Weakening of the cornea due to keratoconus, a complication following LASIK surgery (rare anomaly) or any other corneal disease can be corrected through an in-office procedure known as Corneal Cross-Linking (CXL). The process is performed for re-strengthening of the cornea whereas brand names and alternative medical terminologies for the procedure include corneal collagen cross-linking, KXL, C3-R and CCL.
CXL is minimally invasive which is performed by application of the vitamin B2 as liquid riboflavin on the eye surface. It’s followed by treatment through a controlled ultraviolet light application for elimination of the corneal ectasia. Two of the most basic procedures for corneal cross-linking are;
- CXL Epithelium-off
During this procedure, the thin exterior layer (epithelium) of the cornea is removed after which liquid riboflavin is dosed for easy penetration of the corneal tissue.
- CXL Epithelium-ON
Also known as trans-epithelial CXL; the protective corneal epithelium remain untouched which requires a longer “loading” time for riboflavin!
For the treatment of keratoconus, the corneal cross-linking can be merged with various other procedures such as combination of CXL with implantation of micro arc-shaped corneal inserts known as Intacs. It results in stabilising and reshaping of the cornea in more advanced cases of keratoconus.
CXL – Current status
Back in 2016, a renowned medical device and pharmaceutical company received approval from the FDA for KXL System of the company which provides corneal collagen cross-linking for the treatment of advanced keratoconus.
Certain riboflavin solutions are used with the KXL System during the procedure which includes application of Photorexa Viscous and Photorexa. This is supposed to be the first corneal collagen cross-linking system for the treatment of vision-threatening conditions to gain FDA approval.
Before the cornea takes on excessive irregular shape or there’s a significant loss of vision, the corneal cross-linking procedure is quite effective. Early application of CXL would stabilise and even rectify the corneal shape which results in improved ability to put on contact lenses and better visual acuity. Treatment of corneal ulcers that have been ineffective or unresponsive against topical antibiotics is also performed by CXL application. Medical research also concluded effective outcome for curing of various infections to the cornea in Abu Dhabi following corneal cross-linking.
Some of the surgeons also reported enhanced stability of the cornea who’ve had their radial keratotomy; an invasive/incisional refractive process that has been around since 80s and 90s. For those experiencing frequent fluctuation in their vision, cross-linking seems to be the best choice. Pre-treatment through corneal cross-linking for strengthening of the eye surface is possible among people who’re expecting LASIK for vision correction.
Pre & post-procedure
Corneal thickness is measured by the doctor during preliminary examinations to check if you’re a suitable candidate. Routine eye exam for assessment of visual acuity and general health of the eye is also a prerequisite. Corneal topography to determine overall eye condition would also be performed by the doctor.
Corneal cross-linking takes around 60-to-90 minutes, depending on severity of the case and patient’s condition. Riboflavin eye drops are then applied after which the surgeon would ensure that cornea has become sufficient presence of the drops. UV light is then applied for almost 30 minutes.
Bandages are likely to be placed on the treated eye alongside prescription of topical antibiotics and anti-inflammatory drops.
By: Hassaan Javaid