Vitreous floaters are a common complaint among the adult population. Their most common cause is age-related posterior vitreous detachment. A posterior vitreous detachment is present in approximately 50% of patients by the age of 50 years and 65% of patients by the age of 65 years.1 Most patients complaining of floaters are advised to “learn to live with it.” We typically reassure and educate as we monitor symptomatology and clinical appearance over time while gravity eventually weighs on the floaters. Neuroadaptation often occurs, as our patients may begin to ignore them.

A diagnosis of floaters represents a wide spectrum of severity in both symptoms and clinical characteristics. For mild, asymptomatic floaters, the most appropriate management remains observation. For severe, diffuse, dense, symptomatic floaters, a vitrectomy is probably necessary. Between these 2 extremes lies the great majority of patients who present with a symptomatic Weiss ring or central symptomatic floaters from syneresis or consolidation.2

Opacities in the central vitreous and the outer shell of the vitreous cavity result in floaters and, in advanced cases, vision degrading myodesopsia. When floaters measurably impair vision, a diagnosis of vision degrading myodesopsia can be established based on objective, quantitative criteria.3 The psychological effects of stress and depression associated with vision degrading myodesopsia are well documented.4

Our goal in the management of symptomatic floaters is to achieve improvement in quality of vision and life with the least intervention and risk possible. Pars plana vitrectomy, a surgical intervention with removal of the vitreous gel, has a high success rate.5 Vitrectomy, however, is an invasive procedure with potential complications, such as retinal breaks and detachment, cataract, transient elevation of intraocular pressure (IOP), epimacular membrane, and postoperative infection. Treatment of a stable, symptomatic floater with laser vitreolysis is also a consideration. The procedure involves the use of a Nd:YAG laser to vaporize the opacities and sever vitreous strands. The laser energy evaporates the collagen and hyaluronin molecules to form a gas that is absorbed by the ocular tissues.6–8 The desired final result is that the floater is removed and no longer impedes vision. Laser floater treatment and pars plana vitrectomy are both available to help our patients toward this end.

In the following point-counterpoint article, 2 clinicians are asked to defend or oppose laser vitreolysis for symptomatic, stable floaters. Here, Dr Richa Garg argues for laser vitreolysis treatment for certain symptomatic patients. Dr Joseph Pizzimenti argues against YAG vitreolysis, claiming that the available evidence and studies do not support this treatment modality.

CASE INFORMATION

White male aged 62 years

Case history

  • Presented with a chief complaint of severe floater, left eye x 6 months

  • Floater is relatively stable without changes

  • It occasionally impairs driving and reading and “significantly affects my lifestyle.”

Other pertinent examination findings

  • Distance visual acuity

    • 20/20 right eye, 20/25 left eye

  • Pseudophakia, right eye/left eye

    • posterior vitreous detachment with Weiss ring left eye

  • No other existing anterior or posterior segment disease

POINT

By Dr Richa Garg

In many patients, vitreous floaters can affect daily tasks, such as reading, driving, computer work, and watching television. People older than 50 may develop a posterior vitreous detachment, resulting in complaints of significant floaters. Their prevalence in younger patients is likely increasing because of the evolving global pandemic of myopia. The use of YAG laser vitreolysis for the treatment of floaters has attracted significant attention. The technique offers a fast, relatively inexpensive, nonincisional therapeutic option for the treatment of vitreous floaters.6,7

Clinicians must take patients’ floater-related patient complaints seriously, even for a rather benign condition. We must properly document their concerns in the medical record. Examination of contrast sensitivity function is crucial in our routine floater assessment. Contrast sensitivity testing provides a functional evaluation of the impact of vitreous opacification on vision, going “beyond Snellen” to measure the eye’s ability to distinguish shades of gray, as reported by Sebag and others.3 One study found that patients with bothersome floaters had a 67% reduction in contrast sensitivity function when compared with age-matched controls.5

Sebag also advocates the use of quantitative ultrasound, which gives an index of the structure of the vitreous body.3,5 With contrast sensitivity function and quantitative ultrasound, clinicians are now able to determine vision degrading myodesopsia severity to help guide management. The examination should also include drawings by our patients and detailed descriptions to ensure that the floaters are constant and stable and not intermittent. A specific questionnaire is also a useful tool to incorporate when assessing who is a good candidate for treatment.9 The Vitreous Floaters Functional Questionnaire (VFFQ) was designed similar to the N.E.I. Visual Function Questionnaire (VFQ-25), but with questions that specifically query the impact of floaters on quality of life (VQOL).9

