Ferrara Ring (ICRs)

A-Z

PAULO FERRARA, MD, PHD

Paulo Ferrara Eye ClinicFerrara Ophthalmics

Belo Horizonte – MG - Brasil

Declaration of Conflict of Interest

•Ferrara Ophthalmics

•Ferrara e Hijos

•AJL

•Intacs

1950 - Barraquer, J., Intracorneal implants

1966 - Blavatskaya - Corneal rings from corneal tissue

1986 - Simon, G. - Silicon Rings

1987 - Fleming - Adjustable rings

HISTORY

SHAPE ?

SIZE?

OPTICAL ZONE?

DEPTH?

TOLERANCE?

INFLAMATORY RESPONSE?

STABILITY?

RANGE OF CORRECTION?

SURGICAL TECHNIQUE ?

QUESTIONS TO BE ANSWERER 1985

FERRARA RING

1986

Pocket incision

Intra Corneal Ring Segments Research

ICRS: Well Tolerated in the Deep Stroma

1

2

3

32

1

Intra Corneal Ring Segments Research

ICRS: Well Tolerated in the Deep Stroma

Intra Corneal Ring Segments Research

Reversibility

Superficial stroma Deep stroma

Localization: 80% corneal

thickness

Why deep?

MYOPIA CORRECTION

Remove tissue of the center of the cornea;

Add tissue to the periphery of the cornea.

HYPEROPIA CORRECTION

Add tissue to the center of the cornea

Remove tissue from the periphery of the

cornea

BARRAQUER’s THICKCESS LAW

The larger (diameter) the ring

the lesser the correction

The thicker the ring

the greater the correction

BLAVATSKAYA’S LAW

66,5

77,5

88,5

99,5

1010,5

11

1,32

2,73,4

4,1

0

2

4

6

8

10

12

14

200 250 300 350 400 450

Dio

pte

rsFerrara

(OZ 5)

Intacs

(OZ 7)

More ThicKCess

More Correction

250

100 D

150 D

300 D

ICRS ThicKCess

Less ThiKCess

Less Correction

150

Blavastkaya

FERRARA RING1991

Lamellar keratectomy

One piece ring

FERRARA RING

1994

TUNELIZATION INCISION

1994TUNNELIZATION TECHNIQUE

Ferrara Ring Nomogram(Myopia)

RING THICKCESS SPHERICAL EQAF5/15 µ -2 to -4AF5/20 µ -4 to -6AF5/25 µ -6 to -8AF5/30 µ -8 to -10AF5/35 µ -10 to -12

AF = Ferrara Ring 5 = Ring Diameterµ = micra

1994 Ferrara ring 350°For high myopia

(First Generation)

11 years post op

MYOPIC GROUPVery high

myopic correctionPoor previsibility

FERRARA RING NOMOGRAM

First generation (1997 - 2003): spherical equivalent

Eye 1 Eye 2

Refraction: -10.00 D Refraction: -10.00 D

Are these the same?

NO !

cornea hypercorrection in axial myopia

THE RING AS A PRIMARY REFRACTIVE PROCEDURE SHOWED LOW PREVISIBILITY

DESPITE LONG TERM STABILITY AND GOOD VISUAL PERFORMANCE.

SAFETY AND LONG TERM STABILITYIN DIFFICULT CASES SUGGESTED THEIR

APPLICATION IN CONTACT LENS INTOLERANT KERATOCONUS PATIENTS

1995

MOVING TO OTHER APPLICATIONS...

1995

Ferrara ring as an orthopedic procedure

FERRARA RINGFOR KERATOCONUS

1996

I.M.S. Pre Op.

SURGERY: 08/20/1996

AF5.60.160/25 RE.

