Corneal collagen cross-linking for correction of low myopia?

Abstract

DOI:10.1097/ICU.0b013e3283622cb1 Corneal collagen cross-linking (CXL) was first described in 1997 by Sporl et al. [1]. Since then, it has been increasingly used in the treatment of postlaser-assisted in situ keratomileusis (LASIK) keratectasia as well as keratoconus [2–6]. Recently, this technique has been used as an adjunct to refractive surgery, such as LASIK, to provide increased structural stability following correction of refractive error [7]. Given the corneal flattening that occurs with CXL, the possibility of using this particular technique alone as a method to correct low myopia has been proposed [8]. In this issue of Current Opinion in Ophthalmology, Nguyen and Chuck [9] review the application of CXL in a variety of keratoplastic procedures, including photorefractive keratectomy , LASIK, thermal keratoplasty, and orthokeratology. This review highlights numerous instances in which CXL has been shown to halt regression and even produce additional effects in all of the above keratoplastic procedures, with the exception of orthokeratology. If the addition of CXL to these procedures results in these prolonged and/or additional effects, the potential effects of using CXL alone should be considered. In 2011, Hersh et al. [2] demonstrated significant improvement in both uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) at 1 year in eyes that had undergone CXL in keratoconus or corneal ectasia patients. Their results revealed an improvement in mean UDVA from 0.84 logMAR 0.34 (SD) (20/137) to 0.77 0.37 logMAR (20/117) and an improvement in mean CDVA from 0.35 0.24 log MAR (20/45) to 0.23 0.21 logMAR (20/34). Brooks et al. [10] also suggested that patients experience subjective improvement in visual function, such as night driving, difficulty reading, diplopia, glare, halo, starbursts, and foreign-body sensation, after undergoing CXL for keratoconus and corneal ectasia, corroborating the objective results described by Hersh et al. These results included the following: a decrease in the mean maximum keratometry value by 2.0 D or more in 31% of patients, an increase in the mean maximum keratometry value by 2.0 D or more in 4.2% of