# Optical Coherence Tomography in Infectious Keratitis After Femtosecond Keratorefractive Surgery

## TL;DR

This study shows how optical coherence tomography helps diagnose and monitor corneal infections after laser eye surgeries like LASIK and lenticule extraction.

## Contribution

The paper presents the first analysis of AS–OCT patterns in infectious keratitis specifically after femtosecond keratorefractive surgeries.

## Key findings

- AS–OCT identified initial infiltrates and interface inflammation in post-surgery infections.
- Interface fluid accumulation and stromal reabsorption were observed and documented by OCT.
- OCT effectively guided treatment and evaluated healing and scarring after infections.

## Abstract

Objectives: Anterior Segment Optical coherence tomography (AS–OCT) can help in the diagnosis and treatment of infectious keratitis, but it has not been studied in cases occurring after corneal refractive surgery procedures such as femtosecond laser in situ keratomileusis (FS–LASIK) and keratorefractive lenticule extraction (KLEx). In these procedures, a surgical interface is created, where infections usually start, thus determining a different AS–OCT pattern compared to non–surgical infections, which begin on the corneal surface. Methods: We retrospectively reviewed 22,756 eyes of 13,564 patients who underwent FS–LASIK and KLEx at our surgical center. Results: Four cases of post–refractive surgery infectious keratitis were included (two after FS–LASIK and two after KLEx), in which the AS–OCT identified an initial infiltrate in the interface, followed by interface inflammation. In one case, after FS–LASIK, interface fluid accumulation occurred. In one case, after KLEx, diffuse interface inflammation led to stromal reabsorption, later compensated by stromal reformation and epithelial hyperplasia, well documented by OCT. Conclusions: AS–OCT represents a useful tool for assessing corneal infections after refractive surgery, guiding the treatment, and evaluating the healing process and residual corneal scarring.