Clinical comparison of speculum's influence on intraoperative aberrometry reading

The aim of this study was to evaluate the influence of four different types of speculums on aberrometry reading (OPD SCAN III [OPD]) and on intraoperative aberrometry reading (optiwave response analyzer, ORA).

This prospective, controlled, comparative study of consecutive cases included the evaluation of five eyes of five patients with monofocal intraocular lens (IOL) implantation. Seventeen measures were performed on each patient: for each speculum, there were two measurements on the OPD and another two on ORA with four different types of blepharostats. A control measure was performed on the without blepharostat in the dominant eye of each patient, therefore totalizing 85 measurements. The measures with the blepharostats were as follows: without pressure (WF) or passive measure and after pressure (AF) or active measure to close the eye. The speculum used in all patients was as follows: open-edged wire (Barraquer); threaded with open blade (Lieberman), with 21 mm aperture; wired with solid blade (Barraquer); and threaded with solid blade (Lieberman) with 21 mm opening. An evaluation of the objective refractive data from the OPD and ORA and the corneal astigmatism from the OPD was performed.

Spherical equivalent (SE) of the OPD with the use of blepharostat compared to the OPD without speculum presented only 37.5% of results without statistical significance. Regarding the SE of ORA with speculum usage, compared to the OPD without blepharostat, only 12.5% were not significant. Regarding the accuracy of the ORA refractive axis with the use of blepharostats, all results presented statistical significance.

Thus, in the present study, we reached the conclusion between the studied blepharostats that the most suitable for use in the aphakic and pseudophakic capture of the ORA is the open blade threaded blepharostat (Lieberman).