phakic intraocular lens,phakic iol

1. Phakic Intraocular lens
DR SREEDHANYA SREEDHARAN
PG RESIDENT
AMRITA INSTITUTE OF MEDICAL SCIENCES,KOCHI

2. Phakic intraocular lens
Artificial lens implanted in anterior chamber or posterior chamber
of eye in presence of natural crystalline lens

4. Phakic IOL advantage
1. Preserve normal corneal architecture
2. Predictable results
3. Preserve accommodation
4. Predictable healing
5. Rapid recovery
6. Stable postoperative refraction
7. Reversible and adjustable

5. History
In 1890, Fukala proposed and performed the extraction of the clear
crystalline lens for the correction of high myopia
1950 correct myopia by inserting concave lens to phakic eye
1988 Baikoff AC angle fixed IOL
1980s mid posterior chamber PIOL
1991 artisan worst claw lens

6. Types of Phakic IOLS
1. Anterior chamber angle fixated IOL e g. ZB M5, NuVita MA20,
Phakic 6.
2. Anterior chamber- Iris fixated IOL e g. VerisyseTM , Phakic IOL
(Artisan lens)
3. Posterior chamber sulcus fixated IOL e g. STAAR mplantable
contact lens and phakic refractive lens (PRL)

7. Angle supported anterior chamber PIOL
First generation angle supported IOLs were developed by Baikoff &
Joly 1997
The first model (ZB -DOMILENS) was a modified Kelman type lens
with a 4.0mm optic and 2 haptics with a 4-point fixation in theangle
Then ZBM5 4mm biconcave optic 20 degree angulated haptic
Nuvita MA20 4.5mm optic , large curved footplate
ZSAL4

8. BAIKOFF 1st generation and 2nd generation- associated with
endothelial cell loss,pupillary block

9. Nu vita-Baush and Lomb ie
Baikoff 3rd generation
ZSAL4- planoconvex
lens single PMMA
with Z haptic

10. ANTERIOR CHAMBER PIOL
PHAKIC 6-PMMA 6mm optic
and 2 haptic

11. Foldable - Vivarte
Zeiss
1 piece AC PIOL with 3 point
angle supported lens- tripod
support
Soft hydrophilic
Acrylic soft optic 5.5 mm and
rigid haptic

12. Duet -
2 parts
Tripod haptic-PMMA
Silicone optic 5.5mm
Assembled inside AC

13. Calculate power of AC phakic IOL
white-to-white, a correction factor is added to determine the correct
length.
•1 mm in Phakic 6
•0.5-1.0mm in Vivarte
•1.5mm in Acrysof
power we use Van der Heijde nomogram, takes into account
oSpherical equivalent
oCorneal power
oAnterior chamber depth.

14. Advantage of Anterior Chamber PIOL
 easy insertion
Excellent result
Placement away from crystalline lens- less chance of cataract

15. Problems of anterior chamber phakic IOLs
1. Endothelial cell loss - Intermittent endothelial touch
2. Pupillary ovalisation (4-42%)
a) Immediate post operatively - Iris tuck/ oversized IOL
b) Late onset - Iris root ischemia
3 Iris de pigmentation (2.3-4.5%) - Iris protrusion during surgery
4. Halos & glare - Small optic zones
5. Surgically induced astigmatism - Long incisions
6.IOP elevation – pupillary block, steroids/viscoelastic

16. Iris Supported Anterior Chamber Phakic IOLS
Iris fixated IOLs have
haptics in the form of lobster
claw that fixate the IOL to the
mid peripheral iris.
1.Artisan (Ophtec, Netherlands)
2. Verisyse( AMO).

