This presentation describes indications of intrastromal corneal rings implantation in keratoconus cases and how they are beneficial even in advanced cases.
Size: 5.29 MB
Language: en
Added: Jan 04, 2017
Slides: 49 pages
Slide Content
Intracorneal Ring Segments By
Femtosecond Tunnel Creation
BY
Dr. Amr Mounir
Lecturer of ophthalmology
Sohag university
Keratoconus is a
progressive,
noninflammatory,
bilateral (but usually
asymmetric) ectatic
corneal disease.
Introduction
Treatment modalities
include hard contact
lens, corneal collagen
crosslinking,
Intracorneal ring
segments and
Keratoplasty
Intracorneal Rings
Mechanism of action of rings
Types of Rings
Methods of implantation of rings
- Precise Depth
- Precise Incision site creation
- Easier than manual
- Avoid complications of manual tunnel creation e,g:
Anterior or Posterior corneal perforations ,
epithelial defects, infectious keratitis, asymmetric
segment placement, corneal stromal oedema
around the incision, extension of the incision
towards the central visual axis or the limbus and
persistent incisional gapping
Advantages of Femtosecond Tunnel
Creation
Parameters which guide us
- Refraction
- Pachymetry
- Steepest K axis
- Cone site
- Nomogram
Non central cones.
High cylinder.
High difference between K1, K2.
Thickness at insertion site >400 um
Kerarings
Non of treatment options is satisfactory for the patient.
The disease is progressive by its nature.
Follow up is mandatory.
Combination of treatment options can be done.
Keratoplasty can be a final destiny even with treatment.
Rings mostly will be followed by glasses.
Don't judge on improvement of V\A without correction.
Financial aspect should be taken into consideration.
Rings results are unpredictable
Rules in treatment by rings
Nomogram for Kerarings
Tunnel creation by Femtosecond laser
Kerarings Ring implantation
Pre and post Kerarings Pentacam
About 250 eyes
had been
operated with
Keraringes
implantation by
Intralase
technology
Our provisional
experience in Sohag
Femtocenter
We ask ourselves very important
question
What are factors that affect
the results of ring
implantation ????
Age as a guideline
A 23 ys female with bil. Keratoconus Rt. Eye is advanced
more than Lt. eye.
Preoperative refraction of Rt. eye : -6.00 Ds -3.50 Dc
UNCVA : 4/60
BCVA : 6/30
Postoperative refraction of Rt. eye : -2.50
Ds -1.50 Dc
UNCVA : 6/30
BCVA : 6/18
Symmetry of Bowtie as a guideline
A 37 ys male with bil. Keratoconus Rt. Eye is
advanced more than Lt. eye.
Preoperative refraction of Rt. eye : -4.25 Ds
-7.00 Dc
UNCVA : 3/60
BCVA : 6/38
Postoperative refraction of Rt. eye : +1.00
Ds -1.0 Dc
UNCVA : 6/38
BCVA : 6/18
Corneal thickness as a guideline
A 17 ys male with RT. Advanced Keratoconus .
with thinnest location 348 um with max k: 60 D
Preoperative refraction of Rt. eye : -15.00 Ds
-8.00 Dc
UNCVA : 2/60
BCVA : 6/60
Postoperative refraction of Rt. eye
: -7.50 Ds – 5.00 Dc
UNCVA : 6/60
BCVA : 6/30
Rings in advanced cases
To delay corneal grafting.
To make the eye refractable.
To decrease coma aberrations.
N.B: Keratoplasty is still an option
Aim: