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 surgery or 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 and Sirius 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 and 44.20±0.97D by Sirius, respectively. The difference was statistically nonsignifi cant (p=0.776, p=0.310 respectively). Mean photopic and mesopic pupil 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 was different 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, poor agreement was observed for mean ACD, WTW, and pupillometric measurements. Studies with larger sample sizes are warranted to evaluate whether the magnitude of these differences is clinically important or to see whether two devices can be used interchangeably for these parameters. Keywords : Anterior chamber depth, Axial length, Biometry, Low coherence interferometry, Pupillometry