Abstract
Purpose :
The traditional slit lamp examination with cobalt blue/yellow filter fluorescein staining is subject to the observer's subjective assessment when identifying hyperfluorescent spots of varying intensity and different corneal focal planes. To overcome these limitations, we explored a novel diagnostic technique, Fluorescein Corneography (FCG), using Anterior Segment Optical Coherence Tomography (AS-OCT) in autofluorescence (AF) mode.
Methods :
This retrospective study involved 20 patients diagnosed with punctate epithelial keratitis in the context of Dry Eye Disease, who underwent imaging with both slit lamp using cobalt blue/yellow filter after fluorescein staining and AS-OCT in AF mode. The images acquired for each patient were analyzed and compared using ImageJ to objectively count hyperfluorescent spots on the corneal surface. A color threshold was applied with uniform parameters for brightness, saturation, and hue, followed by binarization to black and white, enhancing the visualization of erosion points for automatic quantification. Considering the slit lamp with fluorescein as the gold standard for evaluating corneal erosions, a Wilcoxon signed-rank test for non-parametric variables and a ROC curve were executed.
Results :
The findings indicated that FCG tends to yield higher measurements than the slit lamp with cobalt blue filter, identifying a significantly higher number of spots (1512.3 ± 821.56 [SD] vs 392.9 ± 195.92 [SD]). The Wilcoxon signed-rank test corroborated these results, revealing a statistically significant difference and confirming that FCG consistently measures more than the slit lamp with fluorescein (p<0.0001). The substantial area under the ROC curve from sensitivity and specificity analysis further validates the accuracy of FCG, demonstrating its non-inferiority to the gold standard in clinical practice (AUC: 0.92).
Conclusions :
FCG is more accurate than slit lamp examination with cobalt blue filter fluorescein staining in detecting epithelial erosions, with potential benefits for identifying less apparent minor erosions that may not be easily visible with the slit lamp. Further studies are necessary to confirm these results.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.