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Vitreolysis Laser Treatment of Floaters

This series of questions and answers will help you to understand the origin of floaters as well as the different types.

Young man having a headache while using smart phone
Kashif Qureshi.
Vitreolysis Laser Treatment of Floaters

What is Vitreolysis?

Also known as floater laser treatment, vitreolysis is a non-invasive, pain-free procedure that can eliminate the visual disturbance caused by floaters. The goal of vitreolysis is to achieve a “functional improvement”. That is, to allow you to return to “normal” day-to-day activities without the hindrance of floaters.

Kashif Qureshi
Kashif Qureshi
Ophthalmology – YAG Vitreolysis, YAG Capsulotomy, Macular Degeneration, Diabetic eye diseases, Cataract Surgery

Vitreolysis involves the application of nanosecond pulses of laser light to evaporate the vitreous opacities and to cut the vitreous strands. During this process, the floater’s collagen and hyaluronin molecules are converted into a gas. The end result is that the floater is removed and/or reduced to a size that no longer impedes vision.

Types of Floaters

Eye floaters are small pieces of debris that float in the eye’s vitreous humor. This debris casts shadows onto the retina (the light-sensitive tissue layer at the back of the eye). If you have eye floaters, it is these shadows that you see “floating” across your field of vision.

Vitreolysis Laser Treatment of Floaters

Fibrous Strand Floater

Most common in young people, this thin, dense floater can appear as multiple dots and/or string-like cobwebs and is a result of clumping of the collagen fibres of the vitreous. Depending on size, and where it is located, it may be treatable with vitreolysis.

Vitreolysis Laser Treatment of Floaters

Diffuse Floater

This cloud-like floater is caused by the natural aging process. Whilst this type of floater can sometimes be treated with vitreolysis, it often requires more overall treatment in order to obtain satisfactory results.

Vitreolysis Laser Treatment of Floaters

Weiss Ring Floater

The ring-shaped Weiss Ring floater is a large, fibrous floater that is usually located safely away from the crystalline lens and the retina. Because of this, it can be treated safely and effectively with vitreolysis.

FAQs

What happens during the procedure?

Vitreolysis is performed as an outpatient procedure; you do not have to stay overnight in a hospital. Immediately prior to treatment, you will have anaesthetic eye drops administered.

A contact lens will then be placed on your eye, with the laser light delivered through a specially designed microscope.

During your vitreolysis treatment, you will likely observe small, dark specks/shadows – signaling that the floaters are being evaporated into small gas bubbles. These gas bubbles quickly dissolve and resorb into the vitreous.

Once the treatment is complete, your ophthalmologist may treat your eyes with anti-inflammatory drops.

Each treatment session typically takes 20-60 minutes to perform and most patients will need to undergo two treatment sessions, sometimes three, in order to achieve a satisfactory result.

What can I expect after vitreolysis treatment?

You may observe small, dark specks in your lower field of vision immediately following treatment, which are gas bubbles and will quickly dissolve. It is also important to note that some patients may experience mild discomfort, redness or temporarily blurred vision directly following treatment.

What can I expect after Lens Replacement Surgery?

Adaptation (Neuro-adaptation)

When one eye is treated at a time, patients often report the following day that their vision in the treated eye is not quite as good as expected. This is often the case in those who were previously farsighted and can find that distance vision is blurred. This happens because the eye muscles which are trying to focus in the untreated eye, result in the implant being pushed forward making the patient short-sighted. For those previously shortsighted, distance vision is reported as very good, however near is initially a struggle and with adaptation improves. The brain eventually picks up the information that it needs and vision improves. With trifocal lenses, we emphasise preoperatively that it is only when BOTH eyes are treated that patients get the benefit from the lenses with no comparative reference points. The eyes see similarly and vision improves rapidly each day.

Visual side effects

Initially halos around headlights interfere with the ability to drive comfortably affects 10% of patients, but improves in all patients with time. With adaptation, the brain is able to suppress unwanted information and patients report noticing a reduction in the size of the halos over the next 6 to 12 weeks, eventually disappearing or being just a nuisance. A few patients take longer to adapt (12 to 18 months). In the worst case scenario the implant can be replaced at a cost with a monofocal lens, which will have the consequence of reducing the depth of focus and result in the need for glasses.

