Dr. Barraquer's Abu Dhabi presentations: 2

Intracorneal Ring Segments

How to Select the Best Combina3on The SA.ANA classifica/on Rafael I. Barraquer, MD, PhD Medical Director Barraquer Ophthalmology Center Barcelona, SPAIN

Management of Keratoconus • Traditional options – (Spectacles), RGP-CL – Special CL (piggyback, hybrid)

– Keratoplasty (penetrating)

• Prevention ?

• Current options

– (Spectacles), RGP-CL Special CLs

– IntraCorneal Ring Segments (ICRS) – Collagen Crosslinking (CXL) – MW-Thermokeratoplasty (Avedro) – Combined CXL +ICRS, PRK, pIOL, etc.

– Keratoplasty: • Penetrating ?

• Deep lamellar (DALK)

• Prevention – Avoid eye rubbing !!

– Genetic counseling?

Remember… § Early ICRS (1990s) were conceived to correct myopia 2 equal, encircling implants

§ Current uses:  Keratoconus, Ectasia  1 single or 2 unequal implants

ICRS in KC & Ectasia

¿What are we trying to correct?

• As3gma3sm (cyl) • Myopia (sph) • Decentered op3cs – Typical of KC & other Ectasia – Not corrected by glasses – Can be measured as Coma

Sector vs. circular effects • Assuming a compressive effect (on the detoured collagen lamellae)

•  Increased tension

• When acting over a sector only… è that axis will be steepened è the opposite axis @90º will be flattened (coupling effect) • This corrects Astigmatism • This sector action is maximal with the less wide segments (90º) • The effects of two opposite implants are additive • This kind of action is the contrary of what Barraquer “Thickness Law” would predict

However, when compression is circular…

360º compression: è General flattening !!

Just like in a tightly sutured PK Corrects mostly Myopia

Now, there MUST be a point where steepening (sector compr.) effect gives way to flattening (circular compr.) effect This is observed as we go from narrow (60º, 90º) to progressively encircling (2 x160º, etc.) segments Cylinder  Spherocylinder

¿How can we correct Coma?

• Astigmatism: • •

•

a Quadrant aberration

Maximal correction  action over 90º 1 or 2 ICRS centered over the flat axis. There is coupling

Coma: a Hemispheric aberration Maximal correction  action over 180º • 1 ICRS only centered over Coma/decentration axis . No coupling •

More Options: Complexity/Versatility

§ Multiple types of ICRS § Diameter: 5, 6, 7 mm § Thickness: 150 - 350 (+ 450) mm § Amplitude: 60º - 90º- 120º- 150º 160º - 180º - 210º ---- 360º q Many combinations !

§ Greater control è enables independent effect over § Sphere § Astigmatism § Coma § Asphericity ? § Other irregularities?

Classic Nomogram (Albertazzi/Keraring)

• 3 types acc. to eccentricity (cone decentering) – Peripheral, asymmetric – Intermediate

– Central, symmetric

Asymmetric KC/ectasia

(marked inf-temp. eccentricity)

red= ast. steep axis blue= ast. flatter axis coma = marked, close to flatter axis

Ă¨ďƒ¨ 1x implant @flatter axis

red= ast. steep axis blue= ast. flatter axis coma = marked, close to flatter axis

(947072 RF)

n

11 y/o male, Dx Keratoconus 7 m. before, progression assessed ► ►

n

OD: UCVA = 0.09 -1.5 -2.5@178º = 0.7 OS: UCVA = 0.08 -4.5@120º = 0.6

Sph Eq = -2.75 D Sph Eq = -2.25 D

AO: Early Keratoconus, visible at slit lamp (Topo= Paracentral inferior) ►

► ►

►

n

Preop

OD: SimK K1= 50.7@149º

K2= 47.1@59º (Astig= 3.6 D) Pach central= 522 µm; min= 512 µm @(-0.2, -0.7) OS: SimK K1= 51.1@30º K2= 45.2@120º (Astig= 5.9 D) Pach central= 528 µm; Min= 504 µm @(0.6, -0.9)

Options: Kerarings vs. CXL (both ?)

Apex= 53.7

6mm circ= 625-670 µm Apex= 54.4

6mm circ= 578-675 µm

(947072 RF) n

AO=1 impl (FsL) ► 200 µm, 160º, Inf-T ► ►

n

incis. @140º/25º Depth = 462 µm

Result @ 1 d: (+LCT) ► ► ► ►

n

AO è Kerarings

OD= 0.15 -2 -1@60º=0.55 OS= 0.15 -2 -1@90º=0.75

@ 3 m.: ► OD= 0.7 Plano ► OS = 0.8 Plano

(947072 RF)

n

n

n

Result @3 m.

