Corneal topography screening for dry eye

Corneal topography provides detailed mapping of the corneal surface, helping to assess irregularities and tear film stability in patients with dry eye disease.

Overview of Corneal Topography

Corneal topography is a non-invasive imaging technique that maps the curvature of the anterior corneal surface using projected keratoscopic rings, while corneal tomography can map both anterior and posterior surfaces for a three-dimensional assessment . In dry eye disease (DED), topography helps detect subtle corneal irregularities caused by tear film instability, epithelial damage, or ocular surface disorders . It is particularly useful for monitoring changes over time and evaluating the effectiveness of treatments.

Clinical Applications in Dry Eye

1. Assessment of Tear Film and Corneal Surface: Topography can reveal irregular astigmatism or localized steepening caused by uneven tear distribution or epithelial disruption, which are common in DED . Devices like the TERA Dry Eye Imager capture corneal topography along with anterior corneal wavefront analysis to guide diagnosis and management .
2. Monitoring Treatment Efficacy: By comparing sequential topography maps, clinicians can track improvements in corneal regularity and tear film stability after interventions such as artificial tears, punctal plugs, or anti-inflammatory therapy .
3. Preoperative Evaluation: For patients undergoing refractive or cataract surgery, corneal topography ensures that dry eye–related surface irregularities are identified and managed before surgery, reducing the risk of postoperative visual disturbances .
4. Integration with Other Imaging Modalities: Topography is often combined with anterior segment optical coherence tomography (AS-OCT), non-invasive tear break-up time (NIBUT), and meibography to provide a comprehensive assessment of DED, including tear meniscus height, lipid layer quality, and meibomian gland function .

Interpretation of Topography Maps

• Axial Maps: Highlight areas of steepening or flattening; red/orange indicates steeper regions, blue/purple indicates flatter regions .
• Elevation Maps: Detect subtle protrusions or depressions, useful for identifying irregularities caused by dry eye–related epithelial changes .
• Pachymetry Maps: Measure corneal thickness, which may be altered in chronic DED due to epithelial thinning or surface damage . Clinicians use these maps to identify patterns of irregular astigmatism, monitor progression, and guide interventions such as customized contact lens fitting or targeted ocular surface therapy .

Summary

Corneal topography is a valuable tool in the evaluation of dry eye disease, providing objective, quantitative data on corneal curvature and surface irregularities. When combined with other imaging modalities, it allows for a comprehensive assessment of tear film stability, epithelial integrity, and ocular surface health, supporting diagnosis, treatment planning, and monitoring of therapeutic outcomes .