Management of Keratoconus for more information about icourses https://www.facebook.com/i.courses.ophthalmology/ https://wa.me/201092909418 https://www.youtube.com/channel/UChSK-t5QtUa7Y6ct889ql7Q?reload=9& https://t.me/icoursesophthalmology https://www.instagram.com/i.courses.ophthalmology/ https://www.linkedin.com/in/ahmed-hamdy-626527188/

1. MD, Msc, MRCSEd, ICO, FRCSG

2. i.courses.ophthalmology
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3. *
Conclusion
Management
Pentacam
Clinical Picture
Introduction

5. Keratoconus is a non-inflammatory, progressive,
bilateral thinning disease of the cornea
It is characterized by the development of a protrusion
of corneal apex often located centrally or in an
inferior eccentric position
usually presents in 2nd decade of life
The exact etiology is unknown, Both genetic and
environmental factors are associated with KC.

6. • 5 to 6 layers of stratified squamous non
keratinized epitheliumEpithelium
• A narrow acellular homogeneous zoneBowman’s
Membrane
• A regularly arranged lamellae of
collagen bundlesStroma
• A strong resistant sheet that’s
considered the basal lamina of the
corneal endothelium
Descemet’s
Membrane
• single layer of hexagonal cells at
posterior aspect of Descemet's
membrane
Endothelium
• Acellular in the pre-Descemet's cornea.
Separating Descemet’s from the last
row of keratocytes
Dua’s Layer

7. Dua’s Layer

9. progressive painless decrease in vision
due to progressive astigmatism & myopia
The patient notices frequent change of
glasses& intolerance to C.L.

10. *According to K reading
Mild <45D in both meridians
Moderate
Advanced
Severe
45D to 52D in both meridians
52D to 62D in both meridians
>62D in both meridians

11. *According to shape of the cornea
small near-central ectasia of 5 mm in diameter or
less .
Displacement of the corneal apex below the midline
results in an island of inferior mid-peripheral
steepening.
This form of the disease affects nearly three-quarters
of the corneal surface.

12. Mild Keratoconus
distortion of the rings of the
Placido disk

13. distortion of the rings of the
Placido disk
The scissoring effect of red
reflex with streak retinoscope
Mild Keratoconus

14. distortion of the rings of the
Placido disk
The scissoring effect of red
reflex with streak retinoscope
Suspicious Corneal topography
Mild Keratoconus

15. Visible thickened corneal nerves
Moderate Keratoconus

16. Visible thickened corneal nerves
Fleischer's Ring:
A brown ring present at base of cone
best detected by cobalt blue filter
Moderate Keratoconus

17. Visible thickened corneal nerves
Fleischer's Ring:
A brown ring present at base of cone
best detected by cobalt blue filter
Lines of Vogt:
Small vertical stress lines disappear
with gentle pressure on globe
Moderate Keratoconus

18. Corneal Thinning:
the cone is often displaced inferiorly.
The steepest part of the cornea
(apex) is generally the thinnest
Moderate Keratoconus

19. Corneal Thinning:
the cone is often displaced inferiorly.
The steepest part of the cornea
(apex) is generally the thinnest
Corneal Scarring:
Sub-epithelial corneal scarring may
occur because of ruptures in
Bowman's membrane
Moderate Keratoconus

20. Munson's sign:
The corneal protrusion may cause
angulation of the lower lid on
downgaze in V-shaped conformation
Advanced Keratoconus

21. Munson's sign:
The corneal protrusion may cause
angulation of the lower lid on
downgaze in V-shaped conformation
Rizzuti's sign:
a sharply focused beam of light near
the nasal limbus produced by lateral
illumination of the cornea
Advanced Keratoconus

22. Munson's sign:
The corneal protrusion may cause
angulation of the lower lid on
downgaze in V-shaped conformation
Rizzuti's sign:
a sharply focused beam of light near
the nasal limbus produced by lateral
illumination of the cornea
Acute Corneal hydrops:
when Descemet's membrane ruptures,
aqueous flows into the cornea causing
edema and opacification
Advanced Keratoconus

24. The Pentacam was originally introduced as an
anterior segment analyzer that utilizes the
Scheimpflug photography technique.
When performing a scan, two cameras are used
to capture the image. One centrally located
camera detects pupil size, orientation and
controls fixation. The second rotates 180
degrees to capture 50 images of the anterior
segment to the level of the iris, and through the
pupil to evaluate the lens.