Dry eye

We check for dry eye before surgery and this is treated if found to be significant. Those with marked tear surface abnormalities are not suitable for multifocal lenses. The abnormal surface can affect the performance of the lenses and cause fluctuation in vision. This condition can be treated in advance and once better, patients can be considered for multifocal lenses. Dry eye after lens replacement surgery can occur as a result of a) no longer wearing glasses or contact lenses and being exposed to the elements or more commonly b) toxicity from the eye drops which are at a high concentration in order to penetrate and enter the eye. Preservatives in drops are also a contributory factor. Dry eye symptoms and effects do improve a few weeks after the course of eye drops has been completed.

Reading and intermediate vision

Trifocal lenses distribute light energy to three points of focus. The majority (60% or more is for distance and the remainder for intermediate and near. Also, some trifocals have more energy concentrated near the centre of the lens, as pupils typically constrict when one reads. However, in dim light, the pupils can dilate and thus affect reading performance, so reading menus in a dimly lit restaurant might be problematic. Using a light to illuminate the object should help. The ability to see at intermediate (computer monitors) can in some patients take time (6 to 12 weeks) and again this is to do with adaptation. The brain adapts and uses the information that is being transmitted from the retina.

What is Degenerative Vitreous Syndrome?

The vitreous humor is the clear, jelly-like substance in the main chamber of the eye, located between the lens and the retina.

At a young age, the vitreous is perfectly transparent. Over time as the eye ages, this vitreous humor can degenerate, losing its form and liquefying. Without the stable vitreous humor, the collagen fibers collapse and bind together to form clumps and knots. It is these fibers, which cast shadows on the retina and appear as spots, strings, or cobwebs that are commonly referred to as “eye floaters.”

In many cases as the eye ages further, the vitreous humor can peel away from the retina entirely. This is known as Posterior Vitreous Detachment (PVD). PVD is often associated with a sudden increase in the number of floaters.

Complications and side effects

Reported side effects and complications associated with vitreolysis are rare. Side effects may include cataract and intraocular pressure (IOP) spike.

Who will benefit from vitreolysis?

It is necessary to undergo an ophthalmic examination to determine your eligibility for vitreolysis treatment.

  • Age: In most cases, younger patients (<45) suffer from microscopic floaters located close to the retina (1-2 mm) and are not considered to be good candidates for vitreolysis treatment.
  • Onset of Symptoms: If your floater symptoms develop very quickly then they may be associated with PVD, which can be treated with vitreolysis.
  • Floater Characteristics: Large floaters with a soft border, situated away from the retina, are ideally suited to treatment with vitreolysis
What are the alternative procedures to Lens Replacement Surgery?

Laser vision correction

Laser eye surgery procedures include LASIK (Laser in situ Keratomileusis) or Transepithelial Photorefractive Keratectomy (PRK), work by changing the shape of the cornea and therefore do not involve a lens implant.

Phakic Intraocular Lenses

These are lens implants inserted into the eye without removal of the clear natural lens.

Both the above options are better for those under the age of 50, who still have clear lenses and good quality of vision with glasses or contact lenses. Both laser vision correction and Phakic intraocular lenses are able to reliably correct one point of focus and usually distance, which means those in their mid-forties might still need to wear reading glasses afterwards. There are options for extending depth of focus and providing the ability to read and include “Monovision” or “Blended Vision” and in the case of laser eye surgery “Supracor Lasik”.

Monovision

Monovision is a technique whereby the non-dominant eye is planned for near vision and the dominant eye for distance. This means both eyes do not see equally at distance and near, however with both eyes open a good depth of focus is achievable. This is not suitable for everyone and a contact lens trial using this scenario is advised prior to undergoing the procedure. Some may already be using this method with their contact lenses.

Supracor Lasik

This is a Lasik laser eye surgery procedure where the cornea is purposefully made to be multifocal. As there is a period of adjustment and adaptation, only the non-dominant eye is treated. More information on Supracor Lasik.

What if vitreolysis doesn’t work for me?

Clinical studies have shown vitreolysis to be a safe, effective treatment in the majority of patients. If floaters persist, however, your ophthalmologist may recommend a surgical vitrectomy.

Depending on your diagnosis, there are several forms of surgery available. Performed in the operating room, surgery involves removal of all or part of the vitreous humor and the accompanying floaters. This type of surgery is very effective but more invasive and has its own risks which are rare but include bleeding, infection and cataract.

Sources & References

Shah CP, Heier JS. YAG Laser Vitreolysis vs Sham YAG Vitreolysis for Symptomatic Vitreous FloatersA Randomized Clinical Trial. JAMA Ophthalmol. Published online July 20, 2017. doi:10.1001/jamaophthalmol.2017.2388