Vitrectomy for Myodesopsia
Vitreous floaters – from ‘nuisance to disease’
While ophthalmologists have not always fully appreciated the extent to which vitreous floaters may severely impact on the quality of life of their patients, that perception is finally changing thanks to research efforts to define objective and quantitative metrics of vitreous structure and visual function in patients suffering with floaters, according to J. Sebag MD, FACS, FRCOphth, FARVO.
“The real question in considering vitreous floaters is whether this is a nuisance or a disease. If you ask the patients it is clearly a disease. Studies have shown that the negative impact of vitreous floaters is considered by patients to be equivalent to age-related macular degeneration and greater than glaucoma and diabetic retinopathy,” said Dr Sebag in the inaugural Robert Machemer Lecture delivered at the European Society of Ophthalmology (SOE) meeting in Nice, France.
Dr Sebag added that patients bothered by vitreous floaters are willing to accept a 7% risk of blindness and exchange one out of 10 years of their remaining life just to be rid of their floaters. Despite the deleterious impact that floaters have on a patient’s quality of life, the medical profession continues to downplay or dismiss their significance, said Dr Sebag, who is Senior Research Scientist at the Doheny Eye Institute/UCLA, Professor of Clinical Ophthalmology at the Geffen School of Medicine, UCLA, and Founding Director of the VMR Institute for Vitreous Macula Retina.
“A typical doctor will say that it is a nuisance – there is no tear or hole in the retina, so just deal with it. Because of this prevailing attitude, we have not met the needs of our patients suffering from vitreous floaters,” he said.
He added that the root of the “callous attitude” of physicians to floaters stems from the absence of objective clinical indices of structural and functional abnormalities with which to define it. To address this gap, Dr Sebag and co-workers have worked to develop specific indices such as contrast sensitivity function (CSF), quantitative ultrasound and floater-specific visual function questionnaires in order to define Vision Degrading Myodesopsia as a disease.
“I’ll be the first to admit that ‘vision-degrading myodesopsia’ does not exactly roll off the tongue, but it sounds like a disease and I think psychologically that is the first step in beginning the process of getting doctors to accept vitreous floaters as a disease,” he said.
Floaters most commonly occur in middle age due to age-related changes in vitreous structure and light scattering by the posterior vitreous cortex after collapse of the vitreous body during posterior vitreous detachment (PVD), explained Dr Sebag.
“The most common event in the life of the human vitreous is PVD and there are two critical components for a PVD: you have to have liquefaction of the gel but also weakening of the vitreoretinal adhesion to allow the collapse of the vitreous body. Both of these events are required in tandem for an innocuous PVD to occur,” he said.
In younger patients, floaters are most often due to myopic vitreopathy, a worrying fact given the worldwide epidemic in myopia, said Dr Sebag.
“This is a real problem because studies have estimated by the year 2050 there will be almost 5 billion people in the world with myopia. If myopic vitreopathy plays an important role in disturbed vision then we need to pay attention to that because it will be a growing problem,” he said.
An increasingly common treatment option for floaters has been Nd:YAG laser vitreolysis, which is largely ineffective, said Dr. Sebag.
Although further study is warranted, a Cochrane Database Review in 2017 concluded that there are no clinical studies proving efficacy of YAG laser vitreoylsis and other scientific papers show only a limited success rate in a small minority of patients.
“This is probably because Nd:YAG photodisruption does not ablate. It takes large particles and renders them smaller and the net effect may not be improvement in vision and account for the disappointing results we have seen in the scientific literature,” he said.
Limited vitrectomy is currently the most effective treatment for severe floaters, said Dr Sebag, who recently published a case series of 195 eyes of 145 patients with good outcomes.
“It normalises contrast sensitivity function and improves patients’ well-being with few short-term complications and even fewer long-term ones,” he concluded.
Thus, greater efforts should be made to listen to patients more attentively when they complain of vitreous floaters, to further study the disease scientifically and to develop new methods to cure the condition safely. Only then will we have achieved what Dr Sebag described as the goal of modern Medicine: “To help people die young… as late in life as possible.” (– Dr Ernst Wynder, American Health Foundation)
J. Sebag: jsebag@VMRinstitute.com