Active Infection or Quiet Scar?

This is a patient sent for evaluation of a neurotrohic ulcer. The patient had been on Vancomycin, Ciprofloxacin, Loteprednol, Restasis and autologous serum tears in the past and the referring physician was considering re-culturing. Prior cultures were negative per report.

On clinical exam there was no active infection. On AS-OCT, the epithelium is fully intact. The active process likely resolved a while ago, indicated by the significant epithelial hypertrophy. Almost all of the stromal thinning has been filled in. The bright white in the AS-OCT represents the haze of the residual stroma.

Prior history notes perforation of the left eye. It is unclear how this was repaired. In the left eye, there is severe central stromal thinning, with some mild epithelial hypertrophy. 

In the posterior cornea, there appears to be some fibrotic material, possibly iris tissue, which likely had plugged the prior perforation.

Images courtesy of Brett Levinson, MD of Specialized Eye Care.

Epithelial Pooling vs Staining in Dense Central Band Keratopathy

Sometimes it can be difficult to tell the difference between a true epithelial defect versus fluorescein pooling, especially in an eye with dense central band keratopathy.  Fluorescein should not stain intact corneal epithelium. However, in areas of stromal loss or fibrosis, fluorescein can "pool," that is, it can fill the potential space and gives the false impression of true staining.


Here are images of a patient with central band keratopathy with three discrete areas of what appear  to be staining centrally that on first look appeared to be epithelial defects, but are clearly pooling with intact epithelium when viewed with OCT.


A red/ green shift in AS-OCT implies a shift in density.  It is not correlated with a pathological change as in the RNFL reading (green normal, red thin), but rather meant to optically distinguish the layers.

The red in this image highlights the area of band keratopathy and accompanying subepithelial fibrosis and sub-Bowman's anterior stromal haze. There is a remarkable change in density in the anterior stroma

In certain patient's with band keratopathy, Bowman's layer can be eroded. However, the destruction of Bowman's layer varies in patient to patient. The black areas above the red under the intact epithelium represent an optical "shadow" behind an area of extreme density like calcium.

Remember, if AS-OCT is not available to you, one clinical exam trick is to use a sterile cotton swab or weck-cel sponge to wick the excess pooling to either demonstrate intact epithelium or true staining below. In this case, upon wicking away the pooled fluorescein, the epithelium was clinically confirmed to be intact.

Images courtesy of Brett Levinson, MD of Specialized Eye Care.