The Influence of Horizontal Corneal Diameter on Corneal Tomography and Belin/Ambrósio Enhanced Ectasia Display of Pentacam Corneal Tomography

Aims: To detect the influence of WTW on corneal tomography parameters and Belin/Ambrósio Enhanced Ectasia Display indices.

Study Design: interventional, retrospective, non-controlled, non-comparative study.

Place and Duration of Study: Department of ophthalmology (Tanta university) and Eshrak Eye Hospital, between January 2019 and December 2021.

Methodology: we collected the preoperative Pentacam images of 126 patients (252 eyes) underwent Laser Vision Correction. Correlations were performed between WTW and Pentacam findings (anterior, posterior K readings, anterior, posterior Astigmatism, Thinnest location (TL), and BAD indices: Db, Db, Dt, Da, Dp, D).

Results: WTW shows a negative correlation with KM (P = < 0.001; r = -0.43), posterior KM (P = < 0.001; r = -0.51), Kmax (P = < 0.001; r = -0.43), posterior corneal astigmatism (P = 0.002; r = -0.218) and TL (P = 0.012; r 34 = -0.17), and a positive correlation with anterior corneal astigmatism (P = 0.038; r = 0.148), There was a negative correlation between the corneal diameter and Db (r = - 0.35 ; P = <0.001), Dp (r = - 0.09 ; P = 0.02) and with final (D) (r = - 0.16; P = <0.095) and a positive correlation with Dt (r=+0.25. P =0.003).

Conclusion: Corneal diameter influences corneal curvature and pachymetry. It also influences BAD display; small diameter is associated with steep cornea and can give a false impression of corneal ectasia in BAD display.