Histopathological Findings of Epithelial Invasion after Arcuate and Radial Keratotomies

Complications after arcuate (АKs) and radial keratotomies (RKs) may include infection, delayed wound healing, and epithelial invasion.

To assess the histopathologic findings of epithelial invasion following АK/RK.

The study included patients who underwent penetrating keratoplasty (PK) after previous АK or RK treatment. In corneas with histologically confirmed epithelial invasion, the following parameters were examined: invasion depth (µm), width (µm) in the superficial, middle, and deep stroma, and the ratio of invasion depth to corneal thickness. The time between АK/RK and PK was compared for corneas with and without detectable epithelial invasion.

Out of 31 excised corneas, 7 (22%) showed epithelial invasion 2 to 19 years (median 6 years) after АK/RK. Histological examination revealed different invasion patterns, with a mean depth of 315 (231 to 395) µm or 57% (46 to 66%) of corneal thickness. The mean width in the superficial stroma was 291 (75 to 789) µm, in the middle stroma 210 (33 to 422) µm, and in the deep stroma 164 (19 to 324) µm. No significant association was found between the presence of the epithelial invasion and the time after PK (p = 0.83).

In almost a quarter of the eyes after АK or RK, epithelial invasion could be detected. The potential biomechanical instability associated with this should be considered in cases of trauma as well as in the context of planning cataract surgery or PK, particularly in the hands of less experienced surgeons. Nonmechanical contact-free excimer laser trephination may be helpful in PK.