Eye Floaters

By Phornrak Sriphon, Board Certified ophthalmologist

Introduction

Many people may have had the unpleasant experience of staring at a bright sky or a plain white wall and noticing dark shadows floating in their vision, resembling spider webs, thin lines or black dots floating freely, unable to determine the direction. Sometimes it can feel annoying or worrying that there is a serious problem with the eyes.

This condition is medically known as Vitreous Floaters or Degenerative Vitreous Syndrome, which in some cases can develop into a condition called Vision Degrading Myodesopsia (VDM). Today, we will take a deeper look at Vitreous Floaters in this article.

Laying the foundation in the easiest way to understand: Knowing the internal structure of the eyeball

Before we understand how “cobwebs” in the eye, or Vitreous Floaters, occur, we must first learn about the “various spaces inside the eye.” Because those clear floaters that bother us often occur in an area called the Vitreous Chamber .

1.1 The eyes have three main chambers (Ocular Chambers).

Imagine an eye as a clear sphere, divided into three main parts:

1. Anterior Chamber

• It is the space between the cornea and the iris.

• It contains a clear fluid called aqueous humor , which lubricates the cornea and lens and helps maintain intraocular pressure.

2. Posterior Chamber

• Located between the iris and the lens of the eye.

• It is the area where aqueous humor fluid is produced from the ciliary body and flows into the anterior chamber of the eye.

3. Vitreous Chamber

• It is the largest space in the eye, located behind the lens to the retina.

• It is filled with vitreous gel, a clear, jelly-like gel composed primarily of water (over 98%), mixed with collagen and hyaluronic acid.

Vitreous gel

It is a transparent, colorless, gel-like structure that fills the vitreous cavity of the eye, accounting for approximately 80% of the total volume of the eyeball. The main functions of the vitreous are to provide structural support to maintain the spherical shape of the eyeball and, most importantly, to act as a completely transparent medium so that light can travel from the eye's lens to the retina without obstruction.

The vitreous gel is not a simple liquid, but a hydrogel with a highly ordered and complex structure. The main component is 98-99% water, while the remaining 1-2% is made up of a complex network of structural proteins, most commonly collagen fibrils and hyaluronic acid (HA).

The relationship between collagen and HA is crucial to the properties of the vitreous gel. Collagen fibers act as an orderly scaffold, while HA molecules are inserted and interwoven within this collagen network.

It also attracts and retains water molecules, which pushes each collagen fiber apart and distributes it evenly. This mechanism is the main reason why the vitreous gel has the highest level of transparency.

The retina is a thin layer of neural tissue lining the innermost part of the eyeball. In embryology, the retina is considered a protrusion of the brain and is therefore part of the central nervous system. The retina's function is similar to that of a camera film: it receives light and converts it into an electrical signal, which is then transmitted through the optic nerve to the brain, where it is interpreted as the image we see.

The macula is a small, crucial area in the center of the retina that is responsible for the sharpest, most detailed vision, such as reading, driving, recognizing faces, and seeing color. At the center of the macula is a tiny pit called the fovea, which is densely packed with cone photoreceptors and is the only part of the retina capable of providing 20/20 visual acuity.

The junction between the vitreous and retina

The vitreous gel does not float freely, but rather has significant attachments to the retina and other structures at various points. The strength of these attachments varies.

Strongest attachment: The vitreous base is a 4-6 mm wide band of attachment at the outermost edge of the retina. This attachment is particularly strong and often remains permanent, even during vitreous detachment. Weaker attachments: Other areas where the vitreous attaches to posterior structures include the edge of the optic nerve head, the fovea at the center of the macula, and along the main retinal blood vessels.

The Inevitable Change: Vitreous Degeneration

Vitreous Degeneration (Vitreous Degeneration) is a natural aging process that occurs in everyone. This process occurs slowly and gradually and may begin as early as childhood. There is evidence from ultrasound examinations that the vitreous fluid has been detected as early as age 4, and by the age of 80, more than half of the vitreous has liquefied.

Vitreous degeneration is comprised of two main processes that occur simultaneously and interrelatedly:

• Liquefaction (or Synchysis): The breakdown of the vitreous gel structure into a more watery fluid. This process occurs when hyaluronic acid molecules separate from the collagen network, allowing the trapped water molecules to release and pool into pools of fluid (lacunae) within the vitreous gel.

• Collapse and Clumping (or Syneresis): As the gel becomes more fluid, the collagen fiber network loses its buoyancy and uniform distribution, causing the fibers to collapse and clump together into visible clumps or cloudy deposits, which are the physical origins of the “cobwebs” or floating black dots.