OD: K1= 48.0@105º (V axis: up 0.9 D) K2= 46.6@15º (H axis: down 5.1 D) ► Astig= 1.3D hypercorr., Ectasia + + central, Apex= 51.6 D (down 2.1D) OS: K1= 49.1@57º (“V” axis: up 3.9 D) K2= 46.9@147º (“H” axis: down 4.2 D) ► Astig= 2.2 D hypercorr., Ectasia + + central, Apex= 51.5 D (down 3.9 D)

Very happy, but there was still progression, required CXL

If same configuration but higher sphere/ cylinder…

red= ast. steep axis blue= ast. flatter axis coma = marked, close to flatter axis

• One 150-160º thicker implant below • One

90º (120º) thinner implant above • Both over the flatter axis • Thickness/width of both implants  additive effect for sphere/cyl., but…

• Coma is corrected by asymmetry  • the upper ICRS must be smaller/thinner

Central KC/ectasia è2xSymmetric ICRS @flatter Axis

Additional uses:

• Regular astigmatism: • Congenital

red= ast. steep axis blue= ast. flatter axis coma = minimal

• Post-Keratoplasty • Low

Myopia: • Essential • Residual (after Qx

(875819 CM)

n

28 y/o male, Myopia + Astigmatism, desires refractive surgery ► ►

n

OD: UCVA= 0.04 -4.5 -5@178º = 0.8 OS: UCVA= 0.04 -5.00 -4@0º = 0.8

(0.9 w CL) (0.9 w CL)

OU: Very symmetric ectasia vs. high curvature, thin regular cornea (“Type 3”) ►

OD:

SimK: K1= 57.4@85º; K2= 52.6@175º (D= 4.8)

Pach: Central= 360 um; Min= 356 um @(-0.1, -0.6); 6mm circle= 446-527 um

n ►

n

Preoperative

OS:

SimK: K1= 55.5@90º; K2= 51.3@180º (D= 4.2)

Pach: Central= 363 um; Min= 360 um @(0.1, -0.4); 6mm circle= 435-529 um

(875819 CM) n

n

Kerarings implant (manual) 2x250 um 160º, incision @90º, 350 um depth Results @ 1 day : ►

n

UCVA= 0.8 plano (=BSCVA)

@ 1 mo. ► ►

n

OS è Kerarings

UCVA= 0.65 -2@85º = 0.85

@ 1 y. ► UCVA= 0.85 ► -1@75º

= 0.95

(875819 CM)

n n n n

OS Postop Topo

SimK: K1= 50.7@155º; K2= 47.8@68º (D= 2.9) Topo: cylinder overcorrection Sphere: very good correction (-0.5 D residual Sph Eq) Patient very happy

Intermediate Ectasia (KC not that eccentric…)

– Displacement (& coma) closer to the steep axis !! è Dilemma: correct astigmatism vs. Coma ?

– Vertical axis evolution?: 1st steeper   as it decenters  more coma…   ends up by being almost the flattter axis ! (oblique) – At a certain point there must have been an inversion !!

Intermediate (I)

Paracentral KC/Ectasia -

“Snowman” pattern (relatively orthogonal)

Coma towards steepest axis

red= ast. steep axis blue= ast. flat axis coma = moderate, closer to steep axis

Difficult choice: if implant placed @coma axis  astigmatism will increase (& vice versa)

è2x equal ICRS,

displaced downward è to “encroach” Coma without losing effect on cylinder

red= ast. steep axis blue= ast. flat axis coma = moderate, closer to steep axis

Intermediate (II) “Duck” pattern (non-orthogonal)

è 1x very wide 180º -­‐ 210º implant è to include both coma & cylinder

red= ast. steep axis blue= ast. flat axis coma = marked, closer to steep axis

If same configuration but higher sphere/ cylinder…

red= ast. steep axis blue= ast. flatter axis coma = marked, close to steep axis § § § § §

One 150º (180º) thicker implant below One 90º (120º) thinner implant above Lower implant @ coma axis Upper implant @flatter semi-axis The 2nd implant will increase effect on sphere/cyl with minor impact on coma correction

How to organize implantation options?: 2x2 major features n

n

Symmetry: è Symmetric

►

2 equal paired ICS

►

1 single / 2 different ICS (or more) è Asymmetric

Axiality: ►

ICS (1 or 2) over flat (-) astig. axis è Axial

ICS (1 or more) over an axis different from flat (-) astigmatism (≥ 30º) è Non-Axial ►

The SA.ANA classification

Combining 2x2 criteria è 4 (+2) types (The SA.ANA classification) SA.ANA type

SA AA1 AA2 SNA ANA1 ANA2

Segments (Symmetric vs.

