Long-term rotational stability and visual outcomes of a single-piece hydrophilic acrylic toric IOL: a 1.5-year follow-up

Modified femtosecond laser-assisted arcuate keratotomy for managing low corneal astigmatism using trifocal intraocular lens implantation in Chinese cataract patients

To evaluate the visual outcome and astigmatic correction following trifocal intraocular lens (IOL) implantation using the modified femtosecond laser-assisted arcuate keratotomy (FSAK) in Chinese cataract patients with low astigmatism. This retrospective study included consecutive cataract patients with regular corneal astigmatism ranging from 0.75 to 1.5 D who underwent FSAK combined with the trifocal IOL implantation between November 2020 and September 2022. Monocular uncorrected distance visual acuity, uncorrected intermediate visual acuity, uncorrected near visual acuity, and refractive data were collected at the 3-month follow-up. The pre- and post-operative high-order aberrations (HOAs) were recorded. The variation in astigmatism was analyzed using Alpins vector analysis. A total of 27 eyes from 23 patients were analyzed. The monocular uncorrected distance visual acuity (UDVA) (5 m) at the 3-month follow-up was 0.04 ± 0.09 logarithm of the minimum angle of resolution (logMAR), which was significantly improved compared with the preoperative value of 0.95 ± 0.51 logMAR (P <.001). The corneal astigmatism was significantly reduced from 1.24 ± 0.42 D to 0.49 ± 0.34 D (P <.001). The target-induced astigmatism (TIA) was 1.25 ± 0.43 D, the surgically induced astigmatism (SIA) was 1.16 ± 0.52 D, and the difference vector (DV) was 0.5 ± 0.34 D. The magnitude of error (ME) (difference between SIA and TIA) was -0.1 ± 0.41 D, and the correction index (CI) (ratio of SIA to TIA) was 0.93 ± 0.36. The angle of error was 3.92° ± 16.90°. Total HOA was reduced from 0.89 ± 1.11 to 0.41 ± 0.55 (P = 0.184), and the corneal HOA was lowered from 0.17 ± 0.18 to 0.10 ± 0.10 (P = 0.129). Implantation of trifocal IOL following the modified FSAK in Chinese cataract patients exhibited excellent visual efficacy and effectively reduced corneal astigmatism.

Insights into the rotational stability of toric intraocular lens implantation: diagnostic approaches, influencing factors and intervention strategies

Toric intraocular lenses (IOLs) have been developed to enhance visual acuity impaired by cataracts and correct corneal astigmatism. However, residual astigmatism caused by postoperative rotation of the toric IOL is an important factor affecting visual quality after implantation. To decrease the rotation of the toric IOL, significant advancements have been made in understanding the characteristics of toric IOL rotation, the factors influencing its postoperative rotation, as well as the development of various measurement techniques and interventions to address this issue. It has been established that factors such as the patient's preoperative refractive status, biological parameters, surgical techniques, postoperative care, and long-term management significantly impact the rotational stability of the toric IOL. Clinicians should adopt a personalized approach that considers these factors to minimize the risk of toric IOL rotation and ensure optimal outcomes for each patient. This article reviews the influence of various factors on toric IOL rotational stability. It discusses new challenges that may be encountered to reduce and intervene with rotation after toric IOL implantation in the foreseeable future.

Long-term outcomes of cataract surgery with toric intraocular lens implantation by the type of preoperative astigmatism

Surgical outcomes of toric intraocular lens (IOL) implantation for 8 years after surgery were analyzed. Data were retrospectively collected in 176 eyes of 176 patients before and 1 month, 1, 3, 5, and 8 years after phacoemulsification and implantation of a toric IOL. Preoperative corneal and postoperative manifest astigmatism was analyzed by converting to power vector notations; horizontal/vertical (J₀) and oblique (J₄₅) astigmatism components. Toric IOL implantation significantly reduced pre-existing astigmatism by decreasing J₀ in eyes with preoperative with-the-rule (WTR) astigmatism, increasing J₀ in eyes with against-the-rule (ATR) astigmatism, and correcting J₄₅ in eyes with oblique astigmatism. After surgery, the eyes with preoperative ATR astigmatism showed a significant ATR astigmatic shift, and J₀ at 5 and 8 years was significantly smaller than that at 1 month postoperatively. Uncorrected distance visual acuity was also significantly worse at 5 and 8 years than at 1 month postoperatively. In eyes with WTR and oblique astigmatism, the effects of toric IOLs on astigmatism and visual acuity were sustained for 8 years. The long-term astigmatism-correcting effects did not differ among the models of toric IOL used in this study, SN6AT3–8 (Alcon Laboratories). In eyes with preoperative ATR astigmatism, astigmatism-correcting effects of toric IOLs decreased at 5 years and later postoperatively, indicating that overcorrection may be considered at the time of cataract surgery. In eyes with WTR and oblique astigmatism, the effects of toric IOLs were maintained throughout the 8-year follow-up period.

Long-term changes in the refractive effect of a toric intraocular lens on astigmatism correction

Purpose

To examine the long-term changes in the astigmatism-correcting effect of a toric intraocular lens (IOL) after stabilization of surgically induced astigmatic changes due to cataract surgery.

