1. Agreement Between Corneal Topography with the Dual-Scheimpflug Placido Corneal Topographer, Scheimpflug Corneal Topographer, and Scanning-Slit Topography in Keratoconus: Implications for Assessing Progression
Pravin K Vaddavalli MD, Shyamsunder T, Parthasarthy K, Preetam Kumar, Shrikant D, Preeji MS, Reekham S, Faiza S
Cornea Service, Contact lens service
LV Prasad Eye Institute
Hyderabad, India
None of the authors has any financial interests or conflict of interest to disclose

2. Purpose
PENTACAM
ORBSCAN
GALILEI
To assess the repeatability of the Orbscan, Pentacam and Galilei topography systems in normal and keratoconus eyes
To assess the agreement between these three topography machines in assessing normal and keratoconus eyes

3. Methods 96 right eyes on normal patients
45 clinically diagnosed keratoconus
2 scans each on Orbscan, Pentacam and Galilei
Intersession variability, instrument agreement

4. INTERSESSION REPEATABILITY (MAX/STEEP KERATOMETRY)
NORMALS
NORMALS
NORMALS
INTERSESSION REPEATABILITY (MAX/STEEP KERATOMETRY)
ORBSCAN
PENTACAM
GALILEI
KERATOCONUS
KERATOCONUS
KERATOCONUS

5. INTER INSTRUMENT REPEATABILITY (MAX/STEEP KERATOMETRY)
NORMALS
NORMALS
NORMALS
INTER INSTRUMENT REPEATABILITY (MAX/STEEP KERATOMETRY)
ORBSCAN vs PENTACAM
PENTACAM vs GALILEI
ORBSCAN vs GALILEI
KERATOCONUS
KERATOCONUS
KERATOCONUS

6. SUMMARY Normals – Pentacam had least intersession variability
Keratoconus eyes – all topographers showed greater intersession variation compared to normals, Galilei was best
Between instruments, Pentacam and Galilei had the highest agreement in both normals and keratoconus eyes