[Refractive precision and objective quality of vision after toric lens implantation in cataract surgery]

[The impact of the position of toric intraocular lenses on the functional outcomes of phaco surgery]

The article reviews data on the impact of the position (orientation) of toric intraocular lenses on the functional outcomes of cataract phacoemulsification surgery, discusses the algorithm of astigmatism correction with intraocular lenses including preoperative determination of the size and position of main meridians, calculation of lens parameters, marking of corneal meridians, intraoperative positioning, as well as rotation and/or repositioning of the lens when necessary.

Management of Cataract in Patients with Irregular Astigmatism with Regular Central Component by Phacoemulsification Combined with Toric Intraocular Lens Implantation

Purpose

To evaluate visual acuity (VA) and refractive status in patients with cataract and irregular astigmatism with a regular central component after phacoemulsification with implantation of a toric intraocular lens (IOL).

Methods

Patients with cataract associated with irregular astigmatism with a regular central component were enrolled. All patients underwent phacoemulsification and toric IOL implantation. Postoperative visual acuity, residual astigmatism, toric IOL rotation, higher-order aberration, and objective and subjective visual quality were measured 3 months after surgery.

Results

Twenty-three eyes were included in the study. The logMAR corrected and uncorrected distance visual acuity values were decreased at 3 months postoperatively (p  <  0.005). The preoperative average corneal astigmatism and postoperative residual astigmatism were 1.15–6.97 D (1.99 ± 1.26 D) and 0–2.75 D (0.65 ± 0.57 D), respectively. The average IOL rotation was 3.17 ± 2.01°. Some objective indicators of visual quality, including the modulation transfer function (p  <  0.05), Strehl ratio (p  <  0.005), 100% VA (p  <  0.005), 20% VA (p  <  0.005), and 9% VA (p  <  0.005), were significantly higher than the corresponding preoperative values. The objective scatter index (p  <  0.005) was significantly lower than that before surgery. The postoperative VF-14 scale score was 83.99 ± 14.58.

Conclusion

Toric IOL implantation has a good corrective effect on certain specific types of corneal irregular astigmatism with cataract. This effect can be attributed to its ability to correct the regular component of irregular astigmatism. The indications for toric IOL implantation could be expanded to some extent, thereby bringing benefit to more patients.

Early outcomes of vision and objective visual quality analysis after cataract surgery with trifocal intraocular lens implantation

AIM

To investigate the early outcomes of vision, objective visual quality and their correlation after cataract surgery with trifocal intraocular lens implantation.

METHODS

The visual examination and objective visual quality analysis using Optical Quality Analysis System (OQAS) at 1mo and 3mo, and defocus curve examination at 3mo were performed in 20 patients (27 eyes) after phacoemulsification combined with trifocal intraocular lens implantation surgery.

RESULTS

The uncorrected distant (UD), intermediate and near visual acuity (VA) were significantly improved after surgery (P<0.001). UDVA at 1mo after the surgery was slightly better than that after 3mo (P=0.026). The defocus curve after 3mo indicated that the peak of distant vision was close to 0 logMAR, and UDVA was lower than 0.3 logMAR in the range of -1.5 D to -3.0 D. The modulation transfer function (MTF) cutoff frequency, strehl ratio (SR), Optical Quality Analysis System values (OVs), includes OV100, OV20 and OV9 after the surgery were significantly better than before surgery (P<0.001), but the objective scattering index (OSI) was significantly decreased (P<0.001). UDVA at 3mo after the surgery had correlations with MTF cutoff, OSI, OV100 and OV20 (r=-0.400, 0.431, -0.437, -0.411, P=0.039, 0.025, 0.023, 0.033). The uncorrected intermediate VA after 3mo of the surgery had correlations with OSI and OV100 (r=0.478, -0.411, P=0.012, 0.033).

CONCLUSION

Trifocal intraocular lens implantation can provide good distant, intermediate and near VA, and the vision shows a well correlation with objective visual quality during early surgery.

Decentration following femtosecond laser small incision lenticule extraction (SMILE) in eyes with high astigmatism and its impact on visual quality

Background

To measure the decentration following SMILE in eyes with high myopic astigmatism and investigate its impact on visual quality.

Methods

The prospective study was conducted to analyze patients who underwent SMILE for correction of myopia and myopic astigmatism ≥2.5D (high astigmatism group, HA) at the ophthalmology department, Eye and ENT hospital, Shanghai, China.. Patients with myopic astigmatism < 1.5D served as controls (low astigmatism group, LA). Decentration was measured using a Scheimpflug camera with a difference map of the tangential curvature at 12 months postoperatively. Also the associations between decentration from the coaxial sighted corneal light reflex (CSCLR) and the visual outcomes, correction efficacy of astigmatism, wavefront aberrations and objective scatter index (OSI) were analyzed.

Results

No significant differences were observed in the decentered distance between HA and LA in either eyes (OD: HA: 0.18 ± 0.10 mm, LA: 0.20 ± 0.14 mm, P = 0.659; OS: HA: 0.22 ± 0.11 mm, LA: 0.20 ± 0.11 mm, P = 0.637). The analysis across the three levels of decentration (< 0.1 mm, 0.1–0.2 mm, and > 0.2 mm) showed no significant association between decentration and visual outcomes of predictability, efficiency, safety, MTF cutoff, OSI, SR and OVs in both groups. Also no significant association was observed between decentration and postoperative astigmatism in either group. A significant relationship between the magnitude of decentration and induced coma and spherical aberration was observed in HA.

