Can We Use Anterior Segment Parameters of an Optical Biometer and a Combined Topography System Interchangeably?

Abstract

Purpose: To compare and analyze the agreement between the anterior segment parameters and pupillometric measurements obtained by Aladdinoptical biometer, and Sirius corneal topographer.Material and Methods: Medical records of healthy patients applying for refractive surgery were reviewed. Anterior chamber depth (ACD), whiteto-white distance (WTW) and keratometry (K), as well as pupillometric measurements, were compared. Subjects with a history of ocular surgeryor disease, refractive errors greater than 3 D and using ophthalmic medication or contact lenses were excluded.Results: Eighty eyes of eighty patients were included. Mean ACD and WTW measured by Aladdin were 3.65±0.25mm and 12.15±0.24mm andSirius were 3.73±0.22mm and 12.48±0.32mm, respectively. The difference in ACD and WTW was statistically signifi cant between two devices(p=0.026, p=0.001 respectively). Mean K1 and K2 were 42.53±0.90 D and 43.98±0.86D with Aladdin, whereas they were 42.49±0.85D and44.20±0.97D by Sirius, respectively. The difference was statistically nonsignifi cant (p=0.776, p=0.310 respectively). Mean photopic and mesopicpupil diameters were 3.21±0.33mm and 4.99±0.44mm with Aladdin while they were 3.65±0.48mm and 4.43±0.63mm with Sirius, which wasdifferent between two devices (p<0.01,p<0.01 respectively).Conclusion: Keratometric measurements obtained by Aladdin seemed to be in agreement statistically with Sirius topographer, however, pooragreement was observed for mean ACD, WTW, and pupillometric measurements. Studies with larger sample sizes are warranted to evaluatewhether the magnitude of these differences is clinically important or to see whether two devices can be used interchangeably for these parameters.