Efficacy of topical microemulsion of fatty acids of the ω-3 series on the sub-epithelial corneal nerves regeneration after epithelium-off corneal collagen cross-linking for keratoconus

Int Ophthalmol. 2020 Jan;40(1):205-212. doi: 10.1007/s10792-019-01170-0. Epub 2019 Sep 30.

Abstract

Purpose: To evaluate efficacy of a microemulsion of fatty acids of the ω-3 series on the regeneration of the sub-epithelial corneal nerve plexus in patients with keratoconus after epi-off cross-linking.

Methods: In this prospective study, we recruited 40 patients, 18 females, mean age 28 years (range 22-37), who were randomly divided in two groups. Group A, 20 patients, after cross-linking were treated with a microemulsion of fatty acids of the ω-3 series. Group B were treated with hyaluronic acid (0.15%)-based tear substitute. Nerve tortuosity, reflectivity and density were examined with in vivo confocal microscopy. Ocular surface disease index (OSDI) questionnaire at the preoperative and at each follow-up visit (1, 3 and 6 months) after treatment was completed.

Results: No significant difference between the two groups was noted at 1 month in terms of nerve density and OSDI. A statistically significant difference between the two groups was detected at 3 months in terms of nerve fibers density (6 ± 0.82 in Group A and 1 ± 0.51 in Group B, P = 0.0001). Reflectivity and tortuosity of the fibers did not show significant differences between the two groups at any time point. At 1 month, OSDI average value in group A and in group B was 31.5 ± 1.94 and 30 ± 1.96, at 3 months 13 ± 1.71 and 28 ± 1.83, and at 6 months 10.5 ± 1.87 and 9.0 ± 1.81, respectively.

Conclusion: The use of a microemulsion of fatty acids appears to ensure a faster regeneration of nerve fibers in patients undergoing epi-off cross-linking.

Keywords: Cross-linking; Eye drops; Omega-3 essential fatty acids; Regeneration; Sub-epithelial corneal nerves.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Administration, Topical
  • Adult
  • Collagen / therapeutic use*
  • Cross-Linking Reagents / therapeutic use*
  • Emulsions / administration & dosage
  • Epithelium, Corneal / diagnostic imaging
  • Epithelium, Corneal / innervation*
  • Fatty Acids / administration & dosage*
  • Female
  • Follow-Up Studies
  • Humans
  • Keratoconus / diagnosis
  • Keratoconus / drug therapy*
  • Male
  • Microscopy, Confocal
  • Nerve Fibers / pathology
  • Nerve Regeneration / drug effects*
  • Photochemotherapy / methods*
  • Photosensitizing Agents / therapeutic use
  • Prospective Studies
  • Riboflavin / therapeutic use
  • Treatment Outcome
  • Ultraviolet Rays
  • Young Adult

Substances

  • Cross-Linking Reagents
  • Emulsions
  • Fatty Acids
  • Photosensitizing Agents
  • Collagen
  • Riboflavin