Table 2

 UBM features of most common anterior segment cystic and solid mass lesions encountered

DiagnosisUBM featuresMLT (mm)MBD (mm)
Mean (range)Mean (range)
MBD, maximal basal diameter; MLT, maximal lesion thickness; ND, not determined.
*Classic cysts may rarely occur in association with naevi and melanoma.
†Determined by a combination of UBM and A/B-scan ultrasound.
Primary neuroepithelial cystHighly reflective, smooth cyst wall <0.2 mm thickND1.7 (0.8–3.5)
Anechoic centre
May be bilateral (42%) or multiloculated (26%)
No solid component*
Iris location: peripheral (n = 22), mid-zone (n = 6) and central (n = 2). Usually inferotemporal iris
Iris naevusSolid plaque-like lesion on the anterior iris surface and/or stroma1.8 (0.9–3.2)2.3 (1.2–5.0)
Heterogeneous internal reflectivity
Posterior iris surface flat or smoothly concave.
Minor degrees of pupil distortion (19%).
Minimal or no growth tendency on serial biometry
Iris melanomaSolid irregular iris mass2.1 (1.3–4.8)4.2 (1.3–9.0)
Variable internal reflectivity
Distortion of surrounding structures (81%)
Irregularity or convex bowing of posterior iris plane
Enlargement on serial biometry
Ciliary body melanomaOval shaped mass centred on the ciliary body6.3 (1.7–10.3)†8.9 (1.7–17.9)†
Usually solid, cavitation may occur (9.5%)
Low to medium internal reflectivity
Invasion of adjacent tissues may be evident
Anterior choroidal melanomaCiliary body /iris extension can currently be appreciated by UBMNDND
Invasion usually appears as tissue of reduced reflectivity compared to the surrounding ciliary body /iris.