Conclusions

The amount of decentration between HA and LA groups showed no differences. Decentration > 0.20 mm from CSCLR resulted in greater induction of coma and SA after SMILE in eyes with HA.

[Toric lens implantation in cataract surgery: Automatic versus manual horizontal axis marking, analysis of 50 cases]

SUBJECT

The main objective of our study is to evaluate the contribution of automated conjunctival recognition in the alignment of toric implants by comparing the automatic alignment optimized with Callisto™ to the manual marking of the horizontal axis.

MATERIALS AND METHODS

We performed a prospective, descriptive, and monocentric study on patients undergoing cataract surgery with toric implantation (Asphina 709 Zeiss), operated by a surgeon with good experience in toricity, between September 2016 and March 2017. We analyzed the agreement between the manual marking of the 0°-180° axis versus the one automatically generated by the Callisto™, as well as the alignment of the IOL and the refractive results at 1 month.

RESULTS

We included 50 eyes of 26 patients. The corrected mean astigmatism was 1.9 D. The mean difference between the 2 axes was 4.7° [0°-12.3°]. Only 50 % of the preoperative manual markings were consistent with the automatic measurement (<5°). At one month, the average rotation recorded was 4.3° [0°-29°]. The alignment was identical for 70 % (n=35) of the IOL (≤5°). As for residual subjective astigmatism, it was on average 0.58 D. The mean visual acuity without correction was 8/10 and 55 % had 10/10 without correction.

DISCUSSION

The refractive performance depends on the preoperative measurement, the correct alignment of the IOL and its stability in the bag. Our study shows the value of automatic conjunctival recognition in the determination of the axis of peroperative alignment, even in an experienced operator. This precision is essential for a good refractive result, especially since the residual astigmatism in case of misalignment will increase with the power of the implant.

CONCLUSION

Our study shows excellent refractive results, whatever the initial astigmatism, using the automatic alignment. The precision of the toric implantation opens the way to the toric multifocal implantation under the best conditions.

Toric lens implantation in cataract surgery: Automated versus manual horizontal axis marking, analysis of 50 cases

SUBJECT

The main objective of our study was to evaluate the contribution of automated conjunctival registration in the alignment of toric intraocular lenses by comparing automated registration optimized with Callisto^® to manual marking of the horizontal axis.

MATERIALS AND METHODS

We performed a prospective, descriptive, monocentric study on patients undergoing cataract surgery with a toric intraocular lens (Asphina 709 Zeiss), performed by a surgeon with good experience in toric implants, between September 2016 and March 2017. We analyzed the agreement between the manual marking of the 0-180° axis versus the one automatically generated by the Callisto™, as well as the alignment of the IOL and the refractive results at 1 month.

RESULTS

We included 50 eyes of 38 patients. The mean corrected astigmatism was 1,9 D. The mean difference between the 2 axes was 4,7° [0-12.3°]. Only 50 % of the preoperative manual markings were consistent with the automated measurement (<5°). At one month, the mean rotation recorded was 4,3° [0-29°]. The alignment was identical for 70 % (n=35) of the IOLs (≤5°). As for residual subjective astigmatism, the mean was 0.58 D. The mean visual acuity without correction was 8/10 and 55 % saw 10/10 without correction.

DISCUSSION

Refractive performance depends on preoperative measurement, correct alignment of the IOL and its stability in the bag. Our study shows the value of automated conjunctival registration in the determination of the intraoperative axis of alignment, even with an experienced surgeon. This precision is essential for a good refractive result, especially since residual astigmatism in the case of misalignment will increase with the power of the implant.

CONCLUSION

Our study shows excellent refractive results, regardless of the initial astigmatism, using automated alignment. Precision of toric implantation opens the way to toric multifocal implantation under the best conditions.

Optical quality of toric intraocular lens implantation in cataract surgery

AIM

To analyze the optical quality after implantation of toric intraocular lens with optical quality analysis system.

METHODS

Fifty-two eyes of forty-four patients with regular corneal astigmatism of at least 1.00 D underwent implantation of AcrySof toric intraocular lens, including T3 group 19 eyes, T4 group 18 eyes, T5 group 10 eyes, T6 group 5 eyes. Main outcomes evaluated at 3mo of follow-up, included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), residual refractive cylinder and intraocular lens (IOL) axis rotation. Objective optical quality were measured using optical quality analysis system (OQAS II(®), Visiometrics, Spain), included the cutoff frequency of modulation transfer function (MTFcutoff), objective scattering index (OSI), Strehl ratio, optical quality analysis system value (OV) 100%, OV 20% and OV 9% [the optical quality analysis system (OQAS) values at contrasts of 100%, 20%, and 9%].

RESULTS

At 3mo postoperative, the mean UDVA and CDVA was 0.18±0.11 and 0.07±0.08 logMAR; the mean residual refractive cylinder was 0.50±0.29 D; the mean toric IOL axis rotation was 3.62±1.76 degrees, the mean MTFcutoff, OSI, Strehl ratio, OV 100%, OV 20% and OV 9% were 22.862±5.584, 1.80±0.84, 0.155±0.038, 0.76±0.18, 0.77±0.19 and 0.78±0.21. The values of UDVA, CDVA, IOL axis rotation, MTFcutoff, OSI, Strehl ratio, OV100%, OV20% and OV9% depending on the power of the cylinder of the implantation were not significantly different (P>0.05), except the residual refractive cylinder (P<0.05).

CONCLUSION

The optical quality analysis system was useful for characterizing the optical quality of AcrySof toric IOL implantation. Implantation of an AcrySof toric IOL is an effective and safe method to correct corneal astigmatism during cataract surgery.