Purpose: To determine if there was a clinically significant difference in clinical outcomes after toric IOL implantation based on intraoperative aberrometry (IA), where eyes were measured either in the aphakic state only or both the aphakic and pseudophakic states.
Methods: A prospective, randomized, contralateral eye study was performed at one site in Poughkeepsie, NY, USA. Subjects included patients presenting for uncomplicated bilateral cataract surgery eligible for toric lens implantation with regular corneal astigmatism in both eyes whose toric IOL implantation was based on IA. One eye was measured when aphakic and the other when both aphakic and pseudophakic. The primary outcome measure was the magnitude of residual refractive astigmatism. Secondary measures included the percentage of eyes with 0.50D or less of residual refractive astigmatism, the spherical equivalent refraction and the time for IA measurement.
Results: Mean residual refractive astigmatism was not statistically significantly different between groups (0.32D ± 0.46D IA_1 vs. 0.23D ± 0.35D IA_2, p = 0.25), nor was the percentage of eyes with a residual refractive cylinder of 0.50D or less (94% in both groups, p = 1.0). The average time to measure the pseudophakic eye was 3 min, 46 s. Aphakic IA measurements appeared to produce better spherical equivalent refractive results relative to preoperative calculations.
Conclusion: Pseudophakic IA measurements took nearly 4 min per case. Residual refractive astigmatism was not appreciably lower when pseudophakic IA measurements were made after aphakic IA measurements, which suggests aphakic IA measurements alone provide good clinical results with toric IOLs.
Keywords: Astigmatism; Cylinder; Intraocular lens; ORA; Phacoemulsification; Time.