UCVA: 20/400

BSCVA: 20/40

Refraction: –5,50 –1,00 x 10

keratometry: 46,00 / 46,50

18 years Post Op

Material PMMA

YELLOW FILTERApical Diameter 5mm

Triangular cross section =

PRISMATIC EFFECT

FLAT BASIS WIDTH 0,6 MM

Variable arch lengh segments

Hole in each extremity

FERRARA RING CHARACTERISTICS

SECOND

GENERATION

TWO RING

SEGMENTS

1996RING SEGMENTS

THIRD GENERATION

RING DESIGN

IMPROVED SURFACE QUALITY AND FINISHINGINCLUSION OF A HOLE IN EACH EXTREMITY

DEFINITION OF A NOMOGRAM ON ASTATISTICAL BASIS

ASYMMETRIC

SEGMENTS

AF

5/20

The flat basis is responsible for the induction of the astigmatism

Evaluation of ring segments

position in the corneal stroma

with respect to the visual axis

and its depth, and thus providing

a better underestanding of the

results

2004

Indications

Primary or Orthopedic indication

Corneal irregularities

Keratoconus

Pellucid Marginal Degeneration

IATROGENIC

PKP

PRK; LASIK; RK

TRAUMA

SECUNDARY

REFRACTIVE

Indications

GOALS:

• Stabilize the evolution and/or progression

• Reduce corneal asymmetry

• Preparing for optical treatment with stable cornea

Keratoconus

Prevalence: 1:2000**Siganos., 2002

Keratoconus

Inclusion Criteria

• Young patients

• Contact lens intolerant keratoconus

• Evidence of evolution of the corneal ectasia,

despite CL tolerance

• Reduce CL dependency

Inclusion Criteria

• Patients with good CDVA, good pachymetry and low asymmetry

Refractive purpose (best cases)

• Patients with bad CDVA, reasonable pachymetry and asymmetry

• Regularize corena

• Patients with bad CDVA, pachymetry and asymmetry, corneal

scars

Lamellar keratoplasty

Exclusion Criteria

• Hidropsia

• Severe corneal opacities

• Ocular or sistemic disease (vernal keratoconjuntivitis,

Severe dry eye(Steven Johnson, Sjogren syndrome, etc)

• Young patients presenting VA ≥ 20/40 CDVA.

• These patients need to be observed every three

months to detect the progression of the condition.

Patient Selection

• Assessment of visual function

• Assessment of CDVA, pH VA plus spheric refraction

• Ectasia classification

• Management

Clinical Case

ICLK

G.M., male, 16 y.o.

1st. Visit 04/01/2011

Ferrara ring RE

LE KC III ( CXL)

Bad visual acuity LE

Ferrara ring implantation LE 07/11/2011 (manual technique)

Clinical Case

CDVA 20/60 CDVA20/30 21/08/201431/03/2011

I.R.G., male, 15 yo

1st. Visit 01/07/2008

CDVA 20/25 both eyes

KC in evolution RE operated in 01/17/2008 (manual technique)

RE UDVA 06 y.o. POST OP 20/20

Last Visit in 08/08/2014

KC in evolution LE operated in 08/08/2014 ( FEMTOSECOND)

LE UDVA post op IMMEDIATE 20/30

Clinical Case

CDVA Pre op20/25 UDVA Post op20/20

ICRS implant in 01/17/2008 (manual technique)

Clinical Case

ICRS implant in 08/08/2014 (Femtosecond)

Comparative Topometric Map 2008 and 2014

Clinical Case

Preop CDVA20/30 Post op CDVA20/20

Clinical Case

Pellucid Marginal Degenration ( PMD)

E.B.,male, 62y.o.

PMD ICL

Visit 04/03/2010

RE +3,50-6,00 x 85 20/400

LE +3,00-4,50 x 95 20/40-

Clinical Case

Pellucid Marginal Degenration ( PMD)

Ferrara ring implant in RE (04/03/2010)

CDVA in 07/04/2010 (33º DPO)

RE -1,50-5,00 x 95º 20/80-

Phaco + LIO in RE

15/06/2010

CDVA in 07/04/2010 (22º DPO)

RE +0,50-3,50 x 85º 20/30

Clinical Case

Pellucid Marginal Degenration (PMD)

+1,50 -1,00 x 95º 20/30+3,50 -6,00 x 85 20/400

10/09/2010

Clinical Case

Pellucid Marginal Degenration ( DMP)

Last Visit

18/02/2013

RE +1,75-4,25 x 85º 20/20

LE +3,75-2,75 x 95º 20/20

Clinical Case

Post RK ring implantation

Y.A.P.,male, 53y.o.

