Elsevier

Ophthalmology

Volume 119, Issue 2, February 2012, Pages 272-277
Ophthalmology

Original article
Correlation between Preoperative Biometry and Posterior Chamber Phakic Visian Implantable Collamer Lens Vaulting

https://doi.org/10.1016/j.ophtha.2011.07.047Get rights and content

Objective

To evaluate (1) the effect of preoperative biometric factors on vault error and (2) the difference in achieved vault (AV) and expected vault (EV) after Visian Implantable Collamer Lens (ICL) implantation.

Design

Retrospective, comparative, interventional case series.

Participants

A total of 129 eyes of 75 myopic patients treated with ICL.

Methods

On the basis of the hypothesis that ICL vaulting is due mainly to an inequality between ICL size and the horizontal sulcus-to-sulcus distance (STS) or horizontal white-to-white distance (WTW), we assumed that EV would linearly correlate with ICL horizontal compression, as demonstrated in an ex vivo experiment. Expected vault was defined as follows: EV(WTW[or STS]) = (ICL size – WTW[or STS]) × 1100 μm. With the use of preoperative data as independent variables (including age, anterior chamber depth measured from the central corneal endothelium to the anterior lens capsule, STS, WTW, ICL size, ICL size – STS, ICL size – WTW, STS – WTW, ICL diopter, and mean K-reading), a multiple regression analysis was performed to evaluate meaningful factors affecting AV.

Main Outcome Measures

Preoperative ICL EV and postoperative ICL AV.

Results

Mean AV was 518.6 (standard deviation [SD] 258.4 μm). The EV(WTW) was 626.6 (SD 220.9 μm), and EV was 242.8 (SD 364.2 μm). Higher ICL compression tended to result in a lower AV than EV, whereas lower ICL compression tended to result in a higher AV than EV. The ICL size – STS was more highly correlated with AV than the ICL size – WTW (Pearson correlation coefficient 0.425 vs. 0.247). Stepwise multivariate regression showed that, in order of the strength of the contribution, ICL size – STS, ICL size, age, and K-reading were significant factors associated with AV (adjusted R2=0.369), but ICL size – WTW was not. Among the meaningful factors, ICL size – STS, ICL size, and K-reading were positively correlated with AV, whereas age was negatively correlated.

Conclusions

The ICL vaulting based on only the horizontal compression could not be quantitatively predicted. Additional factors, such as vertical compression by the iris, dampening effect of the ciliary sulcus structure, or innate ICL vault, should be considered to avoid unexpected vaulting after ICL implantation.

Financial Disclosure(s)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Section snippets

Materials and Methods

The present study was a retrospective chart review that initially included 213 eyes from 124 consecutive patients who underwent Visian ICL (V4 model) implantation for the correction of myopia. Inclusion criteria for patient selection included a postoperative follow-up period of at least 6 months; availability of preoperative and postoperative ultrasound biomicroscopy (UBM) data; no adverse event during surgery; and no abnormal sulcus structure, such as an iridociliary cyst. Of the initially

Results

The mean age of the patients was 32.6 years (standard deviation [SD] 9.3, range 20–45 years), and 57.3% (43/75) of the patients were female. Toric ICL implantation was performed in 26.4% of the patients (34/129) with a mean postoperative follow-up of 17.8 months (SD 12.0, range 6–50 months). The maximum rotational angle of implantation in toric ICLs was 4 degrees. Other baseline clinical characteristics are shown in Table 2.

Table 3 shows descriptive results of 10 preoperative variables. The

Discussion

Many patients with moderate to high myopia and myopic astigmatism may benefit from ICL implantation surgery.2, 14 The resulting ICL vault, however, is difficult to predict precisely.13 Implantable Collamer Lens sizing using UBM-measured STS distance is more accurate than the conventional WTW distance method because the ICL haptic footplates are located on the ciliary sulcus.13, 15, 16, 17, 18 We have used UBM to measure the STS for determining the proper ICL size because we initially started

References (25)

Cited by (0)

Manuscript no. 2010-1533.

Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Funding: This study was supported by the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education, Science, and Technology (2010-0012903). The funding organization had no role in the design or conduct of this research.

View full text