25. 1
4
2
3
5

26. 1
4
2
3
5
Scheimpflug imaging

27. 1
4
25 Pachymetry
Scheimpflug imaging
3

28. 1
4
2
3
5 Pachymetry
Corneal Topography
Scheimpflug imaging

29. 1
4
2
3
5 Pachymetry
3D chamber analyzer Corneal topography
Scheimpflug imaging

30. 1
4
2
3
5 Pachymetry
3D chamber analyzer Corneal topography
Lens
densitometry
Scheimpflug imaging

31. Sagittal Curvature Map Front Elevation Map
Pachymetry Map Back Elevation Map
Patient & Exam data
Ant Corneal Surface
Post Corneal Surface
Corneal Thickness
Pupil Diameter,
AC depth, IOP

32. Diagnosis of
Keratoconus
Sagittal Curvature Map Elevation Maps
Pachymetric
Progression display

34. Sagittal Curvature Map
 Central K > 47.2 D
 Difference between superior & inferior K > 1.9 D
 Isolated area of steepening (Hot Spot)
Diagnois of
Keratoconus

35. Elevation Maps
 Anterior Elevation Map
Central readings of 12 mm are suspicious
Central readings of 15 mm are diagnostic
 Posterior Elevation Map
Central readings of 17 mm are suspicious
Central readings of 20 mm are diagnostic
Diagnois of
Keratoconus

36. Pachymetric Progression display
Diagnois of
Keratoconus
• Quick downward deviation in corneal spatial
thickness profile
• Progression index average > 1
• Irregularity Indices
• Keratoconus level box

37. Detect who is at risk of
developing postopeative
ectasia
Detect form froste
keratoconus

38. Standard elevation maps
Exclusion maps
Difference maps

40. Contact Lenses1
Intracorneal Rings2
Cross Linking
Penetrating Keratoplasty
Deep Anterior Lamellar Keratplasty
FS Laser enabled Keratplasty
3
4
5
6
7

41. In the early stages of keratoconus, visual correction may be adequate
with astigmatic spectacles.
As the condition advances, and the cornea becomes more distorted and
contact lenses become a more suitable option.
Contact lenses create a more uniform refracting surface and decrease
surface irregularity.
Lens Types include :rigid lenses, soft lenses and combined use of both
rigid and soft lenses.

42. (RGP) lenses have ability to permit oxygen to
diffuse into, and Carbon dioxide to diffuse out of
the lens
1- Discomfort
2- Giant papillary conjunctivitis
3- Corneal wrapage
4- Corneal scarring
5- Keratitis
1- Longer wearing time.
2- Reduced corneal edema
3- Rapid adaptation.
4- More Oxygen permeability
5- Larger optic zone offers
increased visual field.
ComplicationsAdvantages

43. It consists of
1- soft lens(carrier) against the cornea to provide comfort
2- rigid lens(optical)over the soft to achieve vision
It consists of
1- (soft) skirt with water content of 28%
2- (rigid) optical center made of gas permeable material
These lenses provide the optic of a rigid lens, and the
comfort and good centration of a soft lens.

