Management of Corneal Ectasia after LASIK with Phototherapeutic Keratectomy Combined with Photorefractive Keratectomy and Collagen Cross-Linking

Abstract

Background: To evaluate the efficacy of phototherapeutic keratectomy (PTK) combined with photorefractive keratectomy (PRK) and riboflavin with ultraviolet-A collagen cross-linking (CXL), performed sequentially on the same day, in the management of corneal ectasia after LASIK.

Methods: This retrospective review comprised consecutive patients with corneal ectasia after LASIK. The patients were administered PTK and PRK on the previous corneal flap, and CXL was given on the same day by the same surgeon. The main outcome measures included age, sex, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent refraction, cylinder equivalent refraction, steep and flat keratometries (K), central corneal thickness (CCT), endothelial cell count, corneal haze, and ectasia stability. Mean follow-up period was 6, 12, and 24 months.

Results: Sixteen eyes of twelve patients were included in the study. Twenty-four months after administration of PTK combined with PRK and CXL, a significant improvement in UDVA was observed. Mean cylinder equivalent refraction was significantly reduced at 6, 12, and 24 months postoperatively. However, no significant reduction was observed in spherical equivalent refraction. A significant reduction in the flat K and steep K values was observed. No significant change in mean CCT value was observed. Mean endothelial cell count and morphology were unchanged between preoperative and postoperative patients. In addition, no obvious corneal haze was observed.

Conclusions: PTK combined with PRK and CXL on the same day is a safe and effective treatment in improving visual acuity in selected patients with corneal ectasia after LASIK.

Figure 1

Schematic representation of phototherapeutic keratectomy (PTK) combined with photorefractive keratectomy (PRK) and riboflavin with ultraviolet-A collagen cross-linking (CXL) performed sequentially on the same day in the management of corneal ectasia after LASIK. (a) Removal of the epithelium in the previous corneal flap (PTK). (b) Tissue ablation in the previous corneal flap (PRK). (c) Riboflavin with ultraviolet-A collagen cross-linking (CXL).

Figure 2

Preoperative and postoperative visual outcomes. (a) Phototherapeutic keratectomy combined with PRK and CXL significantly improved UDVA (P < 0.05) at 6, 12, and 24 months follow-up. (b) Phototherapeutic keratectomy combined with PRK and CXL did not significantly improve CDVA at 6, 12, and 24 months follow-up. ^∗Preoperatively vs postoperatively 6, 12, and 24 months P < 0.05.

Figure 3

Preoperative and postoperative refractive outcomes. (a) Phototherapeutic keratectomy combined with PRK and CXL significantly reduced cylinder values (P < 0.05) at 6, 12, and 24 months follow-up. (b) Phototherapeutic keratectomy combined with PRK and CXL did not significantly reduce spherical equivalent refractions at 6, 12, and 24 months follow-up. ^∗Preoperatively vs postoperatively 6, 12, and 24 months P < 0.05.

Figure 4

Preoperative and postoperative 24-month follow-up of representative corneal topography. (a) Preoperative corneal topography. (b) Corneal topography follow-up at 24-month after same day PTK, PRK, and CXL treatment in patients with corneal ectasia after LASIK.

Figure 5

Preoperative and postoperative keratometry. (a) Phototherapeutic keratectomy combined with PRK and CXL significantly reduced the steep K values (P < 0.05) at 6, 12, and 24 months follow-up. (b) Phototherapeutic keratectomy combined with PRK and CXL significantly reduced the flat K values at 6, 12, and 24 months follow-up. ^∗Preoperatively vs postoperatively 6, 12, and 24 months P < 0.05.

Figure 6

Preoperative and postoperative central corneal thickness and endothelial cell count. (a) Phototherapeutic keratectomy combined with PRK and CXL did not significantly reduce central corneal thickness (P > 0.05) at 6, 12, and 24 months follow-up. (b) Phototherapeutic keratectomy combined with PRK and CXL did not significantly reduce the endothelial cell count at 6, 12, and 24 months follow-up.

Figure 7

Preoperative and postoperative 24-month follow-up of representative slit-lamp photographs. (A) Representative slit-lamp photographs of patient's cornea treated with PTK and PRK before the CXL. (B) Slit-lamp photographs of the patient's cornea at 24-month follow-up.