These two phenomena are not independent, but rather a chain of biomechanical failures. Starting with molecular changes as the bonds between hyaluronic acid and collagen weaken, leading to water release and synchysis, then the unsupported collagen network collapses and forms agglomerates (syneresis), and finally the overall volume of the gel-like compartment decreases, causing the entire vitreous mass to contract and prepare to separate from the retina. This sequence of events provides a clear and logical explanation for how vitreous degeneration occurs.

These fibers form a network within the vitreous fluid and are attached to the surface of the retina. Over time, the vitreous fluid shrinks, causing these fibers to pull on the surface of the retina. Often, these fibers break off, allowing the vitreous fluid to continue to detach and shrink.

The Origin of Cobwebs: Shadows on the Retina

As mentioned, the clumps of collagen (the medical term is myodesopsia) are not directly visible to the patient, but rather are turbid deposits that float within the liquefied vitreous cavity. As light enters the eye, these deposits block light and cast shadows on the retina. The brain interprets these moving shadows as dots, lines, or spider webs.

The visible form of a cobweb can take many forms, including dots, circles, lines, clouds, or the well-known "spider's web." Its unique movement, in which it follows the eye movement but is slightly slower and then floats on its own, is the origin of the English name "floaters."

Weiss Ring

Weiss rings are a special type of cobweb that is of great diagnostic importance. Patients often see them as a fairly distinct circle, oval, or C-shaped appearance.

The origin of the Weiss ring is very specific. It is a remnant of connective tissue and collagen that used to be a peripapillary adhesion between the vitreous and the optic nerve head. When this adhesion is broken during PVD, the ring-shaped tissue floats anteriorly into the vitreous cavity. The appearance of the Weiss ring is clear clinical evidence that vitreous detachment has occurred and that the process has progressed to the point where the vitreous has separated from the optic nerve head.

"Imagine the vitreous gel in our eyes as clear jelly or raw egg white in our eyeball. When we were kids or teenagers, this jelly was crystal clear. But as we get older, it starts to deteriorate, becoming partly watery and having tiny sediments that clump together... that's the 'cobwebs' that we see."

Deep Dive into Causes and Symptoms

The main causes of vitreous degeneration: The major risk factors that promote PVD and its more severe complications include:- Age: This is the most important risk factor. The risk increases significantly after the age of 50.

-Myopia: This is a very significant contributing factor. People with very high myopia (i.e. greater than 400 or -4.00 diopters) are at significantly higher risk than the general population. The reason behind this increased risk is due to a combination of two mechanisms. First, a person’s eyeball in a person with myopia has a greater axial length than normal. This requires the same amount of retinal tissue to cover a larger surface area. As a result, the retina becomes thinner, more fragile, and more susceptible to tears. Second, syneresis tends to occur at a younger age in people with myopia. The combination of earlier onset of PVD and a structurally weaker retina creates a greatly increased risk for a tear.

-History of eye injury or eye surgery: A severe blow to the eye or surgery inside the eye (most commonly cataract surgery) can disrupt the structure of the vitreous humor, causing it to deteriorate more quickly and triggering PVD.

- Associated medical conditions: Conditions such as diabetes (especially diabetic retinopathy with neovascularization, which involves abnormal blood vessel growth) and inflammation inside the eye (uveitis) can change the condition of the vitreous gel and the junction between it and the retina, increasing the risk.

-Personal and family history: Having PVD in one eye greatly increases the chance that the other eye will have it, usually within 6 months to 2 years. A personal or family history of retinal detachment is also a significant risk factor.

Myopic Vitreopathy is a disorder of the vitreous humor that occurs in people with myopia, particularly those with severe or severe myopia. The vitreous humor changes in structure, such as the vitreous fibers becoming more lumpy or cloudy, causing floaters to form in the eye and resulting in reduced vision. This disorder is often associated with posterior vitreous detachment (PVD), and is one reason why people with myopia experience more frequent floaters than the general population.

In summary, Myopic Vitreopathy is a change in the vitreous humor in people with myopia that causes floaters and affects the quality of vision.

Axial myopia is associated with progressive vitreous changes and a significant decrease in visual contrast sensitivity, which may be a common cause of visual complaints and impact on quality of life in myopic patients, and in some cases, vitrectomy may restore eye function.

symptom

• Floaters vs. Flashers (Black Spot vs. Flash):

• Floaters (black spots/cobwebs): Describe the appearance the patient experiences (dots, lines, rings, spider webs).