Underwent RK 1992

Lasek 1998

KC 4 years later

AF surgery LE (14/06/2011)

Clinical Case

Post RK ring implantation

Pre op

CDVA 08/08/2011 (53º DPO)

LE -3,00 -2,50 x 85º 20/60

CDVA in 14/06/2011

LE -2,50 -5,00 x 90 20/80

Ferrara ring LE (14/06/2011)

Post RK ring implantation

Clinical Case

Clinical Case

Post RK ring implantation

-2,50 -5,00 x 90 20/80 -3,00 -2,50 x 85º 20/60

53º

DPO

Clinical Case

High astigmatism post PKP

Clinical Case

M.V.T.P.,female, 32y.o.

ICLK

PKP LE followed by

Ferrara ring implantation

1996Ferrara ring for corneal

irregularities

Clinical Case

18 years AFTER

Phaco+ Lio LE

Post op

CDVA 20/25

Clinical Case

Ferrara ring and ICL

Combination of Techniques

N.O.R.,female, 23y.o.

ICL

Ferrara ring implantation 1 year post op RE

VA RE -8,50 -1,00 x135 20/30+2

15/05/2014

AV preop -8,50 -1,00 x 135 20/30+2

AV post op Plano 20/40

ICL Implantation after FR in RE 07/04/2014

Clinical Case

Ferrara ring and ICL

LASIK in 2002

Clinical Case

Unseccessful Contact LensTest

CXL

Ferrara ring Implatation

pH VA: RE 20/100 LE 20/80

UCVA: RE<20/400 LE<20/100

Imediate post op

UCVA RE 20/100 LE 20/80

Nomogram Based on Corneal

Astigmatism

0%

25%

33%

50%

MapaDistribution of

the ectasiaDescription

Entire ectasia is located onone side of the cornea

75%

75% of the ectasia is located on one side of the

cornea

66% of the ectasia is located on one side of the

cornea

50%

The ectasia is symmetrically

distributed over the cornea

100%

66%

G.M.H.S.,male, 19 y.o.

UCVA RE 20/20

LE< 20/400

20/80 (PH)

biomicroscopy

Grade II KC LE

WHAT TO DO?

LC RGP ???

CXL?

RINGS???

TYPE

NOMOGRAM

Segmentosasimétricos

25/75%

up para 2,00 D 01 segt of 15

2,25 TO 4,00D 01 segt of 20

4,25 TO 6,00D 01 segt of 25

6,25 TO 8,00D 01 segt of 30

8,25 TO 10,00D 02 segts 15/25

10,25 TO 12,00D 02 segts 20/30

.

FERRARA RING

01 SEGMENT 160/25

INCISION 90

DEPTH 450 µm

surgery: 06/26/2008

Last visit (09/26/08):

UCVA 20/80

BSCVA 20/40

MANIFEST Rx:

+0.50 -1.50 x 105

L.F.A., female, 28 y.o

KC III LE

TYPE 3

Pre op Data 06/09/2008

MANIFEST Rx

LE: -14.00 -2.50 x 180

BSCVA

LE: 20/80

NOMOGRAM

Asymmetric Astigmatism33/66%

Up TO 2,00 D 01 segt 15

2,25 TO 4,00D 02 segts 15/20

4,25 TO 6,00D 02 segts 20/25

6,25 TO 8,00D 02 segts 25/30

SURGICAL STRATEGY

2 AFR 160/20

160/25

Incision 75º

Depth 480 µm

L.F.A., female, 28 y.o.

KC III LE

TYPE 3

Post op Data 09/30/2008

MANIFEST Rx

LE: -9.00 sph

BSCVA

LE: 20/40

F.B.S., male, 19 y.o.

