Abstract
Abstract: :
Purpose: To demonstrate 3 clinical examples in refractive surgery of essential diagnostic information available with very high frequency ultrasound Methods: Very high frequency ultrasound imaging (Artemis, UltraLink LLC, St. Petersburg, FL) was used to analyze corneal or anterior chamber (AC) dimensions in patients being evaluated before and/or after refractive surgery. The ultrasonic frequency of analysis was 50 MHz (interface resolution of 35 um, precision of 1–5 um) and the 3D scanning was performed with water immersion. Corneal scans with 3D mapping (ArtPro software) of corneal, flap and epithelial thickness profiles was performed following LASIK flap creation with the IntraLase laser (Irvine, CA) vs. Moria M2 microkeratome (Antony, France). The same corneal analysis was performed in the consult evaluation of an optically aberrated eye following LASIK with presumed decentration. Finally, meridional sections of the AC were viewed to determine angle to angle AC diameter in comparison to the white to white (W2W) diameter of the horizontal cornea as a sizing metric for AC phakic IOL implantation. Results: The IntraLase flap thickness profile (90um depth) showed a uniform thickness of 101um centrally, 103um superiorly, 113um nasally, 103um inferiorly and 98um temporally at distances 3 mm from center, while the Moria M2 (90 head) showed a variable thickness profile of 75um centrally, 165um superiorly, 167um nasally, 116um inferiorly and 147 um temporally. The eye with a presumed decentration after LASIK with inferotemporal (IT) topographic steepening vs. superonasal (SN) flattening and inferotemporal myopic coma by wavefront of 1.82 um (6.5 mm pupil), revealed a corneal thickness of 481um at 3mm IT and 563um at 3mm SN, suggestive of ectasia rather than decentration. Finally, 3 eyes with a W2W of 11.7mm, 12.5mm and 11.8mm had AC diameters of 12.0mm, 12.5mm and 12.2mm, which aided in the sizing of 3 AC angle supported phakic IOLs with good lens vaulting in each case. Conclusions: Very high frequency ultrasound is a useful diagnostic tool for studying the microanatomy of the eye and determining critical measurements used in refractive surgery.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • refractive surgery: other technologies • anatomy