Effects of lighting conditions and accommodation on the three-dimensional position of Visian implantable collamer lens

Pharmacological Accommodative Changes of Haptic Position and Its Impact on Vault After ICL Implantation

PURPOSE

To evaluate dynamic changes in ciliary parameters and Implantable Collamer Lens V4C (ICL) (STAAR Surgical) haptic position using mydriatic and miotic agents and their effects on the central and peripheral vault.

METHODS

This study involved 80 eyes from 40 consecutive patients (mean age: 28.05 years; range: 19 to 42 years) examined 3 months after ICL implantation. Patients were randomly assigned to either a mydriasis group or a miosis group. Ultrasound biomicroscopy was used to measure the following parameters at baseline and after pharmacological induction with tropicamide or pilocarpine: ciliary process length (CPL), iris ciliary angle (ICA), final tip point of the ICL haptic (ftICL haptic), central vault (c-vault), mid-peripheral vault (m-vault), and peripheral vault (p-vault).

RESULTS

In the mydriatic group, the proportion of eyes with all ICL haptics in the ciliary sulcus increased from 70.0% to 77.5% after tropicamide administration, whereas in the miotic group, this proportion decreased from 67.5% to 57.5% after pilocarpine administration. The CPL and ftICL haptic increased significantly in the mydriatic group (all P < .01) but decreased in the miotic group (all P < 0.01). Conversely, the ICA decreased significantly in the mydriatic group and increased in the miotic group (all P < .01). The correlation analysis showed no significant relationship between changes in c-vault, m-vault, and p-vault with alterations in CPL, ICA, and ftICL haptic in both groups.

CONCLUSIONS

Haptic position contributes to the movement of the ICL optical zone during accommodation, but changes in haptic position were not significantly correlated with changes in the vault. [J Refract Surg. 2025;41(1):e22-e28.].

Characterization of vault with two models of posterior chamber phakic intraocular lenses

PURPOSE

To evaluate and compare dynamic vault range (DVR) and asymmetry of the vault during a 3-month follow-up after the implantation of 2 posterior chamber phakic intraocular lenses (pIOLs).

SETTING

Aver Clinic, Madrid, Spain.

DESIGN

Prospective comparative study.

METHODS

119 eyes (65 patients) that underwent refractive surgical correction with implantation of 1 of 2 distinct pIOLs were enrolled: Eyecryl Phakic from Biotech Vision Care (Eyecryl group, 72 eyes) and Evo Visian Implantable Contact Lens from Staar Surgical (ICL group, 47 eyes). Besides evaluation of visual acuity, refraction, and ocular integrity, the pIOL vault centrally and at 2 mm nasally and temporally as well as the DVR from photopic (50 lux) to mesopic (10 lux) illumination conditions were measured.

RESULTS

No significant differences were found between the pIOL groups in visual and refractive outcomes ( P ≥ .454). No significant differences between the groups were found in central (523.72 ± 168.4 vs 494.16 ± 156.7 μm, P = .248) and temporal (499.43 ± 155.8 vs 431.28 ± 150.5 μm, P = .067) vaults. However, nasal vault was significantly lower in the ICL group (465.6 ± 149.1 vs 375.4 ± 144.0 μm, P = .045). A trend of a larger DVR was observed in the ICL group, although differences between groups did not reach statistical significance (54.00 ± 36.39 vs 86.5 ± 57.9 μm, P = .070). The pIOL diameter only correlated significantly with vault measurements in the ICL group ( r ≥ 0.650, P < .001).

CONCLUSIONS

The Eyecryl pIOL showed more symmetric vaults and a trend of fewer light-induced changes in the central vault compared with the ICL pIOL. The clinical relevance of this finding should be investigated further.

Influencing factors comparing different vault groups after phakic implantable collamer lens implantation: review and meta-analysis

BACKGROUND

Studies on the factors affecting vault after posterior chamber phakic Implantable Collamer Lens (ICL) have been carried out, but most of them are single-centered and subjective selections of parameters. The present study aimed to systematically analyze the factors for vault.

METHODS

A systematic review of case series, case-control, and cohort studies derived from the articles published in PubMed, the Cochrane Library, Embase, Web of Science, CNKI, CBM, Wanfang and VIP, as well as ClinicalTrials, which were conducted to search for studies on factors of vault using four core terms: phakic intraocular lenses, vault, risk factor and observational study, from January 01, 1997, to February 20, 2023. The included studies were meta-analyzed quantitatively and described qualitatively. Subsequently, meta-regression and subgroup analysis were used.

RESULTS

We identified 13 studies (1,607 subjects), and 14 factors were considered. Meta-analysis showed that anterior chamber depth (ACD), horizontal corneal white-to-white (hWTW), ICL-size, and age are dual effects of the abnormal vaults; anterior chamber volume (ACV) and lens thickness (LT) are a one-way effect; while axial length (AL), ICL- spherical equivalent (ICL-SE) and Km are insignificant. In addition, descriptive analysis of anterior chamber angle (ACA), horizontal sulcus to sulcus (hSTS), ciliary processes height (T value), crystalline lens rise (CLR), and gender showed that all factors except gender tend to have significant effects on vault. Sensitivity analysis showed stable combined results. Country and design respectively affect the heterogeneity in ACD and ICL-size at low vault, while design affects the heterogeneity in ACD at high vault. No publication bias exists.

CONCLUSIONS

Vault after ICL is related to multiple factors, especially anterior segmental biologic parameters, and they are weighted differently. We hope to provide a reference for the selection and adjustment of ICL.

Three-Dimensional Quantitative Description of the Implantable Collamer Lens in the Ocular Anterior Segment of Patients With Myopia

PURPOSE

To describe the 3-dimensional (3D) location of the implantable collamer lens (ICL) quantitatively in the posterior ocular chamber of patients with myopia.

DESIGN

Cross-sectional study.

METHODS

To obtain visualization models before and after mydriasis, an automatic 3D imaging method based on swept-source optical coherence tomography was created. Parameters like the ICL lens volume (ILV), the tilt of the ICL and crystalline lens, the vault distribution index, and topographic maps were evaluated to describe the ICL location. Using a paired sample t test and the Wilcoxon signed rank test, the difference between nonmydriasis and postmydriasis conditions was compared.

RESULTS

The study investigated 32 eyes from 20 patients. The 3D central vault did not differ significantly before (P = .994) or after mydriasis (P = .549) compared with the 2D central vault. After mydriasis, the 5-mm ILV decreased by 0.85 mm2 (P = .016), and the vault distribution index increased significantly (P = .001). The ICL and the crystalline lens exhibited tilt (nonmydriasis: ICL total tilt 3.78 ± 1.85 degrees, lens total tilt 4.03 ± 1.53 degrees; postmydriasis: ICL total tilt 3.84 ± 1.56 degrees, lens total tilt 4.09 ± 1.64 degrees). The phenomenon of asynchronous tilt of the ICL and lens was found in 5 eyes, leading to the spatially asymmetric distribution of the ICL-lens distance.

CONCLUSION

The 3D imaging technique provided exhaustive and reliable data for the anterior segment. The visualization models offered multiple perspectives on the ICL in the posterior chamber. Before and after mydriasis, the intraocular ICL position was described by the 3D parameters.