44. Characters:
1- Smaller posterior optic
2- Aspheric design of the periphery
Advantages :
1- provide a minimal central corneal touch
2-reduction in tear pooling at the base of the cone
Characters:
Large lenses that rest on the sclera
Advantages :
1- Increase in lens wearing comfort
2- Increase lens stabilization
Disadvantages :
Decreased visual acuity when compared to CCLs

45. Contraindications of CL
• Dry eyes and lid problems such as active blepharitis, stye & chalazion.
• Acute and chronic conjunctivitis, corneal abrasions, 5th nerve paralysis,
uveitis and iritis.
Lens type selection
Depending on level of Keartoconus :
Nipple cone keratoconus can be treated with glasses, soft
contacts, hybrid lens and gas permeable lenses. As the cornea steepens,
the gas permeable contact lenses is the best choice. Their contacts are
large enough to cover the steep cone area and improve vision.
Oval cone best fitted with lenses of larger diameters which have
larger optical zones e.g Scleral lenses
Globus cones are best to fitted with RGP lens of large diameter or
scleral lens, to vault over the big, steep area of cone.

46. They act as passive spacing elements that
shorten the arc length of the anterior corneal
surface and therefore flatten the central
cornea
When ectasia progresses to the point where
contact lenses no longer provide satisfactory
vision, then surgical intervention may be
considered. New methods such as intrastromal
corneal ring segments have evolved

47. A - Ferrara rings
• has a triangular cross section
• It requires 2 corneal
incisions
• It is implanted at 80% depth
• Smaller optical zone
B - Intrastromal
corneal ring segments
• has a hexagonal cross section
• are inserted through a 1.8
mm radial incision in superior
cornea near the limbus
• It’s implanted at two-thirds
corneal depth
• Larger optical zone

49. *Topical anesthesia.
*Marking the centre of cornea
*Intra-operative Corneal pachymetry
*radial incision 1.2 mm long at a depth of 70% of the pachymetry
*lamellar corneal dissection.
*create curved peripheral corneal tunnels >>>
*Application of a vacuum centering guide (VCG)
*The two intrastromal tunnels prepared using clockwise
and counterclockwise dissecting instruments.
*Each of the Intacs manually rotated into the tunnel
until the desired position was reached>>>
*The incision closed using a single 10-0 nylon
Procedure

50. DSIADVANTAGESADVANTAGES
A – Intraoperative
1-Anterior and posterior
perforations during channels
creation
2-extension of incision towards
visual axis
3-uneven or shallow placement of
implant
B – Postoperative
1- Undercorrection or Overcorrection
2- Induced astigmatism
3- Neovasularisation toward the
incision
4- Infection and melting
5- Glare and halos
6- Acute Corneal Hydrops
1-Safe
2-Effective
3-Rapid Effect
4-Adjustable
5-Reversible

51. *Tunnel depth two thirds the corneal thickness
*The entry wound opened with a blunt Sinskey
hook.
* Each of the Intacs then manually rotated into
the tunnel until the desired position was
reached.
* The incision closed using a single 10-0 nylon
suture.
Technique

52. DSIADVANTAGESADVANTAGES
1- Incomplete ring channel
formation
2- Endothelial perforation
3- Migration of ring segments
4- Infection
1-Different, depths, widths and
diameters, defined in advance.
2- Centric and eccentric laser cuts
can be performed
3- Corneal stress is minimal,
because only moderate pressure is
exerted on the eye during surgery
4- Risk of infection is significantly
reduced

53. After the formation of a closed pocket of 9 mm in diameter and
300 μm in depth within the corneal stroma, a flexible full-ring
implant is inserted into the corneal pocket via a narrow incision
tunnel
Intacs SK, Severe Keratoconus, is a newer design of ICRS with a
smaller 6mm optical zone to correct higher grades of keratectasia
with an elliptical cross-section to minimize the glare
Using femtosecond laser to create the tunnels decrease
postoperative spherical, coma and other higher order aberrations
A new Ferrara ring with a 210° arc. The new model has three
advantages over the conventional ring: (1) minimal astigmatic
induction, (2) more corneal flattening (3) implantation of a single
segment
Recent Advances

