The Nurse/Technician Role Within the Emerging Ophthalmic Technology - OCTs/B-Scan

Transcription

1 The Nurse/Technician Role Within the Emerging Ophthalmic Technology - OCTs/B-Scan Margie V. Wilson, COMT Chief Clinical Supervisor UCSD Shiley Eye Center

2 Thanks, Carol!

3 Unfortunately. I have not financial interest in this presentation.

4 Purpose of the Talk Inform you of the specialized diagnostic tests available for the ophthalmic patients. Describe the purpose for each test. Explain the equipment set up for the tests. Understand the importance of the patient positioning for the tests. Show examples of tests being performed and their results.

5 Who am I? Clinical Supervisor at UC San Diego Shiley Eye Center for over 16 years Over 30 years experience in the Ophthalmology Clinical Instructor Ophthalmic Medical Assistant Program for 20 years Certified Ophthalmic Medical Technologist One of 600 worldwide

6 2012

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8 Diagnostic Ophthalmic Tests to be Discussed Optical Coherence Tomography (OCT) Ultrasound A-Scans Ultrasound B-Scans Ultrasound Biomicroscopy (UBM)

9 The secret of joy in work is contained in one word Excellence. To know how to do something well is to enjoy it. Pearl S. Buck

10 Difference between OCT and Ultrasound? OCT uses reflected light instead of reflected sound to image the eye.

11 Optical Coherence Tomography Low coherence interferometry measures the interference of 2 light beams by comparing the backscattering of tissue to light that travels a known reference path with a reference mirror Both paths are combined at a detector, then modulated, and finally sent to a computer Multiple longitudinal scans (A-scans) are performed at a series of lateral locations to form a 2-dimensional image (B-Scan) OCT

12 Better for the patients No fluorescein injections No blinding lights from the camera No long procedure time (OCT about 40 seconds!) No possible allergic reactions Digital images can be viewed to determine course of action for the ophthalmologist Are the treatments working? Surgery needed? Pt and tech/nurse friendly!

13 Types of OCT Time domain Fourier/Spectral domain Swept-Source

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15 Visante OCT OCT Scan Beam Wavelength : 1310nm (Superluminescent Diode) Resolution: Axial : 18 µm Lateral: 50 µm Scan Sizes: 6mm deep, 16mm wide Scan speed: 2000 A scans/sec Internal / External Fixation

16 OCTs on the Market SL-OCT Stratus OCT Cirrus HD-OCT Casia SS-OCT

17 What can you see with the OCT? The cornea layers The anterior chamber The angles The iris The lens visible through the pupil. The areas behind the iris cannot be seen.

18 Anterior Chamber & Cornea This is my cornea after slight complication with DSAEK Air pushed iris against cornea Permanent tattoo

19 Examination S/P DSAEK Dislocation of the donor graft can be see clearly on Visante OCT.

20 Angles OCT can image the angles and document a narrow angle or closed angle Easier than ultrasound (UBM)

21 Optic Nerve OCT can image the nerve and can give an extensive report on changes in the nerve when multiple OCT tests over time.

22 Macula / Fovea OCT is perfect for documentation of macular edema Easier than F/A and no need for injection

23 Applications for the OCT Trauma Trabeculectomy blebs and complications Glaucoma Implants Progression of nerve cupping Corneal applications Angle closure Macular edema AMD

24 Patient Positioning Like at the slit lamp patient needs to keep chin down, forehead against the bar Help is needed for some to keep position Help is needed sometimes for eyelid elevation

25 Quote of the Week The first five days after the weekend are the worst!

26 Ultrasound A-Scans cornea retina First used in ophthalmology in 1956 to evaluate intraocular tumors. The time amplitude-mode (A-scan) showed great potential as a diagnostic tool for the ophthalmic patient.

27 A-Scan Gives you measurements of the eye structures Axial Length (A/L) Anterior Chamber The lens The vitreous Very long eye! Average A/L Floater? cornea Front of lens Back of lens retina

28 Types of A-Scans Immersion Double spike cornea Contact IOL Master B-Scan Double Peaked cornea

29 Immersion Technique Uses the water bath technique Probe mounted in the Prager shell BSS used as the fluid Easy to learn and quick to measure the eye

30 Contact Method Single spike cornea Method easier to learn than immersion Can be done on automatic setting or manual setting Need to be cautious about anterior chamber depth

31 Contact Method Easily performed on infants in the clinic Can provide valuable IOL power information Can be verified at EUA

32 IOL Master Carl Zeiss Meditec Laser measurement of the eye Expensive$$$ Cannot do dense cataracts!

33 IOL Master Great for young children Very patient friendly Find out their favorite toy and tell them it s in there! It will help with fixation!

34 6 yr old, Down Syndrome

35 B-Scan for Measurement This scan works easily for infants and young children Helps to visualize the nerve and macula on an opaque cornea A-scan cornea Back of Front lens Of lens Retina

36 A-Scan vs B-Scan A picture vs spikes! Shows the density of the mass Can be useful in measuring the mass Alerts you to perform more tests if A-scan is difficult to perform

37 Ultrasound B-Scans 1958, the first two-dimensional (immersion) brightness mode (B-scan) was developed. Early 1960 s ultrasound was used to measure distances between eye structures.

38 Gain is important Screen with high gain It s easier to see Lowerthe gain to see cleaner borders for measuring.

39 Use motion to help Vitreous and blood moves like snow in a snow globe It moves smoothly and easily Retina moves stiffly It bounces Remember that although we say total retinal detachment it isn t Retina is always attached at the ora serrata and nerve

40 Movement makes the diagnosis Dense cataract, retinal detachment Posterior vitreous detachment

41 Combined A-scan & B- scan Helpful to identify density of eye tissues Higher spikes for denser tissue. Dense cataract noted here, as well as axial length of the eye. Helps with intraocular lens calculations when A-scan difficult.

42 Special Note If you plan on using the B-scan axial length you need to remember that the length will be longer if you are on the lid. It can also be longer if you are using a gel on your probe.

43 Patient Positioning Can be done with patient in exam chair Can be done with patient lying down

44 UBM Sound Frequency 50 MHz (the higher the MHz the more anterior you can visualize) Resolution: Axial: 25 um Lateral: 50 um Scan Sizes: 4-5 mm deep in tissue, 5 mm wide Scan speed: 8 A- scans/sec External Fixation

45 Ultrasound Biomicroscopy (UBM) Images the anterior chamber, the iris, the posterior chamber and lens. Images cilliary body, ora serota tumors Here the iris is stuck down to the intraocular lens (top) Iris cyst (bottom)

46 UBM At first not very patient or technician friendly Large instrument Cup in the eye Pt lying down Leaks Potential k-abrasion Now, smaller instruments. Probe with balloon head Pt upright or supine Less expensive

47 Specific Test for Specific Task What does the physician want? Perform the test the ophthalmologist requests first Suggest other tests Try other tests to see if you can better image what the physician is wanting Explain the procedure to the patient An informed patient is a happy patient

48 Questions?

49 me

50 Thank You!