Overview
The vitreous body is the substance present between the lens and the retina.
- Gel-like material that provides:
- A clear optical medium
- Structural integrity to the eye
- Consists largely of:
- Water (99%)
- Network of collagen fibrils
- Hyaluronic acid
- Peripheral cells (hyalocytes)
Diagram demonstrating the anatomy of the eye.
Image by Lecturio.Posterior Vitreous Detachment
Definition
Posterior vitreous detachment is the separation of the vitreous body from the internal limiting membrane of the retina.
Epidemiology
- More common in the elderly:
- Usually starts around 60–70 years of age
- Most eyes are affected by 80 years of age.
- Men and women equally affected
Etiology
- Age-related vitreous degeneration (most common cause):
- With age, the vitreous humor changes from a thick vitreous gel to a thin liquid substance.
- Vitreous starts to shrink → can lead to its detachment from the retina
- Ocular trauma
- Ocular surgery (cataract)
- Inflammatory eye disease (uveitis)
- Those with myopia are at higher risk owing to elongation of the eyeball.
Clinical presentation
- Most cases are asymptomatic.
- Myodesopsia (floaters):
- Collection of deposits in the vitreous body
- Floaters are most noticeable against a light background and appear in different shapes and sizes.
- Photopsia:
- Flashes of light that are sudden and brief
- Usually unilateral and occur in dark areas
- Induced by head or eye movement
- Caused by vitreoretinal traction on retina
- Blurred vision
Diagnosis
- Slit-lamp microscopy: A Weiss ring is a characteristic, mobile membrane within the vitreous cavity that is glossy and crinkled.
- B-scan ultrasonography:
- Used to study the condition of the vitreous gel
- Also helps to determine the extent of posterior vitreous detachment
B-scan ultrasonography showing anterior vitreous detachment in image c.
Posterior vitreous detachment is seen in image d.
Management
- No treatment is needed in patients without retinal injury.
- Adaption to visual symptoms will develop over time, and floaters can resolve.
- Vitrectomy is considered for persistent symptoms.
Complications
- Retinal detachment
- Retinal tear
- Vitreous hemorrhage
Vitreous Hemorrhage
Definition
Vitreous hemorrhage is extravasation of blood into the vitreous humor.
Etiology
There are many causes of vitreous hemorrhage. Some common causes include:
- Proliferative diabetic retinopathy
- Posterior vitreous detachment
- Ocular trauma
- Spontaneous retinal tear
- Macular degeneration
- Sickle cell retinopathy
Clinical presentation
Vitreous hemorrhage is usually painless and unilateral. Signs and symptoms include:
- Visual haze
- Floaters
- Photopsia
- Photophobia
- Perception of shadows or cobwebs
- Visual acuity may be affected, depending on the amount of blood present.
Diagnosis
- Funduscopic examination can be used to visualize the hemorrhage.
- Slit-lamp microscopy: Blood can be observed between the posterior vitreous base and the internal limiting membrane.
- Ocular ultrasonography can be used in cases in which the posterior segment is not visible owing to excessive hemorrhage.
- CT/MRI may be needed to assess bony structures and rule out foreign bodies.
Fundus photograph of the right eye showing vitreous hemorrhage.
Image: “Fundus photographs of right eye showing peripapillary, subhyaloid, vitreous hemorrhage and several flame shaped hemorrhages obscuring the view of the optic disc” by Smt Kanuri Shanthamma Center for Retina Vitreous Diseases, L V Prasad Eye Institute, Kallam Anji Reddy Campus, Banjara Hills, Hyderabad 500 034, India. License: CC BY 2.0, edited by Lecturio.Management
- Vitreous hemorrhage might resolve on its own.
- Treatment is directed toward the underlying cause.
- Vitrectomy is done in cases of severe diseases and cases of retinal detachment.
- Laser photocoagulation is planned for proliferative retinopathies or retinal tear.
Synchysis Scintillans
Definition
Synchysis scintillans, also known as cholesterolosis bulbi, is a degenerative condition defined by the accumulation of cholesterol crystals in liquefied vitreous humor.
Epidemiology
- A very rare condition
- Usually occurs in the 3rd decade of life
- No sex or race predominance
Risk factors
- Chronic or recurring vitreous hemorrhage (most common)
- Diabetic retinopathy
- Chronic uveitis
- Retinal detachment
- Ocular trauma
Clinical presentation
- Usually asymptomatic
- May notice floaters
Diagnosis
- Slit-lamp microscopy:
- Bilateral floaters can be seen in the posterior chamber of the eyes
- Highly refractive
- Flat
- Gold/white
- Crystals float freely (“snow globe” effect)
- Bilateral floaters can be seen in the posterior chamber of the eyes
- Vitreous biopsy: can be done as a confirmatory test to identify cholesterol crystals.
Management
- In general, no treatment is required.