55. 1-Topical anesthesia of the eye.
2- Mechanical removal of epithelium
3- 0.1% riboflavin solution is applied manually
every 2 minutes, starting 30 minutes before
UVA exposure to allow stromal saturatuion >>>
4- Ultraviolet A (UVA) is used to deliver an
irradiance of 3 mW/cm2
5- The irradiation is performed from a distance
of 1cm for 30 minutes >>>
6- Repeated applications of riboflavin to the
cornea are performed every 2 minutes during
irradiation.
Procedure

56. Main Parameters
Wavelength 360–370 nm
Riboflavin 0.1%
Time 30 minutes
Diameter 7-9 mm
Cornea > 400 micron

57. DSIADVANTAGESADVANTAGES
1-Corneal haze
2-Infection
3-UV harm to endothelium, lens &
retina
4-Slow healing
1-Minimally invasive
2-Strengthen the cornea
3-Directed to pathology
4-Effective
5-Safe (Affect anterior corneal
layers only)
6- Delays keratoplasty
7- Antimicrobial effect
(Riboflavin/UVA )

58. Combining riboflavin with Intacs augmented the flattening effects of Intacs.
In progressive keratoconus first CXL was performed to stabilize keratoconus and then after 1 year
interval of stability, topography-guided PRK was performed to improve functional vision
Athens Protocol, CXL combined with topography-guided partial PRK followed by application of
mitomycin-C 0.02%
Rapid treatment protocols (10 min at 10 mW/cm2) showed equivalent increases in corneal
stiffness in comparison with the standard protocol (30 min at 3 mW/cm2).
Transepithelial CXL, in which riboflavin is delivered using enhancers of epithelial permeability
rather than epithelial debridement, It has benefits of standard epithelium-off treatments without
the painful rehabilitation and complications of epithelial removal.
Depth and extent of anterior corneal stroma changes induced by CXL could be determined using
high-resolution anterior-segment optical coherence tomography (OCT) post-operative images.
Recent Advances

59. 1) Contact lenses intolerance
2 ) Central corneal scar
3) Progression of the cone after Intacs
4) Recurrent keratoconus (after DALK)
Indications
Note
Acute hydrops is not necessarily an indication for
penetrating keratoplasty, because in many cases the
hydrops resolves and the resultant scar is outside
the visual axis. The scarring may flatten the cornea,
allowing the patient to tolerate contact lenses and
achieve good vision.

60. 1- General Anesthesia
2- Trephination
3- The graft cut from the endothelial side
4- The recipient cornea cut from the epithelial
side
5-The graft temporarily fixed using 10-0 nylon
sutures at the 3, 6, 9, and 12 o’clock position
6-Definitive fixation of the graft performed with
one of three suturing techniques; interrupted,
double running, and single running
Procedure

61. DSIADVANTAGESADVANTAGES
1-Graft rejection
2- Residual myopia
3- Post keratoplasty astigmatism
4-Late progression of astigmatism
5-Fixed dilated pupil
6-Recurrence of keratoconus
7- Endothelial loss
8-Transmitted infection
9-complications of intraocular
surgery such as glaucoma, cataract
formation, retinal detachment,
cystoid macular edema,
endophthalmitis, and expulsive
hemorrhage.
1-Effective
2- Good visual results
3- Stop progression

62. In keratoconic eyes the endothelium cell count is
usually good.
In DALK Descemet’s membrane and endothelium of
the host are preserved thus decreasing the incidence
of rejection

63. (a)Air injection deep into the stroma with
a bevel-down 27-G needle
(b)Round big-bubble formation passing
the trephination borders
(c) Formed big-bubble
(d)Exposed Descemet’s membrane after
removal of the corneal stroma
(e)Removal of donor Descemet’s
membrane
(f) suturing the graft

