Vitrectomy for Vitreous Floaters

Surgery for floaters is controversial, but in select cases, it can be helpful.

FRANK H.J. KOCH, MD • SVENJA K. DEUCHLER, MD • PANKAJ SINGH, MD • MICHAEL MÜLLER, MD • THOMAS KOHNEN, MD • HENDRIK SCHÄFER, MD

As reported in the literature, floaters have a significant impact on patients’ quality of life.¹ When considering the removal of floaters, we mostly deal with an imbalance between visual acuity and vision quality. Surgery will treat floaters, but it does pose potential risks. Therefore, it must be proved that the risk of surgical floater removal is worth the outcome.

PATHOGENESIS OF FLOATERS

Benign causes for floaters include posterior vitreous detachment, vitreous liquefaction, collapse of vitreous cavities, and asteroid hyalosis. Floaters can also be caused by pathological vitreoretinal disorders, eg, vitreous hemorrhages, retinal breaks, and detachment, as well as intraocular inflammation. Systemic extraocular diseases, such as lymphoma, amyloidosis, and disseminated infection, can also manifest as floaters.

There seems to be a consensus that we are referring to the removal of vitreous opacities when these are based on pathology affecting the eye but to floaterectomy if the disturbances are based on physiological processes such as PVD.

TREATMENT MODALITIES FOR FLOATERS

In the past, observation was the treatment option of choice in the majority of cases. As we all are aware, there is no scientific proof for the efficacy of Internet products with “money-back guarantees.”²

Today, an increasing number of surgeons are willing to intervene if symptoms do not resolve on their own over time due to a cut-off of the visual axis or if they do not become less prominent because of peripheral displacement or cognitive adaption.

YAG laser photodisruption has limited efficacy, often leaving clinical relevant vitreous residue, and it may result in significant complications of retinal hemorrhage, damage to the retinal pigment epithelium, and choroidal hemorrhage.³

Thus, lens-sparing, limited vitrectomy is currently the only option for active intervention in vitreous opacities that are unacceptable to patients for long periods of time.

DIAGNOSTIC PROCEDURES BEFORE AND AFTER FLOATERECTOMY

To guarantee that both the patient and the surgeon know what they are dealing with when discussing “floaters,” several diagnostic procedures should be performed before making a decision to perform the procedure.

Patients can record their perceived personal and individual types of floater patterns on paper or using a scanner (Figure 1, next page). Effects on patient quality of life, visual quality, general well-being, and the character of vision disorders can be recorded pre- and postoperatively with the NEI-VFQ-25 questionnaire^4-10 and with a Frankfurt floater questionnaire (FFQ-22), based on the Wellbeing Index (WHO-5) and the customized floater questionnaire (FFQ-17) — which we call the FFQ-22 (Figure 2).¹¹

Figure 1. Scanning vitreous opacities: top) digital pad; and bottom) paper.

Figure 2. Top) Five criteria of the well-being index of the WHO. Bottom) Seventeen criteria customized from the NEI-VFQ-25 questionnaire, summarized as the “FFQ-22.”

After measuring VA, the degree of vision impairment (quality of vision) can be recorded with different devices,^12-14 eg, with the Vimetrics (Media, PA) Central Vision Analyzer (CVA) before and after surgery (Figure 3).¹² The CVA allows the patient and the surgeon to determine the effect of floaters and their removal on their quality of vision under various contrast conditions.

Figure 3. Typical three-port 23-gauge setup plus chandelier illumination (four-port).

Scheimpflug photography is a proven method for detecting early lens changes after minimally invasive intraocular interventions.¹⁵ Furthermore, it can be performed to screen for potential pre- and postoperative lens changes.

TECHNOLOGY FOR FLOATERECTOMY

Until recently, the customary treatment for floaters was limited to three- or four-port pars plana vitrectomy. Modern 20- to 27-gauge three- or four-port PPV equipment, manufactured by a variety of companies, may also offer viable options for the removal of floaters (Figure 3).

As technology evolves, so do the treatment options that are available to patients. The one- or two-site 23-gauge Intrector/Retrector (Insight Instruments, Inc., Stuart, FL; Figures 4 and 5, page 50) allows for a minimally invasive procedure¹⁶ that is perfectly suited for floaterectomies.

Figure 4. Top) Control unit for PPV with up to 1,200 cuts/min; bottom) hand piece.

Figure 5. Top) Intrector setup with manually controlled infusion and aspiration; indirect ophthalmoscope image delivered to control monitor. Bottom) Retrector setup with hydrostatic infusion and manually controlled aspiration.

A careful observation is possible either through the microscope or with indirect ophthalmoscopy to increase the likelihood of detecting future retinal breaks and immediately closing them with laser, cryo, air, or gas with the patient still on the operating table.

