Comparison between the Scheimpflug camera and the topographic modeling system in the corneal assessment before refractive surgery

Purpose To compare corneal measurements by a Scheimpflug camera and a topographic modeling system (TMS 5) in patients seeking refractive surgery. Design Prospective comparative study between two instruments. Setting RoayaLasik Center, Alexandria, Egypt. Patients and methods This study included 30 eyes of patients seeking refractive surgery, selected randomly, between 18 and 35 years old without any history of corneal surgery. An informed consent was obtained from all patients before participation in the study. All the eyes were assessed by the Scheimpflug camera (WaveLight ALLERGO Oculyzer) and the TMS 5. The corneal measurements of the two assessments were compared. Results The mean central corneal thickness (CCT) measurements by the Scheimpflug camera and the TMS 5 were 549.3 ± 28.8 and 537.3 ± 26.6 μm, respectively, with a statistically significant difference between the two devices ( P P P Conclusion CCT readings of the TMS 5 were thinner than the CCT readings of the Scheimpflug system. The keratometric readings were higher in the TMS 5. No statistically significant differences were found in astigmatism or maximum anterior elevations readings between the two devices, whereas there was a statistically significant difference in the maximum posterior elevations readings between the two devices.