Macular optical coherence tomography (OCT) should be included in the preoperative assessment for our patients with floaters, to better visualize the vitreoretinal interface. Cases presented by Dr Paul Singh nicely demonstrated symptomatic amorphous type posterior vitreous floaters using a novel OCT application. This additional information enabled successful treatment using a YAG laser optimized for vitreolysis.8 Scanning laser ophthalmoscopy may also be useful in imaging the floaters. This growing body of evidence suggests that with proper technology and technique, laser vitreolysis may be safer and more effective than previously recognized.10

Proper patient selection can lead to the desired outcomes in YAG laser vitreolysis, whereas poor selection can result in less-than-optimal results. For example, patients with active anterior or posterior segment disease, retinal pathology, or inflammation, asteroid hyalosis or glaucoma are poor candidates for the procedure.6, Patients with phakic lenses, 360 degrees of lattice, those with multiple retinal conditions, and those with unrealistically high expectations should not be treated.7

Optimal candidates for YAG vitreolysis include those with stable, symptomatic floaters and those with a complete posterior vitreous detachment. Using the newest technology, the procedure has been shown to be safe and effective in treating symptomatic Weiss ring vitreous floaters.10,11 Importantly, the patient must have realistic expectations and no concurrent retinal or corneal disease.7

Shah and Heier recommend ensuring a safe distance between the focal point of the laser and the retina and the crystalline lens to minimize the risk of lens or retinal damage. In their study, they required the Weiss ring floater to be 5 mm posterior to the posterior capsule of the crystalline lens and 3 mm anterior of the retina, as measured by ultrasonography.6

In a study by van der Windt and colleagues, 100 eyes with posterior vitreous detachment–related floaters persisting for >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. In addition, over the 8-year follow-up period, no complications occurred among patients in the vitreolysis treatment arm. Ten percent of patients in the vitrectomy group reported the postoperative presence of residual floaters.11

In their review article, Katsanos et al concluded that "YAG laser vitreolysis may be a viable option for the symptomatic relief of selected patients with bothersome complaints due to vitreous opacities. In particular, cases with chronic Weiss rings may represent a patient group that will likely benefit the most from this procedure.12

Although surgical vitrectomy has a high success rate, retinal tears or detachments, hypotony, postoperative infection, and cataract formation are all risks. These have been somewhat mitigated by the use of small incision techniques, which use 27 g wounds.6

The current evidence suggests that YAG laser vitreolysis for primary, stable, symptomatic floaters has the ability to improve subjective and objective short-term visual outcomes for the properly selected candidate:

  • Chronic floater (>6 months)

  • Weiss ring

  • Single floater

  • Clear vitreous

  • Floater >2 mm from the retina

  • Floater >5 mm from the crystalline lens

  • No peripheral retinal pathology

COUNTERPOINT

By Dr. Joseph Pizzimenti

Symptomatic vitreous floaters can result from several etiologies, including posterior vitreous detachment, syneresis, myopic vitreopathy, uveitis, and asteroid hyalosis. These opacities can adversely affect quality of life and may be especially bothersome to patients living with high levels of stress. I agree with Dr Garg that we must treat such patients with the same respect and consideration we afford to those with other vitreoretinal diseases.

Many opacities associated with a posterior vitreous detachment will diminish (in size) over time, move out of the visual axis, or migrate anteriorly, in which they are no longer in focus. Some patients will develop neuroadaptation, in which they are no longer aware of the floaters. When liquefaction of the vitreous humor (synchesis) occurs in combination with dehiscence of vitreoretinal adhesion, the result is a posterior vitreous detachment, the most common cause of floaters and vision degrading myodesopsia.3

Although visual acuity is typically unaffected, studies have detected deficits in contrast sensitivity. Sebag found contrast sensitivity declined by 91% compared with age-matched controls.13 Vitrectomy is a safe, effective treatment for symptomatic floaters. In a study of 139 patients, contrast sensitivity returned to normal within 7 days of the surgery and remained so for years thereafter.14

Although Nd:YAG laser vitreolysis has been widely used to treat vitreous opacities, no definitive studies have proven its efficacy. Evidence of its safety beyond a 6- or 12-month follow-up period is also scant. There is an increased risk of glaucoma, retinal tears and detachment, cataract (if the clinician hits the lens), and other retinal damage (if the clinician hits the retina).12

Reported side effects of YAG vitreolysis include increased floaters, cataract, IOP rise, damage to the posterior lens capsule in patients with phakic lenses, retinal hemorrhage, and retinal detachment.15 Henry and Flynn argue that “the laser sessions can be time-consuming, with a mean number of 218 to 564 laser shots (and a mean total power of 366.7 mJ to 3,384 mJ) being required in single laser sessions, as reported from published series.”2

Are 400 shots and 2,000 mJ to the vitreous cavity really a good idea?

