One and two-year clinical outcomes of LASIK for high hyperopia

©DZ Reinstein [email protected]

One and two-year clinical outcomes of LASIK for high hyperopia

Dan Z Reinstein MD MA(Cantab) FRCSC1,2,3,4

Timothy J Archer, MA(Oxon), DipCompSci(Cantab)1 Marine Gobbe, MSTOptom, PhD1

1. London Vision Clinic, London, UK2. St. Thomas’ Hospital - Kings College, London, UK3. Weill Medical College of Cornell University, New York4. Centre Hospitalier National d’Ophtalmologie, (Pr. Laroche), Paris, France

Financial Disclosure: The author (DZ Reinstein) acknowledges a financial interest in Artemis™ VHF digital ultrasound (ArcScan Inc, Morrison, CO)The author (DZ Reinstein) is a consultant for Carl Zeiss Meditec AG (Jena, Germany)


Methods - Patients• 636 eyes• 371 patients• Age: 18 to 78 years, median 51

years• BSCVA: 66% ≥ 20/20

• Planned two-stage treatments = 20% (none enhanced)

• Enhancement rate: 25%– This includes patients who could

see 20/20– If enhancement had been

denied for 20/25 or better, the enhancement rate would have been 9%

• Hyperopia: +4.00 to +7.50 D, mean +5.35 ± 1.01 D

• Cylinder : 0.00 to -3.00 D, mean -0.98 ± 0.70 D

• Surgery: MEL80 excimer Laser, Hansatome microkeratome or Visumax femtosecondVisual axis centrationOptical zone: 7 mm

4.00 To 4.49

4.50 To 4.99

5.00 To 5.49

5.50 To 5.99

6.00 To 6.49

6.50 To 6.99

7.00 To 7.50

Series1 11% 18% 16% 12% 13% 10% 9%

11%

18%16%

12% 13%

10% 9%

0%2%4%6%8%

10%12%14%16%18%20%

Perc

enta

ge E

yes

Maximum Hyperopia (D)

Distribution of Maximum Hyperopia


Methods: Corneal Vertex CentrationExample: Eye with a large nasal angle kappa

MEL80 Eye Tracker aligned with corneal

vertex

+ Pupil centre + Corneal Vertex

Hansatome flap centred with corneal vertex

• Flap and corneal ablation centred on the corneal vertex• Corneal vertex best approximates the visual axis

No difference in outcomes (accuracy, safety, contrast sensitivity) between a group of eyes with a small angle kappa (pupil centre corneal vertex) and group of eyes with a large angle kappa (pupil offset ≥ 0.55 mm) [1]

Corneal ablation should be centred on the corneal vertex ( visual axis) and not the pupil centre (line of sight)

[1] Reinstein et al – Centration of hyperopic ablations: corneal vertex vs pupil centre – AAO, Atlanta, 2008.

NT

S

I

Orbscan Anterior Elevation Map Orbscan Eye Image

NT

S

I

NT

S

I

Pupil margins

NT

S

I

Flap edge


Methods: Artemis Two-stage treatmentArtemis two-stage treatment for refractions over +5.50D1. Primary treatment: up to +5.50D in the maximum hyperopic meridian2. Post-operative Artemis

Measurement of thinnest epithelium

Calculation of treatable remaining hyperopia based on minimum epithelial thickness

y = 7.2619x + 57.718R2 = 0.8167

y = -1.7158x + 46.819R2 = 0.3032

0

20

40

60

80

100

120

140

0.00 2.00 4.00 6.00 8.00 10.00

Attempted SEQ

Epith

elia

l Thi

ckne

ss

Thickest Epithelium

Thinnest Epithelium

y = 2.3437x - 24.437R2 = 0.1399

y = -0.7217x + 73.843R2 = 0.0886

0

20

40

60

80

100

120

140

40.0 42.0 44.0 46.0 48.0 50.0 52.0 54.0

Max Sim K

Epith

elia

l Thi

ckne

ssThickest Epithelium

Thinnest Epithelium

Patient could have a flat cornea, but thin epithelium: not suitable for retreatment Patient could have a steep cornea, but thick epithelium: suitable for retreatment

Epithelial thickness is a more reliable tool than keratometry to determine the amount of ablation that can be performed [1]

[1] Reinstein et al. Epithelial Thickness After Hyperopic LASIK: Three-dimensional Display With Artemis Very High-frequency Digital Ultrasound. J Refract Surg. 2009 Nov 24:1-10

