Wavefront Measurements afterPenetrating Keratoplasty and itsCorrelation with Refraction and

Corneal Topography

Maria Regina Chalita, MD, PhD

Medical Director - Vision InstituteMedical Director - Vision Institute

Federal University of SFederal University of Sãão Paulo - Brazilo Paulo - Brazil

Co-authors

• Adalia Ferreira,M.D.

• Mauro Campos, M.D.

• Ana Luisa Hofling-Lima, M.D.

Purpose

• Evaluate wavefront measurement in patients

after penetrating keratoplasty(PK) and

correlate it with refraction and corneal

topography

Methods

• 29 patients (35 eyes) who underwent PK betweenJuly 1992 and April 2003

• Mean follow-up: 57.9 months (range 12 to 142)

• UCVA, BCVA, manifest refraction, cycloplegicrefraction, corneal topography and wavefrontanalysis

• Wavefront measurements (LADARWave®)– (MRC)

– 6.0mm pupil size

– Up to 6th order

Methods• Main indications for PK:

– KCN 80%– Leucoma 11.4%– Infectious keratitis 5.7%– Fuchs dystrophy 2.9%

• Exclusion criteria– Aphakic or pseudophakic eyes– Retinal diseases– Previous ocular surgery

Methods• Statistical Analysis

– Vector analysis for MR, CR and WR• M, J0 and J45

– Vector analysis for corneal topography• J0 and J45

– Correlation coefficient (p<0.05)

Results

• 29 patients: 11 F (38%): 18 M (62%)

• Age: Mean: 34.2 years (21-54)

• All PK performed by one surgeon

• PK size: 8.0 – 8.25mm

Descriptive Statistics ofRefraction Components

Comparison of Manifest and Cycloplegic Refraction for M vector component

-14-12-10-8-6-4-202468

-14 -12 -10 -8 -6 -4 -2 0 2 4 6 8

Manifest Refraction - M

R=0.95

P<0.001

Comparison of Manifest and Wavefront Refraction for M

vector component

-14-12-10-8-6-4-202468

-14-12-10 -8 -6 -4 -2 0 2 4 6 8

Manifest Refraction - M

R=0.92

P<0.001

Comparison of Cycloplegic and Wavefront Refraction for M vector

component

-14-12-10-8-6-4-202468

-14 -12 -10 -8 -6 -4 -2 0 2 4 6 8

Cycloplegic Refraction - M

R=0.98

P<0.001

Comparison of Manifest and Cycloplegic Refraction for J0

vector component

-4-3-2-1012345

-4 -3 -2 -1 0 1 2 3 4 5

Manifest Refraction - J0

R=0.87

P<0.001

Comparison of Manifest and Wavefront Refraction for J0 vector

component

-4-3-2-1012345

-4 -3 -2 -1 0 1 2 3 4 5

Manifest Refraction - J0

R=0.89

P<0.001

Comparison of Cycloplegic and Wavefront Refraction for J0 vector

component

-4-3-2-1012345

-4 -3 -2 -1 0 1 2 3 4 5

Cycloplegic Refraction - J0

R=0.95

P<0.001

Comparison of Manifest and Cycloplegic Refraction for J45

vector component

-4-3-2-101234

-4 -3 -2 -1 0 1 2 3 4

Manifest Refraction - J45

R=0.93

P<0.001

Comparison of Manifest and Wavefront Refraction for J45 vector

component

-4-3-2-101234

-4 -3 -2 -1 0 1 2 3 4

Manifest Refraction - J45

R=0.92

P<0.001

Comparison of Cycloplegic and Wavefront Refraction for J45 vector

component

-4-3-2-101234

-4 -3 -2 -1 0 1 2 3 4

Cycloplegic Refraction - J45

R=0.88

P<0.001

Descriptive Statistics ofWavefront Aberrations

Example 1

Example 1

Example 2

Example 2

Good reproducibility

Conclusion• Wavefront measurements were possible in highly

aberrated post-PK eyes, with good quality andreproducibility

• Wavefront refraction showed a statistically significantcorrelation with Manifest and Cycloplegic refractions

• Mean higher order aberration values were greater inpost-PK eyes when compared to normal eyes (otherterms – trefoil and tetrafoil)

• No statistically significant correlations were foundbetween topography and refraction and alsotopography and wavefront

Thank You!