Phacoemulsification induced transient swelling of corneal Descemet's Endothelium Complex imaged with ultra-high resolution optical coherence tomography

Purpose: Thickness changes of corneal sub-layers after phacoemulsification were investigated by spectral domain ultra-high resolution optical coherence tomography (UHR-OCT). Methods: The corneas (n = 26) of 26 age-related cataract surgery patients were studied. UHR-OCT was used to evaluate the thickness of Descemet's Endothelium Complex (DEC), stroma, Bowman's layer, epithelium, and full cornea at the center (CCT) before, one day after, and one week after surgery. Non-contact specular microscopy measured CCT, endothelial cell density, and morphology. Results: The DEC, stroma, Bowman's layer, and epithelium were visualized by UHR-OCT. Before surgery, the DEC in all cases appeared as a translucent space between two smooth opaque lines. One day after surgery, the posterior corneal surfaces in half of the eyes were wavy and irregular. Compared to the baseline, one day after surgery the thickness increases of the DEC, stroma, and CCT were 4.3 ± 2.6 μm, 25.5 ± 24.9 μm, and 32.1 ± 26.6 μm, respectively (P < 0.001). The morphology of the DEC and the CCT recovered to baseline one week after surgery (P >0.05), but endothelial cell density was 8.7% less than at baseline. There were no significant changes in Bowman's layer and epithelium after the operation. The pre-operative DEC thickness was positively correlated with the decreased endothelial cell density at 1 day after surgery (r = 0.55, P = 0.003). Conclusions: The DEC showed edematous thickening and different degrees of morphological changes after phacoemulsification. The DEC deformation and corneal edema recovered by one week after surgery, which indicated recovery of endothelial function. UHR-OCT is a useful tool to evaluate function of the DEC after phacoemulsification. Pre-operative DEC thickness may indicate the integrity of the endothelium and could be used for predicting endothelial cell loss after phacoemulsification.