Prediction of excessively low vault after implantable collamer lens implantation using iris morphology

Abstract

PurposeTo identify the iris morphology-related factors for prediction of outcomes of excessively low vault (< 100 μm) after Implantable Collamer Lens V4c (ICL V4c; STAAR Surgical) implantation.MethodsThis retrospective case-control study included 81 eyes from 2,080 patients who underwent ICL implantation. Twenty-seven eyes of 27 patients with excessively low vault (< 100 μm) constituted the case group (excessively low vault group). Patients with vault (250 to 750 μm) were selected as the optimal vault group by matching anterior chamber depth, white-to-white distance and ICL size with cases with excessive low vault (< 100 μm) at a proportion of 1:2. The preoperative biometric parameters and postoperative vault were recorded. Multiple linear regression analysis was performed to assess the relationship between the postoperative vault and various variables. Conditional logistic regression analysis was used to estimate the risk factors for excessively low vault.ResultsThe postoperative vault was associated with preoperative pupil diameter (PD), crystalline lens rise, iris concavity and the ratio of the iris concavity to chord length (P < 0.05). The larger iris concavity increased risk of excessively low postoperative vault (< 100 μm) (OR = 81.10; 95%CI = 2.87 to 2296.58; P = 0.01).ConclusionsEyes with obviously concave iris were associated with a higher rate of excessively low vault (< 100 μm). Evaluation of iris morphology may provide significant information for predicting excessive postoperative vault.

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

“…A total of 840 articles were identified by computer searching, and 13 studies [9,[17][18][19][20][21][22][23][24][25][26][27][28] finally met the inclusion criteria after screening and extraction (Fig. 1), all of which were single-center studies without the combination of other ocular diseases affecting visual acuity.…”

“…Table 1 summarizes the characteristics of the studies included in the evidence synthesis. Thirteen included studies were all observational (8 case series [9,20,[22][23][24][25][26][27], 4 case-control [18,19,21,28], and 1 cohort [17]); Five of them were in English and 8 in Chinese; For measurement of vault, 6 studies used Pentacam [18,[21][22][23][24][25] and 7 ones used AS-OCT [9,17,19,20,[26][27][28], while ultrasound biomicroscope (UBM) was also used as a complementary measure of correlative indicators, such as horizontal sulcus to sulcus (hSTS), lens curvature and ciliary processes height (T-value). A total of 1,607 patients (2,202 eyes) with 20 factors were included, and the duration ranged from 0.25 to 24 months.…”

“…A total of 1,607 patients (2,202 eyes) with 20 factors were included, and the duration ranged from 0.25 to 24 months. The literature quality was evaluated by the NOS, which showed 7' in 3 articles [23,27,28], 8' in 8 articles [17,18,[20][21][22][24][25][26], and 9' in the remaining ones [9,19]. All were larger than 6 points, indicating the good quality of the included studies.…”

“…Low vault vs. Normal vault (L VS N, Fig. 2): A total of 11 studies [9,17,[19][20][21][22][23][24][26][27][28] involved ACD in the included articles, with a significant heterogeneity (P < 0.05, I 2 = 77%), and random-effects model showed that ACD was a protective factor for the postoperative low vault [SMD=-0.85, 95% CI (-1.13, -0.56), P < 0.00001]; similarly, hWTW and ICL-size were also protective. Four studies [22,23,26,27] involved anterior chamber volume (ACV) without significant heterogeneity (P = 0.81, I 2 = 0%), fixed-effects model proved that ACV was a protective factor for low vault [SMD=-0.69, 95% CI (-0.93, Fig.…”

A review of posterior chamber phakic intraocular lenses

“…Preoperative identification of factors that may influence vault or measurement of lens position and vault in the intraoperative period can be helpful to reduce the risk of vault related complications and improve surgical outcomes. Khan et al [25] performed a retrospective analysis of 81 eyes who underwent ICL surgery to distinguish anatomical features that may be of importance in predicting the risk of insufficient vault (<100 mm). This value of <100 mm was predefined by previous literature [26].…”