The Vitreous Gel: More than Meets the Eye

PURPOSE: To reexamine the role of the vitreous gel in ocular health and disease based on recent information in the ophthalmic literature. DESIGN: Perspective. METHODS: Review, analysis, and discussion of the implications of selected pertinent literature. RESULTS: A new understanding of the vitreous gel is emerging, placing it central to many disease processes affecting the eye, including diabetic retinopathy, retinal vein occlusion, age-related macular degeneration, nuclear sclerotic cataract, and primary open-angle glaucoma. The vitreous gel recently has been found to have the important function of oxygen regulation and distribution within the eye. As the gel undergoes age,related liquefaction or surgical removal this function is impaired. The resultant elevated intraocular oxygen tension likely proves beneficial for vascular endothelial growth factor-mediated retinal diseases. However, it may lead to oxidative stress within the eye and may contribute to disease states such as nuclear cataract and primary open-angle glaucoma. CONCLUSIONS: An intact gel vitreous is central to a healthy human eye. We now understand that age-related liquefaction of the vitreous gel accompanies several age-related ocular diseases. The field of ophthalmology would benefit from future research to understand age, related vitreous liquefaction and to identify its cause. (Am J Ophthalmol 2010;149:32-36. (c) 2010 by Elsevier Inc. All rights reserved.)