LASIK IS A REFRACTIVE PROCEDURE VERY SUCCESSFULLY TREATS MYOPIA BUT NEEDS RETINAL EVALUATION

1. Retinal complications after laser
assisted in situ keratomileusis
(LASIK).
Dr Ajay Dudani
Zen eye center
Khar (W)
Dr Yashesh Maniar
Shreekrishna eye clinic
Borivli (E)

2. Refractive surgery
Has been accepted for correcting ametropias.
Lasik has become one of the most popular options for
the correction of low to moderate myopia world wide.

3. Complications of lasik
•Undercorrections
•Overcorrections
•Flap displacement
•Epithelial ingrowth
•Flap melting
•Retinal hemorrhages
•Macular holes
•Choroidal neovascular
membrane
•Keratitis
•Retinal tears
•Retinal detachments
•Corneosceral perforation
•Macular holes
•Choroidal neovascular membrane
•Irregular astigmatism

4. Retinal detachments and breaks
•Very little has been reported in the literature regarding
retinal detachments after LASIK.
•Ozdamar et al. have reported a case of bilateral retinal
detachment associated wi8th giant retinal tear after LASIK.
• Ruiz-Moreno et al. reported four retinal detachments(an
incidence of 0.25%) in myopic eyes after LASIK.
•Arevalo et al. reported 0.08% developed RRD after LASIK.

5. Retinal detachment characteristics and
retinal breaks distribution
Arevalo et al evaluated the fundus drawings of 33 eyes:
Inferotemporal 14%
Inferonasal 9%
Superotemporal 8%
Superonasal 7%
8 total
25 subtotal

6. Macular hemorrhage
Very few reports have been published regarding macular
hemorrhage after LASIK.
Kim and Jung reported one eye lost more than 2 lines of
preoperative BCVA because of macular hemmorrhage.

7. Lacquer cracks
Lacquer cracks in Pathological myopia
CNV and macular atrophy
Poor visual outcome
Lacquer cracks have been found to be associated to CNV in up to
82% of cases with myopia.

8. Choroidal neovacular membranes
The incidence of of CNV after LASIK seems to be
very low.
Very few cases have been studied.
Choroidal neovascularization is related to myopia
itself and its incidence varies from 4% to 11% in
patient with high myopia.

9. Choroidal neovacular membranes
Break in bruch’s
membrane

10. Choroidal neovacular membranes
Break in bruch’s
membrane
Neovascular
complexes

11. The increase in IOP to levels more than
60 mmHg during suction with the
microkeratome suction ring
Excimer laser
is responsible
for a shock
wave
transmitted to
eye

12. PDT with verteporfin for
subfoveal CNVM after LASIK
Arevalo et al. has reported success in stabilizing or
improving vision in patients with subfoveal CNV from
pathologic myopia after LASIK with PDT.

13. Macular hole
Vitreo retinal interface changes
Macular hole may develop in
myopic eyes after LASIK
Ruiz-Moreno reported PVD was not present before and was
documented after LASIK on 80% of eyes.

14. Corneoscleral perforation
This complication may occur
with microkeratome when a
corneal flap is performed.
Severe cases may be
associated with posterior
segment damage.

15. Corneoscleral perforation
Some cases may be treated by
Therapeutic soft contact lens
•Topical antibiotics
•Oral CAIs
•Eye patching
•Be meticulous in properly
assembling the microkeratome to
creat a corneal flap during lasik.
•The use of currently
availabledisposable
microkeratomes may help to
avoid this complication in
future.

16. Displacement of corneal flap
during vitrectomy
Dislocated corneal flap may occur from corneal epithelial
debridement during vitrectomy after lasik.
Displacement of a corneal flap after lasik is a serious
complication due to
•Losing the flap
•Epithelial ingrowth
•Interface particles
•Striae in the flap

17. Management of displaced corneal
flap during vitrectomy
Avoid debridement of corneal epithelium
If necessary,
Start nasally and advance temporally.(most cases – nasal hinge)
Displaced corneal flap
Reposition of flap, patching and topical steroids, BCL
Refracory cases
Suture fixation

18. Anatomy of vitreous base
• 3-4 mm wide zone straddling ora serrata
• Strong adhesion of cortical vitreous
• Anterior limit of posterior vitreous detachment
Vitreous
base
Pars
Plicata
Pars
Plana
Mechanism of acute vitreoretinal traction at the vitrous base

19. Indirect ophthalmoscopy
• Keep lens parallel to patient’s iris plane
• Avoid tendency to move towards patient
• Ask the patient to move eyes and head
into optimal positions for examination

20. Morphology of tears
a. Complete U-tear
b. Linear
c. Incomplete L-shaped
d. Operculated
e. Dialysis

21. Scleral indentation
Retinal breaks in detached
retina without indentation
Enhanced visualization of
breaks with indentation

22. PROPHYLAXIS OF RHEGMATOGENOUS
RETINAL DETACHMENT
• Lattice
• Snailtrack
• White-without-pressure
1. Retinal breaks
• Laser photocoagulation
• Cryotherapy
3. Treatment modalities
2. Predisposing degenerations
4. Benign peripheral degenerations

23. Retinal breaks
a - Large U-tear with
‘ subclinical RD ’
- treat
b - Large symptomatic U-tear
- treat
c - Operculated tear bridged
by blood vessel
- treat
d - Asymptomatic operculated
tear
- do not treat

