phakic iol’s ( piol’s ) in correcting high myopia
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PHAKIC IOL’S( pIOL’S )
INCORRECTING HIGH MYOPIA
By:H.R. ZIAI MD.
Esfand 1391Isfahan
HISTORY
• 1950s : First ideas formed• 1988 : Angle supported PMMA, ZB5M & MA20, by
Bikoff • But :• Discontinued because of complications
( corneal edema, iritis ,… )
HISTORY
• 1988 : First phakic iris – clawed IOL• introduced for myopia by Worst• 1998 : Artisan – Worst by OPHTEC• Then changed it’s name to Artisan – Verysise • and it’s flexible form to Artiflex
HISTORY
• 1987: First PC pIOL or sulcus support pIOLs introduced :•- Phakic Refractive Lens ( PRL ) by CIBA VISON .• And then :•- Implantable Contact Lens ( ICL )• or Implantable Collamer Lens ( ICL )•- Collamer is a copolymer of • hema ( 99% ) and porcine collagen ( 1% )
CLASSIFICATION OF pIOLS
• Ant.Chamber pIOLS ( AC pIOLS)• - Angle supported 1) PMMA• 2) Foldable -
Iris – Clawed 1)PMMA• 1)Foldable• Post.Chamber pIOLS ( PC pIOLS )• (or sulcus supported )• \\\
INDICATIONS
• High Myopia
• - Myopia > -8.00 to -10.00 D
• - Stromal bed < 300µ after laser ablation
• - Keratometry < 34-36D after laser ablation
•
• FDA Approval for Artisan/Artiflex
•- Myopia : -5.00 to -20.00 D
•- Ast. < 2.5 D
•- Age > 21 y
•- ACD > 3.2 mm
• FDA Approval for ICL :
•- Myopia : -3.00 to -20.00 D
•- Ast.< 2.50 D
•- Age 21 - 45 y
•- ACD > 3.00 mm
• High Hyperopia
• - Keratometry > 50 D after laser ablation
• - Available pIOLS :
• ICL : Up to +20.0 D
• Artisan : Up to +12.00
•
• - Laser ablation is the Tx of choice for Ast. up to 4.00 – 5.00 .
• - PIOLS are available too .
High Ast.
CONTRAINDICATIONS
• - Any intraocular pathology• ( Cat. , Glaucoma , NVI , Uveitis , … )•- ↓ ACD • - ↓ Diameter
ADVANTAGS OF pIOLS
• - Rang of correction >> Laser
• - Easy technique ( Like Cat. Surgery )
• - Less expensive instruments than Laser
• - Removable
• - No ↓ in contrast sensitivity
• even : ↑ Compared with spectacle
• -More predictable
DISADVANTAGES OF pIOLS
•- All intraocular risks
•- Large incision ( in PMMA types )
•- Limitation in hyperopia due to small ant. segment
•- Irreversible complication
PRE-OP EVALUATION
•- Power of IOL
•- Diameter of IOL for angle or sulcus supported IOLs
•- ACD
•- Specular microscopy
•- Optic size in correlation to scotoptic pupil size
•- All other rutin evaluation before cat. surgery
Cont.
• But :• Main challenge in angle or sulcus supported pIOLs
is :
• “ Sizing IOL diameter”• Through Angle-to-angle• And ciliary sulcus diameter
Cont.
• For angle supported pIOLS
•- 0.5 – 1.00 mm add to w-to-w measured manually
or by orbscan, although not always correct .
•- Use of OCT/UBM
Cont.
• Note:
•If diameter measured horizontally the lens must
implanted horizontally; if implanted vertically, it
causes Decenteration , Ovalization , Iritis , Glaucoma.
Cont.
• For PC pIOLS ( sulcus supported )
•- Add 0.50 – 1.00 mm to horizontal W-W
•- New ultrasound techniques like Artemis & UBM
ANGLE SUPPORTED pIOLS
• Surgical Technique (important points)
• -Incision , 2- 6.5mm (based on type )
•- Sup. approach ( more common )
•- Retrobulbar avoided ( glob perforation )
•- IOL dialled to the best pupil-optic matching
Cont.
•- Surgical PI
•- OVD irrigated meticulously
•- Pilo 2 ( useful , but may decentered pupil
Complications
•- Haloes and Glare : more com complication ( 20
% )
• more in 1th year, but : ↓ over time
•- Pupil ovalisation ( 7-22% ) ( if oversized )
•- Iris retraction and atrophy
Cont.
