What they are
Floaters (or vitreous floaters or flying flies) are the clinical manifestation of a degeneration of the gelatinous structure of the vitreous body due to increasing age and other contributing causes, such as myopia, ocular traumas and ophthalmologic surgery, use of certain medications, metabolic disorders and/or low fluid intake during the day. Age-related degeneration of the vitreous body begins around the age of 20-30 but typically occurs after the age of 40-50. In myopic subjects, clinical signs manifest at least 10 years earlier. The vitreous body (also called vitreous humour) is a transparent, colourless, non-vascularised gelatinous connective tissue surrounded by a membrane, which fills the space between the lens (posteriorly) and the retina. The vitreous gel is made up of 99% water and the remaining 1% of collagen fibres, sugars, vitreous cells (hyalocytes), proteins, hyaluronic acid, etc., which constitute its framework. The collagen fibres are immersed in a matrix of hyaluronic acid, proteoglycans (PGs), minerals and vitamins.
The vitreous body
The vitreous body performs several functions:
- It helps stabilise the shape of the eye (in practice, it fills the eyeball and preserves its spherical shape).
- It is able to absorb shocks and mechanical stresses affecting the eyeball (if compressed, it returns to its original shape).
- It is part of the dioptric apparatus of the eye: being transparent, it is crossed by light and allows the complex formed by the cornea, aqueous humour and lens to make the light rays converge on the retina.
- It performs a support, protection and nourishment function for the lens, anteriorly, and the retina, posteriorly.
Over the years, the vitreous gel appears rarefied due to the reduction in its volume: hyaluronic acid gradually loses its ability to retain water and undergoes a gradual depolymerisation, responsible for the "fluidification" of the vitreous gel. This phenomenon, called "synchysis", begins in the rear part and subsequently extends to the entire vitreous body. The result is the formation of vitreous lacunae (optically empty cavities).
The evolution of this process leads to the contraction of collagen fibres, which fluctuate freely within the lacunar cavities or aggregate forming filamentous masses ("vitreous syneresis"). This phase makes it possible to perceive vitreous floaters, often described as "flying flies" or "cobwebs" (in practice, their vision is due to the shadow that the thickenings of the vitreous cast on the retina). Vitreous floaters are mainly perceived in conditions of strong light or when looking at a white surface: the shadows move rapidly with the movements of the eye, then slowly return to their original location. The fusion of liquefied areas leads to the fall of the collagen fibre framework and the vitreous body begins to detach; in this phase, in addition to mobile bodies, phosphenes can be perceived (visual flashes due to the discontinuous vitreous traction on the retina). The next step is the separation of the vitreous body from the retina and posterior vitreous detachment.
The causes of the appearance of floaters are:
- Ageing: The deterioration of the vitreous body, due to the passing of the years, is one of the main causes of the formation of vitreous floaters. It is estimated that more than 50% of people over 70 are affected by floaters.
- Diabetes: Floaters are common in diabetic patients, as the disease causes capillary weakness that could result in small bleeds, which then end up floating in the vitreous gel.
- Eyeball trauma is one of the most easily detectable causes of floaters. Indeed, ocular traumas can damage the eyeball, sometimes severely, and cause the appearance of floaters.
- Myopia: Near-sighted patients, especially if affected by pathological myopia, have a high risk of developing floaters.
- Vitreous inflammation (vitreitis) due to herpes, cytomegalovirus and other viral infections.
- Cataract surgery: Some complications that can arise during cataract surgery could contribute to the formation of vitreous floaters.
Unfortunately, there are no treatments or drugs on the market that can completely eliminate the disorder of floaters. However, there are two types of surgery (Yag laser or vitrectomy) that can reduce their perception. The ophthalmologist can recommend them after ruling out possible more serious complications.
Treatment with the Yag Laser is preferable when floaters are visible and sufficiently distant from the retina and lens. It is an intervention lasting between 10 and 30 minutes that can be performed with different techniques (vaporisation, delocalisation, thinning).
Vitrectomy is an ophthalmic micro-surgery technique due to which the vitreous humour of the eye is partially or totally removed. It is used as a therapy in various eye diseases when the vitreous body is irreparably damaged and is no longer transparent. It involves the aspiration of the vitreous humour by inserting microprobes inside the eyeball. The operation can be performed under local or general anaesthesia and has a variable duration, depending on the severity of the problem. Post-operative recovery takes about 24 hours. Afterwards, the patient will still have to follow precautions such as the instillation of specific eye drops, certain postures for sleep and avoiding efforts and traumas.
However, there are food supplements on the market with targeted formulas containing specific active ingredients for the vitreous body (e.g., collagen, hyaluronic acid, mineral salts, etc.) combined with substances with an antioxidant and anti-inflammatory action that help the patient affected by floaters, in the first place, take a greater amount of fluids during the day, a fundamental recommendation to reduce the risk of worsening the disease. An adequate fluid intake can contribute to a more or less marked reduction in the perception of floaters and to an improvement in the patient's quality of life.