Characteristics and factors associated with the position of the haptic after ICL V4C implantation

Effect of anterior segment structure on vault and position after implantable collamer lens implantation

PURPOSE

To evaluate the effect of anterior-segment structure on vault and position after implantable collamer lens (ICL) implantation using ultrasound biomicroscopy.

METHODS

The retrospective case-control study included insufficient vault eyes (<250 µm), ideal vault eyes (250-750 µm), and excessive vault eyes (>750 µm). The preoperative biometric parameters of the anterior-segment structure and basic data between the three groups were analyzed using one-way analysis of variance.

RESULTS

There were significant differences ( P < 0.05) between the three groups in maximum ciliary body thickness (CBT max ), iris-zonule distance (IZD), and trabecular-ciliary angle (TCA). The vault gradually decreased as CBT max decreased and TCA increased. In the pairwise comparison, the CBT max comparison between the insufficient vault (<250 µm) group and the excessive vault (>750 µm) group was statistically significant ( P = 0.024, 95% CI: -0.17-0.017 µm); the TCA comparison between the insufficient vault (<250 µm) group and the excessive vault (>750 µm) group was statistically significant ( P = 0.005, 95% CI: 1.78°-12.15°); The IZD comparison between the insufficient vault (<250 µm) group and the excessive vault (>750 µm) group was statistically significant ( P = 0.037, 95% CI: 0.0027-0.1119 µm). The analysis of 284 ICL haptics locations showed that there were 16.67%, 32.69%, and 70.83% haptics located in the ciliary sulcus in three groups, respectively.

CONCLUSION

The vault and ICL haptics position are related to anterior-segment structure. A thinner and posteriorly positioned ciliary body would increase the risk of low vault and fewer ICL haptics located in the ciliary sulcus after ICL implantation. This provides guidance for the selection of the ICL size and placement position before surgery.

Distribution and associations of anterior lens zonules lengths in patients with cataract

PURPOSE

To investigate the characteristics and associations of anterior lens zonules lengths in cataract patients via ultrasound biomicroscope (UBM) measurement.

METHODS

Patients with age-related cataracts and high myopic cataracts who planned to undergo cataract surgery were included in the study. After routine ophthalmic examinations, the UBM was performed on both eyes to get images of the anterior lens zonules, and Image J software was used to measure the lengths of the lens zonules. Axial length (AL), anterior chamber depth (ACD), lens thickness (LT), and white-to-white (WTW) diameter of both eyes were obtained by IOL Master 700. Univariate and multivariate regression analyses were used to assess associated factors of anterior lens zonules lengths.

RESULTS

Forty-nine patients with age-related cataracts and 33 patients with high myopic cataracts were enrolled. High myopic cataract patients were younger and had longer anterior lens zonules. Multivariate regression analysis showed that anterior lens zonules lengths were associated with axial lengths (temporal location: β = 0.036, P = 0.029; nasal location: β = 0.034, P = 0.011; superior location: β = 0.046, P = 0.002) and ACD (inferior location: β = 0.305, P = 0.016) in right eyes. In left eyes, anterior lens zonules lengths were associated with axial lengths (temporal location: β = 0.028, P = 0.017; inferior location: β = 0.026, P = 0.016; nasal location: β = 0.033, P < 0.001) and ACD (inferior location: β = 0.215, P = 0.030; superior location: β = 0.290, P = 0.011).

CONCLUSIONS

High myopic cataract patients have longer anterior lens zonules. AL and ACD contributed to the lengths of anterior lens zonules. Thus, for patients with long AL and deeper ACD, lens zonules measurement was crucial.

CLINICAL TRIAL REGISTRATION

www.chictr.org.cn identifier is ChiCTR2300071397.

