This document discusses various refractive surgical procedures including: 1. Epikeratophakia and intracorneal rings for corneal refractive procedures 2. Clear lens extraction and phakic IOLs for lenticular refractive procedures It provides details on indications, contraindications, surgical techniques and complications for these procedures.

1. Dr. Ankit Gupta

2. 2 CATEGORIES
A CORNEAL
 Epikeratophakia
 Intracorneal rings
B LENTICULAR
 Clear lens extraction
 Phakic IOLs

3. KERATOPHAKIA
 In keratophakia, a plus-powered lens is
placed intrastromally to increase the
curvature of the anterior cornea to correct
hyperopia and presbyopia.
 A central lamellar keratectomy is performed
with a microkeratome or femtosecond laser,
the flap is lifted, the lenticule is placed onto
the host bed, and the flap is replaced and
adheres without sutures.

4.  Kaufmann , werblin in 1980
 To eliminate the complexity of the lamellar
dissection
 Epikeratoplasty involved suturing a preformed
homoplastic lenticule directly onto the Bowman layer
of the host cornea.
 Graft rejection did not occur because no viable
cells existed in the donor tissue.

5. SCHEMATIC PRESENTATION

6. INDICATIONS
1. Aphakia
2. Myopia
3. Hyperopia
4. Keratoconus
COMPLICATIONS
1. Poor adherence of
the graft
2. Infection
3. Epithelial ingrowth
into the bed
4. Poor predictiblity
of the results
5. Corneal edema

7.  Are implanted into the peripheral cornea ,
producing a vaulting effect that flattens the
central cornea and corrects upto the 3D of
myopia.

9.  Made up of PMMA
 Outter diameter 8.1mm
 Inner diameter 6.7mm
 Arc length 150 °
 Positioning hole diameter 0.28mm
 Ring cross sectional – hexagonal
 Each package consists of two rings
 Available in 11 thickness from 0.210mm to
0.450mm

11.  Myopia upto -3D
 Keratoconus
 Pellucid marginal degeneration
 Post LASIK corneal ectasias.

12.  Patient should have central clear cornea.
 Thickness of cornea should be greater than
450micron at the incision site.

13.  Collagen vascular disease
 Autoimmune, or immunodeficiency diseases
 Pregnant or breastfeeding women
 Presence of ocular conditions such as
recurrent corneal erosion syndrome
 Corneal dystrophy that may predispose the
patient to future complications.

14.  The procedure involves creating a lamellar
channel at approximately 68%-70% stromal
depth, followed by insertion of the ring
segments.
 Pachymeter is used to measure the thickness
of the cornea over the entry mark

15.  The geometric center of the cornea is marked with
a blunt hook.
 A diamond knife is set to 68%-70% of the stromal
depth and then used to create a 1.0-mm radial
incision.( also by femtosecond laser)
 Corneal tunnels are then created at approximately
2/3rd of stromal depth using pocketing hook.
 Intacs are then implanted.
 Tissue glue or 10-0 nylon sutures may be used to
close the radial incision at the corneal incision.

17.  Removal or exchange rate – 3 % to 15 %
 Most common reason for exchange is
residual myopia.
 Removal of ring is done usually because of
disabling vision symptoms such as glare ,
double vision and photophobia.

18.  Adverse events (defined as events that, if left
untreated, could be serious or result in
permanent sequelae) occur in approximately
1% of patients.
1. Anterior chamber perforation
2. Microbial keratitis
3. Implant extrusion
4. Shallow ring segment placement
5. Corneal thinning over Intacs

19. TIP EXTRUISON

21.  Ocular complications defined as clinically
significant events that do not result in
permanent sequelae occurs in approximately
11% of patients.
1. Reduced corneal sensitivity.
2. Induced astigmatism between 1.00 and 2.00
D.
3. Deep neovascularization at the incision site.
4. Persistent epithelial defect.
5. Iritis/uveitis.

22. DEFINITION
 Artificial lenses implanted in the anterior or
posterior chamber of the eye in the presence
of the natural crystalline lens to correct
refractive errors.

23.  1950s
- correcting myopia by inserting a concave
lens into the phakic eye
 1988
- Baikoff : anterior chamber angle-fixed PIOL
 Mid 1980s
- Posterior chamber phakic IOLs : Fyodorov
 1991
- Artisan-Worst iris claw lens

24.  Can treat a larger range of refractive errors
 Allows the crystalline lens to retain its
function preserving accommodation (as
compared with refractive lens exchange)
 Removable and exchangeable.
 Less expansive
 Lower risk of endophthalmitis and post op
retinal detachment because the barrier of
crystalline lens is present.

