Three-Dimensional Morphology Study of Capsule in Pseudophakic Eyes with High-Speed Swept-Source Optical Coherence Tomography

Comparison of the effect of capsular bend on the rotational stability between 2 toric intraocular lenses

PURPOSE

To compare the effect of capsular bend on the rotational stability between 2 toric intraocular lenses (IOLs).

SETTING

Eye Hospital of Wenzhou Medical University, Hangzhou, Zhejiang Province, China.

DESIGN

Prospective study.

METHODS

Patients with preexisting astigmatism received AcrySof IQ (SN6AT) or TECNIS (ZCT/ZMT) toric IOL during cataract surgery. CASIA2 was used to record the toric IOL axial orientation and capsular bend index (CBI) at the 1-day, 1-week, 1-month, and 3-month interval postoperatively. The postoperative rotational stability and CBI of both models were compared.

RESULTS

A total of 58 eyes from 58 patients were enrolled in this study. The total misalignment of the TECNIS (ZCT/ZMT) group (6.96 ± 5.10 degrees, 7.41 ± 5.19 degrees, 6.93 ± 5.29 degrees, and 6.86 ± 5. 27 degrees) was significantly higher than that of the AcrySof IQ (SN6AT) group (3.55 ± 2.21 degrees, 4.00 ± 2.74 degrees, 3.72 ± 2.72 degrees, and 3.52 ± 2.50 degrees) at all follow-up intervals ( P < .05). The mean rotation of the TECNIS (ZCT/ZMT) group (2.66 ± 2.18 degrees) was significantly greater than that of the AcrySof IQ (SN6AT) group (1.65 ± 1.47 degrees) from 1 day to 1 week postoperatively ( P < .05). The capsular bend formation in the TECNIS (ZCT/ZMT) group was delayed compared with the AcrySof IQ (SN6AT) group ( P < .05, at the 1-week, 1-month, and 3-month interval). The TECNIS (ZCT/ZMT) group showed fibrosis in the peripheral anterior capsule, leading to its stretching away from the IOL surface, while the AcrySof IQ (SN6AT) group exhibited gentle adherence of the anterior capsule to the IOL surface.

CONCLUSIONS

The AcrySof IQ toric IOL (SN6AT) exhibited greater rotational stability than the TECNIS toric IOL (ZCT/ZMT), which may partially result from the delay in capsular bend formation of TECNIS at the 1-day to 1-week follow-up postoperatively.

Effect of capsular bend on the rotational stability of toric intraocular lens

PURPOSE

To assess the effect of capsular bend and axial length on the rotational stability of toric IOL.

METHODS

The prospective study included patients with preexisting astigmatism that were implanted with Acrysof IQ Toric IOL. According to the pre‑operative axial length, all patients were divided into 2 groups: high myopia (AL ≥ 26 mm) group, and emmetropia or low to moderate myopia group (AL <26 mm). High-speed Swept-source Optical Coherence Tomography (SS-OCT) radial scanning was performed after pupil dilation to obtain the toric IOL axial orientation and capsular bending index (CBI) at 1-day, 1-week, 1-month and 3-month intervals postoperatively. The correlation between the rotation of toric intraocular lens and the axial length or CBI was subsequently analyzed.

RESULTS

68 eyes of 57 patients were included in the research. The rotation of toric IOL within the high myopia group was greater than the control group (P = 0.001, 1month postoperative). Capsular contact with the IOL was delayed in highly myopic eyes, although the results were not statistically significant (P = 0.094, 1-month postoperatively). There was a positive correlation between the degree of rotation and axial length at the interval found between 1-week and 1-month after the operation (r = 0.333, P = 0.005). There was a significant negative correlation between the IOL rotational speed and CBI (P < 0.001). The regression equation was Y = -0.441*X + 1.712 (R2 = 0.323, P < 0.001).

CONCLUSION

There was a significant negative correlation between the IOL rotation speed and the CBI, while the influence of the axial length and capsular bending mainly occurred between one week and one month after the operation.

The Relationship Between the Change of Intraocular Lens Position and Capsular Bend After Cataract Surgery

PURPOSE

To explore the relationship between the change in intraocular lens (IOL) position and capsular bend after cataract surgery.

METHODS

Patients underwent phacoemulsification and IOL implantation (Alcon Laboratories, Inc). Patients were divided into two groups based on preoperative axial length: long axial length group (axial length ⩾ 26 mm) and normal axial length group (axial length > 22 but < 26 mm). Swept-source optical coherence tomography was performed at 1 day, 1 week, 1 month, and 3 months after mydriasis to obtain postoperative aqueous depth (PAD) and capsular bend index (CBI). The relationship between CBI and PAD changes was analyzed.

RESULTS

Eighty patients (80 eyes) were included in the study. PAD decreased gradually from 1 day to 1 week and increased from 1 week to 3 months. Mean CBI was moderately positively correlated with PAD changes (r = 0.586, P < .001). The IOL moved forward gradually when the CBI was less than 2.30 and the IOL gradually moved backward when the CBI was 2.30 or greater. The root mean square of the change in PAD was smaller in the long axial length group (0.08 ± 0.04 mm) than in the normal axial length group (0.09 ± 0.05 mm) during the 3 months after surgery (P = .036).

CONCLUSIONS

The position of the IOL was almost stable 1 month after operation, and postoperative capsule adhesion mainly occurred within 1 month. The change in PAD was related to capsule adhesion. The postoperative position of the IOL was relatively stable and capsular bend was relatively slow for the long axial length group over 3 months. [J Refract Surg. 2021;37(5):324-330.].