The comparison of white-to-white via triple person-times caliper measuring and machine-measuring in V4c implantable collamer lens implantation

This study aimed to compare the differences and characteristics of white-to-white (WTW) values obtained before V4c implantation using triple person-times caliper, IOL-Master 700, Pentacam HR, and UBM, and to assess their correlation with vaulting. A total of 930 myopia patients (1842 eyes) who were interested in undergoing ICL surgery were assessed before the procedure using various instruments. The WTW measurements were obtained using a triple person-times caliper, Pentacam HR, and IOL-Master 700, whereas the angle-to-angle (ATA) measurements were obtained using UBM. The size of the ICL was subsequently calculated using triple person-times caliper measurements. The vault of the ICL was assessed using Pentacam HR three months after the surgery. The WTW was determined to be 11.30 ± 0.29 mm, 11.43 ± 0.29 mm, and11.86 ± 0.38 mm, respectively, using the triple person-times caliper, Pentacam HR, and IOL-Master 700. The measurement of ATA was 11.57 ± 0.51 mm, as done by UBM. The ICL vault was measured to be 400.97 ± 198.46 µm when examined with Pentacam HR three monthsafter the procedure. The linear regression analyses of ICL size and WTW of triple person-times caliper, ICL vault and WTW were (R = 0.703, p < 0.001; R = 0.0969, p < 0.001) respectively. The highest correlation was found between IOL-Master and Pentacam HR (r = 0.766, p = 0.000). The lowest correlation was found between UBM and Pentacam HR (r = 0.358, p = 0.002). Bland-Altman analysis showed that the 95% limits of agreement (LoA) were the triple person-times caliper and Pentacam HR (- 0.573, 0.298) and the triple person-times caliper and UBM (- 1.15, - 0.605). This indicated a strong agreement between the triple person-times caliper and Pentacam HR and a lack of agreement between the triple person-times caliper and UBM. Triple person-times caliper measurements offer excellent maneuverability, practicality, and reliable outcomes for determining ICL vaults. Measurements obtained using the triple-person caliper were less differece than those obtained using the Pentacam HR.

Evaluation of a new dynamic real-time visualization 25 kHz swept-source optical coherence tomography based biometer

BACKGROUND

To evaluate the intraobserver repeatability and interobserver reproducibility of a newly developed dynamic real-time visualization 25 kHz swept-source optical coherence tomography (SS-OCT) based biometer (ZW-30, TowardPi Medical Technology Ltd, China) and compare its agreement with another SS-OCT based biometer (IOLMaster 700, Carl Zeiss Meditec AG, Jena, Germany).

METHODS

Eighty-two healthy right eyes were enrolled in this prospective observational study. Measurements were repeated for three times using the ZW-30 and IOLMaster 700 in a random order. Obtained parameters included axial length (AL), central corneal thickness (CCT), aqueous depth (AQD), anterior chamber depth (ACD), lens thickness (LT), mean keratometry (Km), astigmatism magnitude (AST), vector J0, vector J45, and corneal diameter (CD). The within-subject standard deviation (Sw), test-retest (TRT) variability, coefficient of variation (CoV), and intraclass correlation coefficient (ICC) were adopted to assess the intraobserver repeatability and interobserver reproducibility. The double-angle plot was also used to display the distribution of AST. To estimate agreement, Bland-Altman plots were used.

RESULTS

For the intraobserver repeatability and interobserver reproducibility, the Sw, TRT and CoV for all parameters were low. Meanwhile, the ICC values were all close to 1.000, except for the J45 (ICC = 0.887 for the intraobserver repeatability). The double-angle plot showed that the distribution of AST measured by these two devices was similar. For agreement, the Bland-Altman plots showed narrow 95% limits of agreements (LoAs) for AL, CCT, AQD, ACD, LT, Km AST, J0, J45, and CD (- 0.02 mm to 0.02 mm, - 7.49 μm to 8.08 μm, - 0.07 mm to 0.04 mm, - 0.07 mm to 0.04 mm, - 0.07 mm to 0.08 mm, - 0.16 D to 0.30 D, - 0.30 D to 0.29 D, - 0.16 D to 0.16 D, - 0.23 D to 0.13 D, and - 0.39 mm to 0.10 mm, respectively).

CONCLUSIONS

The newly dynamic real-time visualization biometer exhibited excellent intraobserver repeatability and interobserver reproducibility. The two devices both based on the SS-OCT principle had similar ocular parameters measurement values and can be interchanged in clinical practice.

Risk factors associated with haptic malposition in eyes implanted with implantable collamer lenses

PURPOSE

To examine the risk factors for haptic malposition in eyes with implantable collamer lens (ICL).

