Intracorneal Ring Segments (ICRS) are a surgical treatment for Keratoconus that reshape and stabilise the cornea, improving vision and reducing distortion.
During the procedure, vitamin B2 (riboflavin) eye drops are applied to the cornea and activated with a controlled ultraviolet (UV) light. This creates new collagen bonds within the cornea, increasing its strength and stability.
ICRS are typically recommended for patients with moderate Keratoconus where vision is not adequately corrected with glasses or contact lenses, but where the cornea is still clear and thick enough to support the implant. It is not usually suitable for advanced Keratoconus with scarring or extreme thinning.
The procedure is usually performed under local anaesthetic and takes about 15–30 minutes. Patients remain awake but comfortable. After the rings are placed, vision may be blurred initially but gradually improves over the following weeks.
ICRS should be considered when glasses or standard contact lenses no longer provide adequate vision, but before the disease progresses to the point where a corneal transplant becomes the only option. Acting early allows for better outcomes and the possibility of combining ICRS with cross linking for maximum stability.