Vitreous Cysts

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Vitreous Cyst.JPEG

Vitreous cysts are rare clinical entities that can occur in a normal eye or in an eye associated with other pathologies.

Disease Entity

ICD 10- CM Code H43.89- Other disorders of vitreous body

Disease

•Floating vitreous cysts are extremely rare clinical entities that are regarded as ‘ocular curiosities’. [1]

•They can either be an incidental finding in a normal eye or associated with other ocular pathologies.

•It was first described by Tansley in 1899 as an irregular spherical cyst that showed lines of pigment on its surface. [2]

A red-free fundus photo showing a vitreous cyst anterior to the optic disc
Photo Courtesy- Rajan Eye Care Hospital, Chennai

Etiology

Vitreous cysts can be congenital or acquired.


Congenital Cysts [3]

•Remnants of the hyaloid vascular system

•Located at hyaloid canal and found in conjunction with a Mittendorf's dot or Bergmeister's papillae

•They are usually stable and do not progress

•They are usually non-pigmented pearl-gray cysts with a smooth surface, can be sessile or pedunculated

•They are located anterior to the optic disc

•Some can be limited in movement due to vitreous strands attaching the cyst to the optic disc

Acquired Cysts

•They occur secondary to:

o Ocular trauma

o Intraocular inflammation/infection/ uveitis eg. Intermediate Uveitis, Toxoplasmosis [4][5]

o Retinal diseases such as Retinitis pigmentosa, Choroidal atrophy, Retinoschisis, High myopia with uveal coloboma etc. [6] [7] [8]

o Retinal detachment surgeries


Types

•Pigmented Cysts

Likely originates from the pigment epithelium of the iris or ciliary body [9]

They are brown in colour.

•Non-Pigmented Cysts

Congenital cysts are usually non-pigmented

They are translucent, mobile and yellow-gray in colour.

General Pathology

Histopathological examination:

•Congenital cysts are choristomas (normal tissues growing in abnormal location) of the primary hyaloidal system

•Derived from the pigment epithelium

•Contains immature melanosomes [10]


Light & Electron Microscopy:

•Orellana et al studied aspirated pigmented cyst by light microscopy and electron microscopy. [11]

•They found that the pigmented layer of cuboidal cells contains large mature melanosomes and few immature melanosomes suggesting origin from the pigment epithelium.


Pathophysiology of Acquired Cysts

oTrauma can cause damage to the pigment epithelium of ciliary body and create pigment cysts

o Other theories: Vitreous reaction to underlying retinal degeneration can causes cysts, Ciliary adenoma breaking into the vitreous, cystic growths that occur at site of coloboma that enter the vitreous [12]


Diagnosis

History

•History of ocular trauma

•History of infections or inflammations of the eye

•History of ocular surgery


Clinical Presentation

•Age of patients usually between 10-20 years

•Mostly unilateral, but bilateral cases have also been reported especially in retinitis pigmentosa [13]

Symptoms

•Usually asymptomatic [13]

•When a cyst floats into and obstructs the visual axis, patients can complain of transient blurring of vision, floaters, shifting visual field defects and occasionally photophobia.

Signs and Morphological appearance of the cysts

Numbers and Positioning- Single unilateral, Single Bilateral, Multiple unilateral

Dimensions - 0.15-12 mm

Shapes- Spherical, Oval, Lobulated

Surface- Smooth or Crenated

Colour- Yellow-gray (non-pigmented) or Brown (Pigmented) [14]

The cysts can move with patient’s eye movements while examining with the indirect ophthalmoscope.

Differential diagnosis

A detailed clinical examination is required to rule out other infectious and malignant conditions.