KC II

TYPE 4

Pre op data 07/31/2007

UCVA 20/200

BSCVA 20/200

MANIFEST Rx

IMPOSSIBLE

Central

Symmetric Bow-tie

Up to 1,00D 02 segts of 15

1,25 to 2,00D 02 segts of 20

2,25 to 3,00D 02 segts of 25

3,25 to 4,00D 02 segts of30

Surgical Strategy

2 AFR 160/20

Incision 60º

Depth 440 µm

F.B.S., male,

19 y.o.

KC II

TYPE 4

Post op data

09/30/2008

UCVA 20/20

NIPPLE KC

A.M.A, 30 y.o., male

Ectasia Post PRK

Pre op date 23/04/2008

BSCVA = <20/400

MANIFEST Rx+1.00 -6.50 X 140

Contact lens intolerant

NIPPLE TYPE

Central nipple 210 Segments

Up to 2,50 D 01 segt of 15

2,75 to 4,00 D 01 segt of 20

4,25 to 5,75 D 01 segt of 25

6,00 to 8,00 D 01 segt of 30

3,79

5,79

8,01

2,52

-

1,00

2,00

3,00

4,00

5,00

6,00

7,00

8,00

9,00

Segm

ento

15

Segm

ento

20

Segm

ento

25

Segm

ento

30

Surgical Strategy

01 SEGMENT 210/25

A.M.A 30 yo male

Post op data (04/08/2008)

MANIFEST Rx-0.50 -2.50 x 90

BSCVA = 20/30

FERRARA RING NOMOGRAMA

Third generation (2006 - 2009):Topografic astigmatism

Eye1 Eye2

Keratometry: 42.00 x 47.00 D

Are the same?

NO !Same topografic astigmatism- different changes after the ICRS implantation

Keratometry: 52.00 x 57.00 D

PAULO FERRARA, MD, PhD

LEONARDO TORQUETTI, MD, PhD

GUILHERME FERRARA, MD

JESUS MERAYO-LLOVES, MD,PhD

PAULO FERRARAEYE CLINIC

BELO HORIZONTE – MG

Comparison of clinical Results after implantation of

ring segments using two different NOMOGRAMS:

Corneal topographic astigmatism vs asphericity

Results

Preoperative and post operative BCVA, according to

keartoconus stage

TA = parapograficoastigmatismo - Q = Asfericidad

Results

TA Q

Preop Postop p Preop Postop p

Asphericty (Q) -0.88 -0.35 0.000 -0,77 -0,13 0.000

Keratometry (D) 49.18 45.72 0.000 48,91 45,54 0.000

Pachymetry (μm) 448 465 0.000 447 465 0.000

160 arc ring

Results

TA Q

Preop Post op p Preop Post op p

Asphericity(Q) -1.17 -0.56 0.000 -0,89 -0,40 0.000

Keratometry(D) 51.92 48.10 0.000 52,82 48,87 0.000

Pachymetry (μm) 418 435 0.000 423 445 0.000

210 arc ring

There’s a tendency to implant less tissue to achieve the

same (or better) correction than the past;

Value of Q = Quality of the vision

NOMOGRAM

SELECTION OF THE RING BASED ON

CORNEAL ASPHERICITY

Corneal Eccentricity (E-value)

Define the shape of the cornea (conic section)

Center of the cornea flattening to the periphery

(Q= - e2)

Behavior of the Asphericity

Healthy and ectasic cornea

What is prolate, and oblate?

Radius of curvature

Sphere: Same radius of curvature

Prolate surface (negative Q), periphery radius > center

radius

Oblate surface (positive Q), periphery radius < center

radius

Behavior of the Asphericity

Healthy and ectasic cornea

•Corneal Asphericity (Q) –shape of thecornea;

•Oblate…………………….Prolate;

• “Normal”:lightly prolate

•Keratoconus: hiperprolate cornea;

• Normal Value of Q: - 0.231

Asphericity

1. Yebra-Pimentel E, González-Méijome JM, Cervino A, et al. Asfericidadcornealen una

poblácion de adultos jóvenes. Implicaciones clínicas. ArchSocEspOftalmol 2004: 79:385-392

Keratoconus (KC) Phenotypes

Central KC:

Hiperprolate (nipple)

High regular astigmatism (bow-tie)