17. The Artisan lens is a onepiece
UV wavelength absorbing PMMA
compression
molded lens with
Diameter- 8.5 mm
optic vaulted suitably (0.5mm) to
stay clear of the iris cone
5.0mm optic
Same size for all

18. Problems of Iris fixated phakic IOLs
1. Anterior chamber inflammation: early post-op- 6.4- 16% of eyes
(Fechner et al 1992)
2. Glaucoma
3. Iris atrophy: on fixation sites - 81% cases( Santonja et al)
4. Implant dislocation: lens instability & haptic disincarceration in
9.3% ( Santonja et al.)
5. Decentration : 23.4-56% (Manejo et al.)
6. Endothelial cell loss: mean endothelial cell loss 5.3%, 7.63%
&17.9% at 1, 2 &5 years respectively

19. Selection of patients for phakic IOLs-ICL
1. Age above 18 years (22-45)
2. Moderate to high myopes (>-9.00D) & hyperopes (> 4.5 D)
Hyperopia +5 D - +11 D
Myopia -10 to -23 D
3. Also indicated in lesser degrees of ametropias
if LASIK is contraindicated
 Corneas thinner than 500 microns
 Steep or flat corneas
Topographic change suggestive of keratoconus

20. 4. Endothelial cell density: at least 2250-2500 mm3
5. Pupil smaller than 6 mm in scotopic luminance.
6. Stable refraction for at least 1 year
7. Anterior chamber depth (excluding corneal thickness) at least 2.8mm
8. Angle width at least 30 degrees
9. AC angle Shaffers grading 3-4 in atleast 270 degree
10. No eye pathology except refractive
11. No systemic pathology such as diabetes, collagen diseases etc

22. 6 important parameter
1.Refraction
2.AS OCT
3.W-W diameter
4.Specular
5.corneal topography -
6.Gonioscopy

23. Phakic IOL planning- AS OCT
ACD less than or equal 3.5 then
1.1 mm added to W-W diameter
ACD >3.5 add 1.6 to W-W till
maximum 13.7
anterior chamber depth – > 2.8 mm

24. Angle assessment
Angle >30 degree

25. 3.horizontal white to white diameter-Orbscan /digital caliper
Proper vaulting 500 microns or corneal thickness
If vault
•Too short lens vault small, more risk anterior capsular cataract
•Too long –excessive vault
angle crowding, increased change of angle closure
Iris shaffing and pigment dispersion glaucoma

26. Posterior chamber PIOL
Silicone -PRL
Collamer - ICL
Hydrophilic acrylic - Sticklens

27. Implantable collamer lens- ICL
Collamer – hybrid of silicone and
collagen
STAAR surgical
Recent Visian ICL –single piece foldable
lens-copolymer of HEMA (99%) &
porcine collagen (1%)
Planospherical
High biocompatibility
Toric version can correct upto 6 D
ICL rests on ciliary process than on
sulcus

28. The white arrow indicates the ICL and the blue
arrow indicates the crystalline lens

29. PRL
CIBA vision
Ultra thin hydrophilic silicone
New generation
+15 D to -30 D with cylinder
upto 8D

31. Refractive Implantable Lens – APPA
Swamy
Hydrophilic acrylic
Size 4.5-5mm
11.5 to 13 mm size
-1 D to 21 D

32. SURGICAL TECHNIQUES
Loading ICL
taken from glass vial using special
applicator

33. Implantable collamer is placed in groove of catridge

34. ICL held with Aus de Aur forceps

35. 2.5 mm incision Apply viscoelastic

37. After implanting through a small clear corneal incision, the plate
haptics of the ICL are tucked into the sulcus. PI done in all cases

39. Problems of phakic posterior chamber
IOLs
Ø Inverted implantation- iatrogenic
Ø Endothelial cell damage (2.3-3.0% at 2 yrs)
Ø Inflammation
Ø Pigment dispersal
Ø Elevated IOP
Ø Cataractogenesis -0.82 to 4.38% at 5 years
Ø Decentration

40. Reference
1. AIOS ready reckoner in ophthalmology
2.Cornea -Krashmer
3. Phakic Intraocular Lenses-Namrata Sharma MD, Jeewan S. Titiyal MD, Nishant Taneja MBBS,
Rasik B. Vajpayee MS, FRCS (Ed)
4.Phakic intraocular lens – Principle and practise David R. Hardten, MD, FACS & Richard L.
Lindstrom, MD

41. Thank you