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Automated digital analysis of intraoperative keratoscopy and its correlation with postoperative astigmatism after deep anterior lamellar keratoplasty for keratoconus

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First Author: G.Giannaccare ITALY

Co Author(s):    A. Lucisano   M. Pellegrini   F. Bernabei   G. Scuteri   V. Scorcia        

Abstract Details

Purpose:

To investigate the correlation between postoperative corneal astigmatism (PCA) and values of intraoperative keratoscopy analyzed with a newly-developed automated technique in patients with keratoconus (KC) undergoing big-bubble (BB) deep anterior lamellar keratoplasty (DALK).

Setting:

Department of Ophthalmology, University Magna Græcia of Catanzaro, Catanzaro, Italy.

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 1 day (V1), 3 months (V2) and 12 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 92 KC patients were included. The mean value of R was 0.935 ± 0.040 (range 0.760 - 0.997). The R showed a significant correlation with PCA at V3 (R = 0.412, P < 0.001). Conversely, no significant correlation between R and PCA was found at V1 and V2 (respectively, P = 0.775 and P = 0.495). The ROC curve had an AUC of 0.652 (95% CI: 0.529 - 0.775). A cutoff value of R = 0.940 had a sensitivity of 60.0% and a specificity of 65.2% for identifying patients with PCA < 3D at V3.

Conclusions:

This new automated analysis of keratoscope rings allows to identify with good diagnostic accuracy patients with post-DALK astigmatism correctable with spectacles.

Financial Disclosure:

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