PRK results in better outcomes than CXL in cases of low myopia

This paper compares the visual and refractive outcomes of transepithelial corneal crosslinking (CXL) and photorefractive keratectomy (PRK) in eyes with low myopia.

Study design

This prospective nonrandomized study was conducted at a single center in France and compared outcomes of CXL with PRK for 19 patients with low myopia (-1.0 to -2.5 D) with low cylinder (≤0.75D). The dominant eye of each patient received PRK and the non-dominant eye received transepithelial photorefractive intrastromal CXL.

The primary outcome was change in manifest refraction spherical equivalent (MRSE); uncorrected and corrected distance VA, mean keratometry, endothelial cell count and adverse events were also measured during the 6-month follow-up.

Outcomes

The mean preoperative spherical equivalent of the PRK and CXL group were -1.26 D and -1.43 D, respectively. After surgery, the PRK group experienced a significantly greater treatment effect in terms of refraction (+1.35 vs. +0.72 D at 6 months) and uncorrected distance acuity (-0.66 vs. -0.35 logMAR; both P<0.001). Thirteen patients (68%) preferred the PRK eye, and 8 CXL eyes required retreatment at 6 months. No complications were reported.

Limitations

This is a small study with eyes that have very low myopia and astigmatism. These patients were followed for only 6 months postoperatively.

Clinical significance

Although refractive application of CXL is an intriguing technique, it remains inferior to PRK in accuracy and requires further refinement.