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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