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Francisco Sánchez León, M.D. Centro Nacional para Corrección del
Queratocono novavisionlaser.com.mx pacornea@yahoo.com
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KERARING 355° FOR KERATOCONUS
ESCRS Amsterdam, 2013
Disclosure No financial interest
Corneoplasty Techniques
• Mechanical – Intracorneal Segments – Incisional Procedures
• Biochemical – Cross-linking – Conductive Keratoplasty (CK)
• Mix – Keraflex (Avedro) – Excimer Laser Ablation – Inlays (Acufocus)
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Intrastromal corneal ring segments and posteriorchamber phakic intraocular lens implantation
for keratoconus correctionJos!e F. Alfonso, MD, PhD, Carlos Lisa, MD, Luis Fern!andez-Vega, MD, PhD,
David Madrid-Costa, OD, MSc, PhD, Arancha Poo-L!opez, OD, Robert Mont!es-Mic!o, PhD
PURPOSE: To evaluate the efficacy, safety, and predictability of sequential implantation of Keraringintrastromal corneal ring segments (ICRS) and an Implantable Collamer Lens phakic intraocularlens (pIOL) with corneal relaxing incisions for refractive correction of keratoconus.
SETTING: Fern!andez-Vega Ophthalmological Institute, Oviedo, Spain.
DESIGN: Cohort study.
METHODS: This study comprised patients with keratoconus who had ICRS implantation followed 6months later by pIOL implantation with corneal relaxing incisions. The uncorrected (UDVA) andcorrected (CDVA) distance visual acuities and residual refractive errors, analyzed using vector anal-ysis, were recorded preoperatively, 6 months after ICRS implantation, and 6 months after pIOLimplantation.
RESULTS: The study enrolled 40 eyes (31 patients). The mean UDVA (decimal) was 0.11 SnellenG 0.05 (SD) preoperatively, 0.18 G 0.14 Snellen 6 months after ICRS implantation (PZ.001),and 0.50 G 0.27 Snellen 6 months after pIOL implantation (P<.0001). The mean CDVA was 0.56G 0.23 Snellen, 0.68 G 0.25 Snellen, and 0.73 G 0.20 Snellen, respectively (all P<.0001). Sixmonths after pIOL implantation, the efficacy index was 0.88 and the safety index, 1.28. At 6 months,65% of eyes were withinG1.00 diopter (D) of the desired refraction and 45%were withinG0.50 D.The mean spherical equivalent after pIOL implantation was !1.19 G 1.33 D.
CONCLUSION: Sequential ICRS and pIOL implantation plus corneal relaxing incisions providedgood visual and refractive outcomes, indicating that it is a predictable procedure for refractivecorrection of keratoconus.
Financial Disclosure: No author has a financial or proprietary interest in any material or methodmentioned.
J Cataract Refract Surg 2011; 37:706–713 Q 2011 ASCRS and ESCRS
Keratoconus is a progressive noninflammatorydisorder in which the cornea assumes a conical shape.The corneal thinning induces irregular astigmatism,myopia, and protrusion, leading to a mild to severedecrease in the quality of vision.1,2 Recent studieshave shown that intrastromal corneal ring segment(ICRS) implantation with femtosecond laser tunnelcreation is an effective method for improving theshape of the cornea, thus reducing astigmatism andcorneal higher-order aberrations (HOAs) in patientswith clear corneas and contact lens intolerance.3–7
Previous studies5–7 report that ICRS implantationwith femtosecond laser tunnel creation is a minimallyinvasive procedure for improving visual acuity in
patients with keratoconus. However, many eyes withkeratoconus have high myopia. Although the cornealshape in these eyes may improve after ICRS implanta-tion, most patients require contact lenses or spectaclesto correct the residual refractive error. A recent study8
found that implantation of a phakic intraocular lens(pIOL) was a safe, effective, and predictable way tocorrect myopia associated with keratoconus.
