Correction of post-radial keratotomy corneal instability and irregularity with Bowman layer and stroma onlay graft...

To report the clinical outcome of a patient with radial keratotomy (RK)-induced corneal ectasia and severe visual fluctuation who underwent Bowman layer and stroma onlay (BLST-o) grafting followed by staged wavefront-guided excimer laser surface ablation.

A 33-year-old man presented with bilateral post-RK ectasia. In the left eye, a manually peeled BLST-o graft was sutured on the anterior stroma in an attempt to reduce visual fluctuations and regularize the cornea. After two years, with the cornea remaining stable, two sequential wavefront-guided PRK procedures were performed to further regularize the corneal surface and optimize refraction.

Preoperatively, uncorrected distance visual acuity (UDVA) in the left eye was 0.34 (decimal) with manifest refraction +4.00 -1.25 × 60° and corrected distance visual acuity (CDVA) 1.00 (decimal). Topography showed ectasia (Kmean 42.83 D, Kmax 59.70 D), focal thinning (thinnest 390 μm), and high higher-order aberrations with pronounced coma. Two years after BLST-o, diurnal visual fluctuation largely resolved. Thinnest pachymetry increased to 560 μm, with mild steepening (Kmean 48.33 D, Kmax 77.37 D) and reduced anterior cylinder. UDVA was 0.30 and CDVA 0.44, improving to 0.74 (decimal) with a scleral lens. Following two wavefront-guided PRKs, anterior topography became more regular and refraction simplified to plano. Final UDVA was 1.00 (decimal) with plano refraction and a clear, stable cornea.

Manual BLST-o peeling yields a Bowman layer graft with a thin stromal component that, in this case, may provide anterior reinforcement and additional anterior tissue in post-RK ectasia, allowing a cautious staged approach in which customized PRK was subsequently performed after prolonged clinical stability.