Financial Disclosure Calhoun Vision consultant, equity Clarity Massey Labs consultant, equity

Cornea and Anterior Segment Imaging OCT: Diagnosis and Surgical Planning Ronald E. Smith, M.D. Doheny Eye Institute USC Keck School of Medicine

OCT now approaches histology in resolution Normal retina imaged by RTVue OCT (5 micron resolution) Histology of human retina

Optical coherence tomography (OCT) has higher resolution than other imaging modalities. 1 mm 100  m 10  m 1  m OCT Ultrasound Axial Resolution (FWHM) CT MRI

There is a revolution in OCT technology – speed is taking off!

A generational leap RTVue has 65x speed & 2x resolution of Stratus Zeiss OCT1/ Zeiss Stratus 2002 OptoVue RTVue , Speed (A-scans /sec) Resolution (  m) Fourier domain Time domain

FD OCT Simultaneous 2048 pixels at a time TD OCT Sequential 1 pixel at a time Higher speed, higher definition and higher signal A-scans in 0.04 sec 512 A-scans in 1.28 sec Motion artifact Small blood vessels IS/OS Choroidal vessels

Optical Coherence Tomography (OCT) Retinal OCT –In common clinical usage –Macular diseases –Glaucoma Corneal and Anterior Segment OCT (CAS-OCT) –Early clinical development –Keratorefractive surgery –AC-IOL planning –Narrow Angle –Other surgical anatomy and pathologies

OCT is used to for anterior eye diseases and surgery as well LASIK Lens implantation Seeing through opaque cornea Narrow angle glaucoma

Higher resolution allows better visualization of LASIK flap 4 months after LASIK with Moria CB Average of 16 frames

CAS-OCT in LASIK Planning Corneal thickness map –Determine available ablation depth –Distinguish FF keratoconus from warpage Flap & stromal bed thickness maps* –Distinguish ectasia from normal regression –Calculate available enhancement ablation depth * Not available on slit-scanning tomography

Scan Pattern for Corneal Mapping 8 x 10-mm radial line scans 3-D reconstruction

Conclusion: OCT Pachymetry Map Excellent repeatability (SD < 2  m) Agrees well with ultrasound OCT (1%) Agrees well with programmed ablation depth (5%, better than ultrasound) Useful in confirming keratoconus

Post-LASIK interface fluid & epithelial ingrowth 056-CP Fibrosis Epithelial ingrowth Fluid

Case 2 Unrecognized Keratectasia Consulted for poor vision OS LASIK OU 9 years ago 2 enhancements OS MR x 60º 20/40 OS

Cornea Stroma LASIK Flap OS

Case 2 Conclusions Keratectasia –LASIK enhancement not advised –RGP v. Intacs OCT shows –Thick flap –Thin residual posterior stromal bed: may be cause or result of keratectasia

Intacs

CASE # 2 Opaque corneal graft and glaucoma

OCT: IOL synechiae & pupil block 0 degree-45 degree -90 degree-135 degree

DLEK (Jonathon Song, MD)

Linking OCT to lasers to performed the most precise corneal surgeries OCT scanning Corneal thickness map Femtosecond laser cutting Partial thickness corneal transplant

This will greatly benefits patients whose vision is limited by corneal irregularity and opacity (i.e. corneal scars and keratoconus) Deep corneal scar Advanced keratoconus

Anterior Segment OCT for Narrow Angle Glaucoma Vikás Chopra MD Assistant Professor Doheny Eye Institute Dept of Ophthalmology USC Keck School of Medicine

Results: Angle Configuration Pre- & Post-PI vs. post- CE/IOL

Example: Angle Configuration  in Dark and Light Conditions Room Lights ON Room Lights OFF

Conclusions: Narrow Angle Detection using AS-OCT AS-OCT has the potential for large-scale screening for narrow, occludable angles Rapid Non-contact Ease of image acquisition Ease of image analysis with custom software

Corneal & Anterior Segment OCT LASIK –Pachymetry map –Flap & stromal bed thickness Intacs implant depth Corneal opacity, edema Uveitis –AC cell counting Iris mass IOL –AC width –Corneal Clearance Accommodation Narrow angle glaucoma –Angle opening distance, TISA

Center for Ophthalmic Optics & Laser (COOL) David Huang, MD, PhD Maolong Tang, PhDYan Li, MS Ou Tan, PhD Sylvia Ramos, COA Yimin Wang, PhD Ake Lu, PhDJulie Schallhorn