Comparing Outcomes Of Toric Iols Using The Barrett Toric Calculator And Barrett Tk Toric Calculator From Iol Master 700

Cataract surgery is one of the most commonly performed surgeries. Residual astigmatsism may lead to suboptimal postoperative results. The gold standard for astigmatic corrrection are Toric intraocular lenses. Barrett Toric calculator has been the standard of care for toric IOL calculation and is based on prediction of  posterior corneal astigmatism by estimating and not measuring it. Total Keratometry (TK) is the new method that directly measures the posterior corneal curvature which can be done using IOL master 700. In this study, we compared refractive and visual outcomes of Toric IOLs using standard keratometry values with the Barrett calculator and Total Keratometry (TK) with the Barrett TK Toric calculator from the IOLMaster 700. 

Tertiary eye care centre in North Delhi 

Prospective randomized single centre interventional study. Consecutive patients undergoing cataract surgery with Toric IOL implantation were recruited and assigned into 2 groups. Toric IOL power was calculated in Group 1 using the online Barrett Toric Calculator and in Group 2 using Toric IOL power calculated by in-built Barrett TK Toric Calculator from IOLMaster 700. Patients having astigmatism between 1.00 to 2.50 D were taken & corresponding Toric IOL models were implanted. 

Targeted versus achieved postoperative 1-month refractive error, we compared refractive sphere and refractive cylinder separately in each group. Inter-group comparison of median targeted and achieved post-operative 1-month refractive sphere measurement showed that the median targeted refractive sphere in Group 1 was 0.25 D and in Group 2 was -0.25 D.The median post-operative 1-month refractive sphere in Group 1 was 0.25 D and in Group 2 was 0.00 D. The median targeted refractive cylinder in Group 1 was -0.25 D and in Group 2 was -0.25 D( P =0.951).Whereas, the median post-operative refractive cylinder at 1-month was -0.25 D in Group 1 and -0.37 D in Group 2 (P =0.770). There was no significant difference in UDVA and CDVA in the two groups. 

Postoperative refractive error achieved by implanting Toric IOLs by using online Barrett Toric Calculator in Group 1 and Barrett TK Toric Calculator in Group 2 was comparable (p>0.05). There was no statistically significant difference between the two groups in terms of visual acuity and refractive outcomes.