as the sky when taking a walk along the beach or the ceiling of my bedroom just after waking in the morning. Sometimes I would see discrete small black dots or lines that would move slowly on a random direction, but quickly change or reverse direction if I executed a quick eye saccade. I would also see what seemed like small pieces of a very fine white veil. Although sometimes annoying, these floaters were merely of curiosity value and did not significantly compromise my vision per se.

Second, and more insidious, was the very frequent occurrence of a general degradation of vision, presumably caused by large, diffuse floaters that got between my macula and pupil. Here is a classic example of what would happen: I would be attending a lecture in a large auditorium, looking alternately at the lecturer and projected information on a large screen. I would all of a sudden realise that things were not clear, execute a quick sideways saccade, then voilà – all would be clear again. The same would happen when working on my computer. I would cross a threshold in time when I would suddenly realise that it was too difficult to see the text, and again, a quick saccade solved the problem.

The difficulty with the occasional saccade strategy is that a saccade would literally need to be performed at intervals ranging from about 10 to 60 seconds, depending on the visual task, and vision would be degraded for much of the inter-saccade interval. As you might image, this makes for an uncomfortable visual experience.

I have tried to simulate the nature of this visual debilitation in the attached pair of identical images. On the left is a clear scene of the view I have on one of my much-enjoyed beach walks. On the right is a simulation of the beach scene as it would appear being obscured by floaters. It is sort of like a defocus effect, or maybe a diffuse degradation akin to looking through a finely ground glass panel. General forms can be easily seen, but contrast is diminished and details are obscured. Very frustrating.

Floaters and Monovision

But, you ask, we have two eyes, so if a large floater obscures the macula in one eye, wouldn’t this be compensated by clear vision in the other eye, such that you would not notice anything averse with both eyes open? Well, this is largely true, especially if you only have floaters in one eye. With floaters in both eyes, visual degradation would only occur if both maculas were obscured at the same time. So the extent of visual compromise depends very much on the severity of the floaters and whether the floaters are in one eye or both.

But my situation was different. I have been a contact lens wearer for over three decades, and have dealt with presbyopia using a monovision correction, whereby one eye is corrected for distance and the other for near. The intrinsic visual compromise inherent in such an optical approach, floaters aside, has never been a problem for me (although I am aware it is a problem for some). However, monovision compounds the potential for visual compromise for those with floaters, because floater-impaired vision in one eye can not be offset by good vision in the other eye. For example, when I am watching a lecture with my distance-vision-corrected left eye – if a large floater gets in the way in that eye – vision is degraded and is not compensated by my near-vision-corrected right eye, which is already blurred for distance. The same problem occurs for near vision. So, monovision exacerbates the visual degradation caused by floaters.

“So dispense with monovision and revert to alternative forms of ophthalmic correction” I hear you shout. Well, that’s easy to say, but I love my monovision correction! Anything else for me would represent considerable compromises of other sorts. None of the other options, such as putting on reading glasses over distance vision contact lenses, wearing bifocal contact lenses, or ceasing contact lens wear in favour of varifocals or separate distance and reading spectacles, are especially appealing to me. I found this all rather depressing, really.

A Social Inconvenience

Another seldom mentioned drawback of floaters is debilitating veiling glare, caused by intraocular backscatter of light. I found this to be a particular problem at social gatherings. I often found it extremely difficult to identify any facial features of a person standing against a bright background, and would suffer the embarrassment of being castigated for apparently failing to acknowledge or recognise a friend or colleague who was so obscured. Even engaging in conversation would be difficult, as I could not see lips move or facial expressions. After a while, I found myself deliberately manoeuvring around and positioning myself with bright fields behind me wherever possible to try to avoid this problem. It might sound trivial, but I noticed this time and time again. Very frustrating.

The Big Decision

Every time I encountered these difficulties, I harkened back to Bill’s suggestion that these floaters could be dealt with via a bilateral vitrectomy. This would certainly be a radical approach. There are many benefits and drawbacks of proceeding in this way, and I will deal with these in my next blog. However, as summer approached and I started more beach walks in bright sunny weather, these floaters began to really annoy me… and I had just been to a conference where I found myself sitting in the front row so that I could read the text on the screen.

Basically, I’d had enough. At a routine examination with Bill in December, I told him I wanted to proceed with the ‘V option’. After a detailed discussion (the essence of which I will again relate in some detail in my next blog) we booked a surgical slot for the following March, in part because I was about to go to France for a lecturing engagement in February, and wanted that out of the way before proceeding. That visit to France was to have a profound effect on what would happen next.

Professor Nathan Efron is a researcher at the Institute of Health and Biomedical Innovation and School of Optometry and Vision Science, Queensland University of Technology. He is currently President of the Australian College of Optometry and is the only person to have served as President of both the British Contact Lens Association and the Cornea and Contact Lens Society of Australia.