Paracentral KC (oval)

Morphological Classification

KC Classification for ICRS

Other ectasias Phenotypes

Pellucid Marginal degeneration (DMP)

Pelucid “Like”

Morphological Classification

KC Classification for ICRS

Spherical Surface (Q = 0)

Several focal points (More light bean refracted at the

Periphery than in thecenter)

Behavior of the Asphericity

Healthy and ectasic cornea

e2 = 0

SA = +0.30 µm

Behavior of the Asphericity

Healthy and ectasic cornea

Prolate Surface(Q < 0)

Single focal point (reduction of spherical aberration)

e2> 0

SA ≈ 0.0 µm

e2≈+0.60

Behavior of the Asphericity

Healthy and ectasic cornea

Oblate surface (Q > 0)

Many focal points (Increase in spherical aberration)

e2< 0

SA > 0.30 µm

•High reproducibility between the same devices

But poor reproducibility between different devices

!

•Different topographers can provide different

values in the same patient. (each unit has its own

reference point)

Asphericity

Retrospective Study

165 eyes operated between january and luly of 2013. (Dr. Paulo Ferrara Eye Clinic)

Groups (keratoconus grade*)

Group I – Grade I keratoconus (Km < 48 D)

Group II –Grade II keratoconus(48 < Km < 52 D)

Group III –Grade III keratoconus(52 < Km < 58 D)

Group IV –Grade IV keratoconus (Km > 59 D

Group V –Control

Evaluation of SimK. Maximunkeratometry and conrealasphericity at 20º, 25º, 30, 35º e40º.

(Pentacam)

BehavioroftheAsphericity

Healthyandectasiccornea

*Ferrara-Amsler

Results

Behavior of the Asphericity

Healthy and ectasic cornea

Mean corneal asphericity

n = 38 EYES

-0.60

-0.50

-0.40

-0.30

-0.20

-0.10

0.00

20 25 30 35 40

Normal Corneas

Results

Behavior of the Asphericity

Healthy and ectasic cornea

Mean corneal asphericity

Km < 48 D

n = 54 EYES

-0.63

-0.61

-0.59

-0.57

-0.55

-0.53

-0.51

-0.49

-0.47

-0.45

20 25 30 35 40

KCN 1

KCN 1

Results

Behavior of the Asphericity

Healthy and ectasic cornea

Mean corneal asphericity

48 < Km < 52 D

n = 43 EYES

-1.20

-1.10

-1.00

-0.90

-0.80

-0.70

-0.60

20 25 30 35 40

KCN 2

KCN 2

Results

Behavior of the Asphericity

Healthy and ectasic cornea

Mean corneal asphericity

52 < Km < 58 D

n = 38 EYES

-1.55

-1.45

-1.35

-1.25

-1.15

-1.05

-0.95

-0.85

20 25 30 35 40

KCN 3

KCN 3

Results

Behavior of the Asphericity

Healthy and ectasic cornea

Mean corneal asphericity

Km > 58 D

n = 7 EYES

-1.80

-1.70

-1.60

-1.50

-1.40

-1.30

-1.20

-1.10

-1.00

20 25 30 35 40

KCN 4

KCN 4

Results

Behavior of the Asphericity

Healthy and ectasic cornea

Asphericity: Healthy vs ectasic cornea

-1.80

-1.60

-1.40

-1.20

-1.00

-0.80

-0.60

-0.40

20 25 30 35 40

Corneas Normais

KCN 1

KCN 2

KCN 3

KCN 4

CLINICAL CASE

R.S.C.female, 29 y.o.

CLINICAL CASE

-0.9

-0.8

-0.7

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

20º 25º 30º 35º 40º

CLINICAL CASE

R.M.B.,male, 26y.o..

Inferior keratoconus

CLINICAL CASE

-0.25

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

20º 25º 30º 35º 40º

Inferior keratoconus

CLINICAL CASE

R.S.O.C.,female, 17 y.o.

