A Toronto-based research team recently found that accelerated collagen crosslinking (CXL) alone, CXL with simultaneous intrastromal corneal ring segments  and CXL with simultaneous topography-guided photorefractive keratectomy are all good treatment options for patients with progressive keratoconus, pellucid marginal degeneration (PMD) or LASIK-induced ectasia.

The study assessed 452 eyes with ectatic disorders. Of those, 204 underwent accelerated CXL alone, 126 combined crosslinking with corneal rings and 122 underwent CXL plus PRK. The researchers compared visual and topographic outcomes, adjusting for preoperative maximum keratometry (Kmax), one year post-op.

They found the change in uncorrected distance visual acuity was significant for the CXL-plus-rings (-0.31logMAR) and CXL-plus-PRK (-0.16logMAR) groups; however, the study found no significant differences between the three cohorts. Change in corrected distance visual acuity (CDVA) was significant in all three groups, but CDVA improvement was greater with CXL-ICRS. The researchers also found a significant change in Kmax with those who added corneal rings (-3.21D) or PRK (-3.69D) to the protocol but not with crosslinking alone (-0.05D).

The researchers concluded that combined CXL and ring implantation may be more effective for eyes with more irregular astigmatism and worse CDVA, while crosslinking plus PRK may be more useful for eyes with good CDVA that require improvements in irregular astigmatism.