If you are young and suffer from annoying, dark, moving shadows in your vision, please read this section carefully. It contains important information about the prognosis for treatment and safety issues that are common to the younger age group that loosely describe as younger than 30 years of age. After reading this page, I also suggest you read the Frequently Asked Question about Floaters in Young People.
Most of the patients we successfully treat here at Vitreous Floater Solutions are over the age of 45 and have suffered some of the ravages of the aging process to include the breakdown of the vitreous fluid. In some ways it is like the generalized breakdown of collagen elsewhere (sagging skin and wrinkles). With aging, structural changes will occur: The vitreous will thicken and dehydrate and get cloudy in some areas, and liquify in other areas.
Younger people rarely experience these diffuse, generalized changes in the vitreous. Our examination in younger patients more often reveals overall very healthy eyes and overall quite clear vitreous fluid. The floaters in younger people tend to be microscopic, dense, and most important, they are almost always within 0.5-3.0 millimeters from the retina. They are very difficult to see, and sometimes they are below the optical resolution of our ability to see them despite the most diligent and motivated efforts!
This graph approximates the distribution of patients who have come in for evaluation in our office. This is a self-selected population and not meant to represent the distribution of eye floaters in the general population. The majority of patients seen by us are over 40 years of age (the blue curve above). Of the younger group of patients (red curve) we can safely and successfully treat only about 10-20%.
The below illustration set is a nice example of some of the difficulty and challenge of treating younger patients. A 26 year old male had seen at least two eye doctors. There was conflicting conclusions as one doctor told the patient he had had a “partial” posterior vitreous detachment and the other said nothing specific. On my exam, I initial saw nothing of any significance in either eye. Upon very close scrutiny, I found this small, dense vitreous condensation approximately 0.5mm from the retina. With appropriate magnification we can see a fine vertical strand that tethers the floater in place which correlates quite nicely with the patient’s drawing. There is much more that the patient is seeing that I am unable to see despite the most motivated effort on my part. For explainable reasons, the patient will ALWAYS see more than the doctor. This patient was not treatable as the laser can not safely treat this close to the retina. This is an all to common scenario for those under the age of 30-35.
Younger patients bothered by moving shadows in their vision often describe very distinct, hard-edged, lines and dots that move around much like vitreous floaters. We have nick-named some of them “crystal worms” because of their refractile, and glass-like appearance. They tend to be seen in the central vision region. For the patient population that visit our office, we find these moving shadows occur mostly in young men in their twenties through early thirties. They are still described occasionally in the third decade and very rarely occur in the 40 and older population.
Here are some actual pictures some of our patients have drawn in their effort to describe them to us:
These “moving shadows” were ultimately either barely visible, invisible to the doctor, or otherwise not good candidates for treatment. Note how they are very accurately drawn with very distinct shapes, lines and balls or knobs. These also tend to be seen well even when the pupil is dilated whereas floaters in the mid-position of the eye nearly disappear when the pupil is dilated (in dim light naturally, or when dilating drops are administered).
Regardless of your age, type or location of vitreous densities, you do not actually “see” the floater. You see the SHADOW that is cast onto the retina. The closer the object is to the retina, the most defined and distinct the shadow will be.
As in the case of most younger people with floater symptoms and in all of the illustrations above, the shadows are very defined and distinct. We can infer that the source of the shadows lie closer to the retina rather than closer to the lens and cornea. In fact no object near the lens or cornea (or even in the middle part of the eye) can cast a distinct well-defined shadow.
“Small, thin, well-defined moving shadows are almost always very close to the retina. If they are too close to the retina they cannot be safely treated.“
So on examination we expect to find something very close to the retina. Finding these floaters can be very challenging. Dr. Johnson has described it as “as looking for a strand of fiberglass, in a pool, at night, with a flashlight”. If we are lucky, with a narrow beam of light we may get lucky and see a slight reflection of light on something small. Very often, with young people we simply cannot see anything. Anywhere. The vitreous will be crystal clear.
Here is a rarely photographed microscopic vitreous density sitting right on the surface of the retina. It is only seen with great magnification and narrow slit beam retro-illumination. Most doctors would not find this floater with a typical examination. Dr. Johnson spent about 15 minutes looking in this area before getting the illumination and angle just right. This floater was unfortunately not treatable.How is it the patient can see the shadow so clearly and the doctor can’t see the source? People can see shadows as small as a red blood cell. For the doctor to see it, he has to shine a light into the eye and reflect light off this microscopic, low contrast, semi-translucent object. The reflected light must pass back through the patient’s vitreous fluid > the lens > the aqueous fluid > the cornea > a thick, diagnostic contact lens > several lens elements of the microscope > 2 mirrors > a few more lens elements > the doctor’s cornea > aqueous > lens > vitreous > and finally be imaged by the doctor’s retina. There are many layers of optical degradation in this process. If your doctor can’t see your floater, they may not be trying hard enough, or they simply may not be able to!
Regardless of how much these distinct shadows may bother the patient, there are safety issues that may prevent treatment. The use of the YAG laser is an adaption of an already available and FDA approved laser. It is an adaption to focus the laser and apply the energy to the vitreous chamber instead of near the front of the eye when treating post-cataract surgery issues. The laser can only be adapted so far, and treating too close to the retina is not safe. Here and elsewhere on this web site we have tried to give general guidelines to help determine if someone might be eligible for treatment. We have described how floater may appear differently to the patient depending on how close or far it may be from the retina. Ultimately, it is very difficult to determine without examining it here in person.
We have not found it very helpful to depend on another doctor’s assessment and evaluation of the floaters. Your local doctor may confidently see some vitreous condensation in the middle (and treatable) part of the vitreous. What they may not be able to assess is whether or not what THEY see is the same as what YOU are seeing. We recently had a young man in his mid-twenties who was reassured by his very well qualified local eye surgeons that they could see his floaters and they were in a very treatable area in the middle of his vitreous. This young man flew several thousand miles at no small expense with high expectations for treatment success. Dr. Johnson saw what this patient’s doctor’s had seen, but Dr. Johnson also found a small cluster of vitreous condensations approximately 0.5mm away from the retina. It was Dr. Johnson’s final assessment that the mild vitreous condensations that the other doctors saw were not responsible for his symptoms. Ultimately he was not considered a candidate for treatment. It was a major disappointment for this young man and another humbling realization that the laser can not treat all floaters.
Over the last 4 years, we have become less aggressive and in fact somewhat pessimistic when communicating with younger patients. We will highlight it here:
“If you are under the age of 35 or so, your chances of a successful treatment of your floater-like symptoms using the laser are greatly diminished. Adjust your expectations appropriately.”
There are a few occasional exceptions and so we do not refuse appointments for evaluation and consultation from younger patients.Whether it is worth it for you to travel to see Dr. Johnson (or one of the few other doctors proficient with the later procedure) is a question we can not answer for you. It depends on the distance you must travel and whether it will be of some value to definitively know where your floaters are located and whether or not you are a candidate for treatment with the YAG laser and to take that chance that you may be of the smaller percentage of young patients that are indeed treatable.
Read more here: FAQ’s for Young People with Floaters