Artemis tm II VHF Ultrasound for Sizing the Visian ICL ASCRS 2008 Philip C. Roholt, MD N. Canton, Ohio, USA The author has no proprietary interest in products discussed in this paper.
Artemis tm II VHF (50K) Ultrasonic Biometry High-resolution B-scan imaging Integral immersion water bath system Single-sweep 3D arc-scan for full sulcus-to- sulcus (SS) measurements Infra-red video monitoring of pt eye position Patented design, unique fixation device In-line fixation optics Reproducible visual axis centered scan
Visian tm ICL Sizing External limbal white-to-white (WTW) is used Poor correlation of WTW to sulcus-to-sulcus (STS) measurements Cadaveric eyes 1 1 st generation UBM 2 No correlation of WTW to STS 3. “One size fits all would work better than using WTW.” Myopia R 2 =0.0165, Hyperopia R 2 =0.204 Angle-to-angle (ATA) is also not predictive of STS 3 Multivariate regression analysis: age, sphere, cylinder, SEQ, WTW, ACD, avg K, pachymetry, ATA Only ATA & ACD statistically significant But, 95% confidence interval of predicting STS with this equation is ±0.91 mm ie the error of estimating STS would be more than 0.91 mm in 5% cases 1.Werner, L et.al. Correlation between different measurements within the eye relative to phakic intraocular lens implantation. JCRS. 2004;30: Pop, M et.al. Predicting sulcus size using ocular measurements. JCRS. 2001;27, Reinstein, D. Personal communication, Sept, Reinstein, D. Personal communication, Sept, 2007.
Artemis UBM for STS Measurement Artemis has been shown to be accurate, repeatable, and reproducible for SS measurements Reinstein, DZ. Accuracy, repeatability, and reproducibility of Artemis very high-frequency digital ultrasound arc-scan lateral dimension measurements. JRS. 2006;32:1799.
Artemis ICL Study 45 pts, 85 eyes examined with Artemis as part of complete pre-op workup Artemis measurements included STS at the Theoretical Sulcus (TS) and ciliary processes (CP) Post-op Measurements on 15 patients (28 eyes) with minimum 3 mo f/u.
Artemis ICL Study - Results PRE-OP MR D +/ D SE -6.0 to D ACA: m o Lens Radius m 10.11mm +/- 1.01mm STS-TS: mm sd STS-CP: mm sd mm POST-OP MR / D >20/ % >20/40 100% Gain > 1 line 28.2% Vault: m 282u +/-106u (range 0 to 524u) ACA: m o No loss BCVA No ICL explantation
ICL Position as Imaged by Artemis ICL haptic rests in the posterior ciliary sulcus, abutting against the ciliary processes The ICL does not rest in the “Theoretical Sulcus.” (Usually reported as the STS) CB acts as a “shock absorber” and is compressed by the pliable ICL haptic.
STS Measurements Published UBM STS Measurements 35 MHz Optikon Hiscan UBM 1 : STS-TS /- 0.72mm 50 MHz Artemis I 2 : STS-TS /- 0.10mm Current Study (Artemis tm II) STS-TS: / mm STS-CP: / Measured STS is less in the current study 1.Oh J, Shin H, Kim J, et al. Direct measurement of the ciliary sulcus diameter by 35-Megahertz ultrasound biomicroscopy. Ophthalmology, 2007;114: Rondeau MJ, Barcsay G, Silverman, R, et al. Very high frequency ultrasound biometry of the anterior and posterior chamber diameter. J Refract Surg 2004;20:
PreOp: OS STS LRadius 8.08 OS Theoretical STS is longer than STS at ciliary process Pre-op VHF UBM for sizing the ICL
OS Vault 66u ICL 12.6 OS Note position of ICL haptics against ciliary process (arrows), not in “Theoretical Sulcus” Post-op VHF UBM with ICL Anterior ICL Posterior ICL
Accommodation and ICL Recent reports of impairment of accomodation Tanzer DJ. US FDA clinical trial of the toric implantable collamer lens for moderate to high myopic astigmatism. Paper presented at the AAO Annual Meeting. November 10, 2006, Las Vegas, NV.
Conclusions Theoretical sulcus measurements in this study differed from other reports STS is measured at the ciliary process for ICL estimation because of the actual haptic positioning Ciliary body and processes act as a “shock absorber” and is compressed by the pliable ICL haptic. ICL may influence accommodation Artemis is useful in imaging of anterior segment and specifically the ciliary sulcus and anterior lens, to aid in Visian ICL selection.