Comparison of the variability of Scheimpflug imaging measurements between normal eyes, progressive and non-progressive keratoconus eyes at one year of follow-up

Session Details

Session Title: Keratoconus

Session Date/Time: Monday 16/09/2019 | 14:00-16:00

Paper Time: 14:48

Venue: Free Paper Forum: Podium 2

First Author: : M.Henriquez PERU

Co Author(s): :    R. Zúñiga Iracheta   M. Camino   K. Ruiz-Montenegro   J. Camargo   C. Maldonado   L. Izquierdo              

Abstract Details

Purpose:

To compare the variability on pachymetry, elevation and keratometry measurements using Scheimpflug imaging analysis between normal eyes and progressive and no progressive keratoconus (KC) eyes at 1 year of follow up.

Setting:

Research Department, Oftalmosalud Institute of Eyes, Av. Javier Prado Este 1142, San Isidro, Lima 27, Perú

Methods:

Prospective, cohort study included 34 normal and 81 KC eyes attend to Instituto Oftalmosalud, Peru, between January 2015 to august 2018. Visual acuity, refraction and Scheimpflug analysis (maximum keratometry [Kmax], pachymetry at thinnest point [TP], posterior elevation [ElevP], and D index was performed at initial evaluation and one year apart, no treatments were performed on that time interval. KC group was divided according to progression or not, progression was defined as an increase on Kmax of 1D and increase on D index of 0.42 at 1 year. Variability was assessed using Intraclass Correlation (ICC) and Wilcoxon signed rank test.

Results:

On normal eyes mean change were -0.06±0.33D, 2.32±6.58um, 0.53±2.86um, 0.15±0.38 on Kmax, TP, ElevP and D index respectively at 1 year of follow up. Non-progressive KC mean change were -0.02±0.49D, -1.75±14.61um, -0.36±7.14um and 0.15±0.52 in Kmax, TP, ElevP and D index. Progressive KC mean change were -2.26±0.76D, -8.73±20.55um, 2.18±4.58um and 0.14±0.49 in Kmax, TP, ElevP, and D index. IQR for pachymetry was 8.00, 18 and 28 in normal, non-progressive and progressive KC. There were no significant differences in the variability of these values at 1 year of follow up between the 3 groups in pachymetry (p=0.21) and posterior elevation (p=0.60)

Conclusions:

Both progressive and non-progressive keratoconus had big variability on pachymetry and elevation measurements at 1 year of follow up, which makes difficult to assess progression. Also, normal eyes experienced variability on measurements, but with less magnitude than progressive and no progressive KC.

Financial Disclosure:

None