What is Degenerative Vitreous Syndrome?
Degenerative Vitreous Syndrome (DVS) is the term used to describe substantial cloudiness in the aging vitreous humour which interferes with the activities of daily living.
The vitreous humour is the gel-like substance which fills the space in the eye between the lens and the retina. It is primarily composed of water with the remainder being hyaluronic acid and collagen fibers. It is transparent which enables light to pass through while the gel form provides support to the retina and helps the eye hold its shape, essentially acting as a shock absorber. As the eye ages, the vitreous gel begins to degenerate. It loses its form and liquefies – a process referred to as syneresis. Eventually the vitreous can pull away from the retina entirely. Without the stable gel form, the collagen fibers can collapse upon themselves, bind together, and become mobile. These fibers cast shadows on the retina and appear as spots, strings, or cobwebs in the visual field and are commonly referred to as floaters.
In most cases, floaters are part of the natural aging process and simply an annoyance. They can be distracting at first, but eventually tend to "settle" at the bottom of the eye, below the line of sight, and although they become less bothersome, they do not go away completely. Many people have floaters and eventually learn to ignore them; they are usually not noticed until they become numerous or more prominent but even the most innocuous floaters can become apparent when looking at something bright, such as white paper or a blue sky.
However, on rare occasions, opacities can occur prematurely and be so dense and numerous that they no longer resemble the common experience of "floaters", but significantly affect vision and quality of life. Sufferers cite practical difficulties such as having difficulty driving, reading or working, having to suspend studies, negative impacts on finances, relationships and general enjoyment of life to the extent of living in a darkened environment and depressive illness. It therefore cannot be characterised as a benign condition. As one sufferer explained, "there is definitely a life before DVS and after it"
For these people, options are limited. A surgical procedure that removes the vitreous from the eye is available; however, the possibility of complications (e.g., retinal detachment, retinal tears, pressure changes, cataract and blindness) can discourage some patients and eye surgeons may be reluctant to recommend or perform this surgery unless the floaters seriously interfere with vision. Laser disruption is also available but may only be effective for specific types of floaters. Patients of laser treatment report variable results. Alternative treatments have no proven benefits.
References:
National Eye Institute: Facts about Floaters
Moorfields: Common Eye Conditions - Floaters
More Information:
Helen Keller Foundation for Research and Education - DVS
Scott, J.E., “Secondary and Tertiary Structures of Hyaluronan in Aqueous Solution. Some Biological Consequences.” Glycoforum, Mar. 15, 1998.
http://www.glycoforum.gr.jp/science/hyaluronan/HA02/HA02E.html
Bishop, P. N., Takanosu, M., le Goff, M., and Mayne, R., “The Role of the Posterior Ciliary Body in the Biosynthesis of Vitreous Humor”, Eye (2002) 16, 454-460
http://www.nature.com/eye/journal/v16/n4/abs/6700199a.html
Suri, S. and Banerjee R., “Biophysical Evaluation of Vitreous Humor, Its Constituents and Substitutes”, Trends Biomater. Artif. Organs, (2006) 20(1), 72-77 (Requires registration with IOS Press)
http://www.angelfire.com/space2/trends/pdf/2017277.pdf
Hoerauf, Hans; "Vitrectromy Against Floaters." In Essentials in Ophthamology: Vitreo-Retinal Surgery ; Kirchof, B., Wong, D. Eds.; Springer Berlin Heidelberg 2007; pp. 115-124
http://pasargad.cse.shirazu.ac.ir/~moaddeli/floater.pdf
Alwitry A, Chen H, Wigfall S. Optometrists' examination and referral practices for patients presenting with flashes and floaters. Ophthalmic Physiol Opt. 2002 May;22(3):183-8 [abstract]
http://www.ncbi.nlm.nih.gov/pubmed/12090631