CLINICAL CASE

-2.15

-2.05

-1.95

-1.85

-1.75

-1.65

-1.5520º 25º 30º 35º 40º

RSOC

RSOC

Selection of the segment based on corneal

asphericity

CLINICAL CASE

CDVA OD post op: + 0,50 - 1,00 x 95º 20

02/02/2012

17/01/2014

CDVA OD pre op: plano - 4,50 x 90º 20/40

CLINICAL CASE

Pre Post op

Behavior of corneal asphericity

Pre and post Ferrara ring implantation

-2.1

-1.9

-1.7

-1.5

-1.3

-1.1

-0.9

-0.7

-0.5

-0.3

-0.1

20º 25º 30º 35º 40º

Pre op

Pos op

CLINICAL CASE

CDVA LE post op: + 0,50 // -1,25 x

125º 20/30

02/02/2012

17/01/2014

CDVA LE preop: +3,00 // -5,00 x

90º 20/70 +

CLINICAL CASE

Preop Post op

-2.1

-1.9

-1.7

-1.5

-1.3

-1.1

-0.9

-0.7

-0.5

-0.3

-0.1

20º 25º 30º 35º 40º

Pre op

Pos op

Behavior of corneal asphericity

Pre and post Ferrara ring implantation

160 arc = (“standard” ring)

- negative Q (prolate to hiperprolatecornea)

-HighvaluesofK

-Highastigmaitisms

140 arc = PMD

- Q 0 or positive

- Low values of K

- High astigmatism

210 arc = Nipple

- Q negative (hiperprolatecornea)

- High values of K

- Low astigmatism

Variationof K (Keratometry) according to the

thickness of the ring

0.1 1 10

250-250

200-200

150-200

250

150

5.300000191

6.269999981

5.650000095

3.859999895

4.349999905

3.400000095

2.74000001

1.820000052

0.779999971

Diopters

Variationof Q (asphericity) according

To the thickess of the ring

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

150 200 250 150-150 150-200 150-250 200-200 200-250 250-250

-0.07

-0.310000002-0.340000004

-0.569999993

-0.730000019

-0.800000012

-0.860000014

-1.019999981-0.99000001

Q

Clinical Case

20/200 -6.00-2.50x10

SURGICAL PLANNING ?

PREOP

POSTOP

20/40 pl-5.000x50

AF 150/160

AF 250/160

Clinical Case

20/200

SURGICAL PLANNING ?

PREOP

POSTOP

20/40 -2.50-1.50x45

AF 200/160

Clinical Case

20/400 +3.00-6.00x85

Cataract + PMD

SURGICAL PLANNING ?

PREOP

POSTOP

20/30 +0.50-3.00x85

AF 150/140

3 months after: Phaco+ IOL: 20/30 +2.00-3.00x85

Clinical Case

Nipple

20/60 -8.50-1.50x140

SURGICAL PLANNING ?

PREOP

POSTOP

20/40 --0.50-1.50x40

AF 250/210

Clinical Case

Nipple

20/60 -8.50-1.50x140

SURGICAL PLANNING ?

PREOP

POSTOP

20/40 -5.50

AF 200/210

CLINICAL CASE

Q = 0,13

Cil = -5.2 D

K1 = 39.8 D

K2 = 44.9 D

PREOP

SURGERY

STRATEGY?

CLINICAL CASE

AF 150/140

Q = 0,08

Cil = -2.2 D

K1 = 40.7 D

K2 = 42.9 D

POSTOP

IF THE astigmatism WAS USED IN THE SELECTION OF SEGMENT (160/250):

Oblate CORNEAovercorrection

CLINICAL CASE

Ambliopia

BCVA: 20/80

-2.50-4.50x20

Q = -0.31

Cil = -3.5 D

K1 = 41.2 D

K2 = 44.7 D

PREOP

Surgical

Strategy??