• Flashers (Flashing Lights): This is an important point that I want everyone to listen to carefully!

• Explains the mechanism: "When the vitreous gel in the eye contracts, it pulls on the retina, which is like the photographic film in our eyes. This pulling stimulates the photoreceptors, causing the brain to interpret that there is a 'flash' or 'lightning' in the eye, even though there is no actual light."

• Emphasis: Seeing flashes of light is a sign that needs to be given more attention.

Vision Degrading Myodesopsia (VDM)

Vision Degrading Myodesopsia (VDM) is a condition in which deposits in the vitreous humor are not just internal structures of the vitreous humor, but rather an illusion that the brain perceives when it sees them. This condition results in significant visual disturbances, particularly a decrease in contrast sensitivity, which results in less sharp images. People with VDM often have more visual disturbances than people with simple vitreous deposits, and these symptoms have a significant impact on their quality of life and daily activities.

The word myodesopsia comes from the Greek word for “floating eyes” or “floating tears,” and is a term commonly used by ophthalmologists to describe the appearance of floating spots or clear lines in the vision.

Diagnosis of VDM requires a thorough assessment of both vitreous structure and visual function testing to distinguish patients with mild symptoms who can be monitored from those who require appropriate treatment, such as vitreous shunt surgery.

3 warning signs that you need to see a doctor immediately

This section will be presented with clarity and emphasis on utmost urgency. These symptoms are signs that warrant a thorough dilated pupil examination by an ophthalmologist as soon as possible (within 24 hours).

1. The sudden increase in the number of new cobwebs, similar to a "meteor shower": a rapid and profuse increase in the number of tiny black dots, often described as looking like a "swarm of flies", "pepper powder", or "smoky smoke".

2. New or significantly increased flashes: Although flashes are an expected symptom in common PVD, a sudden, persistent, or severe increase in the frequency or brightness of flashes is a particularly important warning sign.

3. Shadows or Curtains: The appearance of a dark, gray, or curtain-like shadow that permanently obscures part of one's vision. It usually begins at the periphery of vision and may spread to the central part of vision.

Explain the reason: "Why rush? Because this could be a sign of a retinal tear or detachment, which if not treated within 24-72 hours can lead to permanent vision loss."

Understanding what each warning sign indicates about the physical events occurring inside the eye is crucial for enhancing patient knowledge and safety.

• Flash (indicating TRACTION): This is the force acting on the vitreous body that is actively pulling on the retina, which is the condition prior to a tear. A change in the flash indicates a change in the traction force.

• Cobwebs that grow like a meteor shower (indicating a tear and/or hemorrhage): This is a breakthrough. The pulling force is strong enough to tear the retina. The tear may also rupture the capillaries on the retina, causing a vitreous hemorrhage. Or it may dislodge pigment cells from the retinal pigment epithelium (RPE) layer beneath the retina. The "meteor shower" you see is actually hundreds of red blood cells or pigment cells floating in the vitreous.

• Shadow or Curtain (indicating detachment): This is the end result. Liquid vitreous fluid has leaked through the tear and is eroding the retina from the back wall of the eye, much like wallpaper peeling off a damp wall. The detached portion of the retina is no longer functional and is unable to send signals to the brain, resulting in a corresponding blind spot or "curtain" in the field of vision.

Diagnosis and treatment

What will you find when you visit a doctor?:

• It is important to emphasize that the only way to accurately diagnose the underlying cause of recurrent flashes and cobwebs is with a detailed dilated fundus examination by an eye specialist.

• The examination begins with the use of eye drops to dilate the pupil. This allows the doctor to use special lenses and light sources (such as a slit lamp and an indirect ophthalmoscope) to obtain clear, three-dimensional, wide-angle images of the entire retina, including the outermost edge, where tears are most common.

• In some cases, special imaging tools may be used to aid in diagnosis, such as an optical coherence tomography (OCT) scan, which provides high-resolution cross-sectional images of the retina and is very useful in assessing the macular area, or an ultrasound scan, which is invaluable if the retina is not clearly visible due to severe cataract opacity or extensive vitreous hemorrhage.

Treatment Method: From “Watchful Eye” to “Latest Technology”

• Approach 1: Observe and adapt (Conservative Approach)

• For 95% of cases, it is harmless.

• Explains that our brains are very clever. They gradually learn to "ignore" (neuro-adaptation) and some of the sediment may float out of our line of sight on its own.

