Table 2

(A) Differential diagnosis of vortex keratopathy and (B) grading system of amiodarone-induced corneal deposits as described by Orlando et al

A: Vortex keratopathy
Endogenous causesFabry’s disease
Multiple myeloma
Neurotrophic keratitis
Multiple sulfatase deficiency
Lisch corneal dystrophy
Generalised gangliosidosis (Ganglioside-monosialic acid (GM1) gangliosidosis type I)
Iron deposition
Epidemic keratoconjunctivitis
Exogenous causes
Cationic amphiphilic drugs
Antimalarial drugs
Amiodarone
Suramin Tamoxifen Chlorpromazine Anionic amphiphilic drugs Non-steroidal anti-inflammatory drugs
B: Grading system of amiodarone-induced corneal deposits as described by Orlando et al
Grade IGolden-brown microdeposits just anterior to Bowman layer
Appear as dusting at the inferior pupillary margin in the midperiphery
No fluorescein staining
Asymptomatic
Transient stage
All patients with >1 year consumption pass to grade II
Grade IIDeposits become aligned in a linear pattern
Appearance of ‘cat’s whisker’
Clear zone between the margin of the deposits and limbus
Do not necessarily pass to grade III
Grade IIIIncrease in number of the filament-like deposits seen in grade II
Extend as branches from the inferior pupillary area into the visual axis
Whorled pattern is seen in the pupillary axis
Amiodarone >1 year
Grade IVAdditional ‘clumps’ of gold-brown deposits
Whorled branching patterns