In this study, we evaluated eyes with keratoconusthat had sequential Keraring ICRS (Mediphacos Ltd.)implantation followed by Visian ImplantableCollamer Lens posterior chamber pIOL (Staar Surgi-cal) implantation with corneal relaxing incisions forthe refractive correction of keratoconus. To our
Q 2011 ASCRS and ESCRS 0886-3350/$ - see front matter
Published by Elsevier Inc. doi:10.1016/j.jcrs.2010.10.060
706
ARTICLE
20. Coskunseven E, OnderM, Kymionis GD, Diakonis VF, Arslan E,Tsiklis N, Bouzoukis DI, Ioannis Pallikaris I. Combined Intacsand posterior chamber toric implantable Collamer lensimplantation for keratoconic patients with extreme myopia. AmJ Ophthalmol 2007; 144:387–389
21. van der Heijde GL. Some optical aspects of implantation of anIOL in amyopic eye.Eur J ImplantRefractSurg 1989; 1:245–248
22. Ali!o JL, Shabayek MH, Artola A. Intracorneal ring segments forkeratoconus correction: long-term follow-up. J Cataract RefractSurg 2006; 32:978–985
23. Spoerl E, Huhle M, Seiler T. Induction of cross-links in cornealtissue. Exp Eye Res 1998; 66:97–103
24. Wollensak G, Spoerl E, Seiler T. Riboflavin/ultraviolet-A-induced collagen crosslinking for the treatment of keratoconus.Am J Ophthalmol 2003; 135:620–627
25. Spoerl E, Wollensak G, Seiler T. Increased resistance of cross-linked cornea against enzymatic digestion. Curr Eye Res 2004;29:35–40
26. Sp"orl E, Raiskup-Wolf F, Pillunat LE. Biophysikalische Grundla-gen der Kollagenvernetzung [Biophysical principles of collagencross-linking]. Klin Monatsbl Augenheilkd 2008; 225:131–137
27. Caporossi A, Baiocchi S, Mazzotta C, Traversi C, Caporossi T.Parasurgical therapy for keratoconus by riboflavin-ultraviolettype A rays induced cross-linking of corneal collagen; prelimi-nary refractive results in an Italian study. J Cataract RefractSurg 2006; 32:837–845
28. Caporossi A, Mazzotta C, Baiocchi S, Caporossi T. Long-termresults of riboflavin ultraviolet A corneal collagen cross-linkingfor keratoconus in Italy: the Siena Eye Cross Study. Am JOphthalmol 2010; 149:585–593
29. Hafezi F, Majo F, El Danasoury AM. Effect of the direct applica-tion of riboflavin and UVA on the Visian Implantable CollamerLens. J Refract Surg 2010; 26:762–765
First author:Jos!e F. Alfonso, MD, PhD
Surgery Department, School ofMedicine, University of Oviedo,Oviedo, Spain
713SEQUENTIAL INTRASTROMAL CORNEAL RING SEGMENTS AND PHAKIC IOL
J CATARACT REFRACT SURG - VOL 37, APRIL 2011
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ICRS Procedure Objectives: • Corneal Surface Regularization • UCVA and BCVA improvement • Refractive Error Reduction • Reduce low order and high order optical
aberrations • Improve contact lens tolerance • Allow spectacle correction • Corneal stabilization • Delay or avoid corneal transplantation
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Courtesy F. SANCHEZ
Plano -7.50 X 145°= 4/10
+0.50/-1.00 X 65° = 8/10
200µ/120°
AsSgmaSsm: short segments ( 120°)
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OD +0.50 / -1.00 X 100° = 20 / 25
OD -4.00 / -2.50 X 90° 20 / 40
250 µ / 210° Courtesy F. SANCHEZ !
New Developments
New arc length (355º)
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Keraring SI-‐355º
• New concept to improve central corneal flattening
• Indicated for advanced central nipple • Pocket Femtosecond laser with small
incision (2mm) • Ring dissection • Diameter 5.7 mm (5.0 mm / 6.4 mm) 700 µ Base
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Indica<ons • Nipple Cone, Low As<gma<sm • Vision with H.C.L < 0.5 (func<onal VA) BCVA with spectacles < 0.3
• K mean up to 55 D • K max > 60 D • Corneal thickness 400 µ at center • Transparency central corneal (4mm over the pupil)
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Nommogram
• 200 µ <6.00 Dt SE • 300 µ >6.00 Dt SE • 400 µ corneal thickness • The 5º break in the ring can be posi<oned long any axis but recommenda<on is to posi<on it along the incision axis
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Implanta<on Techniques
1. Ring Femtosecond Dissec<on 2. Pocket implanta<on 3. Simultaneous X-‐Linking for either
technique
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Keraring 355º IntraLase iFS 150Hz parameters
• Depth in Cornea 80% at 5.7 mm • Incision Axis at steepest meridian • Entry Cut Length 1 mm • Inner Diameter 5.3 mm • Outer Diameter 6.7 mm
• Ring Energy 1.3 • Entry Cut Energy 1.3
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Keraring 355º Ring Disec<on
Keraring 355º Pocket Technique
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IntraLase IEK So[ware for Pocket !
iFLAP for Pocket and Mask !
355º Keraring
Se]ngs for lntraLase Femtosecond Laser
• IEK program • Pocket size: 8.5mm • Energy: 0.5 • Spot/line separ: 3/3 µ • Incision length: 30 -‐ 45º • Pocket depth:300 µ
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8.5 mm
Sim X-‐Linking & Keraring 355º Pocket 6X6 µ double Raster
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Sim X-‐Linking & Keraring 355º Pocket 3X3 µ double Raster
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Sim X-‐Linking & Keraring 355º Pocket 6X6 µ double Raster
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Sim X-‐Linking & Keraring 355º 6 Months Results
• Enrolled: 7 eyes (4 pa<ents). • Age mean: 28.96 years (19 to 39), • UDVA mean : Preop 0.17, Postop 0.5 • CDVA mean : Preop 0.47, Postop 0.65 • 100% of eyes were within 1.00 diopter (D) • SE mean: Preop -‐7.05 D (-‐4.00 D to -‐ 8.25 D) • SE mean: Postop -‐ 0.59 D (-‐0.75 D to +1.00 D)
CONCLUSIONS • New 355º Keraring (ICRS) provides
reasonable visual acuity and good refractive outcomes, indicating it is an alternative procedure for the correction of nipple type keratoconus.
• High flattening effect • Maintains of corneal asphericity • Improves customization of treatment
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