64. (A)The corneal diameter is marked using a
manual trephine
(B) A 2 mm corneal incision at the 12-
o'clock position is performed
(C) Trephination of 70% of the corneal
thickness
(D)The superficial lamella is removed using
a crescent knife
(E) Starting from the deep corneal incision,
a peripheral pocket is created using a
sharp disc knife
(F) A full diameter peripheral pocket is
created using a sharp disc knife and
Vannas scissors
(G) A blunt spatula is used to reach a deep
pre-Descemetic plane in the central 7
mm of the cornea.
(H)A continuous 10.0 nylon running suture
is placed

65. Microkeratome is used to perform both the recipient
bed dissection and lamellar dissection of the donor
cornea
Technique :
Shaving off the superficial 250 μm of the
keratoconic cornea by a microkeratome
The 350 μm donor lenticule is sutured on to the
recipient bed
The advantages :
*smooth graft–host interface
*technically easy procedure compared with DALK
*it can be used with corneal thickness ≥380 μm.
Before
After

66. DSIADVANTAGESADVANTAGES
1)-More complex procedure
2)-Longer operating time
3)- Descemet’s membrane
perforation
4)-Double anterior chamber
5)-Recurrent keratoconus
6)- Rise in intraocular pressure
7)- Fixed dilated pupil following
deep lamellar
(Urrets-Zavalia syndrome(UZS))
1)-No endothelial rejection
2)-Extraocular
3)-Stored cornea can be used
4)-Less topical steroids course
5)-Faster visual recovery
6)-Strengthen the cornea
7)- Rapid wound healing

67. *Femtosecond (FS) laser is used for creation of shaped
corneal incisions.
*complex patterns of laser trephination cuts include
A-Standard
B-top-hat
C-mushroom
D-zig-zag
E-Christmas tree
*All of these wound configurations
 create more surface area for healing
 improve tissue alignment
 require less suture tension for alignment of tissue
 have superior biomechanical strength
 rapid visual recovery

68. any condition preventing proper laser docking such as
severe ocular surface irregularity
elevated glaucoma filtering bleb
glaucoma shunt implant
small orbits
extremely narrow palpebral fissures
recent corneal perforations
Contraindications

69. ADVANTAGES DSIADVANTAGES
Top Hat cut
• improved wound seal and
stability due to its internal
flange
• less astigmatism
Muschroom cut
• provide greater anterior
stromal replacement
Zigzag cut
• the most biomechanically
sound incision pattern
• less potential for tissue
misalignment and overall
optical distortion
• improved seal of the incision
site, improved tensile
strength of the wound &
faster wound healing
Top Hat cut
• possibility of tissue
misalignment
• posterior wound gap
Muschroom cut
• ring-shaped microcystic
edema over the interface of
the graft-host overlap zone
• protrusion of the anterior
lamella between sutures
associated with ointment
deposits and bacterial
infiltrates

71. Keratoconus is a degenerative, non-inflammatory
disease of the cornea, characterized by central
and para-central thinning and subsequent
ectasia
Corneal topography represents a significant
advance in the measurement of corneal
curvature over keratometry. Topography provides
both qualitative and quantitative evaluation of
corneal curvature.
New pathways for keratoconus management
address two essential aims: shape stabilization
and visual rehabilitation.

72. Shape Stabilization is achieved by Cross Linking which is
thought to stop the corneal ectatic disorder, new modalities
include Rapid CXL, Transepithelial CXL, Simultaneous CXL and
Topo-guided PRK.
Visual Rehabilitation is achieved by contact lenses in early stage,
Intrastromal corneal ring segments which are effective in
flattening the corneal shape and improving vision, novel
modalities include combined ICRS and CXL, INTACS SK and use of
Femtosecond laser to create channels for INTACS insertion.
Keratoplasty is the only treatment for advanced keratoconus with
corneal scarring. Recent advances include lamellar keratoplasty
techniques and the advanced shaped side-cut techniques,
particularly with the use of femtosecond lasers.

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