24. Retinal breaks not requiring treatment
e - Asymptomatic dialysis
surrounded by pigment
f - Breaks in both layers of
retinoschisis
g - Small asymptomatic holes
near ora serrata
h - Small inner layer holes in
retinoschisis

25. Typical lattice degeneration
• Present in about 8% of general population
• Present in about 40% of eyes with RD
• Spindle-shaped islands of retinal thinning
• Network of white lines within islands
• Variable associated RPE changes
• Small round holes within lesions are common
• Overlying vitreous liquefaction
• Exaggerated attachments
around margin of lesion
Retina Vitreous

26. Complications of lattice degeneration
Indications for prophylaxis
• No complications - in most cases
• RD associated with atropic holes, particularly in young myopes
• RD associated with tractional tears in eyes with acute PVD
• RD in fellow eye
• Extensive lattice in high myopia

27. Snailtrack degeneration
Indications for prophylaxis - presence of holes
Sharply demarcated, frost-like bands
which are longer than lattice
Large round holes which carry
high risk of RD

28. White-without-pressure
Indications for prophylaxis - giant tear in other eye
Translucent grey appearance of retina Occasional giant tear formation along
posterior margin of lesion

29. Benign peripheral retinal degenerations

30. Rhegmatogenous - caused by a
retinal break

31. PRINCIPLES OF RETINAL
DETACHMENT SURGERY
1. Scleral buckling
2. Pneumatic retinopexy
• Configuration of buckles
• Preliminary steps
• Localization of breaks
• Cryotherapy
• Insertion of local explant
• Encircling procedure
• Drainage of subretinal fluid
• Causes of early failure
3. Vitrectomy
• Giant tears
• Proliferative vitreoretinopathy (PVR)
• Diabetic tractional RD

32. Configuration of scleral buckles
Radial
Segmental
circumferential
Encircling
augmented by
radial
sponge
Encircling
augmented by solid
silicone tyre

33. Preliminary steps
Peritomy Insertion of squint hook under
rectus muscle
Insertion of bridle suture Inspection of sclera for thinning
or anomalous vortex veins

34. Localization of breaks
• Insert 5/0 Dacron scleral suture
at site of apex of break
• Grasp cut suture with curved mosquito
forceps close to knot
• While viewing with indirect
ophthalmoscope check position of
indentation in relation to break

35. While viewing with indirect
ophthalmoscope
indent sclera gently with tip of
cryoprobe
Freeze break until sensory retina
just
turns white
Cryotherapy

36. Technique of cryotherapy
• Surround lesion with single row of
cryo-applications
• Preferred for treatment of large
areas

37. Insertion of local explant
Distance separating sutures
measured and marked
Ends trimmed
Sutures tightened over explant
Insertion of mattress-type suture

38. Encircling procedure
Strap fed under four recti Ends secured with Watzke sleeve
Strap slid posteriorly and secured
in each quadrant
Strap tightened to produce required
amount of internal indentation

39. Drainage of subretinal fluid
Indications
Haemorrhage
• Difficulty in localizing break
• Immobile retina
• Longstanding RD
• Inferior RD
Retinal incarceration
Complications
Technique

40. Causes of early failure
May be associated
with communicating
radial retinal fold
Insert additional radia
buckle
Buckle failure
‘ Fishmouthing ’ of retinal tear
Buckle inadequate
size or height
Buckle incorrectly
positioned

41. Technique
(a) Cryotherapy
Pneumatic retinopexy
Indications
RD with superior breaks
(b) Gas injection
(c) Postoperative positioning
(d) Flat retina

42. Vitrectomy for giant tears
Unrolling of flap with light
pipe and probe
Completion of unrolling Injection of silicone oil or
heavy liquid

43. Mechanism of acute vitreoretinal
traction at the vitrous base and
post. Pole (A)
Suction ring- deforms AP axis
Increased AP diameter
Closed system- contract along
horizontal axis
Decreased equatorial diameter

44. Mechanism of acute vitreoretinal
traction at the vitrous base and
post. pole (B)
Suction stops and ring released-
decompression dynamic overshoot
Equatorial elongation and AP contaction

45. Mechanism of acute vitreoretinal
traction at the vitrous base and
post. Pole (C)
Excimer laser
Shock waves
Pulsed energy

46. Prophylaxis of retinal detachment
before LASIK
Based on published data indication of prophylactic treatment can
not be determined.
It is not possible to determine scientifically whether peripheral
retinal lesions should be treated in a way different from standard
practice just because a patient is to undergo LASIK.

47. Prophylaxis of retinal detachment
before LASIK
Careful examination with IO and scleral depression
Normal
Go for lasik
No obvious lesion and
very high myope
Explain to patient
Go for lasik
Obvious lesion
Treat aggressively
Go for lasik

48. Lasik in scleral buckled cases
•Change of ap and axial length.
•How to decide parameters.
•Pre op precautions.
•Post of care.

49. Relative contraindications
•Macular disease
•High myopia and lacquer cracks Macular
hemmorhage and CNV
•Eyes at risk of needing vitreoretinal surgery
•Angioid streaks
•Tramatic choroidal ruptures

50. Conclusion
Serious complications after lasik are infrequent.
Inform patient not only for lasik but also the
vitreoretinal abnormalities and complications.
Dilated fundus examination with IO and scleral
depression.