Dr. Madhu Karna Consultant Pediatric Ophthalmologist

1. Cross eyes Crossword
Dr. Madhu Karna
Consultant Pediatric Ophthalmologist

2. There are many roads to orthophoria.
If we only knew:
• The trick to measure correctly.
• The tip when to investigate.
• The clue to avoid being trapped in a
complicated result of a seemingly simple
case.

3. What do you do when you see this
kind of a patient?

4. Or one like this

5. If you operate what you measure
over glasses then
• If glasses are plus
Measured deviation = True deviation – 2.5 D
%
[D-lens power]
• If glasses are minus
Measured deviation = True deviation + 2.5 D
%
In clinical practice it is the measured deviation
that is found first and true deviation must then
be calculated

6. Plus lenses decrease and minus lenses
increase the measured deviation.
Spectacle lens
power
True deviation
as %of
measured
deviation
To find true deviation
Change
measured
deviation by Example
-20 67 Decrease by
33%
4/6
-10 80 Decrease by
20%
4/5
PLANO 100 No change 4/4
+10 133 Increase by
33%
4/3
+20 200 Increase
by100%
4/2

7. • High Plus lenses in both exo & eso – M D <T D
[undercor]
• High Minus lenses in both exo & eso – M D >T D
[overcor]
• This becomes Sx significant with refractive
errors of + 5 d
• This formulae deal with strabismus
measurements with distance fixation
• While fixing for near the visual axes no longer
pass through optical centre of lenses, prismatic
effects get important.

8. If you have not measured with C L,
with this formulae you can still achieve orthophoria

9. Beware of a patient like this before
you operate her
• High myope – Status post OD:CLE,
OS:Lasik

10. DO IT BUT AFTER MRI
• Coronal/transverse/parasagittal T1 weighted
high resolution MRI of orbits
• Dynamic /motion MRI –nine gazes
• Intraoperatively,
– Distances betn insertion sites of EOMs
– Distances of EOMs from corneal limbus
• MRI findings of dislocation of recti to decide
surgery
• Postoperative MRI –for alignment & motility

11. • New methods of eye muscle surgery
in
–high myopic patients with esotropia and
hypotropia
–with respect to pathological findings in
high resolution MRI

12. • Herzau/Ionnakis – intraoperatively abnormal
path of LR. Good results with R&R +
suprapositioning of LR
– Verified by MRI scan
• Pathophysiology
– with increase in Axl- bubble like superotemporal
distension of globe-in middle & post segment ,
– causes increased stretching of LR with downward
dislocation
– sparing the ant. segment with insertion sites
– accumulation of retinal degn betn insertion of SO & IO

13. A
P
L
M

14. New Approach in Strabismus
Surgery in High Myopia*
Modified retroequatorial myopexia, in
addition to conventional R&R surgery for
dislocated horizontal recti in high myopes,
is a promising & effective surgery
* T H Krzizok,H Kaufmann,H Traupe ,British Journal Of
Ophthalmology 1997 Vol 81 Pg 625-630

15. Investigate the track of the muscles
before you set them straight

16. New Approach in Strabismus
Surgery in High Myopia
T H Krzizok
H Kaufmann
H Traupe
British Journal Of Ophthalmology
1997 Vol 81 Pg 625-630

17. This squint may trap you by
seeming simple but

18. Before you operate this patient
Just remove the glasses

20. • High hyperopia with Accomodative
Esotropia with Consecutive ExotropiaExotropia
• Reduce hyperopic power by half
• If exotropia still manifest or there is a dropIf exotropia still manifest or there is a drop
in visual acuity then operate on thein visual acuity then operate on the
consecutive Exotropia after measuringconsecutive Exotropia after measuring
over maximum cyclopegic refraction.over maximum cyclopegic refraction.

22. Thank you
May God bless you with many
more ortho eyes