CLINICAL CASE

AF 150/140

BCVA: 20/30-3.50

Q = -0.26

Cil = -1.5 D

K1 = 41.4 DK2 = 43.0 D

FOLLOWED BY

CORRECTION

OF

AMETROPIA BY

PRK

POSTOP

• Normal Value of Q: - 0.23 1

•Corneal asphericity in KC:

The target of the correction is - 0.23

OR

The Q value of the unaffected fellow eye

Asphericity

1. Yebra-Pimentel E, González-Méijome JM, Cervino A, et al. Asfericidadcornealen una

poblácion de adultos jóvenes. Implicaciones clínicas. ArchSocEspOftalmol 2004: 79:385-392

SURGICAL TECHNIQUE

Manual

Femtosecond

1-Pachymetryat thesteepestaxisofthecornea (manual technique) (ZO 5 mm)

OR thethinnestpointonthepathofthering (Femtosecond)

2- Incision 80% depth of the thickness of the cornea at site of the incision

(if manual technique)

The incision is always performed at the steepestaxis

AND

Incision 80% depth of the thickness of the cornea at thinnest point

onthepathofthering (Femtosecond)

SURGICAL TECHNIQUE

RING SELECTION BASED ON THE

NOMOGRAM

SURGICAL TECHNIQUE

-1.20

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

150 200 250 150-150 150-200 150-250 200-200 200-250 250-250

-0.07

-0.310000002-0.340000004

-0.569999993

-0.730000019

-0.800000012

-0.860000014

-1.019999981-0.99000001

MANUAL TECHNIQUE

FERRARA RING

FEMTOSECOND

FERRARA RING

SURGICAL TECHNIQUE

ADVANTAGES FEMTO ADVANTAGES MANUAL

TECHNIQUE

Easytoperform Cheap

Reproducible Portability

Less trauma

Fast visual recovery

Long termresults are thesame

ICRS IN COMBINED SURGERIES

PAULO FERRARAEYECLINICBELO HORIZONTE – MG

PAULO FERRARA

KERATOCONUS

Highand irregular keratometricvalues

Associateornottohighametropia

Needforsurgicalassociationoftechniquesto

obtainresults more satisfactory

Phakic IOL’s

ICL

CACHET

ARTISAN …

FERRARA RINGS + CXL…

PSEUDO PHAKIC LENS

FERRARA RING +PHAKIC IOL

FERRARA RING +TORIC ICL

FR + ARTISAN

FR + ARTISAN

C.G.B.

FR + PSEUDOPHAKIA

SAFETY AND EFFICACY ANALYSIS OF A LARGE

SAMPLE OF EYES IMPLANTED WITH INTRASTROMAL

CORNEAL RING SEGMENTS

GUILHERME FERRARA, MD

LEONARDO TORQUETTI, MD, PhD

JESUS MERAYO-LLOVES, MD,PhD

PAULO FERRARA, MD, PhD

PAULO FERRARA EYE CLINIC

BELO HORIZONTE – MG

•Sample: 1073 eyesof 810 patientsoperatedconsecutivelybetweenJanuary2006

and July 2008

•Twogroups (TYPE OF RING IMPLANTED):

Group I - patientsimplantedwith 160-degreearch (n = 972)

Group II - patientsimplantedwitharcsof 210 degreesofarch (n = 101)

•Parametersstudied:

Uncorrected visual acuity (UCVA)

Best corrected visual acuity (BCVA)

Keratometry (K)

Asphericity (Q)

Cornealthickcess at thethinnestpointofthe cornea

METHOD

•Average of age: 29.2 ± 9.4 (grupo I) and 30.2 ± 8.7 (grupo II);

• Follow-up: 23.8 ± 12.2 (groupI) y 22.9 ± 15.1 months (groupII).

Allpatientscomplited at least 6 monthsoffollow-up

• Statistical analysis: tStudent´s Test for paired data- SPSS software

(SPSS, Chicago, IL).

