• Written By:
    Cornea/External Disease, Refractive Mgmt/Intervention

    Investigators evaluated the outcomes of transepithelial phototherapeutic keratectomy (PTK) with corneal collagen crosslinking (CXL) in patients with pellucid marginal degeneration.

    Study design

    This retrospective study included 20 eyes of 15 patients with progressive pellucid marginal degeneration who received transepithelial phototherapeutic keratectomy (PTK) combined with accelerated CXL. Surgeons applied UVA at 9 mW/cm2 power for 10 minutes, with a total dose of (fluence) 5.4 J/cm2. Visual acuity, refraction, topographic keratometry, pachymetry and aberrations were recorded pretreatment and 6, 12, 24 and 36 months after treatment.


    Visual acuity, maximum keratometry and higher order aberrations were stable through the 36-month follow-up period (P>0.05). Mean cylindrical value was significantly lower postoperatively at all follow-up visits compared with baseline.

    Spherical equivalent was significantly lower at month 24 (P=0.02) and 36 (P=0.01). Compared with baseline values, mean average keratometry was significantly decreased, while central and minimum corneal thicknesses were significantly lower at all postoperative follow-up visits.


    This was a retrospective study of a limited number of eyes, and without any control group for comparison.

    Clinical significance

    The combination of transepithelial PTK with accelerated CXL demonstrated improvements in average keratometry, astigmatism and spherical equivalent at 3 years postoperatively. Larger, prospective trials will be needed to validate the results of this study.