ICL surgery is a safer and more effective option for these patients in case they want to avoid glasses or contact lenses since ICL surgery does not involve removing a part of the corneal tissue to correct the refractive error, unlike conventional laser surgery.
A subgroup of Keratoconus patients who can benefit significantly from ICL surgery are those who whose disease is stable and has stopped progressing. Once the condition has stabilized, that is, there is no change in the refraction in the eye or the power of glasses, with no surgical intervention for two years, Toric ICLs can offer these patients a better quality of life.
Eyes having riboflavin-ultraviolet-A collagen cross-linking (CXL or C3R) tend to have a fluctuation in refraction in the initial post-treatment. After the refraction stabilizes, these patients may be offered ICL surgery.
Similarly, in patients with an off centre cone, the surgeon may first offer the use of adjunct Intracorneal Ring Segments (ICRS) to centralize the cone. Once the keratoconus is stabilized, better sight without glasses may be offered by the use of ICL.
However, there are three major caveats to this:
The visual results obtained after ICL surgery in severe keratoconus are less predictable than in patients without keratoconus
The vision obtained with the use of Toric ICL in severe keratoconus is same as the best-corrected vision with glasses or soft contact lenses. It is believed that keratoconus associated corneal aberrations would have an impact on the final visual quality.
Before considering a keratoconus patient for ICL surgery, the surgeon must establish that the refractive status of the eye has been stable for at least two years, In addition to that, the central cornea must be clear, with a keratometry reading of =52.00 D and a central or centralized cone.
The use of ICLs for correcting the refractive error in keratoconus is an off-label use of the lens, even though it is widely practiced and accepted by both patients and ophthalmologists all over the world. Keratoconus patients unfit for corneal procedures and intolerant to refractive correction by spectacles or contact lenses have significantly benefited from Toric ICL implantation alone or as an adjunct with other surgical procedures to correct the refractive errors associated with keratoconus after proper informed consent from the patients.