Polychromatic lustre is seen in

COMPLICATED CATARACT It refers to opacification of the lens secondary to some other intraocular disease. Etiology: 1. Inflammatory conditions. These include uveal inflammations (like iridocyclitis, parsplanitis, choroiditis), hypopyon corneal ulcer and endophthalmitis. 2. Degenerative conditions such as retinitis pigmentosa and other pigmentary retinal dystrophies and myopic chorioretinal degeneration. 3. Retinal detachment. 4. Glaucoma (primary or secondary). 5. Intraocular tumours such as retinoblastoma or melanoma may give rise to complicated cataract in late stages. Clinical features: Typically the complicated cataract stas as posterior coical cataract. Lens changes appear typically in front of the posterior capsule. The opacity is irregular in outline and variable in density. In the beam of slit- lamp the opacities have an appearance like 'bread- crumb'. A very characteristic sign is the appearance of iridescent coloured paicles the so-called 'polychromatic lustre' of reds, greens and blues. A diffuse yellow-haze is seen in the adjoining coex. Slowly the opacity spreads in the rest of the coex, and finally the entire lens becomes opaque, giving chalky white appearance. Deposition of calcium is common in the later stages. Ref:- A K KHURANA; pg num:-181,182