•Endothelial cell damage:
•-Surgical trauma -
Presence of IOL - 5-7%
in 1th year and less in next years
Too small size : ↑ damage
Cont.
•- ↑ IOP • - Transient , 2’ to OVD• - Topical CS• - Pupilary block•- Uveitis : 4.5%• - Usually transient , 2’ to iris manipulation• - In over sized IOL , may chronic, causing
glaucoma cat. , PAS, Iris damage , …
Cont.
•- Cataract
• - Less common than PC pIOL
• - Caused by trauma , uveitis
• - Age > 40 y at time of surgery
• - AL > 30 mm
•- RD : 3%
• If pIOL have additive risk for RD over the myopia??
Cont.
•Rare complications
• - Corneal decompensation
• - Urretis – Zavalia synd.
• - Malignant glaucoma
• - Endophthalmitis
• - Hyphema
IRIS FIXATED pIOLs
• General information of Artisan
• - 0.5 mm vault ( 0.8 mm distance between IOL &
crystalin lens)
• - Diameter : 8.5 mm
• - Optic : 6.5 & 6.0 mm
• - Center :0.2 mm thickness
Indications ( FDA ) :
•- Myopia
•- Hyperopia
•- RE After PK
•- Sever anisometropia in children
•- Aphakia
•- KCN
•- Progressive high myopia in psudophakic children
Complications •- Glare & haloes: 0-9% more in small optics ( 5mm ) and Large pupil ( > 5.5 mm )•- AC inflammation: 0.5%
•- Pigment dispersion : 2” to poor enclavation
• -Crystalin lens rise: like Hyeperopia
( Artiflex > Artisan ) because of step in
optic-haptic junction
Cont.
•Endothelial cell loss• - Intraoperative trauma ( main cause )• - more in first 6m post op.• - ACD < 3.2 → ↑ risk•Glaucoma• - Usually transient• - OVD , CS , pigment , inflammation
Cont.
•Cataract : 3% - NS•- Age > 40 at implantation time →↑risk•- AL > 30 mm →↑ risk
• Other complications• - Hyphema• - Intermittent myopic shift• - RD
PC PIOLs ( SULCUS SUPPORTED )
•- PRL : Silicon , hydrophobe
•- ICL : Hydrophyl , biocompatible , permeable
Complications
•-Glare & halos• 8.4 % , ↓ over time• -Flare ; 27%, Up to 2y•-Cataract• - The major concern• - 0.6 – 3 %• - Traumatic contact , metabolic disturbance• - Ant. sub capsular
Cont.
•Pigment dispersion & deposition
• - Iris rubbing
• - ↑ Size ( ↑ Vault ) →↑ dispersion
•Glaucoma • - 2’ to pigment dispersion• - Angle closure• - Pupilary block ( if fibrin formed )• - ICL > PRL•Decenteration : The most complication• - Small size IOL, difficult problem• - Even sometime dislocation into vitreous cavity
• Note :• In PC pIOL, vault is of critical importance•- ↑ Vault → ↑ Pigment dispersion•- ↓ Vault → ↑ Cataract
BIOPTICS
•Implantation of pIOL followed by Laser ablation
•- In case of extremely myopia , high Ast. , lens power
not available.
•- Safe and effective
FEW SELECTED POINTS
•- PIOLs have been used successfully for post PK Ast.
•- Artisan induces HOA less than APT because of
reserving prolate shape of cornea.
•- Toric pIOL + CXL successfully have been used for
correcting RE in mild to moderate KCN & PMD.
Cont.
• - AC pIOLs have been used for TX of children with
sever myopic anysometropia ( > -8.00 ) that resist or
no cooperative for traditional amblyop therapy with
encouraging results .
CONCLUSION
• Compared with corneal laser ablation, pIOLs are excellent in :
• - Predictability• - Efficacy• - Safety• - Quality of vision
پو1زش عرض ضمن
باالی حجم در LECTUERبدلیل نمیباشد پذیر امکان اسالیدها ادامهآموزشی مرکز بصری و سمعی واحد به لطفا ادامه به نیاز صورت
تلفن شماره با یا و مراجعه فیض داخلی 03114476010درمانیتماس حاصل نمائید 392
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