Study on binocular visual quality after bifocal and astigmatic bifocal intraocular lens hybrid implantation

Abstract

AIM: To compare binocular visual quality of bilateral implantation of a toric bifocal intraocular lens(IOL)or a nontoric bifocal IOL and mix-and-match implantation of a toric bifocal IOL and a nontoric bifocal IOL.METHODS: A cross-sectional study. One hundred and eight eyes of 54 cases were included from January 2020 to January 2021. All participants were divided into three groups according to preexist corneal astigmatism and IOL type. In group A, cornea astigmatism was less than 1.0D in both eyes of 21 cases and bifocal IOLs were implanted. In group B, cornea astigmatism was more than 1.0D in both eyes of 15 cases and toric bifocal IOLs were implanted. In group C, 18 cases of one eye with cornea astigmatism less than 1.0D were implanted with bifocal IOLs, and the other eye with astigmatism more than 1.0D were implanted with toric bifocal IOLs. Preoperative intraocular pressure(IOP), monocular uncorrected distance visual acuity(UDVA), equivalent spherical, postoperative binocular corrected distance visual acuity(CDVA), UDVA, uncorrected intermediate visual acuity(UIVA), uncorrected near visual acuity(UNVA), residual astigmatism, defocus curve and contrast sensitivity were compared among the three groups. Postoperative questionnaire was conducted to evaluate the visual quality of the three groups.RESULTS: There were no significant differences in preoperative UDVA and IOP among the three groups(P>0.05). The postoperative residual astigmatism in group A was significantly higher than the other two groups(P=0.012, P0.5).CONCLUSION: Mix-and-match implantation of a toric bifocal IOL and nontoric bifocal IOL can effectively improve postoperative binocular visual quality in cataract patients. Correcting astigmatism helps improve the visual contrast sensitivity, however, when astigmatism is completely corrected, it may result in a loss of intermediate vision in patients after surgery.

Keywords

• astigmatism
• multifocal
• intraocular lens
• cataract
• defocusing curve
• contrast sensitivity