Contact Lens Update

1
Contact Lens Update

• A discussion of new (and old) lenses for
  keratoconus, post surgery, and severe dry eye.
• Cathy Wittman, OD
• Texas Tech University

2
Topography Review

• The numbers (indices)
• SimK Simulated Keratometry Instead of using
  two data points in each of two orthogonal
  meridians as in traditional keratometry, the
  topographer samples multiple points along the
  steepest and flattest meridians.

3
Topography Review

• CEI Corneal Eccentricity Index (aka E-VALUE)
  A measure of corneal eccentricity, a global shape
  factor.
• Negative e-value A negative e-value indicates a
  flat central zone with a steep mid-periphery
  (oblate surface).
• Zero e-value A perfectly spherical cornea.
• Positive e-value A cornea that is steep
  centrally and flattens peripherally (prolate
  surface). This is the most common.
• The average e-value of the normal cornea is about
  0.43.
• Greater than 0.7 suspect keratoconus.

4
Topography Review

• SAI Surface Asymmetry Index (similar to the I-S
  Value- the Inferior-Superior Value)
• Measures the difference in corneal powers at
  every ring (180 degrees apart) over the entire
  corneal surface). The I-S Value typically
  compares five points of the superior half of the
  cornea with five points of the inferior half.
• Corneas with a difference of 1.4-1.9D within one
  meridian, suspect keratoconus. Over 1.9D highly
  suspect keratoconus.

5
Topography Review

• Color Scale Normalized and Absolute
• Normalized The color scale is normalized around
  the median dioptric value for that specific map.
• Absolute The color scale is fixed from map to
  map, so a certain color represents a certain
  dioptric value for every patient.

6
Topography Review
With-the-rule astigmatism
7
Topography Review
Against-the-rule astigmatism
8
Topography Review
Normal Cornea
9
(No Transcript)
10
Topography Review
Pellucid Marginal Degeneration
11
(No Transcript)
12
(No Transcript)
13
Topography Review
Keratoconus
14
(No Transcript)
15
(No Transcript)
16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
19
(No Transcript)
20
Topography Tip
BEFORE
AFTER
If you are having trouble capturing a topo image,
use thin disp SCL, NPATs, have pt blink just
before capture.
21
Topographers
22
Confoscan Corneal Confocal Microscope
23
Case 1
Penetrating injury caused corneal scarring
nasally (blue) and distorted the pupil nasally.
Because of the position of the cone superior
temporally, all standard sized RGPs decentered
temporally and caused the patient to see through
the peripheral curves nasally.
BVA with specs 20/150
24
Case 1
25
Case 1
20/60
15.0mm Digiform-N Corneal-Scleral Lens
26
Truform Tru-Scleral and Digiform CScleral

• The Tru-Scleral lens by Truform has a diameter
  range of 16-20mm, with a standard size of 18mm
  that is vented by radial channels that are cut
  into the periphery. The Digiform corneal-scleral
  lens has a diameter range of 13.5 to 16mm. We
  have two fitting sets of 15.0mm lenses at TTU
  the N (normal) and the K (keratoconic).
• To avoid bubbles, have patients fill the lens
  with solution and look down when inserting the
  lens.
• Remove using a DMV positioned close to the bottom
  edge of the lens or remove without a DMV using
  one finger at top edge and another finder at
  lower edge.

27
Truform Tru-Scleral and Digiform

• Biggest Caution Do not fit this lens tightly!
• Even though the lens is fenestrated, you can
  cause harm by fitting too tightly.
• Let the lens sit in patients eye for 15 to 30
  minutes and re-assess.
• You cannot assess fit by looking at movement.
  Scleral lenses have minimal if any movement.
• Observe for blanching vessels, NaFl indentions at
  lens edge, and difficulty removing the lens
  because of lens suction. These things mean the
  lens is too tight.
• You should have tear exchange underneath the
  lens.
• The Digiform also available in a post surgical
  fitting set.

28
Tru-Kone and Digiform
29
(No Transcript)
30
(No Transcript)
31
(No Transcript)
32
Case 2 Stevens Johnson Syndrome

• Pt required a PKP OD because of a perforated
  cornea. Pt also required a partial tarsorrhaphy
  OD.
• First presented to our clinic after being
  discharged from the burn unit after treatment of
  Stevens Johnson Syndrome.
• Subconj Avastin injection given during follow up
  care after PKP for neovascularization.
• Pt is using Vitamin A ointment in each eye.
• Fit into Digifrom N1 15.0mm scleral lens by
  Truform.

