Artemistm II VHF Ultrasound for Sizing the Visian ICL

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Artemistm 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.

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Artemistm 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

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Visiantm ICL Sizing

• External limbal white-to-white (WTW) is used
• Poor correlation of WTW to sulcus-to-sulcus (STS)
  measurements
• Cadaveric eyes1
• 1st generation UBM2
• No correlation of WTW to STS3. One size fits all
  would work better than using WTW. Myopia
  R20.0165, Hyperopia R20.204
• Angle-to-angle (ATA) is also not predictive of
  STS3
• 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.
2004301982 2.Pop, M et.al. Predicting sulcus
size using ocular measurements. JCRS.
200127,1033. 3. Reinstein, D. Personal
communication, Sept, 2007.
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Artemis UBM forSTS 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. 2006321799.

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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.

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Artemis ICL Study - Results

• PRE-OP
• MR -9.75 D /- 1.85 D
• SE -6.0 to -14.5 D
• ACA m 35.19o
• Lens Radius m 10.11mm /- 1.01mm
• STS-TS 11.081 mm sd 0.504
• STS-CP 10.462mm sd 0.476 mm

• POST-OP
• MR -0.35 /- 0.64 D
• gt20/20 83.2
• gt20/40 100
• Gain gt 1 line 28.2
• Vault m 282u /-106u (range 0 to 524u)
• ACA m 26.43o
• No loss BCVA
• No ICL explantation

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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.

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STS Measurements

• Published UBM STS Measurements
• 35 MHz Optikon Hiscan UBM1 STS-TS 11.32 /-
  0.72mm
• 50 MHz Artemis I2 STS-TS 12.32 /- 0.10mm
• Current Study (Artemistm II)
• STS-TS 11.08 /- 0.504mm
• STS-CP 10.462 /- 0.476
• 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,
   20071141685-8
2. Rondeau MJ, Barcsay G, Silverman, R, et al. Very
   high frequency ultrasound biometry of the
   anterior and posterior chamber diameter. J
   Refract Surg 200420454-64.

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Pre-op VHF UBM for sizing the ICL
LRadius 8.08 OS
Theoretical STS is longer than STS at ciliary
process
PreOp OS STS 10.98
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Post-op VHF UBM with ICL
ICL 12.6 OS
Anterior ICL
Posterior ICL
OS Vault 66u
Note position of ICL haptics against ciliary
process (arrows), not in Theoretical Sulcus
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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.

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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.