Nonpigmented cysts can mimic parasitic cysts such as Cysticercosis, Echinococcus etc.
A colour fundus photo showing a well-defined round parasitic cyst of cysticercosis in the vitreous cavity
Photo Courtesy- Rajan Eye Care Hospital, Chennai
Pigmented cysts can mimic pigmented ocular tumours such as malignant melanoma [15] [16]

Investigations

General Investigations:


•Complete blood count

•Erythrocyte Sedimentation Rate

•Serologies for Cysticercosis, Echinoccous, Toxpoplasma gondii, Toxocara canis

•Stool examination for ova and cysts

•Chest radiography

•Abdominal Ultrasound

•Brain computer tomography [17]


Ocular Investigations:

•B Scan Ultrasound to look for scolex in case of cysticercosis

•Optical coherence tomography (OCT) can also help characterize the cyst

•Ultrasound biomicroscopy (UBM) to rule out anomalies of ciliary body or posterior iris

•Fluorescein angiography – assists in characterization of intra and extra cystic vascularization [14]


B scan Ultrasonography showing a vitreous cyst with a hyperechogenic wall and acoustically hollow interior with no connections to any part of the eye ie free floating. No scolex seen. Suggestive of a primary floating vitreous cyst. Photo Courtesy- Rajan Eye Care Hospital, Chennai

Management

Asymptomatic cysts

•Observation and follow-up

Symptomatic cysts

•Laser cystotomy by Argon laser or Nd:Yag laser [10] [13]

•Pars plana vitrectomy with cyst excision


References

  1. Duke-Elder S. System of Ophthalmology. Vol. 3. Normal and Abnormal Development. Part 2.Congenital Deformities. London: Henry Kimpton, 1964:763
  2. Tansley JO. “Cyst of the vitreous”. Transactions of the American Ophthalmological Society 8 (1899): 507-509.
  3. Bullock JD. Developmental vitreous cysts. Arch Ophthal. 1974;91:83–84. 
  4. Pannarale C. On a case of preretinal mobile cysts in a subject affected by congenital toxoplasmosis (in Italian) G Ital Oftalmol. 1964;17:306–317. 
  5. Tranos PG, Ferrante P, Pavesio C. Posterior vitreous cyst and intermediate uveitis. Eye. 2010;24:1115–1116. 
  6. Tuncer S, Bayramoglu S. Pigmented free-floating vitreous cyst in a patient with high myopia and uveal coloboma simulating choroidal melanoma. Ophthalmic Surg Lasers Imaging. 2011;42(Online):e49–e52
  7. Asiyo-Vogel MN, el-Hifnawiel-S, Laqua H. Ultrastructural features of a solitary vitreous cyst. Retina. 1996;16:250–254. 
  8. Mannino G, Malagola R, Abdolrahimzadeh S, Villani GM, Recupero SM. Ultrasound biomicroscopy of the peripheral retina and the ciliary body in degenerative retinoschisis associated with pars plana cysts. Br J Ophthalmol. 2001;85:976–982. 
  9. Lisch W, Rochels R. Pathogenesis of congenital vitreous cysts (in German) Klin Monbl Augenheilkd. 1989;195:375–378. 
  10. 10.0 10.1 Nork TM, Millecchia LL. Treatment and histopathology of a congenital vitreous cyst. Ophthalmology. 1998;105:825–830. 
  11. Orellana J, O'Malley RE, McPherson AR, Font RL. Pigmented free-floating vitreous cysts in two young adults. Electron microscopic observations. Ophthalmology. 1985;92:297–302
  12. Lavric A, Urbancic M. Floating vitreous cyst: two clinical cases. Case Rep Ophthalmol. 2013;4(3):243–247. doi: 10.1159/000356569. 
  13. 13.0 13.1 13.2 Jones WL. Free-floating vitreous cyst. Optom Vis Sci. 1998;75:171–173. 
  14. 14.0 14.1 Cruciani F., et al. “Monolateral idiopathic cyst of the vitreous”. Acta Ophthalmologica Scandinavica 77.5 (1999): 601-603.
  15. Wood TR, Binder PS. Intravitreal and intracameral cysticercosis. Ann Ophthalmol. 1979;11:1033–1036. 
  16. Tuncer S, Bayramoglu S. Pigmented free-floating vitreous cyst in a patient with high myopia and uveal coloboma simulating choroidal melanoma. Ophthalmic Surg Lasers Imaging. 2011;42(Online):e49–e52. 
  17. Gupta SR, Gupta N, Anand R & Dhawan S (2012): Idiopathic pigmented vitreous cyst. Arch Ophthalmol 130: 1494–1496.