ULTRASOUND BIOMICROSCOPY OF TANGENTIAL KERATOTOMY INCISION DEPTH AFTER PENETRATING KERATOPLASTY

Purpose: To assess the accuracy and reproducibility of using ultrasoun d biomicroscopy to measure corneal refractive incisions in vivo. Setti ngs: Department of Ophthalmology, University of Vienna, Austria. Metho ds: Ultrasound biomicroscopy was performed in five eyes of five patien ts who had previous tangential keratotomy for high postkeratoplasty as tigmatism. Depth of the incision scar was documented, and the measurem ents were compared with those obtained preoperatively by ultrasound pa chymetry readings of the corneal thickness and with the settings of th e diamond knife blade. Results: The measured depths reached 84.7% +/- 12.9 (SD) of corneal thickness compared with the intended 89.1 +/- 6.7 % depth of incision. The relation between knife setting and achieved d epth was 95.3 +/- 15.9%. Conclusion: Ultrasound biomicroscopy provided high-quality images of the incision scars, accurately measuring actua l incision depth in vivo. It may become a clinically useful tool for t he refractive surgeon as it contributes to the predictability and accu racy of keratorefractive procedures.