PATIENT SATISFACTION AND COMPLICATIONS

Pre-2012

Between 2000 and 2012, several series were published with increasing numbers of floaterectomies. Schiff and coworkers¹⁷ reported on six eyes with PVDs, one aphakic and five pseudophakic, with symptoms present for at least one year. Symptoms did improve (tested with the National Eye Institute-Visual Function Questionnaire (NEI-VFQ), with a minimum follow-up of eight months without complications.

Delaney and coworkers³ reported on 15 eyes with PVDs, 11 of them after prior unsuccessful YAG vitreolysis. Resolution of symptoms was achieved in 93%, with one eye developing a retinal detachment after 15 months of follow-up.

Schulz-Key et al¹⁸ published a retrospective long-term follow-up study of PPV (73 cases, 61 patients, up to 44 months of follow-up, 1998-2010) for vitreous floaters, including phakic and pseudophakic eyes with and without PVD. Of the 80% of patients having completed a questionnaire, 66% were satisfied.

Among the side effects and complications, the authors reported cataracts, inflammation, hemorrhage, macula edema and retinal detachment in 6.8%: in one eye immediately postoperatively, and in four eyes after at least two years. There was no difference between 20- and 23-gauge surgery.

Tan et al¹⁹ performed vitrectomy for floaters in 116 eyes (PVD in 74%), both phakic and pseudophakic. Some phakic eyes underwent simultaneous cataract extraction. The authors detected a high cataract rate, choroidal hemorrhages, and epiretinal membrane formation. In addition, there were intraoperative breaks in 16% of eyes: 12% in eyes with pre-existing PVDs and 31% in eyes with PVD induction; retinal detachment occurred in 2.5% of eyes, and one eye developed proliferative vitreoretinopathy.

On the basis of these studies, statements have been made, including “Vitrectomy for removal of floaters is justified in selected cases,” “Vitrectomy should be reserved for markedly symptomatic patients,” “Before vitrectomy, patients should be informed about the risks of cataract progression, unexpected inflammation, and increased risk for retinal detachment several years after the procedure,” and “The idea that vitrectomy for floaters is simple and less dangerous than vitrectomy for other indications should be banned.”

Wilkinson²⁰ summarized the situation in an editorial: “Patient satisfaction regarding visual outcomes is generally very high, and significant and potentially blinding complications do occur.”

Since 2012

Since Sebag¹ in his 2011 editorial concluded that many patients are willing to face the risks of blindness and even death to alleviate the symptoms related to floaters and improve their quality of life, it has become quite obvious that doctors should develop strategies to select the right group of patients and develop a proper procedure for an individual patient’s eye.

However, the complication rates reported at that time, including retinal detachment in up to 7%, did not make it easy for surgeons to discuss the pros and cons with the patient and then choose the right technology to perform a floaterectomy safely.

A study by de Nie et al²¹ in 2013 reported on 110 eyes with a limited satisfaction rate of approximately 90% and an even higher complication rate, mainly based on retinal detachments in almost 11% after floaterectomy.

Certain parameters are very helpful for comparing the results of this group with our own experience,¹¹ as well as for our upcoming studies. The surgeons had induced PVD in 37% of cases, a routine scleral depression was not performed at the end of the procedures, and 4.5% of the retinal detachments developed within 3 months.

OUR PROCEDURE

Since our own group started to prospectively follow up floaterectomies in 2010, with a variety of diagnostic tools and new technologies, our goal has been to establish an optimized satisfaction and safety profile.

To meet patient and doctor expectations, meticulous procedures must be undertaken before potential PPV. We screen lens changes with Scheimpflug photography, measure vision quality with the CVA,¹¹ and the patient expresses his or her visual disturbances with the adjusted FFQ-22 questionnaire and then draws the floaters with a scanner and on paper. Drawing on paper best reveals the degree of transparency loss, whereas the geometry of floaters is best recorded with a scanner. As an alternative, we allow more tech-savvy patients to use their smartphones, together with a panoptic device, to record their own floaters.

Once the mutual decision to proceed with the floaterectomy is reached, we have different device options available, such as the single-incision Intrector or the two-incision Retrector, to perform floaterectomy safely. If necessary, we can also combine laser or cryocoagulation, all under the control of an indirect head-mounted ophthalmoscope. This minimally invasive surgery is performed without causing PVD or with PVD induced only at the posterior pole.

We have removed floaters in 112 patients with one-site/two-port PPV (no PVD) or two-site/three-port PPV for revision (plus PVD induction, in 3.6%). The lens stayed unaffected in 92% of cases (follow-up of two years), and the retina detached in one eye (9%) (history of myopia and LASIK surgery); 17 of 20 patients (85%) were satisfied after the initial intervention (one-site) and 100% after the second (three-port PPV for the removal of symptomatic vitreous attached to the posterior pole).

The NEI-VFQ-25 and the FF-22 showed the benefit of floaterectomy and was correlated well pre- (rho=0.510, P<.05) and postoperatively (rho=0.476, P<.05). Final improvement in quality of life quality occurred in 99% of cases.