Methods

Unilateral eyes of 120 patients that received a toric IOL for against-the-rule (ATR) or with-the-rule (WTR) astigmatism were enrolled. Manifest refractive and anterior corneal astigmatism, and ocular residual astigmatism which is mainly derived from internal optics were examined preoperatively, at approximately 2 months postoperatively (baseline) and at 5 ~ 10 years postbaseline. The astigmatism was decomposed to vertical/horizontal (Rx) and oblique components (Ry), which was compared between baseline and 5 ~ 10 years postbaseline.

Results

In the eyes having ATR astigmatism, the mean Rx and Ry of the manifest refractive and corneal astigmatism significantly changed toward ATR astigmatism between the baseline and 5 ~ 10 years postbaseline (p ≤ 0.0304), but those of ocular residual astigmatism did not change significantly between the 2 time points. In the eyes having WTR astigmatism, the Rx and Ry of refractive, corneal, and ocular residual astigmatism did not change significantly between the 2 time points. Double-angle plots revealed an ATR shift in refractive and corneal astigmatism and no marked change in the ocular residual astigmatism in the eyes with ATR astigmatism, and there is no change in this astigmatism in the eyes with WTR astigmatism.

Conclusion

The long-term changes with age in the effect of a toric IOL significantly deteriorated due to an ATR shift of corneal astigmatism in the eyes having ATR astigmatism, while it was maintained in eyes having WTR astigmatism, suggesting that ATR astigmatism should be overcorrected.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00417-021-05406-7.

Rotational stability of a new multicomponent intraocular lens

Purpose

To evaluate the rotational stability of the Precisight multicomponent intraocular lens (MCIOL) following primary implantation and after enhancement procedures.

Patients and methods

Prospective, single-center study of eyes that underwent routine cataract surgery with implantation of a non-toric MCIOL, (Precisight, InfiniteVision, Optics, Strasbourg, France). The axis of the MCIOL was measured with a line bisecting the two dialing holes in the front lens. Intraoperative orientation was determined using a digital surgical guidance system while the postoperative orientation was determined using slit-lamp imaging. Two populations were analyzed: eyes that only underwent cataract surgery (PRIM) and eyes that also underwent enhancement (ENH), consisting of surgical front optic exchange. Both populations had 3 observation visits: first implantation (P-Op); 3 months (3mo) and 6 months (6mo) after primary surgery. The ENH group had an additional fourth visit that corresponded to the enhancement surgery (E-Op). The main outcome measure was mean absolute change in MCIOL orientation (degrees). The effects of axial length (AL) and anterior chamber depth (ACD) on IOL rotational stability were examined.

Results

Thirty-three eyes received MCIOL of which 29 had usable orientation images. Of these, 12 were in the PRIM group and 17 underwent ENH. Regarding the mean absolute rotation, among PRIM eyes, P-Op to 3mo was 3.03±2.45 degrees; P-Op to 6mo, 2.28±1.54 degrees; and 3–6mo, 2.37±1.56 degrees. Among the ENH eyes, P-Op to 3mo was 3.09±1.68; E-Op to 6mo, 2.71±3.30 and P-Op to 6mo, 3.62±3.42. There were no significant differences in the IOL rotation. There were no statistical differences in rotational stability between the ENH and PRIM groups. There was no correlation between IOL rotation and AL or ACD.

Conclusion

Precisight appears to be rotationally stable. The enhancement procedure does not affect rotational stability.

Early Postoperative Rotational stability and its related factors of a single-piece acrylic toric intraocular lens

Purpose

In the present study, we aimed to evaluate the early postoperative rotational stability of TECNIS toric intraocular lens (IOL) and analyse its correlation with preoperative and intraoperative parameters.

Methods

A total of 102 eyes from 87 cataract patients who underwent implantation of TECNIS toric IOL during July 2016 to November 2017 were enrolled in this retrospective study. Preoperative parameters including corneal astigmatism, axial length (AL), lens thickness (LT), anterior chamber depth (ACD) and sulcus-to-sulcus (STS), were determined. The area of capsulorhexis was measured with Rhinoceros 5.0 software. The follow-up examinations including the residual astigmatism (RAS) and postoperative toric IOL axis, were performed at 1 month and 3 months after surgery.

Results

RAS was −0.84 ± 0.88 D at 1 month and −0.81 ± 0.89 D at 3 months after surgery. The rotation of toric IOL at 3 months was 4.83 ± 3.65°. The Pearson’s r of ACD, horizontal and vertical STS, and toric IOL target axis was 0.011, 0.039, 0.045 and 0.082. The toric IOL rotation was positively correlated with the area of capsulorhexis (r = 0.522, P = 0.0003), LT (r = 0.288, P = 0.003) and AL (r = 0.259, P = 0.009). As for the area of capsulorhexis, the regressive equation was: y = 0.682 × −13.105, demonstrating that the diameter of capsulorhexis should be controlled within 5.8 mm to maintain the toric IOL rotation within 5.0°.

Conclusions

TECNIS toric IOLs possessed great early postoperative rotational stability. The area of capsulorhexis, AL and LT were positively correlated with postoperative rotational stability. A capsulorhexis within 5.8 mm had an important significance in improving rotational stability.