VITREOUS FLOATERS

The treatment of vitreous floaters is controversial. Surgical interventions are available, but are only rarely offered to select patients with symptomatic primary floaters, despite several small-scale studies that suggest that good results can be obtained, with great patient satisfaction and relatively low complication rates. “To many vitreoretinal surgeons, floater treatment is somewhat of a taboo,” says Prof Marc de Smet of the University of Amsterdam in the Netherlands, and chief of MIOS sa, a centre specialised in retina and ocular inflammation in Lausanne, Switzerland. “And some surgeons consider floaterectomy unnecessary cosmetic surgery, with all its associated risks.”

These risks include retinal breaks, vitreous incarceration and retinal detachment, not to mention intraoperative choroidal haemorrhage and postoperative endophthalmitis. Further, cataract developed within a few years in more than half of the phakic patients, necessitating a second operation. Given the elective nature of the procedure and the scarcity of objective parameters to support the indication for surgery, many vitreoretinal specialists are understandably hesitant to perform a floaterectomy. “However, there are those for whom the position and size of the floater is a major hindrance, and for them a therapeutic solution is needed,” continued Prof de Smet.

A large study published in the American Journal of Ophthalmology1 has shown that patients are willing to trade off an average of about one out of every 10 years of their remaining life to get rid of the symptoms associated with floaters. Furthermore, the authors claim that patients are willing to take, on average, an 11 per cent risk of death and a seven per cent risk of blindness to get rid of symptoms relating to floaters. Whether these results reflect a realistic truth is debatable. Does patient personality play a role in the desire for surgery? Does it matter? Some patients are clearly willing to accept the risk of an invasive procedure. Indeed, in contrast with vitrectomy for retinal detachment or macular hole, the indication for floaterectomy is primarily driven by patient demand rather than by a surgeon’s recommendation. A great deal of information regarding treatment options is readily available online, the majority of which comes via non-peer-reviewed medical education websites. Because of this, patients may have a very optimistic impression of the procedure prior to the visit to the ophthalmologist.

Ophthalmologists tend to be more cautious. Most patients with primary floaters – those not due to ocular pathology such as uveitis – have objectively “perfect” vision. Snellen acuity, the standard clinical test of visual function, does not detect the visual disability associated with vitreous floaters, and patients’ distress does not correlate with visual acuity. Prof de Smet and his team recently presented data at ARVO which show that light scattering is significantly higher in eyes with floaters.

“Surgeons are currently willing to operate a cataract based on increased light scattering rather than decreased Snellen visual acuity. In time, the same may be true for floaters,” according to Prof de Smet. Further, the status of the posterior vitreous detachment (PVD) seems to be of crucial importance, with a well-developed PVD being associated with less bothersome symptoms. Despite the evidence, the question for many ophthalmologists is, “Are floaters a disease or simply a nuisance?” That depends on whom you ask.

“I consider the risks of surgery, particularly in phakic patients, to be excessive,” said Prof Charles Wilkinson of Johns Hopkins University in Baltimore, Maryland at the 2012 Amsterdam Retina Debate. “I have, however, done it,” he admitted. “Selected patients will demand the operation, and it is the patient’s right to undergo surgery.”

The traditional management of vitreous floaters usually includes only education and reassurance, but invasive treatments exist, including Nd:YAG laser vitreolysis; cataract surgery combined with deep anterior vitrectomy; and pars plana vitrectomy. Among those surgeons who do treat vitreous floaters, most opt for pars plana vitrectomy. The procedure, primarily utilised for other indications, is routine and sophisticated, with a well-known risk profile and high rates of success. Patient satisfaction is high.2

Nd:YAG laser vitreolysis currently has a limited role. It has not yet been widely accepted, as published data are limited to a small series of highly motivated patients. In the most comprehensive study to date, postoperative patient questionnaires indicated that in no eye was laser treatment 100 per cent successful in eliminating symptoms. Moderate improvement was noted in about one-third of cases, but 7.7 per cent experienced a worsening of symptoms.3 Vitreolytic agents might offer an alternative, although it is too early to say. More research needs to be done.

References:

1. Wagle AM, Lim WY, Yap TP, Neelam K, Au Eong KG. Utility values associated with vitreous floaters. Am J Ophthalmol. 2011 Jul;152(1):60-65.

2. Schiff WM, Chang S, Mandava N, Barile GR. Pars plana vitrectomy for persistent, visually significant vitreous opacities. Retina. 2000;20(6):591-6.

3. Delaney YM, Oyinloye A, Benhamin L. Nd:YAG vitreolysis and pars plana vitrectomy: surgical treatment for vitreous floaters. Eye 2002;16:21-6.