Recommendations for follow-up appointments

• If no tear or bleeding is detected: A repeat dilation and scleral depression examination is necessary in 2 to 4 weeks. If no retinal detachment is detected at that examination, a repeat dilation examination is performed at 3 and 6 months from the date of first symptom onset.

• If no tear is found but slight bleeding is found: If no tear is found but there is slight bleeding in the vitreous or small bleeding spots at the edge of the retina, dilation of the pupils is required at week 1, week 2-4, month 3, and month 6 from the date of onset of symptoms.

• In cases where no tear is found but there is excessive bleeding or abnormal cells: In cases where no tear is found

• If there is a retinal tear but there is a large amount of bleeding into the vitreous or there are pigment cells in the anterior vitreous, a retinal specialist should perform a thorough examination the next day immediately because there is a high risk of a subsequent retinal tear.

• Approach 2: Although most patients are able to adjust or become accustomed to their symptoms on their own, some may experience improvement once the floaters are moved out of their line of vision. However, some people find that their floaters are affecting their quality of life to the point where they cannot be tolerated and seek treatment.

There are currently two main treatment options.

Pars plana vitrectomy)Vitrectomy :

Latest research: Micro-incision Vitrectomy technique is said to speed healing and reduce risks compared to previous times.

Principle: "It's like changing the water in a fish tank. We will suck out the old vitreous gel that has sediment and replace it with a special saline solution that is safe for the eyes."

Suitable for: Cases with a large number of floaters that severely obstruct vision and cannot be treated with laser.

Pros/Cons: Almost 100% removal of floaters / Surgical, higher risk than laser (e.g. cataract, retinal detachment, infection)

YAG laser vitreolysis

YAG Laser Vitreolysis (Laser Vitreolysis):

Latest research: Referring to studies showing higher efficacy and safety in newer lasers, they can break up the deposits into smaller pieces or even evaporate them.

Who is it suitable for: Large deposits that are quite far from the lens and retina (e.g. Weiss ring)

Pros/Cons: No surgery, Fast/May need multiple treatments, Not effective on all types of sediment

Future Outlook:

Eye Drops: Talking about the research "Low concentration Atropine eye drops" that slightly dilate the pupils, causing less shadow from the Floater to hit the retina, making it less annoying (but not eliminating the Floater).

Pharmacologic Vitreolysis Injection: Discussing the concept of developing an injection drug to directly break up the bonds of the sediment, which is still in the research phase and is a hope for the future.

• In 2002, Delaney et al. used the YAG laser to treat 38 patients with vitreous detachment. The results showed that 38% of the patients had moderate or greater improvement in their self-reported symptoms. Of these, 11 patients were dissatisfied with the YAG laser treatment and subsequently underwent vitrectomy.

• In 2017, Shah et al. [7] conducted the first randomized controlled trial comparing YAG laser treatment with sham laser for intravitreal glaucoma. The results showed that 53% of patients in the true laser group experienced significant self-reported improvement in their symptoms, while no significant improvement was seen in the sham group. There were no important differences in side effects between the two groups.

• Lin et al., 2023 Summary: This study was a retrospective study of patients with PVD-induced VDM who underwent YAG laser treatment at He Eye Specialist Hospital during 2019–2020. A total of 221 patients were included. The median follow-up period was approximately 21 months. After laser treatment, 57% of patients had a significant improvement in VDM (≥50%). No retinal complications such as tearing or detachment were found.

  The factor significantly affecting symptom improvement was age — older age had a higher tendency for improvement (OR = 1.049, 95% CI = 1.007–1.092, P = 0.021).

  The limitations of this study are that it was a retrospective, single-center study, was non-randomized, and did not use OCT to assess the retina, and did not measure the quality of vision in detail.

• Zhou et al. (2024) aimed to compare the efficacy and safety between immediate and delayed YAG laser treatment. This is the first double‑blind trial comparing immediate versus delayed YAG laser treatment in patients with floaters lasting less than 1 month.

Laser Summary

-Short-term results from several studies have found that YAG laser can reduce the appearance of eye floaters by approximately 53-77%.

-And in the long term, following up for more than 2 years, the treatment results are still around 50%.

- Approximately one-third of patients do not achieve significant benefit after YAG laser treatment, with “cloudy” and “lamelliform” lesions having a lower response rate than other patterns.

- Patients with severe myopia or hyperopia (high myopia) often have a large number of floating spots that are scattered, making it difficult to treat with YAG laser, which has a relatively low response rate. Therefore, in this group, vitrectomy may be more appropriate.

-Older adults tend to respond better to YAG laser treatment due to reduced contrast sensitivity, which makes them more tolerant of bleb spots.

