title: Combined femtosecond laser-assisted intracorneal ring segment implantation and corneal collagen cross-linking for correction of keratoconus.
abstract: OBJECTIVE
  To assess the safety, predictability, and effectiveness of Keraring intrastromal corneal ring segments (ICRS) insertion assisted by femtosecond laser and corneal collagen cross-linking (CXL) for keratoconus correction.
  
  
  METHODS
  In this prospective, noncomparative, and interventional case series, 160 eyes of 100 adult keratoconus patients with poor best-corrected visual acuity (BCVA) (less than 0.7) and intolerance to contact lens wear were included. Patients underwent femtosecond laser-assisted placement of ICRS and CXL. All patients were examined for a complete ophthalmological test: uncorrected visual acuity (UCVA), BCVA, spherical equivalent, keratometry (K1-flat and K2-steep), pachymetry, and Scheimpflug imaging with the Pentacam at 1 week and at 1, 3, and 6 months postoperatively.
  
  
  RESULTS
  At 6 months, a significant difference was observed (P<0.001) in mean UCVA and BCVA from 0.92±0.677 and 0.42±0.600 logMAR preoperatively to 0.20±0.568 and 0.119±0.619 logMAR, respectively. Mean spherical equivalent refractions were significantly lower (P<0.001) at 6 months. Mean keratometry (K) also significantly reduced (P<0.001) from 50.93±5.53 D (K1-flat) and 55.37±5.76 D (K2-steep) to 47.32±4.61 and 51.08±5.38 D, respectively. In terms of pachymetry, no significant difference was observed preoperatively versus postoperatively (P=1.000).
  
  
  CONCLUSIONS
  Keraring ICRS insertion assisted by femtosecond laser and corneal CXL provided significant improvement in visual acuity, spherical equivalent, and keratometry, which suggests that it may be effective, safe, and predictable for keratoconus correction.
authors.affiliation: Department of Ophthalmology, Alexandria University, Alexandria, Egypt.
authors.forename: Osama
authors.initials: O
authors.lastname: Ibrahim
authors.affiliation: Department of Ophthalmology, Alexandria University, Alexandria, Egypt.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Elmassry
authors.affiliation: Department of Ophthalmology, Alexandria University, Alexandria, Egypt; Roayah Vision Correction Center, Alexandria, Egypt.
authors.forename: Amr
authors.initials: A
authors.lastname: Said
authors.affiliation: Roayah Vision Correction Center, Alexandria, Egypt.
authors.forename: Moones
authors.initials: M
authors.lastname: Abdalla
authors.affiliation: Department of Ophthalmology, Alexandria University, Alexandria, Egypt.
authors.forename: Hazem
authors.initials: H
authors.lastname: El Hennawi
authors.affiliation: Department of Ophthalmology, Alexandria University, Alexandria, Egypt.
authors.forename: Ihab
authors.initials: I
authors.lastname: Osman
keywords: Pentacam; irregular astigmatism; keratectesia; keratometry; pachymetry