Keratoglobus is a special corneal thinning disease that differs from keratoconus in one important way: instead of a single point of thinning of the cornea (which results in a bulging and the development of a cone), the cornea in people with keratoglobus is thin everywhere in topography.1
The causes of keratoglobus are still unclear. Treatment options for keratoglobus were limited until recently: corneal transplant surgery is a good option in patients with advanced keratoconus, but it is riskier to perform in patients with keratoglobus. Full-thickness corneal transplants result in problems placing the corneal sutures (into a thinner, less stable region of the existing cornea increasing the risk of failure) and partial-thickness (“lamellar”) transplants often have problems with small perforations and issues where the transplant meets the patient’s cornea, loss of immune privilege (meaning that the patient will require to take immune suppressing eyedrops for the rest of your life), and these procedures can fail and can require multiple surgeries to successfully treat the patient.2,3
If corneal cross-linking (CXL) can treat keratoconus and reduce the number of corneal transplants, can it also do the same in keratoglobus?
Recently, we reported the first case of CXL, using the sub400 protocol, in a cornea with keratoglobus that, at its thinnest point, had a pre-irradiation (post-abrasion/ riboflavin saturation) thickness of 231 µm.9 The UV irradiation duration was 2 minutes, according to the sub400 protocol algorithm. The treatment was a success: the epithelial cells had completely repopulated after 8 days, and the patient’s keratometry (corneal shape) remained stable at his most recent check-up, 32 months after the procedure, and with scleral contact lenses, the patient can achieve 20/20 vision when spectacles are worn. Based on this treatment success, CXL using the individualized sub400 protocol could become a more widespread treatment option for the eyes of patients with keratoglobus.