No abstract

Purpose The aim of this study was to assess the impact of cataract progression using the Haigis formula-calculated intraocular lens (IOL) power and investigate the accuracy of IOL power measured at different time points. Methods This prospective study was performed on 75 eyes of 75 patients who underwent uneventful cataract surgery. Preoperative ocular parameters including axial length (AL), keratometry (K), anterior chamber depth (ACD), corneal astigmatism, corrected distance visual acuity (CDVA) and uncorrected distance visual acuity (UDVA) examined at the two time points, more than 3 months preoperatively and preoperative 1 day were compared. The ocular parameters measured in the two time points were used to calculate the predicted implanted IOL power and the actual IOL power was chosen on the basis of parameters measured earlier before surgery using the Haigis formula. The mean numerical error (MNE) and mean absolute error (MAE) predicted by the two time points were also compared. Results There were significant differences in the ACD, IOL power, UDVA and CDVA (P<0.01), but no statistical differences in AL, mean K and corneal astigmatism (P>0.05) during the average of 5.6 months before surgery. No statistically significant difference was detected in MNE (P>0.05), while the MAE had a significant difference in the two time points (P<0.05). Conclusion The IOL power measured earlier before surgery might result in a higher accuracy and the postoperative refractive outcome tended towards emmetropia.

This study compared the clinical outcomes after cataract surgery with implantation of refractive rotationally asymmetric bifocal intraocular lens (IOL) (LS-313 MF30) and apodized diffractive bifocal IOL (ReSTOR SN6AD1). Methods: This was a prospective, non-randomized, controlled study, where patients diagnosed with age-related cataracts were selected for phacoemulsification combined with bilateral IOL implantation. Based on the type of IOL voluntarily implanted, the patients were divided into two groups, ie, refractive and diffractive groups. In total, 30 cases (60 eyes) were in a refractive group, while 30 cases (60 eyes) were in diffractive group. Three months after surgery, we examined the uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), uncorrected near visual acuity (UNVA), defocus curve, objective visual quality, and subjective questionnaire. Results: Three months after surgery, the UIVA of the refractive group (0.18 ± 0.08) logMAR was better than that of the diffractive group (0.29 ± 0.16) logMAR (P < 0.05). No significant difference in UDVA and UNVA was noted between the two groups. For a 4mm pupil diameter, the intraocular and total eye aberration, higher-order aberration (HOA), coma, spherical aberration, and trefoil in the refractive group were significantly higher than those in diffractive group (P < 0.05). The intraocular modulation transfer function (MTF), intraocular strehl ratio (SR), total eye MTF, and total eye SR in the refractive group were lower than those in diffractive group (P < 0.05). No significant difference in glare incidence, spectacle independence rate, and patient satisfaction was observed between the two groups (P > 0.05). The halos incidence in the refractive group was lower than the diffractive group (P < 0.05). Conclusion:Both bifocal IOLs obtained satisfactory UDVA and UNVA, with higher patient satisfaction. Unlike the apodized diffractive bifocal IOL, the refractive rotationally asymmetric bifocal IOL yielded slightly better UIVA, lower halos incidence, whereas the apodized diffractive bifocal IOL showed a better objective visual quality.