Abstract
Purpose: :
To investigate the effect of corneal haze, measured as intensity profiles using Optical Coherence Tomography (OCT), on clinical visual outcomes after DSAEK over time.
Methods: :
This is a prospective human study in which 20 eyes of 20 patients with either Fuchs’ endothelial dystrophy or pseudophakic bullous keratopathy underwent DSAEK surgery. All subjects received an ophthalmic examination pre-operatively and at 1, 3, 6, and 12 months post-DSAEK. OCT was used to quantify haze at the graft-host interface by measuring pixel intensity across the interface. At each timepoint, monocular best spectacle corrected visual acuity (BSCVA) and glare-disability (using brightness acuity testing (BAT) with BSCVA in place) were recorded. When comparing a single measure across time, Kruskal-Wallis (K-W) tests with Dunn’s multiple comparisons post-tests and Bonferroni adjustments were performed. Spearman Rank tests were conducted to determine correlations.
Results: :
Significantly different interface intensities, BSCVA, and BAT results were identified across timepoints (p<0.0002, p<0.0001, p<0.005, respectively). Dunn’s post hoc tests indicated significantly less intensity, improved logMAR BSCVA, and improved BAT performance at 12 months [1.46 +/- 0.12, (mean +/- SD), 0.22+/- 0.14, Snellen 20/33, and 0.33 +/- 0.18, Snellen 20/43, respectively] as compared to 1 month (1.80 +/- 0.27, 0.47 +/- 0.21, Snellen 20/60, and 0.50+/- 0.29, Snellen 20/63) (D=26.3, p< 0.001 for intensity and D=36.5, p<0.001 for BSCVA, and D=-25.5, p<0.01 for BAT). Significant negative correlations were found between mean interface pixel intensity and BSCVA (Spearman r = -0.3363, 95% CI -0.54 to -0.10, p = 0.005) and mean interface pixel intensity and BAT testing (Spearman r = -0.1989, 95% CI -0.33 to -0.06, p = 0.005).
Conclusions: :
Between 1 and 12 months post-DSAEK, mean interface intensity significantly decreases, while BSCVA and BAT significantly improve. Both BSCVA and BAT testing were negatively correlated with mean interface intensity. These data suggest that light scatter plays a significant role in limiting visual performance in post-DSAEK patients. Further research focused on elucidating the cause of interface-induced light scatter is indicated.
Keywords: cornea: endothelium • transplantation • visual acuity