33
Case 2
Good apical clearance. The goal is no corneal
contact to maintain thick tear layer between
cornea and lens. (Pt is on Vitamin A ointment
which is which is causing disruption of tear film
on surface of the lens).
34
Case 3
PKP patient who discontinued wearing her RGP six
months ago due to discomfort and was 20/70 in
that eye in her spectacles.
35
Case 3
Digiform corneal-scleral 15.0, BC 7.4 Actually
too flat. Nasal edge lift. Bearing. See next
slide.
36
Case 3
Digiform K1 15.0, BC 7.1 Edge lift eliminated.
Nice NaFl pattern. Minimal bearing in flat
meridian.
37
Salzmans Nodular Degeneration
38
Digital Camera
39
Truform Trukone

• Fitting set recommended.
• We have a fitting set here at TTU.
• Works with most mild to moderate keratocones and
  some more advanced cones.
• If you cannot find a good fit with the Trukone,
  move on to the Quadrakone.

40
Truform Quadrakone

• Peripheral curve system can be altered in
  different quadrants, in order to provide a
  customized fit for each patient. They dot the
  steepest quadrant.
• When the keratoconus has progressed to a point
  where you cannot eliminate the inferior edge lift
  caused by the cone, you can steepen the base
  curve in the inferior quadrant to lip the lens
  in and minimize edge lift.
• I have found that if you decrease the overall
  diameter as much as possible without getting the
  peripheral curves into the pupil, you can
  minimize edge lift.

41
RevitalEyes

• A soft contact lens developed by Metro Optics
  that is FDA approved for post laser refractive
  surgery patients.
• Is not recommended for PKP patients.
• Made of Hioxifilcon B

42
Synergeyes

• Hybrid Lens with a rigid center and soft skirt.
• Biggest complaint has been the Dk of the skirt.
  Low oxygen permeability has been attributed to
  neo and corneal edema.
• Some practitioners feel the skirt can tighten
  over time contributing to less oxygen
  permeability and prefer piggyback (RGP with
  silicone hydrogel).
• SynergEyes A For patients with astigmatism
• SynergEyes Mutifocal For presbyopes
• SynergEyes KC For keratocones
• SynergEyes PS For post-surgical patients PKP,
  refractive surgery, corneal trauma

43
Fitting Sets
44
RevitalEyes and Synergeyes
45
Wavefront Technology

• Myopia, Hyperopia, and Astigmatism are Low Order
  Aberrations.
• Aberrometers measure High Order Aberrations
  Coma, Trefoil, Spherical Aberration, and
  Irregular Astigmatism.
• Readings from the aberrometer are then used to
  design a lens. This is similar to the iZone
  spectacle lenses that are available.
• Most dramatic results with patients who did not
  have a good outcome with refractive surgery.

46
Wavefront Analyzer
47
Pediatric Contact Lenses

• Silsoft
• Made of Elastofilcon A
• Can be worn overnight.
• Parameters
• Kontur
• Cannot be slept in.
• Occluder Lenses (can also use Adventures in
  Color)
• Parameters
• SpecialEyes
• Made of Hioxifilcon
• Any curve, any power, any axis

48
Mutifocal and Bifocal Contact Lenses

• Frequency and Proclear Multifocal contact lenses
  still working well. Proclear has a toric
  multifocal that weve had some success with.
• Bausch and Lombs Purevision Multifocal is still
  working well.
• Vistakon is coming out with a new multifocal.
• Best clarity still with RGPs.

49
RD Here at TTU

• Dr. Ted Reid is doing research on a selenium
  coating that would give protection against
  microbial infection.

50
Selenium Treated Contact Lenses
Pseudomonas Treated CL
Pseudomonas Untreated CL
51
Selenium Treated Contact Lenses
Staph Aureus Treated CL
Staph Aureus Untreated CL
52
New Treatments for Keratoconus

• Collagen Crosslinking and Riboflavin (C3-R)
• Over the course of a lifetime the cornea becomes
  progressively stiffer due to natural
  cross-linking between the collagen fibres.
• Epi is abraded from the cornea and the riboflavin
  drops are applied. UV light is then focused onto
  the cornea for 30 minutes then a bandage contact
  lens is worn for 3-4 days.
• This causes the cornea to become more rigid
  because riboflavin strongly absorbs UV light
  which increases the cross-linking of the collagen
  fibers.

