Influence of Topical Fluorescein on Scheimpflug-Based Corneal Densitometry and Potential Applications

Area of Science:

• Ophthalmology
• Corneal Imaging
• Diagnostic Technologies

Background:

• Corneal densitometry measures light scatter to assess corneal tissue.
• Scheimpflug imaging is a non-invasive technique for corneal analysis.
• Dry eye disease (DED) can cause superficial punctate keratitis (SPK), impacting corneal surface integrity.

Purpose of the Study:

• To evaluate how topical fluorescein affects Scheimpflug-based corneal densitometry.
• To determine the optimal timing for reliable corneal densitometry imaging after fluorescein instillation.
• To assess fluorescein-enhanced densitometry's potential for detecting SPK in DED patients.

Main Methods:

• Twenty healthy participants underwent Scheimpflug imaging at various time points after fluorescein instillation.
• Corneal densitometry was measured in different corneal layers and zones.
• Reproducibility was assessed, and one DED patient with SPK was examined.

Main Results:

• Fluorescein significantly increased anterior corneal densitometry, peaking at 5 minutes and returning near baseline by 20 minutes.
• High reproducibility was observed for measurements taken 10-20 minutes post-instillation.
• In the DED patient, fluorescein-enhanced densitometry identified localized signal elevations corresponding to SPK.

Conclusions:

• Topical fluorescein causes transient, time-dependent changes in anterior corneal densitometry.
• Fluorescein may enhance the detection of epithelial defects, offering an objective method for assessing corneal surface integrity in DED.
• Further research is needed to validate the clinical utility of this technique.