- Also called Keratopigmentation.
- Impregnation of coloured substances into the corneal stroma to mimic the patient’s iris and central pupillary area.
- Cosmetic purposes.
- For optical purposes to reduce scattering of light.
- To cover iris defects due to trauma/surgery when associated with glare/ diplopia.
CONTRAINDICATIONS: Thin corneas/ Corneal ectasias.
1) Chemical reduction method:
- Involves the precipitation of a pigment into the corneal tissues.
- Easier and quicker but the results are less precise.
- Fading of the color is more rapid because the metallic compounds are mainly deposited in the extracellular matrix of cornea thus allowing early fading of the color.
- Chemicals used: Gold chloride (golden brown colour), Platinum chloride (jet black), Gold chloride, Palladium oxide.
2) Direct innoculation method:
- Older and crude method of tattooing.
- More difficult and more time consuming.
- But, it produces more permanent results as compared to the chemical reduction methods.
- This is due to the fact that these dyes tend to be phagocytosed by the keratocytes thus preventing leaching of the dyes.
- Benefits: Easy availability, prevents inadvertent full thickness corneal peforation.
3) Corneal Needle Tattooing with Pigments:
- Lampblack/ India ink used.
- Autoclaved for sterility.
4) Lamellar pocket method:
- Beneficial for cases with a clear superficial cornea.
- A partial thickness incision is made in the peripheral cornea which is extended to a lamellar intracorneal pocket in a plane anterior to the opacity and dye is inserted into the pocket.
5) Femto-assisted corneal tattooing (FACT):
- A femtosecond laser is used to make a superficial corneal pocket into which tattoo ink is injected.
- Ink lasts longer and achieve more uniform cosmetic results.
- Limitation: High cost, inability of laser to penetrate opaque cornea.
- Corneal infection
- Risk of inadvertent globe penetration via entry into the anterior chamber.
-This procedure is rarely done nowadays.
Image from Rajan Eye Care Hospital