-There are reports of minor complications from YAG laser such as localized cataract, open glaucoma, and retinal hemorrhage, but these were not found in this study.

-Although there is no clear randomized controlled trial comparing YAG laser with vitrectomy, vitrectomy has a higher success rate but a higher risk of complications, such as increased cataracts, glaucoma, and macular edema.

The Future of Eyelid Floatation Treatment

In recent years, several new research and technologies have gained attention as “superior” alternatives to traditional lasers, such as the YAG laser, which is the current treatment method.

1. New Generation Lasers: Picosecond and Femtosecond Lasers

Dr. Sebag, an eye specialist, commented that:

"Picosecond and femtosecond lasers may offer greater efficacy than the YAG laser, particularly if the laser energy can be precisely targeted using 3D imaging as a guiding system."

The key differences are:

• The YAG laser acts to “cut” or disrupt the cloud spots.

• While new high-powered lasers may be able to directly ablate the collagen that causes floaters,

These lasers may be used alone or in conjunction with a YAG laser to increase precision and reduce side effects.

2. Vitreolysis injection: Pharmacologic Vitreolysis

Another approach that has gained attention is the use of drugs to break up collagen in the vitreous humor, which is the cause of floaters.

"The use of medication may help 'dissolve' or separate aggregated collagen fibers, which are responsible for the shadows seen in vision and the reduction in contrast sensitivity."

This idea is not new, but in the past there were no effective and safe enough drugs. However, there are continuous developments and it is interesting to see if the right drug formula can be found, it may become a non-surgical approach.

Dr. Sebak added:

"Now that we’ve become familiar with intravitreal anti-VEGF injections for treating retinal diseases, the idea of injecting medication to dissolve the vitreous is no longer far-fetched — we just need a drug specifically designed for this purpose."

3. Nanobubble Therapy: New Hope from Nano Technology

At Ghent University in Belgium, nanobubble technology has been developed using nanoparticles that are designed to bind to specific collagen groups in the vitreous humor. When injected into the vitreous humor:

• Use a low-power laser to shoot without precise aiming.

• The nanoparticles absorb energy and release it as nanobubbles that specifically destroy the cloudiness in the vitreous humor.

"The laser energy required is up to 1,000 times lower than that used in YAG laser treatment, which may offer greater long-term safety."

This technology is in vitro and animal studies (e.g., rabbits) and has shown promising results.

4. Optical Compensation

Although still in the conceptual stage, adjusting the "light" could be an interesting approach, without touching the vitreous humor.

"If we can gain a deeper understanding of the physics of light refraction within the vitreous, it may be possible to design a ‘light-canceling device’ that alleviates symptoms of VDM without the need for surgery or medication."

Such technology could come in the form of special glasses or optical interface devices that address the light scattering effects seen by VDM patients.

Conclusion

It is rare to encounter an unmet medical need as clearly defined as that of patients with floaters. If we simply open our minds and listen to our patients, we will come to understand that what they are experiencing has a real impact on their quality of life — and that understanding can lead to the development of safer and more effective diagnostic and treatment approaches.

Reference

Lin, T.-Z., Shi, C., Yang, X., Pazo, E.E., Hui, Y.-N., & Shen, L.-J. (2023). Long-term efficacy and safety of YAG laser vitreolysis for vision degrading myodesopsia. International Journal of Ophthalmology, 16 (11), 1800–1805. https://doi.org/10.18240/ijo.2023.11.10

Bergstrom, R., & Czyz, C.N. (2022, December 23). Vitreous floaters . In StatPearls [Internet]. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK470420/

Zhou, H., Jin, Y., Zhou, Y., Zhao, G., Wu, H., & Chen, F. (2024). Efficacy and safety of early YAG laser vitreolysis for symptomatic vitreous floaters: The study protocol for a randomized clinical trial. Trials, 25 (1), 48. https://doi.org/10.1186/s13063-024-07924-1

Gui, W., Silverman, R.H., & Sebag, J. (2022). Etiology and diagnosis of vision degrading myodesopsia: Part 1 of a 3-part series on a vitreous pathology that can profoundly impact patients' lives. Retinal Physician , 19 (June), 30–33.

Nguyen JH, Nguyen-Cuu J, Mamou J, Routledge B, Yee KMP, Sebag J. Vitreous structure and visual function in myopic vitreopathy causing vision degrading myodesopsia. Am J Ophthalmol . 2021;224:246-253. doi:10.1016/j.ajo.2020.09.017

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