Transepithelial Phototherapeutic Keratectomy Followed by Corneal Collagen Crosslinking for the Treatment of Pellucid Marginal Degeneration: Long-term Results

Cornea. 2019 Aug;38(8):980-985. doi: 10.1097/ICO.0000000000002003.

Abstract

Purpose: To evaluate visual, refractive, topographic, and aberrometric outcomes of transepithelial phototherapeutic keratectomy (PTK) + corneal collagen crosslinking in the treatment of pellucid marginal degeneration.

Methods: This retrospective study includes 20 eyes of 15 patients with pellucid marginal degeneration treated with transepithelial PTK + accelerated corneal collagen crosslinking. Visual acuity, refraction, topographic keratometry, pachymetry, and aberrations were recorded pretreatment and 6, 12, 24, and 36 months after treatment.

Results: Stabilization in visual acuity was observed throughout the 36 months of follow-up (P > 0.05). The cylindrical value was significantly lower (P < 0.05) during the follow-up compared with the baseline (4.97 ± 2.00, 3.86 ± 2.01, 3.92 ± 2.27, 2.87 ± 1.70, and 3.28 ± 3.12 D at the baseline and postoperative 6th, 12th, 24th, and 36th month, respectively). Spherical equivalent was significantly lower at the 24th (P = 0.02) and 36th month (P = 0.01) follow-up intervals. A significant decrease (P < 0.05) in average keratometry readings was observed in all follow-up points (47.12 ± 4.66, 46.65 ± 4.38, 46.57 ± 4.57, 46.46 ± 4.81, and 46.27 ± 4.46 D, respectively). The maximum keratometry value remained stable (P > 0.05) in all visits (64.30 ± 10.70, 63.49 ± 10.05, 62.97 ± 9.50, 63.33 ± 10.06, and 62.27 ± 10.36 D, respectively). The Baiocchi Calossi Versaci index was significantly lower (P < 0.05) at all follow-up points compared with the baseline (3.21 ± 1.93, 2.99 ± 1.96, 2.96 ± 1.93, 2.82 ± 1.95, and 2.86 ± 1.99 μm, respectively). Central and minimum corneal thicknesses were significantly lower (P ≤ 0.01) compared with the baseline throughout the follow-up. Higher order aberration, trefoil, coma, and spherical aberration values remained stable during the follow-up compared with the baseline (P > 0.05).

Conclusions: The combination of transepithelial PTK with accelerated corneal collagen crosslinking seems to be an effective treatment in patients with pellucid marginal degeneration in the long-term.

MeSH terms

  • Adult
  • Collagen / metabolism*
  • Combined Modality Therapy
  • Corneal Dystrophies, Hereditary / drug therapy
  • Corneal Dystrophies, Hereditary / metabolism
  • Corneal Dystrophies, Hereditary / surgery
  • Corneal Dystrophies, Hereditary / therapy*
  • Corneal Stroma / metabolism*
  • Corneal Topography
  • Cross-Linking Reagents*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Photochemotherapy / methods*
  • Photorefractive Keratectomy / methods*
  • Photosensitizing Agents / therapeutic use
  • Refraction, Ocular / physiology
  • Retrospective Studies
  • Riboflavin / therapeutic use
  • Ultraviolet Rays
  • Visual Acuity / physiology

Substances

  • Cross-Linking Reagents
  • Photosensitizing Agents
  • Collagen
  • Riboflavin