Even Sloan VA improved in 85%, with remarkable CVA test values including all values (Figure 6, previous page) under mesopic and glare conditions, mainly for those eyes (50%) with denser floaters centered around the visual axis before floaterectomy.¹¹

Figure 6. Vimetrics Central Vision Analyzer (CVA) before and after floaterectomy in both eyes.

Performing the same tests after floaterectomy contributed substantially to our patients’ satisfaction as well as to their decisions regarding the removal of potential symptomatic vitreous opacifications in their second eye. After two years, none of the eyes developed cataracts.

After surgery, eventual improvement occurred in VA (Sloan letters) and, most importantly, in CVA values under mesopic and glare conditions of different degrees (in both eyes, pre- to postoperatively).

PATIENT SELECTION AND SURGICAL CONSIDERATIONS

Floaters caused by partial or complete PVD are not considered to be “a pathology,” but they have a significant impact on patients’ quality of life.

All of the authors reporting their results, at a minimum, included in their pre-examinations questionnaires that helped both patient and doctor to better understand what to treat and what to expect as a result of a floaterectomy.

There is no way to overestimate the importance of the preoperative analysis because it also seems to sharpen the sensitivity of the patient and the doctor to detecting the signs of potential complications, such as endophthalmitis, retinal breaks, and detachments. Surgeons can extend the preoperative diagnostic tools to include floater drawings on paper or using scanners.

A quality of life questionnaire, such as the NEI-VFQ-25, considered the “gold standard,” can be used; however, it should be customized with the WHO-5 Wellbeing Index, resulting in the new FFQ-22. This questionnaire perfectly matches the floater condition.

For patients who are concerned about potential lens transparency loss, we can screen the lens with Scheimpflug photography. We must carefully evaluate the state of the vitreous, whether it is attached or partially or completely detached.

Then we can decide whether conventional pars plana equipment (three-/four-port PPV) will be used or whether to limit the trauma to a minimum and employ the one-site, 23-gauge vitrectomy probe (Intrector) or two-site, 23-gauge probe (Retrector), with its separate 27-gauge microinfusion line.

Once the patient and the surgeon decide on floaterectomy (a procedure accepted worldwide), they must agree on the appropriate procedure. This would include the diagnostic examination and procedure adjusted to the specific demands of patients suffering from symptomatic vitreous. Taking all of the data into account for removal of floaters generated due to PVD, the authors recommend the following standard operating procedure.

Suggested SOP

1. Inform the patient about expectations, side effects, and complications whether surgery is performed or not, as well as about the potential necessity to operate on both eyes if cataract surgery must be performed in one eye.

2. Take a history of symptoms over three to six months (at least two visits), including an evaluation of the spontaneous course of disease.

3. Use all diagnostic options available (OCT, ultrasound, biomicroscopy) to classify the state of the vitreous.

4. Use all diagnostic options available to screen, record, and document the patient’s floater pathology (questionnaire, drawings, impact on VA, impact on vision, contrast viewing measurements, eg, CVA¹² or others,^13,14 and to define which opacities are the main cause of disturbances.

5. Eventually document lens status (eg, Scheimpflug photography) because the location and amount of vitreous removal might have a significant impact on lens transparency changes, which has varied greatly in the literature.^22,23

6. Carefully examine eyelids and conjunctiva to exclude or treat blepharitis, if necessary.²⁴

7. Choose the preferred technology to perform removal of opacities with minimal effort (minimally invasive), considering the possible need to detach vitreous pathology from the posterior pole. Several three-/four-port PPV systems are available, as well as the two-site Retrector and one-site Intrector, and the intervention can be performed under topical, peribulbar, or general anesthesia.

8. Perform meticulous indirect ophthalmoscopy and eventually contact lens examinations and prophylactic laser/cryo before surgery. Repeat these exams intraoperatively, eventually with scleral indentation, and schedule postop examinations.

9. Postoperatively reiterate to the patient the possible side effects and complications (eg, flashes, pain, monocular self-examination).

Additionally, although we as surgeons consider ourselves to be a conservative group, we seriously evaluate eyes without PVD and eyes at higher risk for pathologic myopia.

CONCLUSION

These and possible future criteria for diagnostics and therapy of symptomatic floaters or the removal of vitreous opacities after PVD may convince surgeons in our community to reanalyze their positions on the treatment of floaters to increase their patients’ quality of life, although they are not considered a disease.

As Jerry Sebag^25,26 concluded in 2011, many patients are willing to face the risks of surgery; therefore, we should neither treat the decision to remove floaters lightly nor refuse to treat the patient. Rather, we should design and follow an SOP that is adjusted to the individual patient’s eye needs, regardless of the surgical gauge and how many incision sites we decide to apply for the removal of floaters.^15,27-31 RP

REFERENCES