SETTING

Eye and ENT Hospital, Fudan University, Shanghai, China.

DESIGN

Prospective nonrandomized observational study.

METHODS

This study included 134 (77.9%) of 172 initially enrolled patients who underwent ICL implantation and completed a 1-year follow-up. The extent of haptics present in the ciliary sulcus (ICS) was measured. Patients were categorized based on ICS count (0 to 4). The position of the haptics was quantified as the distance between the iris root and the terminal tip of ICL haptics (iris root to haptic tip, IRH). The related factors to the ICS count and its correlation with the central vault were analyzed.

RESULTS

ICS distribution was 0 ICS in 19 eyes (14.2%), 1 in 22 eyes (16.4%), 2 in 32 eyes (23.9%), 3 in 29 eyes (21.6%), and 4 in 32 eyes (23.9%). Parameters like maximum ciliary body thickness (CBTmax, P = .008), iris-ciliary process distance (ICPD, P < .001), and ciliary process length ( P = .034) varied significantly across ICS groups. A multiple linear regression analysis revealed that the iris-ciliary angle ( P = .006), CBTmax ( P = .007), the distance between the sulcus-to-sulcus plane and the anterior crystalline lens surface (STSL, P = .035), and ICL size ( P = .015) were significantly associated with IRH. Spherical equivalents ( P = .042), STSL ( P = .001), and ICS count ( P = .020) significantly correlated with the central vault.

CONCLUSIONS

Shortened ciliary process is a primary risk for haptic malposition. The ICS count significantly relates to the central vault.

Clinical decision support system based on deep learning for evaluating implantable collamer lens size and vault after implantable collamer lens surgery: a retrospective study

OBJECTIVES

To aid doctors in selecting the optimal preoperative implantable collamer lens (ICL) size and to enhance the safety and surgical outcomes of ICL procedures, a clinical decision support system (CDSS) is proposed in our study.

DESIGN

A retrospective study of patients after ICL surgery.

SETTING

China Tertiary Myopia Prevention and Control Center.

PARTICIPANTS

2772 eyes belonging to 1512 patients after ICL surgery. Data were collected between 2018 and 2022.

OUTCOME MEASURES

A CDSS is constructed and used to predict vault at 1 month postoperatively and preoperative ICL dimensions using various artificial intelligence methods. Accuracy metrics as well as area under curve (AUC) parameters are used to determine the CDSS prediction methods.

RESULTS

Among the ICL size prediction models, conventional neural networks (CNNs) achieve the best prediction accuracy at 91.37% and exhibit the highest AUC of 0.842. Regarding the prediction model for vault values 1 month after surgery, CNN surpasses the other methods with an accuracy of 85.27%, which has the uppermost AUC of 0.815. Thus, we select CNN as the prediction algorithm for the CDSS.

CONCLUSIONS

This study introduces a CDSS to assist doctors in selecting the optimal ICL size for patients while improving the safety and postoperative outcomes of ICL surgery.

Analysis of biometric parameters of cataract eyes measured with optical biometer Lenstar LS900, IOL Master 700, and OPD-SCAN III

BACKGROUND

To compare the characteristics of biometric measurements among the LS900, IOL Master, and OPD-SCAN III in patients with mild-to-moderate cataract.

METHODS

We recruited 85 eyes of 78 patients diagnosed with mild-to-moderate cataract at our hospital between January and April 2023. The K (average corneal curvature; K1 and K2), astigmatism (AST), and white to white (WTW) were measured using those three devices, respectively. Differences and correlations between those measures based on the device were explored.

RESULTS

The K1, K2, and AST were highly consistent among the groups (P = 0.851, P = 0.626, P = 0.473, respectively). The WTW measured by IOL Master were larger than those measured by the LS900 and OPD-SCAN III (all P < 0.001). However, all three devices were highly correlated in all measures (P < 0.001). Bland-Altman plots indicated a significant agreement between three devices in all measurements (P < 0.001).

CONCLUSIONS

K1, K2, and AST in patients with mild-to-moderate cataract were similar among all three devices, whereas the WTW were not. WTW measurement differences between three devices should be concerned in cataract cases.