BlueCross BlueShield of Tennessee Medical Policy Manual

Intrastromal Corneal Ring Segments (ICRS) for Vision Correction


Intrastromal corneal ring segments consist of micro-thin soft plastic inserts of variable thickness that are placed in the periphery of the cornea. Intrastromal corneal ring segments have been investigated as a means of improving vision in diseases such as keratoconus, pellucid marginal degeneration, and for refractive surgery to correct myopia.

Intrastromal corneal ring segments (e.g. Intacs®) are prescribed, removable implants designed to reshape the anterior surface of the cornea. The rings consist of 2 arc-shaped segments that are surgically inserted in the corneal stroma. The procedure is performed in an ambulatory setting under local anesthesia. These rings are designed to correct myopia by raising the peripheral cornea and indirectly flattening the central cornea. If required, the implants can be removed at a later date, and the eyes return to preoperative refractive status within 3 months.

Keratoconus, a progressive bilateral dystrophy, is a non-inflammatory eye condition in which the normally round dome-shaped cornea progressively thins in some places causing a cone-like bulge to develop. This results in significant visual impairment.

Pellucid marginal degeneration is a noninflammatory progressive degenerative disease, typically characterized by bilateral peripheral thinning (ectasia) of the inferior cornea. Deterioration of visual function results from the irregular astigmatism induced by asymmetric distortion of the cornea. Intracorneal ring segment implantation has been investigated as a treatment for pellucid marginal degeneration. Rigid gas permeable contact lenses may also be used to treat pellucid marginal degeneration.





No controlled studies were found in the published literature that validates the application of intrastromal corneal ring segments for the treatment of other conditions / diseases of the eye. No evidence was found to demonstrate that outcomes of this procedure for conditions other than keratoconus were significantly better than currently accepted treatments.


Alio, J., Vega-Estrada, A., Esperanza, S., Barraquer, R., Teus, M., and Murta, J. (2014). Intrastromal corneal ring segments: how successful is the surgical treatment of keratoconus? MEA Journal of Ophthalmology, 21 (1), 3-9. (Level 3 evidence)

American Academy of Ophthalmology. (2013). Refractive Errors & Refractive Surgery Preferred Practice Patterns. Retrieved October 2, 2010 from

BlueCross BlueShield Association. Evidence Positioning System. (3:2018). Implantation of intrastromal corneal ring segments (9.03.14). Retrieved September 17, 2018 from  (22 articles and/or guidelines reviewed)

BlueCross BlueShield of Tennessee network physicians. February 2004.

Fernández-Vega-Cueto, L., Romano, V., Zaldivar, R., Gordillo, C.H., Aiello, F., Madrid-Costa, D., & Alfonso, J.F. (2017). Surgical options for the refractive correction of keratoconus: myth or reality. Journal of Ophthalmology, doi: 10.1155/2017/7589816 Published online 2017 Dec 18. (Level 2 evidence)

National Institute for Health and Care Excellence. (2007). Corneal implants for keratoconus. Retrieved November 14, 2016 from

Torquetti, L., Ferrara, G., Almeida, F., Cunha, L., Araujo, L., Machado, A., et al. (2014). Intrastromal corneal ring segments implantation in patients with keratoconus: 10-year follow-up. Journal of Refractive Surgery, 30 (1), 22-26. Abstract retrieved February 9, 2016 from PubMed database.

U. S. Food and Drug Administration. (1999, April). Center for Devices and Radiological Health. Premarket Approval Decision for P980031. Retrieved November 18, 2014 from

U. S. Food and Drug Administration. (2004, March). Center for Devices and Radiological Health. Summary of Safety and probable benefits H040002 (INTACS®). Retrieved September 26, 2011 from

Vega-Estrada. A., Alio’, J. L., & Plaza-Puche, A. B. (2015). Keratoconus progression after intrastromal corneal ring segment implantation in young patients: Five-year follow-up. Journal of Cataract Refractive Surgery, 41 (6), 1145-1152. Abstract retrieved February 8, 2016 from PubMed database.

Winifred S. Hayes, Inc. Medical Technology Directory. (2018, March). Intacs for the treatment of keratoconus. Retrieved September 17, 2018 from (44 articles and/or guidelines reviewed)




Policies included in the Medical Policy Manual are not intended to certify coverage availability. They are medical determinations about a particular technology, service, drug, etc. While a policy or technology may be medically necessary, it could be excluded in a member's benefit plan. Please check with the appropriate claims department to determine if the service in question is a covered service under a particular benefit plan. Use of the Medical Policy Manual is not intended to replace independent medical judgment for treatment of individuals. The content on this Web site is not intended to be a substitute for professional medical advice in any way. Always seek the advice of your physician or other qualified health care provider if you have questions regarding a medical condition or treatment.

This document has been classified as public information.