Comparison of corneal aberrations from anterior segment swept source OCT versus Placido-topography combined spectral domain OCT in cataract patients

BACKGROUND

To comprehensively evaluate the agreement of component corneal aberrations from the newly updated wavefront analysis software of a swept-source optical coherence tomographer (SS-OCT) and a referential Placido-topography combined OCT device in elderly cataract patients.

METHODS

Retrospective study including 103 eyes from 103 elderly patients scheduled for cataract surgery that were measured on the same day with a SS-OCT (Heidelberg Engineering, Germany) device and a Placido-topography combined OCT device (CSO, Italy). Anterior, total, and posterior corneal wavefront aberrations were evaluated for their mean differences and limits of agreement (LoA) via Bland-Altman plots. Vector analysis was additionally employed to compare corneal astigmatism measurements in dioptric vector space.

RESULTS

Mean differences of all corneal aberrometric parameters did not exceed 0.05 μm. Total corneal aberrations were not significantly different from 0 except for vertical coma (- 0.04 μm; P = 0.003), spherical aberration (- 0.01 μm, P < 0.001), and root mean square (RMS) higher-order aberration (HOA) (0.03 μm, P = 0.04). The 95% LoA for total corneal aberration parameters between both devices were - 0.46 to 0.42 μm for horizontal astigmatism, - 0.37 to 0.41 μm for oblique astigmatism, - 0.19 to 0.17 μm for oblique trefoil, - 0.33 to 0.25 μm for vertical coma, - 0.20 to 0.22 μm for horizontal coma, - 0.22 to 0.20 μm for horizontal trefoil, - 0.11 to 0.08 μm for spherical aberration, and - 0.22 to 0.28 μm for RMS HOA. Vector analysis revealed no statistically significant mean differences for anterior, total, and posterior corneal astigmatism in dioptric vector space.

CONCLUSION

In eyes undergoing cataract surgery with a regular elderly cornea, corneal wavefront analysis from the SS-OCT device showed functional equivalency to the reference device. Nevertheless, clinically relevant higher order aberration parameters should be interpreted with caution for surgical decision-making.

Repeatability of intraoperative Hartmann-Shack wavefront sensing in cataract surgery

PURPOSE

To evaluate the repeatability of aphakic intraoperative wavefront aberrometry and compare it with preoperative and postoperative aberrometry.

SETTING

Department of Ophthalmology, Hanusch Hospital, Vienna, Austria.

DESIGN

Prospective case series.

METHODS

Patients scheduled for cataract surgery were each measured 3 consecutive times using Hartmann-Shack wavefront sensing (HS-WFS) preoperatively, intraoperatively in aphakia, and 2 months postoperatively after intraocular lens implantation by a single examiner. Intraclass correlation coefficients (ICCs) of spherical equivalent (SE) values were evaluated for each timepoint. Intrasubject standard deviation (Sw) as repeatability (Sr) with corresponding repeatability limit () and mean SE differences with corresponding limits of agreement (LoA) were calculated for comparison.

RESULTS

A high consistency of repeated measurements was found with ICCs above 0.9 for each of the 3 timepoints. Intraobserver repeatability (Sr) and repeatability limit (r) of intraoperative aberrometry SE measurements (30 eyes of 30 patients) were 0.34 diopters (D) and 0.95 D, respectively. The LoA for intraoperative aphakic SE across 3 consecutive measurements were -0.71 to +0.85 D. For comparison, Sr and r for phakic preoperative measurements in the cataractous state (30 eyes of 30 patients) and postoperative measurements in the pseudophakic state (24 eyes of 24 patients) were 0.33 D and 0.93 D and 0.23 D and 0.64 D, respectively. Similarly, the LoA for preoperative and postoperative SE measurements were -0.66 to +0.60 D and -0.27 to +0.45 D, respectively.

CONCLUSIONS

HS-WFS test-retest reliability was high for all 3 timepoints, but the intraoperative setting resulted in a lower repeatability and broadened the agreement range.