Asymmetric)

Symmetric 2 ICS (equal)

Implantation Axis

(Axial= same, flat A axis vs. Non-Axial= other axis >30º)

Axial (red= plus axis blue= minus axis)

Asymmetric

Axial

1 ICS 2 ICS (unequal)

(red= plus axis blue= minus axis green= coma axis)

Symmetric

Non-Axial

2 ICS (equal)

(red= plus axis blue= minus axis green= coma axis)

Asymmetric

Non-Axial

1 ICS (wide) 2 ICS (unequal)

(red= plus axis blue= minus axis green= coma axis)

The SA.ANA classification: Actual frequency in 1097 implants (763 eyes)

SA.ANA type

Segments / Axis

(Axial= same, flat A axis vs. Non-Axial= other axis >30º)

SA AA1 AA2

Symmetric & Axial (red= plus axis blue= minus axis)

Asymmetric & Axial (red= plus axis blue= minus axis green= coma axis)

Frequency found

≈10 % ≈ 40% ≈ 30% (Total

Symmetric & Non-Axial

SNA ANA1 ANA2

(red= plus axis blue= minus axis green= coma axis)

Asymmetric & Non-Axial (red= plus axis blue= minus axis green= coma axis)

≈

≈ 70% )

7%

≈ 8% ≈ 5%

(Total ≈13%)

Early –”Intermediate” KC n n n n

n n n n n

30 y/o w male Vernal conjunctivitis KC diagn. 6 y. ago OS: UCVA = 0.1 -2 -2.5@160º = 0.85 SphEq = -3.35 D SimK = 41.5/45.8 Cyl (orbscan)= 4.3D Steep axis vertical Coma axis vertical too…

(984429 JMGM)

n n n n

After single inferior 450 µm INTACS

Refractive astigmatism increased to -5 D (7 D by Orbscan Sim K) UCVA improved to 0.4 !! (BSCVA: -5@160º = 0.85) Coma (mostly vertical) reduced from 0.90 µmè 0.20 µm (iTrace) Ectasia pattern changed è more central & symmetric

(984429 JMGM)

After adding 2x90ºx150 µm Kerarings…

n UCVA @day 1 = 0.65 plano; @18 m.= 0.95 plano n Topography cylinder = 2.6 D (Orbscan Sim K) n Ectasia pattern changed to more central & symmetric n Apparent combination of centering & astigmatic effects in two stages

ANA 1 è +SA è = ANA 3

red= steep ast. axis blue= flat ast. axis coma = significant, towards steep axis

n Two

step procedure n It is possible to deal independently with coma and astigmatism

Intracorneal Segments (ICS) implanta3on types (The SA.ANA classifica3on) Type SA.ANA

Segments (Symmetric or Asymmetric)

SA

Symmetric

AA1

Asymmetric

AA2

ImplantaPon Axis

2 ICS (equal)

1 ICS

(Axial = same, minus cyl axis Non-­‐Axial = different axis)

2 ICS (unequal)

SNA

Symmetric

ANA1 ANA2

Asymmetric

ANA3

3 ICS (2-­‐step)

2 ICS (equal)

1 ICS (wide) 2 ICS (unequal)

Frecuency

Examples

Central (symmetric) ectasia Regular as3gma3sm (congenital or post-­‐PK) Mild myopia (congenital or residual a[er Rx.)

Asymmetric ectasia (markedly displaced inferiorly)

Coma ± towards minus cyl axis (roughly coincident <30º dif.)

(1 or 2 ICS depending on amount of cylinder/sphere)

Non-­‐Axial

Intermediate ectasia (paracentral, relaPvely orthogonal) Sphere mild/moderate Cylinder moderate/high Coma ± towards plus cyl axis

Non-­‐Axial

Intermediate ectasia (paracentral, non-­‐orthogonal) Sphere variable Cylinder moderate/high Coma ± towards plus cyl axis (inferiorly)

Intermediate ectasia (peripheral, ± incipient) Sphere mild Cylinder mild/moderate Coma ± towards plus cyl axis (almost at 90º of minus axis)

≈

Axial

(red= plus cyl blue= minus cyl)

Axial

IndicaPons

(red= plus cyl blue= minus cyl)

(green= mid-­‐ICS axis, displaced)

≈

10%

≈ 68%

≈ 6%

11%

Summary q Treating

KC & ectasia requires dealing with astigmatism, sphere and optical decentration (= coma). q The availability of multiple ICRS types enables addressing these multiple goals but requires a rationalization of the many options. q Based

on 2 criteria: symmetry & axiality we can organize implantation modalities in a few types (4 +2) è the SA.ANA classification.

Summary Most cases of KC (70%) are eccentric enough for 1 (single) or 2-asymmetric ICRS@flatter astigmatism=coma axis (AA1 & AA2 types). q 10% cases have central KC (with little coma), can be treated with 2 symmetric ICRS@flatter astigmatism axis (SA type). q The remaining 20% cases have intermediate decentration and coma is not close to the flatter astigmatism axis. The require special Non-Axial implants (SNA, ANA1, ANA2), even sequential (ANA3) q

Thank You for Your Attention