Abstract
Purpose :
Determining postoperative refraction with EDF IOLs can be complicated by the elongated depth of focus that allows patients to see clearly at a range of distances. Therefore, the maximum plus refraction technique is recommended for these technologies, so that the full depth of focus can be effectively used. This study assessed two different refraction methods to determine which technique provides maximum plus refraction for best-corrected distance visual acuity (BCDVA) and whether autorefraction is a reliable starting point for pseudophakic refraction with EDF IOLs.
Methods :
This was a prospective, single-center, non-interventional, randomized testing sequence, comparative study of eyes implanted with EDF IOL Model A (n=13), Model B (n=12) or enhanced monofocal IOL, Model C (n=10). Manifest refraction was determined using fogging (MR#1) and duochrome techniques (MR#2, randomized sequence) by the same optometrist. Spherical equivalent was determined by autorefraction (AR), manifest refraction with both techniques to achieve BCDVA.
Results :
Pooled results from all three IOL groups found no statistically significant mean difference between the methods for MR (-0.04 D ± 0.34 D, 95% CI [-0.16, 0.07]) and in associated BCDVA (-0.01 ± 0.06 LogMAR, 95% CI [-0.02, 0.01]). The AR of Model A (-0.61 D ± 0.73) was significantly more minus compared to Model B (0.21 D ± 0.61, p=0.006) and to Model C (0.06 D ± 0.60, p=0.030), and no difference was noted between Model B and Model C (p=0.580). There was no significant difference in manifest refraction between the three IOLs using MR #1 (Model A 0.27 D, 95% CI [0.04, 0.50]; Model B 0.19 D, 95% CI [-0.05, 0.42]; Model C -0.05 D, 95% CI [-0.36, 0.17]) and MR #2 (Model A 0.17 D, 95% CI [-0.06, 0.40]; Model B 0.31 D, 95% CI [0.08, 0.55]; Model C 0.03 D, 95% CI [-0.23, 0.29]). There was also no significant difference noted comparing MR#1 and MR#2 with all three IOLs.
Conclusions :
Clinicians should be mindful when refracting EDF patients that there is a tendency to over-minus the endpoint, so either the fogging or duochrome technique should be used to achieve the maximum plus refraction for BCDVA. However, duochrome should not be used with chromatic aberration-correcting IOLs. When using autorefraction as a starting point for refraction, some EDF designs can give an over-minused autorefraction, effectively decreasing the IOL depth of focus.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.