Non-Invasive Laser Treatment for Floaters
For patient who experience floaters, YAG Laser Vitreolysis (vitreolysis) is a highly effective, outpatient-based procedure, which involves the use of a nano-pulsed YAG laser to vaporize vitreous strands and opacities. Highly effective, it has a low complication rate and offers a high degree of patient satisfaction. It can also delay or obviate the need for surgery.
What is Degenerative Vitreous Syndrome?
The vitreous is a clear gel-like substance, comprising mainly of fluid and a small amount of collagen, that fills most of the interior of the eye. It is located behind the lens and is attached to the surface of retina (light sensitive tissue) by means of fine fibres. Vitreous helps to maintain the shape of our eyes; it acts as a shock absorber; it allows the transmission of light from the external environment to the retina.
In early life, the vitreous is clear and transparent. With progressing age however, the vitreous shrinks, pulling the intertwining collagen fibres from the retina. The fibres may break, detaching the vitreous from the retina. It is these fibers, which cast shadows on the retina and appear as spots, strings, or cobwebs that are commonly referred to as “floaters.”
Most cases of vitreous detachment do not affect vision and require no treatment. Posterior vitreous detachment is the commonest type of vitreous detachment.
What is YAG Vitreolysis?
YAG vitreolysis is a non-invasive, pain-free laser procedure that can eliminate or greatly reduce the visual disturbance caused by floaters. The main aim of YAG vitreolysis is to achieve a functional improvement for patients so they can return to routine activities without the symptoms caused by shadows cast on the retina. .
What Type of Patient is Best Suited to Vitreolysis?
Vitreolysis is well suited to the Weiss-ring type of floater caused by a PVD. Because these floaters are fibrous, they absorb the laser energy well and can be vaporized more efficiently. In addition, they are usually located safely away from the crystalline lens and the retina.
However to ensure suitability for YAG vitreolysis treatment, it is necessary to undergo an ophthalmic examination.
How is YAG Vitreolysis performed?
Using a specialised contact lens, the YAG laser is focused onto the front surface of the floater. The laser emits a short 3 nanosecond (0.000000003 seconds) burst of energy. It is important to note that the laser energy does not simply break the floater into smaller pieces. Instead, the high power density of this laser energy converts the collagen and hyaluronin molecules to a gas, which is then resorbed into the eye. The procedure is performed in clinic as an out-patient. THe treatment usually lasts between 20-30 minutes. It is not uncommon to require up to 3 courses of treatments over the course of 4 to 6 weeks.
What is the evidence of success?
The use of vitreolysis dates back to the eighties when Professor Aron Rosa, Paris, France, and Professor Franz Fankhauser, Berne, Switzerland, who were pioneers in the use of YAG lasers, published on their success with vitreolysis. Since then, clinical studies have shown vitreolysis to be an effective treatment approach, which offers a high degree of patient satisfaction. Despite these advantages, vitreolysis is generally not widely available.
This is due, in part, to the belief that floaters are benign and do not require treatment. Indeed, many ophthalmologists consider floater treatment to be unnecessary. Furthermore, the technical constraints of conventional YAG laser technology, which offer a limited view of the vitreous, can make it difficult to visualize the vitreous strands and opacities and to perform the procedure. These conventional YAG lasers also require the use of high levels of energy, which poses a significant risk of damage to surrounding ocular tissue, as well as of side effects such as cataract and intraocular pressure (IOP) spike. As a result, vitreolysis has not been widely practiced and is performed only by a small number of specialists.
Unlike vitrectomy, which carries a small risk of bleeding and infection, vitreolysis is a non-invasive, pain-free procedure that can eliminate the visual disturbance caused by floaters. John Karickhoff, MD, USA has performed the procedure more than 1,400 times and reports a success rate of 90%. In a recent Dutch study by Cees van der Windt, MD, and colleagues, 100 eyes with PVD-related floaters persisting for more than nine months were treated with vitreolysis (n=65) or pars plana vitrectomy (n=35). After all eyes were treated, both the YAG and vitrectomy groups reported an improvement in vision at 80% and 90% respectively. Furthermore, over a follow-up period of eight years, no complications were observed among patients treated with vitreolysis.
Complications and side effects
Clinical studies have shown vitreolysis to be a safe, effective treatment in the majority of patients with reported side effects and complications being rare. Side effects may include cataract and intraocular pressure (IOP) spike.
In the small percentage of patients who fail to respond to treatment, then surgical vitrectomy may be necessary to alleviate the symptoms of floaters. This type of surgery is very effective but more invasive and has its own risks which are rare but include bleeding, retinal detachment, infection and cataract.
- 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