- Treatment of underlying diseases is necessary.
Asteroid Hyalosis
Definition
Asteroid hyalosis is a condition in which calcium-lipid (calcium soap) complexes are attached to the collagen framework of the vitreous body.
Epidemiology
- Seen in approximately 1 in 200 individuals
- Most commonly seen after 50 years of age
- More common in men
Etiology
The disease etiology is unknown.
- Strongly correlated with age
- Not clearly associated with other diseases
Clinical presentation
Asteroid hyalosis is usually asymptomatic.
Diagnosis
The diagnosis is made with slit-lamp microscopy, showing:
- Unilateral
- Multiple yellow/white, round opacities
- Floaters are suspended (“stars in the night sky”) → may move, but usually return to their original position
Multiple bright opacities suspended in the vitreous, consistent with asteroid hyalosis.
Image: “Asteroid hyalosis: multiple yellow mobile vitreous particles” by University of Mohamed V souissi, hôpital des Spécialités, Ophtalology A Department. License: CC BY 2.0, edited by Lecturio.Management
- Treatment is rarely needed.
- Vitrectomy may be indicated in cases of severe loss of visual acuity.
Persistent Fetal Vasculature
Definition
Persistent fetal vasculature, formerly known as persistent hyperplastic primary vitreous, is a condition in which embryonic blood vessels fail to regress.
Etiology
- Failure of the embryonic primary vitreous and hyaloid vascular system to regress
- Majority of cases are not genetic
Clinical presentation
This condition is usually unilateral and may present with:
- Leukocoria: white pupillary reflex (also associated with retinoblastoma)
- Decreased visual acuity
- Microphthalmia (abnormally small eye due to failure to develop) of the affected eye
- Strabismus
Diagnosis
Persistent fetal vasculature is usually diagnosed right after birth.
- Funduscopy and slit-lamp exam:
- Rotated and elongated ciliary process
- Fibrous stalk above the optic nerve
- Ultrasonography may show a fibrovascular stalk between the lens and the optic nerve.
- CT can show:
- Shallow anterior chamber
- Increased vitreous chamber density
- Intravitreal tissue enhancement
- Irregular lens
Persistent fetal vasculature:
On slit-lamp examination, traction of the ciliary processes to the center of the posterior capsule of the lens in the left eye and a retrolental mass are identified.
Management
- Treatment is symptomatic
- Vision correction may be needed.
- Surgery may be recommended to prevent or treat complications.
Complications
- Glaucoma
- Cataract
- Intraocular hemorrhage
- Retinal detachment
References
- Ahmed F., Tripathy K. (2021). Posterior vitreous detachment. StatPearls. Retrieved October 10, 2021, from https://www.ncbi.nlm.nih.gov/books/NBK563273/
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- Jena S, Tripathy K. (2021). Vitreous hemorrhage. StatPearls. Retrieved October 10, 2021, from https://www.ncbi.nlm.nih.gov/books/NBK559131/
- Johnson, B. B. (2021). Vitreous hemorrhage. EyeWiki. Retrieved October 10, 2021, from https://eyewiki.aao.org/Vitreous_Hemorrhage
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- Ramasubramanian, A., Duff-Lynes, S. M. (2021, September 5). Persistent hyperplastic primary vitreous. EyeWiki. https://eyewiki.aao.org/Persistent_Hyperplastic_Primary_Vitreous
- Goncalves, M.B. (2020). Asteroid hyalosis and synchysis scintillans. In: Rodrigues, E., Meyer, C., and Tomazoni, E. (Eds.), Trauma and Miscellaneous Disorders in Retina. Retina Atlas. Springer, Singapore, pp. 67–71. https://www.researchgate.net/publication/336072427_Asteroid_Hyalosis_and_Synchysis_Scintillans
- Ramkissoon, P. (2018). Asteroid hyalosis versus synchisis scintillans. Vision Magazine Online. http://visionmagazineonline.co.za/2018/04/01/asteroid-hyalosis-versus-synchysis-scintillans/
- Columbia University Department of Ophthalmology (n.d.), Asteroid hyalosis. Retrieved October 10, 2021, from https://www.columbiaeye.org/education/digital-reference-of-ophthalmology/vitreous-retina/tumor-others/asteroid-hyalosis.
- Sihota R, Tandon R. (2014). Parson’s Diseases of the Eye, 22nd ed., pp. 341–348.
- Vitreous degeneration. (n.d.). Retrieved October 11, 2021, from http://www.med.umich.edu/1libr/Ophthalmology/comprehensive/VitreousDegeneration.pdf
- Mai, A., et al. (2018). Persistent fetal vasculature. University of Iowa Health Care. Retrieved October 10, 2021, from https://webeye.ophth.uiowa.edu/eyeforum/cases/270-persistent-fetal-vasculature.htm
