SLIT LAMP EXAMINATION:
On examination the patient has a whorl-like pattern of golden brown or gray opacities in the basal layer of the corneal epithelium.
Look for!
Reduction in visual acuity (– if only due to VK, then usually a single line is dropped)
Optic neuropathy – optic nerve function tests – amiodarone or tamoxifen
Glare testing.
Corneal sensitivity and staining – for neurotrophic keratopathy
Fundus examination to rule of retinal toxicity – , HCQ, CQ, Chlorpromazine, tamoxifen *
Radial keratotomy – iron deposition
Fabry's disease
Dilated and tortuous conjunctival vessels with or without aneurysms
Anterior capsular and posterior subcapsular cataracts)
Retinal vascular tortuosity
Disc edema.
Systemic Assessment
Arthritis – Indomethacin intake
Photosensitivity of skin - Amiodarone
Fabry disease
Superficial cutaneous dark red angiokeratomas
Renal failure with A-V fistula
Hyperkeratotic lesions of the skin
Ocular investigations to be performed:
Automated Visual fields – to rule out retinal toxicity *
SD-OCT – to rule out retinal toxicity *
VK is a common physical sign in the examination, but the patient always has other unrelated signs in the anterior segment.
Questions:
What are the causes of cornea verticellata?
Most commonly, the condition is associated with amiodarone use and Fabry disease.
Other causes are as follows
Medications: chloroquine and hydroxychloroquine, indomethacin and phenothiazines, gentamicin, tamoxifen, meperidine, chlorpromazine, atovaquone etc.
Non-pharmacologic Etiologies:
Multiple Myeloma
Generalized gangliosidosis
Neurotropic keratitis
What is the pathophysiology of this condition?
Medications causing cornea verticillata possess cationic and amphiphilic characteristics, enabling their penetration into lysosomes within the basal epithelial layer of the cornea. Here, they form complexes with cellular lipids, becoming resistant to enzymatic breakdown and accumulating as deposits in the cornea.
The whorl-like pattern of cornea verticillata results from the centripetal migration of deposit-laden limbal stem cells as the corneal epithelium undergoes natural growth and repair.
What is Fabry's disease?
It is a lysosomal storage disorder. It is an X-linked disorder due to a deficiency of alpha-galactosidase. This deficeincy causes the deposition of glycosphingolipid in the body tissues. Renal involvement can cause renal failure. Skin lesions termed angiokeratoma corporis discusum consist of clusters of superficial cutaneous dark-red angiokeratomas.
Apart from vortex keratopathy, tortuosity and aneurysmal dilatation of the conjunctival and retinal vessels may exist.
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