Refractive Outcomes Following Implantation Of An Ultra-Low Cylinder Powered (0.90 D) Toric Iol In Eyes Predicted To Have Low Amounts Of Visually Significant Postoperative Astigmatism

To evaluate and compare refractive outcomes of eyes predicted to have low amounts of visually significant astigmatism implanted with the enVista ultra-low powered 0.90D toric or non-toric enVista IOL during cataract surgery.

A single-site, retrospective, controlled study in Canada. 

This study included case records of patients who underwent implantation of enVista 0.90 D toric (N =64 eyes) or non-toric IOL (N = 64 eyes). Only eyes that were eligible to undergo implantation of 0.90 D toric IOL based on the Barrett Toric Calculator and underwent implantation of enVista 0.90 D toric or non-toric IOL and for whom postoperative data at 4 or more weeks were available were included. Patients with visually significant comorbidities (e.g., retinal pathology, etc.), postoperative corrected distance visual acuity (CDVA) of less than 20/25 were excluded.  Outcome measures were mean reduction in astigmatism and residual manifest refractive cylinder. 

In the 0.90D toric group, astigmatism reduced from a mean preoperative corneal astigmatism of 0.84±0.23D to mean postoperative astigmatism of 0.25±0.25 D, a mean astigmatism reduction of 0.59D. In non-toric controls, astigmatism reduced from 0.63±0.31D to 0.52±0.35D post-op, a mean astigmatism reduction of 0.11D. The proportion of eyes achieving residual astigmatic error within 0.25 (67.2% vs 34.4%, p=0.0002), 0.50 (92.2% vs 60.9%, p<0.0001) and 0.75D (100% vs 85.9%, p=0. 0029) were statistically significantly higher in the 0.90D group vs non-toric controls. The 0.9D toric group showed higher odds of achieving residual refractive cylinder within 0.25D (odds ratio (OR) 3.91) and 0.50D (OR 7.59) compared to the non-toric control group.

The enVista 0.90 D, the lowest power toric IOL available in Canada, achieved significantly greater cylindrical correction compared to the non-toric IOL when implanted in eyes that qualified for the 0.90D toric IOL. The results of the present study demonstrate that ultra-low-powered toric IOLs can accurately target smaller amounts of visually significant astigmatism than previously possible, which may contribute to better visual function for patients undergoing cataract surgery.