Impact of Intacs Implantation on Impact of Intacs Implantation on

High Order Corneal Aberrations High Order Corneal Aberrations

in Keratoconusin Keratoconus

Bluwol E, Doat M, Alfonsi N, Legeais JM, Renard Bluwol E, Doat M, Alfonsi N, Legeais JM, Renard GG

Hôtel-Dieu, Paris Hôtel-Dieu, Paris

Authors have no financial interest

PurposePurpose

Relationship between high HOAs rate, low quality of vision Relationship between high HOAs rate, low quality of vision

and contrast sensitivityand contrast sensitivity loss in keratoconic eyes loss in keratoconic eyes Vertical coma = most important HOA in Keratoconus (KC)Vertical coma = most important HOA in Keratoconus (KC)

To report the aberrometric effect of 1 single Intacs To report the aberrometric effect of 1 single Intacs implantation in KCimplantation in KC

Intacs is a safe, reversible and non penetrating procedureIntacs is a safe, reversible and non penetrating procedure Indication in KC : Indication in KC :

intolerance to intolerance to rigid gas-permeable contact lenses rigid gas-permeable contact lenses No corneal scarNo corneal scar

MethodsMethods

Retrospective study 36 KCPentacam Topography

+ UCVA, BSCVA

One single segment Intacs inferiorly based with femtosecond laser

Comparison ofUCVA, BSCVA (LogMAR), Coma et Tréfoil (0°,90°)

At 1 and 3 Months postoperatively (Paired Student Test )

Exclusion criteria:

-Good tolerance to rigid gas-permeable contact

lenses -Corneal opacities

-KC crossing horizontal meridian

VA ResultsVA Results

Visual Acuity Evolution

0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

Mean UCVA Mean BSCVA

LogMAR

Preop

1 Month Postop

3 Month Postop

Visual Acuity Evolution

0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

Mean UCVA Mean BSCVA

LogMAR

Preop

1 Month Postop

3 Month Postop

* ** *

Mean ± SDparameter preoperative 1 month 3 months

UCVA (LogMAR) 1.03 ± 0.48 0.45 ± 0.36* 0.45 ± 0.37*

BSCVA (LogMAR) 0.49 ± 0.31 0.30 ± 0.28* 0.28 ± 0.29*

* : statistically significant difference between preoperative and postoperative values (p<0.001)UCVA = uncorrected visual acuity in Mean LogMAR ± SD (standard deviation)

BSCVA = best spectacle-corrected visual acuity

UCVA gain after surgery

77,80%

19,40%

2,80%

≥ 2 lines

1 line

Stable

BSCVA gain after surgery

61,10%19,50%

19,40%

≥ 2 lines

1 line

Stable

- VA Gain : 97,2%

• 83,3% ≥ 2 lines

• 13,9% 1 line

- Stable VA : 2,7%

- VA Loss : 0%

HOAs HOAs ResultsResults

Evolution of High Order Aberrations

-0,005

-0,004

-0,003

-0,002

-0,001

0

0,001

0,002

Coma 90° Coma 0° Trefoil 90° Trefoil 0°

µm

Preop

1 Month Postop

3 Month Postop

Mean ± SD (10 -3 µm)parameter preoperative

1 month p 3 months p

Coma 90° -4,43 ± 2.3 -3,06 ± 2.4 0,01* -3,44 ± 2.7 0,01*

Coma 0° -0,99 ± 2.1 -0,62 ± 2.0 0,38 -0,64 ± 1.6 0,37

Trefoil 90° -0,20 ± 0.7 -0,06 ± 0.9 0,20 -0,08 ± 0.7 0,70

Trefoil 0° 0,28 ± 0.6 0,001 ± 1.6 0,27 0,31 ± 0.6 0,93

postoperative

*: statistically significant difference between preoperative and postoperative values (p<0.05)

Keratometric effect of one single Intacs Keratometric effect of one single Intacs inferiorly basedinferiorly based

Preoperative Postoperative Differencial

Inferior flattening

Superior bulge

ConclusionConclusion

97.2% increasing VA (UCVA and/or BSCVA)97.2% increasing VA (UCVA and/or BSCVA) No VA lossNo VA loss

Significant vertical coma reduction Significant vertical coma reduction (and reduction of almost every Third (and reduction of almost every Third HOAs)HOAs)

Quality vision improvement even in stable VA casesQuality vision improvement even in stable VA cases

Short term efficacyShort term efficacy Simple and reversible surgical procedureSimple and reversible surgical procedure No complication reported in our study No complication reported in our study (infection,Intacs extrusion or (infection,Intacs extrusion or

migration, tunnel misplacement …)migration, tunnel misplacement …)