METHOD

grupo I grupo II

Preop Postop p Preop Postop p

UCVA 20/220 20/80 0.000 20/350 20/130 0.001

BCVA 20/100 20/40 0.000 20/110 20/60 0.000

Sph. Eq. (D) -3.99 -2.26 0.000 -8.52 -4.14 0.000

Asphericity -0.88 -0.35 0.000 -1.17 -0.56 0.000

Keratometry(D) 49.18 45.72 0.000 51.92 48.10 0.000

Pachymetry (m) 448 465 0.000 418 435 0.000

RESULTS

UCVA pre y post op

210

60

220

80

250

100

400

200

0

50

100

150

200

250

300

350

400

I II III IV

Preop

Postop

I II III IV

RESULTS

I II III IV

6035

94

40

400

55

800

90

0

100

200

300

400

500

600

700

800

I II III IV

Preop

Postop

BCVA pre y post op

RESULTS

Complicatios (treatment) ojos (%)

Undercorrection (implantationofadditional segment) 16 (1.49)

Overcorrection (segmentremovalfollowed by reimplantation) 11 (1.02)

Extrusion (removal of the segment) 6 (0.56)

Malposition (repositioning of the segmento) 4 (0.37)

KC progression (keraparaplasty) 2 (0.18)

Neovascularization (bevacizumab) 2 (0.18)

TOTAL 41 (3.82%)

RESULTS

• RELATED TO SURGICAL TECHNIQUE

• RELATED TO THE NOMOGRAM

• RELATED THE RING

COMPLICATIONS

- Extrusion 0.1%

- Infection 0.08%

- Descentration of the segment

- Migration

- Rotation

-Deviation or asymmetry of the segments

RELATED TO SURGICAL TECHNIQUE

Shallow tunnelExtrusion

EXTRUSION

INFECTION

MIGRATION

RING ASYMMETRY

RING MALPOSITION

(Corneal biomecanics)

1 - Hipocorrection

2 - Overcorrection

RELATED TO THE NOMOGRAM

Halos and Glare

Peri ring deposits

Neovascularization

RELATED TO THE RING

Preoperative 1 month 1 year 2y.o. 3y.o. 4y.o. 5y.o.

KMAX52.95 ± 6.78 49.36 ± 6.66 47.69 ± 5.43 47.77 ± 5.26 47.81 ± 5.87 48.07 ± 6.26 48.09 ± 5.92

KMIN47.86 ± 5.19 45.27 ± 5.39 44.03 ± 4.52 44.29 ± 4.46 44.04 ± 4.85 44.82 ± 5.57 44.45 ± 5.97

KMEAN50.36 ± 5.68 47.29 ± 5.91 45.79 ± 4.85 45.96 ± 4.65 45.83 ± 5.08 46.44 ± 5.90 46.24 ± 5.89

UCVA 0.12 ± 0.14 0.25 ± 0.19 0.33 ± 0.23 0.29 ± 0.18 0.34 ± 0.23 0.42 ± 0.31 0.31 ± 0.23

BCVA 0.41 ± 0.24 0.56 ± 0.24 0.67 ± 0.25 0.68 ± 0.24 0.63 ± 0.21 0.65 ± 0.19 0.59 ± 0.19

Calculated exponential cell loss rate over the mean

interval of follow-up (4y.o.):

1.4% per year

Endothelial Cell Loss (per year) in:

Young normal ojos: 1.1%

Old normal ojos: 0.6%

después cataract surgery: 2.5%

después PKP: 4.2-9.4%

The mean BCVA increased from 20/125para20/55 (p=0.0001)

Preoperative Posparaperative

UCVA 20/185 20/66 p = 0.005

BCVA 20/125 20/40 p = 0.008

Apex Pachymetry 457.7 466.2 p =0.025

Asfericidad (Q) -0.95 -0.23 p = 0.006

Queraparametría (K) 45.41 42.88 p = 0.000

Take home message

• Identify the KC

• Central

• Eccentric -inferior

• Corneal Asphericity: Nomogram for ring size and

thicKCess

• One or two

• ThicKCess

• Incision on steep meridian at 80% depth

Conclusions

• Improve UCVA and BCVA

• Reduce Rx measurements

• Reduce Avg Ks and increase asphericity

• Mechanically stabilize cornea

• Improve CL tolerance and/or spectacle use

Conclusions

•Restore of Functional VisionFunctional Refraction with Soft, Soft-Toric, or Rigid Contact

Lenses

•Post-Surgical RecoveryImmediate Visual Improvement

•High Potential to Avoid Corneal Transplant

Thank You