1. Wound Construction
Dr. Devin Prabhakar MS,DNB,FRCS

2. ????????? WTR/ATR/None
 In
pseudophakia, low
, simple, ATR
myopic
astigmatism is
better than WTR
astigmatism
because it
provides superior
uncorrected near

3. What is WTR astigmatism?
This is when the axis of the +cylinder
in a pair of glasses is at 90 degrees.
WTR astigmatism is typically seen in
children, ATR is seen in older eyes.

4. Astigmatism
 With-theRule
 This is when the vertical meridian is
steepest.
 Against the-Rule
 This is when the horizontal meridian is
steepest.
 Oblique
 This is when the steepest curve lies in
between 120 and 150 degrees and 30
and 60 degrees.

5. ???? Limbus: Blue/White

6. Effect of Incision
 Eventual flattening of surgical
meridian
 Longer Incision: Greater
Flattening
 Closer to corneal Apex:
Greater Flattening

7. Incision
 Site
 Position
 Shape
 Length

9. Temporal Incision
 By Fine
 Less Manipulation
 No need for birdle suture
 Less Astigmatism
 Natural drainage of irrigating fluid
 Undergoes ATR Astigmatism
 Good red glow
 Good for topical anesthesia

10. Creating a scleral incision
 Make a fornix-based conjunctival peritomy
 Make a shallow groove-incision in the sclera (preferably
frown), slightly larger than the width of your keratome,
 Tunnel in the sclera. Move keratome to both sides.
 Advance the keratome in the cornea, going slightly up-hill
 Having advanced up to clear cornea, tilt the keratome so
thatthe keratome’s tip points to the macula and cut
through Descemet’s membrane
 Once through Descemet’s membrane, advance the knife
parallel to the iris-plane until the shoulders of the
keratome have passed the internal edge of the incision.

11. Tips for creating incisions
 Maintain appropriate pressure in anterior
chamber.
 Underpressure will lead to a tunnel that is too
long and wound’s edges that are not straight
 Overpressure will lead to a tunnel that is too
short
 When in doubt, perform a Seidel test with a
fluorescein strip to test for leakage
 Fixate the eye by grasping the conjunctiva at
the limbus with forceps

12. Creating a clear corneal incision
 Make a shallow straight groove-incision in the clear
cornea, as large as the width of your keratome,
 Place the tip of your keratome in the groove and
advance the keratome through the corneal
stroma, going slightly up-hill
 Having advanced ± 2 mm in the cornea, tilt the
keratome so that the keratome’s tip points to the
macula and cut through Descemet’s membrane,
 Once through Descemet’s membrane, advance the
knife parallel to the iris-plane until the shoulders of
the keratome have passed the internal edge of the
incision

20. ON AXIS CATARACT INCISION
AND OPPOSITE CCI
 3.2 mm incision induces 0.25 to 0.50 D of
astigmatism. Incision on the steep axis
will lower the Pre Existing Astigmatism.
 By adding an identical, penetrating Clear
Corneal Incision opposite it is possible to
correct about 1.0 to 4.0D of astigmatism.
 No extra instruments or training.

26. Confusion Cleared
"The idea that you should leave a little
WTR or ATR are old myths that come from
articles written about 10 or 15 years ago,"
said Dr. Holladay. "It's not true. Residual
astigmatism is like any other aberration.
The best vision and the best result are
with zero residual astigmatism. WTR or
ATR are not beneficial. They blur the
image, particularly if you don't wear
glasses."

27. Please do join us on
www.facebook.com/DivyaPrabhaEyeHospital
www.facebook.com/devin.prabhakar
www.DivyaPrabha.in