Astigmatism Correction With Toric Intraocular Lenses
Astigmatism Correction With Toric Intraocular Lenses
Mean age of the patients, sex and mean preoperative spherical equivalent were similar in the three groups (p>0.05) ( Table 1 )
Mean preoperative corneal topographic astigmatism and refractive astigmatism (OPD Scan II) were similar in the toric group and astigmatic SN60AT group (p>0.05); their values were higher than those in the control group (p<0.001) ( Table 1 ).
Mean change in IOL axis orientation was 3.2°±1.0, 3 months after surgery. No postoperative IOL realignment was needed.
Postoperative mean cylindrical power, measured with the OPD Scan II, in the toric and control groups was similar (p>0.05), and significantly different from the astigmatic SN60AT group (p<0.001) (figure 1). Similar results were found for postoperative spherical equivalent (figure 2).
(Enlarge Image)
Figure 1.
Preoperative and postoperative (3 months after surgery) refractive cylinder (Cyl) values measured by the OPD Scan II. Mean postoperative refractive cylinder values were significantly lower in the toric group in comparison with the astigmatic SN60AT group. The toric group values were similar to the control group. Results are reported as mean±SD. p<0.05 is considered statistically significant. **p<0.001 between two groups. This figure is only reproduced in colour in the online version.
(Enlarge Image)
Figure 2.
Preoperative and postoperative (3 months after surgery) mean spherical equivalent. Mean postoperative spherical equivalent was significantly lower in the toric group in comparison with the astigmatic SN60AT group. The toric group values were similar to the control group. Results are reported as mean±SD. p<0.05 is considered statistically significant. **p<0.001 between two groups. This figure is only reproduced in colour in the online version.
The difference in postoperative UDVA between the toric group and the astigmatic SN60AT group was statistically significant (p<0.001), while there was no statistically significant difference between the toric group and the control group (p>0.05) (figure 3).
(Enlarge Image)
Figure 3.
Preoperative and postoperative (3 months after surgery) uncorrected distance visual acuity (UDVA) (LogMAR). Mean postoperative UDVA was significantly better in the toric group in comparison with the astigmatic SN60AT group. The toric group values were similar to the control group. Results are reported as mean±SD. p<0.05 is considered statistically significant. **p<0.001 between two groups. This figure is only reproduced in colour in the online version.
There was a statistically significant difference in postoperative mean aberrometric values (MTF A/D, Strehl ratios and second order astigmatism) between the toric group and the astigmatic SN60AT group (p<0.001), while the difference between the toric group and the control group was not significant (p>0.05) (figures 4, 5). Preoperative and postoperative second order astigmatism RMS values (Z2, Z2) at a pupil diameter of 4 mm were 0.98±0.31 μm and 0.36±0.21 μm in the toric group, 0.68±0.46 μm and 0.63±0.26 μm in the astigmatic SN60AT group and 0.37±0.24 μm and 0.25±0.13 μm in the control group.
(Enlarge Image)
Figure 4.
Preoperative and postoperative modulated transfer function (MTF) area ratio (A/D), calculated by the OPD Scan II at spatial frequency from 0 to 60 cpd at a pupil diameter of 4 mm. Mean postoperative MTF A/D was significantly higher in the toric group in comparison with the astigmatic SN60AT group. The toric group values were similar to the control group. Results are reported as mean±SD. p<0.05 is considered statistically significant. **p<0.001 between two groups. This figure is only reproduced in colour in the online version.
(Enlarge Image)
Figure 5.
Preoperative and postoperative Strehl ratio, calculated by the OPD scan II at a pupil diameter of 4 mm. Mean postoperative Strehl ratio was significantly higher in the toric group in comparison with the astigmatic SN60AT group. The toric group values were similar to the control group. Results are reported as mean±SD. p<0.05 is considered statistically significant. **p<0.001 between two groups. This figure is only reproduced in colour in the online version.
The NEI-RQL 42 questionnaire scores at 3 months postoperatively were significantly better in the toric group compared with the astigmatic SN60AT group, including items related to astigmatism correction such as clarity of vision (p<0.001), far vision (p=0.021), glare (p=0.038) and satisfaction with correction (p=0.001) ( Table 2 ).
Results
Mean age of the patients, sex and mean preoperative spherical equivalent were similar in the three groups (p>0.05) ( Table 1 )
Mean preoperative corneal topographic astigmatism and refractive astigmatism (OPD Scan II) were similar in the toric group and astigmatic SN60AT group (p>0.05); their values were higher than those in the control group (p<0.001) ( Table 1 ).
No Intraoperative or Postoperative Complications Occurred During the Study
Mean change in IOL axis orientation was 3.2°±1.0, 3 months after surgery. No postoperative IOL realignment was needed.
Postoperative mean cylindrical power, measured with the OPD Scan II, in the toric and control groups was similar (p>0.05), and significantly different from the astigmatic SN60AT group (p<0.001) (figure 1). Similar results were found for postoperative spherical equivalent (figure 2).
(Enlarge Image)
Figure 1.
Preoperative and postoperative (3 months after surgery) refractive cylinder (Cyl) values measured by the OPD Scan II. Mean postoperative refractive cylinder values were significantly lower in the toric group in comparison with the astigmatic SN60AT group. The toric group values were similar to the control group. Results are reported as mean±SD. p<0.05 is considered statistically significant. **p<0.001 between two groups. This figure is only reproduced in colour in the online version.
(Enlarge Image)
Figure 2.
Preoperative and postoperative (3 months after surgery) mean spherical equivalent. Mean postoperative spherical equivalent was significantly lower in the toric group in comparison with the astigmatic SN60AT group. The toric group values were similar to the control group. Results are reported as mean±SD. p<0.05 is considered statistically significant. **p<0.001 between two groups. This figure is only reproduced in colour in the online version.
The difference in postoperative UDVA between the toric group and the astigmatic SN60AT group was statistically significant (p<0.001), while there was no statistically significant difference between the toric group and the control group (p>0.05) (figure 3).
(Enlarge Image)
Figure 3.
Preoperative and postoperative (3 months after surgery) uncorrected distance visual acuity (UDVA) (LogMAR). Mean postoperative UDVA was significantly better in the toric group in comparison with the astigmatic SN60AT group. The toric group values were similar to the control group. Results are reported as mean±SD. p<0.05 is considered statistically significant. **p<0.001 between two groups. This figure is only reproduced in colour in the online version.
There was a statistically significant difference in postoperative mean aberrometric values (MTF A/D, Strehl ratios and second order astigmatism) between the toric group and the astigmatic SN60AT group (p<0.001), while the difference between the toric group and the control group was not significant (p>0.05) (figures 4, 5). Preoperative and postoperative second order astigmatism RMS values (Z2, Z2) at a pupil diameter of 4 mm were 0.98±0.31 μm and 0.36±0.21 μm in the toric group, 0.68±0.46 μm and 0.63±0.26 μm in the astigmatic SN60AT group and 0.37±0.24 μm and 0.25±0.13 μm in the control group.
(Enlarge Image)
Figure 4.
Preoperative and postoperative modulated transfer function (MTF) area ratio (A/D), calculated by the OPD Scan II at spatial frequency from 0 to 60 cpd at a pupil diameter of 4 mm. Mean postoperative MTF A/D was significantly higher in the toric group in comparison with the astigmatic SN60AT group. The toric group values were similar to the control group. Results are reported as mean±SD. p<0.05 is considered statistically significant. **p<0.001 between two groups. This figure is only reproduced in colour in the online version.
(Enlarge Image)
Figure 5.
Preoperative and postoperative Strehl ratio, calculated by the OPD scan II at a pupil diameter of 4 mm. Mean postoperative Strehl ratio was significantly higher in the toric group in comparison with the astigmatic SN60AT group. The toric group values were similar to the control group. Results are reported as mean±SD. p<0.05 is considered statistically significant. **p<0.001 between two groups. This figure is only reproduced in colour in the online version.
The NEI-RQL 42 questionnaire scores at 3 months postoperatively were significantly better in the toric group compared with the astigmatic SN60AT group, including items related to astigmatism correction such as clarity of vision (p<0.001), far vision (p=0.021), glare (p=0.038) and satisfaction with correction (p=0.001) ( Table 2 ).