Simultaneous topography-guided PRK followed by corneal collagen cross-linking after lamellar keratoplasty for keratoconus

Abstract

BackgroundThe purpose of this paper is to report the results of using combined treatment of customized excimer laser-assisted photorefractive keratectomy (PRK) and prophylactic corneal collagen crosslinking (CXL) for residual refractive error in a group of patients who had previously undergone lamellar keratoplasty for keratoconus.MethodsThe study included 14 eyes from 14 patients who had originally been treated for keratoconus in one eye by excimer laser-assisted lamellar keratoplasty (ELLK), and subsequently presented with residual ametropia (−6.11 D ± 2.48, range −2.50 to −9.50). After a mean 40.1 ± 12.4 months since ELLK they underwent combined simultaneous corneal regularization treatment with topographically guided transepithelial excimer laser PRK (central corneal regularization) and corneal CXL induced by riboflavin-ultraviolet A.ResultsAfter a mean 15 ± 6.5 (range 6–24) months, all eyes gained at least one Snellen line of uncorrected distance visual acuity (range 1–10). No patient lost lines of corrected distance visual acuity, and four patients gained three lines of corrected distance visual acuity. Mean manifest refractive spherical equivalent was −0.79 ± 2.09 (range +1 to −3.0) D, and topographic keratometric astigmatism was 5.02 ± 2.93 (range 0.8–8.9) D. All the corneas remained clear (haze < 1).ConclusionThe combination of customized PRK and corneal CXL provided safe and effective results in the management of corneal regularization for refractive purposes after ELLK for keratoconus.

Corneal stromal demarcation line after collagen cross-linking in corneal ectatic diseases: a review of the literature

“…Combined CXL and limited topography-guided photorefractive keratectomy in selected eyes with moderate ectasia and adequate corneal thicknesses have been evidenced to be effective with improvements in visual, refractive, and topographic data and stabilization of the ectatic disease in many eyes. 33 – 35 Such different treatment modalities have been reported to be associated with significant improvements in the quality of life. However, the follow-up in these studies is limited to 1–3 years so that the long-term results are not known.…”

Donor cross-linking for keratoplasty: a laboratory evaluation

“…Although the effects of donor cross-linking on keratoplasty have not been evaluated previously, cross-linking has previously been applied in the setting of existing keratoplasty without concern. Spadea and Paroli investigated combined photorefractive keratectomy and cross-linking after lamellar keratoplasty in 14 eyes, with no noted adverse effect at a mean of 15 months [ 6 ]. Labiris et al applied cross-linking to an infected penetrating keratoplasty with no noted adverse effect [ 14 ].…”

“…In the case of DALK these outcomes in large series appear slightly worse or at best comparable [ 2 , 5 ]. The dominant cause of limited visual outcome following PKP and DALK is the induction of regular and irregular astigmatism [ 3 , 4 , 6 ]; this has been elegantly demonstrated by the improvement in vision granted by adaptive optical correction [ 7 ]. Various refinements of surgical technique over the past decades have been developed to address keratoplasty astigmatism, with varying success.…”

Corneal Collagen Crosslinking Techniques: Updates

“…Combined treatment with customized excimer laserassisted PRK and prophylactic corneal CXL in these patients seems to be a safe and effective option for managing visual rehabilitation [92] .…”