Advanced Cornea and Anterior Segment Imaging
: Refractive workstation which includes the following: corneal topographer, autorefractor, wavefront refractor, wavefront analyzer, internal optical path difference analyzer (OPD), and light/dark pupillometer.
How: Uses 19 placido rings (concentric rings) to acquires 11,880 data points in order to map the corneal topography.
Why: Advanced software can calculate the effective central corneal power after LASIK, analyze higher-order aberrations in both the entire optical system and broken down by corneal aberations and lens aberrations.
Tomey EM-4000 Specular Microscopy
What: Captures images of the endothelium, or inner layer of the cornea, and provides an automated analysis of cell density and variation.
How: Captures a 0.25 x 0.54 mm area with a 190 optical magnification.
Why: Direct imaging can not only confirm a diagnosis of Fuch's Dystrophy but allow a physician to track cell density over time. It can also assess graft health after corneal transplantation.
Accutome Ultrasound Biomicroscopy (UBM)
What: Enables visualization of structures posterior to the iris such as the ciliary body, zonules and the peripheral lens.
How: Uses a 50-MHz ultrasound scan to produce an ultrasound image with a 40 µm resolution.
Why: Can help to diagnose causes of low eye pressure, visualize malpositioned intraocular lenses, and differentiate between and iris and ciliary body cysts from a potential cancerous melanoma.
Anterior Segment Optical coherence tomography (OCT)
Zeiss Cirrus HD-OCT and Optovue RT-Vue
What: Generates very high resolution cross-sectional scans of corneal and anterior segment tissue.
How: Uses 1310 nm light to capture 8 frames per second with a 15 µm resolution.
Why: Can gauge the depth of corneal scars for surgical planning, evaluate angle structures and iris structures which are difficult to view in cross-section at the slit lamp.