Giuseppe Giannaccare1, Andrea Lucisano2, Marco Pellegrini3, Federico Bernabei3, Gianfranco Scuteri2, Vincenzo Scorcia2. 1. Department of Ophthalmology, University Magna Graecia of Catanzaro, Viale Europa, 88100, Germaneto, Catanzaro, Italy. giuseppe.giannaccare@gmail.com. 2. Department of Ophthalmology, University Magna Graecia of Catanzaro, Viale Europa, 88100, Germaneto, Catanzaro, Italy. 3. Ophthalmology Unit, S. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
Abstract
PURPOSE: To investigate the correlation between postoperative corneal astigmatism (PCA) and values of intraoperative keratoscopy analyzed with a newly developed automated technique in patients undergoing big-bubble (BB) deep anterior lamellar keratoplasty (DALK). METHODS: Photographs of keratoscope rings taken at the end of BB-DALK were analyzed using ImageJ for the calculation of "roundness" (R): values = 1 indicate a perfect circle. Pearson's correlation was used to evaluate the relationship between R and PCA that measured 1 week (V1), 3 months (V2), and 18 months (V3), postoperatively. The area under the curve (AUC) of receiver operating characteristic (ROC) curve was used to evaluate the accuracy of R for identifying patients with PCA < 3 diopters (D). The point on the ROC curve nearest to the coordinate (0,100) was used as a cutoff to determine sensitivity and specificity. RESULTS: Data from 121 patients were included. The mean value of R*was 0.93 ± 0.04 (range 0.76-0.99). R showed a significant correlation with PA at V3 (R = - 0.42, P < 0.01). The ROC curve had an AUC of 0.69 (95% CI 0.59-0.79). A cutoff value of R = 0.93 had a sensitivity of 70.3% and specificity of 61.0% for identifying patients with PA < 3D at V3. CONCLUSIONS: This new digital analysis of keratoscope rings allows to identify with reasonably good diagnostic accuracy patients with low values of post-DALK astigmatism correctable with spectacles.
PURPOSE: To investigate the correlation between postoperative corneal astigmatism (PCA) and values of intraoperative keratoscopy analyzed with a newly developed automated technique in patients undergoing big-bubble (BB) deep anterior lamellar keratoplasty (DALK). METHODS: Photographs of keratoscope rings taken at the end of BB-DALK were analyzed using ImageJ for the calculation of "roundness" (R): values = 1 indicate a perfect circle. Pearson's correlation was used to evaluate the relationship between R and PCA that measured 1 week (V1), 3 months (V2), and 18 months (V3), postoperatively. The area under the curve (AUC) of receiver operating characteristic (ROC) curve was used to evaluate the accuracy of R for identifying patients with PCA < 3 diopters (D). The point on the ROC curve nearest to the coordinate (0,100) was used as a cutoff to determine sensitivity and specificity. RESULTS: Data from 121 patients were included. The mean value of R*was 0.93 ± 0.04 (range 0.76-0.99). R showed a significant correlation with PA at V3 (R = - 0.42, P < 0.01). The ROC curve had an AUC of 0.69 (95% CI 0.59-0.79). A cutoff value of R = 0.93 had a sensitivity of 70.3% and specificity of 61.0% for identifying patients with PA < 3D at V3. CONCLUSIONS: This new digital analysis of keratoscope rings allows to identify with reasonably good diagnostic accuracy patients with low values of post-DALK astigmatism correctable with spectacles.
Entities:
Keywords:
Astigmatism; DALK; Deep anterior lamellar keratoplasty; Digital analysis; Keratoscopy