How YAG laser vitreolysis can be used in practice for treatment of floaters

Inder Paul Singh, MD, shares his surgical pearls for how advances in YAG laser vitreolysis can make the procedure a safe, effective option for the treatment of floaters.

Take-home: Inder Paul Singh, MD, shares his surgical pearls for how advances in YAG laser vitreolysis can make the procedure a safe, effective option for the treatment of floaters.

By Inder Paul Singh, MD, Special to Ophthalmology Times

Until recently, patients suffering from bothersome floaters had only one of two options: learn to tolerate them, or undergo vitrectomy.

Given that the latter option can be a highly invasive procedure often associated with complications-including infection, macular edema, and retinal detachment-many ophthalmologists, understandably, reserve vitrectomy for only the most severe and distressing cases.¹

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In contrast, vitreolysis-which involves the use of a specially designed YAG laser to vaporize the vitreous strands and opacities-has shown to be highly effective in providing functional improvement with a low complication rate.²

In a study by Cees van der Windt, MD, and colleagues, 100 eyes with posterior vitreous detachment-related floaters persisting for more than 9 months were treated with vitreolysis (n = 65) or pars plana vitrectomy (n = 35). Findings showed that both the YAG and vitrectomy groups reported an improvement in vision at 80% and 90%, respectively.

Additionally, over the 8-year follow-up period, no complications occurred among patients in the vitreolysis treatment arm. Moreover, data from two studies carried out in 1990, demonstrated a near-100% rate of floater removal with vitreolysis. No intra- or postoperative complications occurred in any patient.^{3, 4}

Although vitreolysis is a much safer procedure than vitrectomy, medical schools generally do not teach it. Also, because of some problems associated with traditional YAG lasers, some ophthalmologists may be a little reluctant to offer the procedure to their patients. Though initially a little skeptical about vitreolysis, after incorporating multimodality YAG laser technology (Ultra Q Reflex, Ellex Medical Lasers) into daily practice, I have revised my opinion.

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Surgical pearls for adding vitreolysis into daily practice

For surgeons considering offering vitreolysis, be aware that a learning curve is involved. For example, when I began performing vitreolysis, I hit the lens in two patients; one of these patients required cataract surgery. Consequently, I recommend starting with cases that involve a solitary floater in the middle of the vitreous-i.e., not close to the lens or to the retina-at least until a good degree of comfort with the procedure has been attained.

The floater should also be visible preoperatively when viewed through the slit lamp because it is difficult to start chasing floaters once the patient is positioned at the laser.

Surgeons should also be aware that high-energy levels may be required-e.g., 4.0 to 5.0 mJ-and they should not be afraid of this.

It is also important to understand that a high number of laser shots will likely be required-from a few hundred and potentially up to 900 or even 1,000. If only a low number of shots are used, for example, 200, the procedure may not work. This will depend on the density, size, number, and location of the vitreous opacity.

Some surgeons may be fearful to offer upward of 500 shots in case they cause a retinal detachment or tear, and this is perhaps one of the reasons behind the perception that vitreolysis is not effective. In my experience, it is safe to offer more shots than may be thought to be required.

Additionally, I typically select patients who have had a posterior vitreous detachment. Since the vitreous has detached from the retina, the stimulus for a retinal detachment is decreased.

My final piece of advice would be to build realistic patient expectations. For example, if a patient has a particularly dense floater, he or she may need to be informed that it may take multiple sessions to resolve the issue.

Evolving technology + video

Evolving technology

Traditional YAG lasers typically have larger and less-controlled plasma with more inconsistent power output. Since it can be difficult to focus on small structures, such as vitreous strands, collateral ocular tissue damage may occur.

In contrast, the multimodality YAG laser features an ultra-Gaussian beam mode, teamed with a fast-pulse rise time and a small-spot size meaning with a higher-power density and tightly controlled plasma, fewer shots are required to perform procedures with less cumulative energy delivered to the patient.

In this video interview, Inder Paul Singh, MD, shares his pearls for success with vitreolysis. Drawing on his experience with the multimodality YAG laser, Dr. Singh addresses a number of topics ranging from patient selection to treatment protocol, including recommended laser lenses and energy settings.

Furthermore, the new laser platform incorporates a proprietary slit lamp illumination tower design, which converges the operator’s vision, the target illumination, and the treatment beam along the same optical path and onto the same optical plane. The patent-pending illumination mirror-which briefly moves out of the laser pathway during firing-ensures that the laser beam is coaxial for anterior, mid, and posterior vitreous treatment applications and is never obstructed. The illumination tower can be used coaxially to enhance the view of the target opacity and more effectively vaporize it.

In contrast, traditional YAG lasers have illumination delivered from a low, non-coaxial position making it extremely difficult to target the vast array of vitreous opacities in more posterior vitreous locations.

These features are vital when working in the vitreous, as they minimize the potential for focusing errors and reduce the risk of damage to the natural lens or the retina. There is no risk of under- or overdosing the energy due to poor positioning of the illumination tower, while the precision of the two-point aiming system and the wide-offset range ensure accurate positioning of the optical breakdown, thus further protecting surrounding tissue from accidental damage.⁵

Another important benefit of the laser system is its multimodality. Optimized for both posterior and anterior YAG laser treatment, the platform allows surgeons to perform capsulotomies with new-generation IOLs, peripheral iridotomies for glaucoma, and treat vitreous strands-all with one instrument. Not as much energy is used when performing iridotomies and simple capsulotomies. This, in turn, reduces the incidence of side effects, such as lens pitting, retinal thickening, increased IOP, or collateral damage to surrounding structures.

Quality-of-life benefits

Having now performed more than 200 vitreolysis procedures with the laser, the effect on patients’ quality of life is remarkable-on par with such procedures as cataract surgery and refractive surgery. Some patients tend not to divulge symptoms unless asked, since they have often been told there is nothing that can be done to resolve floaters. However, there are very few procedures that have such great benefits with so few risks.

Findings from a retrospective, observational study undertaken at my practice which included 168 eyes of n = 124 patients (mean age, 66 years [range, 42 to 89 years]) who underwent YAG vitreolysis with the laser (power range 2.0 to 5.5 mJ) demonstrated 92% of patients were satisfied with the procedure. There was one case of IOP spike, and two phakic lenses were damaged, one of which required cataract surgery. No retinal detachment or other retinal complications were seen and there was no anterior chamber or vitreous reaction.

References

References

1. Sendrowski DP, Bronstein MA. Current treatment for vitreous floaters. Optometry. 2010;81:157-161.

2. Fankhauser F, Kwasniewska S, van der Zypen E. Vitreolysis with the Q-switched laser. Arch Ophthalmol. 1985;103:1166-1171.

3. Tsai WF, Chen YC, Su CY. Treatment of vitreous floaters with neodymium YAG laser. Br J Ophthalmol. 1993;77:485-488.

4. Toczolowski J, Katski W. Use of Nd:YAG laser in treatment of vitreous floaters. Klinika Oczna. 1998;100:155–157.

5. Ultra Q Reflex. http://www.ellex.com/products/treatment/photodisruption-parent/ultra-q-reflex/overview/ Last accessed March 5, 2014.

Inder Paul Singh, MD, is in private practice at The Eye Centers of Racine & Kenosha in Wisconsin. Dr. Singh serves on the speakers’ bureau with Ellex. Readers may contact Dr. Singh at ipsingh@amazingeye.com.