25.  Potential risks of an intraocular procedure
 Nonfoldable models require large incision that
may result in high postoperative astigmatism.
 PC PHAKIC IOLs have a higher incidence of
cataract formation.
 At the time of cataract surgery posterior
PHAKIC IOL has to be removed possibly
through a larger than usual wound.
 AC PHAKIC IOLs may damage corneal
endothelium.

26.  Anterior chamber –angle supported PIOL
 AC iris fixated
 Posterior chamber PIOL

27. MODEL AVAILABLE
POWER
OPTIC SIZE/
EFFECTIVE
DIAMETER (mm)
MATERIAL
Acrysof -8.00 to -
16.00D
5.5 Acrylic
Phakic 6 H2 -4.00 to -20.00
+2.00 to
+10.00
5.5-6.0 PMMA
KELMAN DUET -6.00 to -20.00 6.3 Silicon optics
PMMA haptics

29. (A). The haptics are implanted initially through a small incision
(B), then the optic is injected
(C). The complex optic-haptics is assembled inside the anterior chamber

30. MODEL AVAILABLE
POWER
OPTIC SIZE/
EFFECTIVE
DIAMETER (mm)
MATERIAL
VERISEYE MODEL -5.00 to -20.00 5.0 PMMA
Artiflex/ Veriflex -3.00 to -23.50 8.5 Polysiloxane
Foldable iris-fixated Artiflex lens

31. MODEL EFFECTIVE
POWER
OPTIC SIZE/
EFFECTIVE
DIAMETER (mm)
MATERIAL
VISIAN ICL -3.00 to -20.00 4.9-5.8 Collamer

32.  Age above 21 years
 Stable refraction for more than one year
 AC depth >= 3.2mm for iris-claw lens
>= 2.5mm for pc PIOLs
 Minimum endothelial cell density
> 3500 cells/mm² at 21 yrs age
> 2800 cells/mm² at 31 yrs age
> 2200 cells/mm² at 41 yrs age
> 2000 cells/mm² at 45 yrs age
 No other ocular pathology (corneal disorders,
glaucoma, uveitis, cataract)

33. A) FOR HIGH MYOPIA
-8.00 D to -20.00 D
 FDA APPROVED
1. Artisan (iris supported)
 Myopia -5.00 to -20.00 D
 Astigmatic correction of 2.5D
 Age ›21 yrs
 ACD ›3.2mm

34. A) FOR HIGH MYOPIA
-8.00 D to -20.00 D
 FDA APPROVED
2) ICL (POSTERIOR CHAMBER PIOL)
 Myopia -3.00 to -20.00D
 Astigmatic correction of 2.5D
 Age 21 yrs to 45yrs
 ACD ›3mm

35. B) FOR HYPERMETROPIA
Available power in
1. ICL upto +20.00 D
2. ARTISAN upto +12 D

36. C) FOR ASTIGMATISM
 PIOLs are available upto 6D
 But treatment of choice is laser ablation upto
4 to 5 D

37.  Preexisting ocular diseases –
1. Compromised corneal endothelium
2. Iritis
3. Rubeosis iridis
4. Cataract
5. Glaucoma
 AC depth
 AC diameter
 Pupil size
Must be appropriate

38. The critical parameter in sizing the ICL is
the white-to-white (WW) measurement
which can be measured with a Pentacam,
OrbScan, UBM or using calipers.
When implanting a angle supported PIOL – 2
peripheral iridotomies are done between 10’O
clock to 2’O clock position 2 to 7 days prior to
the surgery.

39.  Vault is the space between the posterior
surface of PIOL and the anterior lens capsule.
 Shallow vault - will cause ICL contact with the
crystalline lens and increases the risk of
cataract formation over time.
 High vault will rub against the iris and will
cause the chronic iritis and pigment dispersion
glaucoma
VAULT
SMALL Less than 0.25mm
EXCESSIVE More than 0.75mm
IDEAL 0.5mm

42.  Changes in vaulting with accommodation.
 Loss of Corneal Endothelial Cells.
 Pupil Ovalization / Iris Retraction.
 Glare,Halos.
 Pigment dispersion glaucoma.
 Chronic Inflammation or Uveitis.
 Pupillary Block Glaucoma.
 Phakic Intraocular Lens Rotation.
 Cataractogenesis.
 Retinal Detachment.

43.  The combination of phakic IOL implantation
followed by LASIK in patients with extreme
myopia or hypermetropia and high levels of
astigmatism.
 When an anterior chamber phakic IOL is planned
to be combined with LASIK, the corneal flap can
be created just prior to the insertion of the lens;
then, at a later time, usually after 1month, the
flap is lifted for laser correction of the residual
ametropia. This two-step technique was called
adjustable refractive surgery (ARS) by Guell.
 The rationale in performing the flap first is to
avoid any possibility of contact between the
endothelium and the IOL during the suction and
cut for the LASIK procedure.