To mitigate surgical complications, such as cataract and retinal detachment, limited vitrectomy was developed. This technique preserves 3 mm to 4 mm of retrolental gel vitreous and avoids surgical posterior vitreous detachment induction. In a series of 195 cases, the incidence of retinal tears and detachment was reduced to 1.5% compared with traditional vitrectomy with surgical posterior vitreous detachment induction, which has a reported incidence of 30% for retinal tears and 6.8% to 10.9% for retinal detachment.14,16–18

If a patient remains significantly symptomatic from floaters after an acceptable period of observation, small-gauge pars plana vitrectomy is an excellent option, at least in terms of efficacy and predictability. In a study of 143 consecutive patients (168 eyes), Mason et al reported a high success rate. Ninety-four percent of patients in the study described their experience as a “complete success” and 92% reported either “no symptoms” or “very mild symptoms” following pars plana vitrectomy for symptomatic vitreous floaters. Reported complications included 12 eyes (7.1%) with iatrogenic retinal breaks, 2 eyes with vitreous hemorrhage, 1 eye with cystoid macular edema, and no eyes with postoperative retinal detachment or endophthalmitis at a mean follow-up of 18 months.19

Similarly, Sebag et al reported on 76 eyes with vitreous floaters undergoing pars plana vitrectomy. The researchers prospectively evaluated contrast sensitivity in 16 patients. Complete resolution of symptoms was seen in 15 of 16 (93.8%) patients in this group. Complication rates were retrospectively assessed in 60 patients and included 1 eye (1.7%) that developed an epiretinal membrane and no eyes experiencing iatrogenic retinal breaks, retinal detachment, or endophthalmitis at a mean follow-up of 17.5 months.5

It is true that a small percentage of patients undergoing pars plana vitrectomy for vitreous floaters could develop significant vision loss from secondary retinal complications, anesthesia complications, or endophthalmitis. That said, it appears that pars plana vitrectomy is a more efficacious procedure to address symptomatic vitreous floaters.

The good news is that most patients who have vitreous floaters associated with a posterior vitreous detachment will improve on their own and will not require intervention. Although promising, the current evidence on the safety and efficacy of Nd:YAG laser vitreolysis in the treatment of vitreous floaters is inadequate in quality and quantity. YAG laser vitreolysis is not ready for widespread adoption because of limited comparative data, lack of US Food and Drug Administration approval or CPT code, and a variable success rate. This is not acceptable in a cash payment model.

Future trials are likely forthcoming to evaluate safety comparisons between YAG vitreolysis and small-gauge pars plana vitrectomy. At the current time, the role for laser vitreolysis of vitreous floaters should remain limited.

Common Ground: Where Can We Agree?

  • Patient education and 2-way communication about their diagnosis are critical.

  • Monitor the condition for at least 1 year before considering treatment.

  • Use conservative, careful patient selection for any intervention.

  • Test contrast sensitivity, OCT, and ultrasound A-scan and B-mode.

  • Lay out the options:

    • Continued periodic monitoring (safest option)

    • Vitrectomy: imperative to receive informed consent

    • YAG vitreolysis: imperative to receive informed consent

      • This is an off-label procedure

  • YAG vitreolysis may be a reasonable treatment option to fill the gap between observation and vitrectomy, perhaps improving symptoms enough to allow patients to avoid vitrectomy if that is their desire.

Impact of Intervention

The impact of YAG vitreolysis on symptomatic, stable floaters is still not completely known and warrants further investigation. Taken together, the evidence does not support the use of YAG vitreolysis as a first-line treatment option. After thoroughly educating our patient, our plan is to monitor the condition for 6-12 more months before considering treatment.

Financial disclosures

Dr. Pizzimenti has received consulting fees from Zeiss Zeavision, and Notal Vision. Dr. Garg has no financial relationships to declare.