This study was done to check the Pentacam (Oculus Optikgeräte) Scheimpflug tomography findings in Chinese patients with different corneal diameters.

A total of 643 eyes were included (corneal diameter ⩽ 11 mm, n = 206; 11 to 12 mm, n = 219; ⩾ 12 mm, n = 218). The corneal powers and the thinnest pachymetry were negatively correlated with corneal diameter (linear regression analysis, P < .001). However, the corneal astigmatism was positively correlated with corneal diameter (R2 = 0.03, P < .001). Both the front (FE) and back (BE) elevations were negatively correlated with corneal diameter (FE: R2 = 0.027, P < .001; BE: R2 = 0.274, P < .001). The three pachymetry progression indices (PPI) (minimum, maximum, and average) were negatively correlated with corneal diameter (PPImin: R2 = 0.164, P < .001; PPImax: R2 = 0.06, P < .001; PPIavg: R2 = 0.158, P < .001). The maximum Ambrósio’s relational thickness (ARTmax) also was positively correlated with corneal diameter (R2 = 0.031, P < .001). Five normalized indices were negatively correlated with corneal diameter (deviation of normality of the front elevation [Df]: R2 = 0.122, P < .001; deviation of normality of the back elevation [Db]: R2 = 0.47, P < .001; deviation of normality of pachymetry progression [Dp]: R2 = 0.159, P < .001; deviation of normality of relational thickness [Da]: R2 = .031, P < .001; Belin/Ambrósio Enhanced Ectasia display: R2 = 0.32, P < .001) and Dt was positively correlated with corneal diameter (R2 = 0.015, P = .002). Additionally, it was noted that corneal diameter had the greatest influence on Db, Belin/Ambrósio Enhanced Ectasia display (BAD-D), and BE.

The study concluded that corneal diameter has an influence on the BAD parameters, especially Db, BAD-D, and BE.

Reference: https://doi.org/10.3928/1081597X-20200730-02