53
New Treatments for Keratoconus

• Intacs Corneal Implant
• Flattens the steep part of the cornea or cone to
  reduce vision distortions.

54
Prosthetics

• Donnie Franklin, B.C.O., B.A.D.O. (Board
  Certified Ocularist, Board Approved Diplomate
  Ocularist) of Fort Worth Eye Prosthetics comes to
  our department monthly to fit prosthetic eyes.
  If you have a patient who has a prosthetic eye
  that needs polishing or replacing, Donny can do
  that for you. His number is 817-429-8086 or Toll
  Free at 866-427-8130.

55
TTU Friendly Staff and Residents
56
Low Vision Update

• A demonstration and discussion of electronic low
  vision devices.
• Cathy Wittman, OD

57
CCTVs

• They have become more compact with flatter
  screens.
• Merlin LCD
• Monitor sizes 17, 19, and 22
• 2.4x to 77x mag

58
CCTVs

• The Acrobat
• Up to 65x
• 19 monitor
• Can be used for
• distance or near
• Pivoting, sliding arm
• Luggable
• Good for students
• Can be used for
• applying cosmetics.

59
Portable CCTVs

• Amigo
• 3.5x to 14x
• Tilting Screen
• Freeze Frame
• Can connect to TV for
• increased mag

60
Portable CCTVs

• Nemo
• 4.5x to 9x
• Freeze Frame

61
Jordy

• 2x to 28x distance viewing
• 2x to 70x near viewing on 20 monitor (not
  included) or can view the material on the virtual
  reality monitors built into the Jordy.
• Optional desktop stand attached to a monitor, it
  can be used as a desktop video magnifier.

62
Max and Max Panel

• The Max 16-28x
• Connects to any tv or monitor
• Cost Effective
• The Max Panel Its the Max with a slim LCD
  platform.
• Less mag than the Max (10-14x) because of the
  small LCD.

63
Videolupe Plus

• 3x stand magnifier when used without a monitor or
  tv.
• Up to 16.5x on a 28 tv.
• Made by Eschenbach.

64
Compact

• Thin and light.
• Provides up to 10x on a 4.3 inch widescreen.
• Collapsible handgrip.
• Snapshot button for capturing images
• 5 viewing modes.

65
KNFB Reader
66
Recommended Reading

• Keratoconus What Do We Know? Eef van der Worp,
  BSc, FAAO, FIACLE http//www.clspectrum.com/articl
  e.aspx?article100943
• "Eccentricity" is in Against Thin DIANNE
  ANDERSON, O.D., F.A.A.O. AND RANDY KOJIMA,
  F.O.A.A. http//www.optometric.com/article.aspx?ar
  ticle102288
• Contact Lenses and Wavefront Aberrometry Kenneth
  A. Lebow, OD, FAAO http//www.clspectrum.com/artic
  le.aspx?article102254
• Post-Penetrating Keratoplasty Association of
  Optometric Contact Lens Educators
  http//www.aocle.org/livlib/post_surgB.htm

67
Recommended Reading

• Corneal Topography Tips Paul M. Karpecki, OD
  http//www.optometric.com/article.aspx?article507
  7
• Validating Corneal Topography Maps Randy
  Kojima, FOAA http//www.clspectrum.com/article.asp
  x?article100638
• Corneal Topography and Imaging Michael W Fung,
  MD http//emedicine.medscape.com/article/1196836-o
  verview
• Advanced Keratoconus (hydrops) Bruce W.
  Anderson, OD http//gpli.info/education/book/case-
  39.htm
• Contact Lens Case Report (VLK) Mark Andre,
  FAAO, Patrick Caroline, COT, FAAO
  http//www.clspectrum.com/article.aspx?article129
  82

68
Thank You!

• Dr. Cathy Wittman
• Appts 806-743-2020
• Direct Office Line 806-743-9500 ext 270
• Cathy.wittman_at_ttuhsc.edu