Table 3.
Summary of vitreous seed classification and clinical characteristics
| Class | Type | Description5 | Response to Intravitreal Melphalan5 |
Median age (mos) |
Typical location |
Typical laterality |
Typical distribution |
|---|---|---|---|---|---|---|---|
| Type I |
Dust | Small granules of vitreous opacities Can be seen as a vitreous haze overlying tumor |
2–3 weeks to regress, receives least drug/injections |
11 | All | U/B | Localized |
| Type 2 |
Spheres | Spherically shaped opacities within vitreous Dust may be present around spheres Can be homogenously opaque or have a translucent/opaque outer shell with contrasting center |
6–7 weeks to regress, receives medium amount of drug/injections |
15.5 | Macula- Equator |
U/B | Localized/ Diffuse |
| Type 3 |
Cloud | Dense collection of punctate vitreous opacities Can appear as a sheet or globule of seed granules and often with wispy edge Dust and spheres are sometimes also visible |
30–32 weeks to regress, receives most drug/injections |
32 | Equator-Ora | U | Diffuse |
U = unilateral, B = bilateral