Max Sim KAttempted SEQ

Epi

thel

ial T

hick

ness

Epi

thel

ial T

hick

ness


Results: Accuracy

-2.00 To -1.51

-1.50 To -1.01

-1.00 To -0.51

-0.50 To -0.14

-0.13 To

0.13

0.14 To

+0.50

+0.51 To

+1.00

+1.01 To

+1.50

+1.51 To

+2.00Accuracy 1% 3% 9% 20% 24% 18% 15% 6% 2%

1%3%

9%

20%

24%

18%

15%

6%

2%

0%

5%

10%

15%

20%

25%

Perc

enta

ge E

yes

Accuracy of Spherical Equivalent

Accuracy: Within Range of I ntended

Within ±0.50 D 62%

Within ±1.00 D 85%


Results: Efficacy(excluding eyes not intended plano)

Monocular UDVAn=237mean max hyperopia +5.37 ± 1.00D

20/12.5 20/16 20/20 20/25 20/32 20/40 20/63Pre BSCVA 1% 26% 70% 86% 96% 100%Efficacy 3% 17% 59% 76% 88% 95% 100%

1%

26%

70%

86%96% 100%

3%

17%

59%

76%

88%95%

100%

0%

20%

40%

60%

80%

100%

Perc

enta

ge E

yes

Monocular UCVA

Efficacy: Monocular UCVA

3 or more worse 2 worse 1 worse Pre BSCVA 1 better 2 better

Success 5.9% 10.5% 23.6% 40.5% 15.6% 3.8%

6%11%

24%

41%

16%

4%

0%5%

10%15%20%25%30%35%40%45%

Perc

enta

ge E

yes

Post UCVA vs Pre BSCVA

Post UCVA vs Pre BSCVAPost UDVA vs Pre CDVA83% within 1 line of Pre CDVA

Post-op, 83% of eyes achieved unaided VA that was within 1 line of the pre-op spectacle corrected vision. 94% within 2 lines of Pre CDVA

Pre-op, 70% of eyes had 20/20 best-spectacle corrected VA.Post-op, 59% of eyes achieved 20/20 unaided.


Loss 3 or More Loss 2 Loss 1 No

Change Gain 1 Gain 2 or More

Safety 0.0% 0.0% 22% 60% 17% 1%

0.0% 0.0%

22%

60%

17%

1%0%

20%

40%

60%

80%Pe

rcen

tage

Eye

s

Lines Change BSCVA

Safety: Lines Change BSCVA

Results: Safety – BSCVA and Contrast Sensitivity

* ***

No eyes loss 2 lines or more

Slight statistically significant decrease in contrast sensitivity at all spatial frequenciesAverage decrease: less than 1 patchLittle clinical significance


Stability

Pre-op 1 Day 1 Month 3 Months 6 Months 1 Year 2 Years

Mean±SD +4.19±1.38 -0.31±0.62 -0.10±0.75 +0.04±0.75 +0.16±0.78 +0.36±0.85 +0.52±0.94

# eyes 636 517 561 594 514 405 201

-2.00

-1.00

0.00

1.00

2.00

3.00

4.00

5.00

6.00

Sphe

rica

l Equ

ival

ent

(D)

Time Point

Stability: Change in Spherical Equivalent

3 Mo 6 Mo 12 Mo 24 Mo

• If we assume that the refraction is stable at 3 months (post-operative oedema has resolved), the hyperopic shift at 2 years is 0.48 D (0.52 D at 2y – 0.04 D at 3m)

• We know that the average hyperopic shift with age is 0.42 D in 5 years = 0.08 D/year [1,2]

The hyperopic shift due to LASIK regression is 0.32D at 2 years (0.48D – 0.08 D x 2)[1] Guzowski et al. Five-year refractive changes in an older population: the Blue Mountains Eye Study. Ophthalmology. 2003 Jul;110(7):1364-70.[2] Gudmundsdottir et al. Five-year refractive changes in an adult population: Reykjavik Eye Study. Ophthalmology. 2005 Apr;112(4):672-7.


Outcomes Comparison: Accuracy, Safety, Efficacy of Phakic IOLs vs LASIK – High Hyperopia

Accuracy withinLoss 2 lines

Efficacy

Rx treated ± 0.50D ± 1.00 D UCVA≥20/40

Artisan IOL FDA [1] +4.00 to +12.00D 65.5% 98.2% No data 85.5%

Artisan phakic IOL [2] +2.75 to +9.25 D 50% 78% 0 89%

Posterior chamber phakic IOL [3] +4.00 to +11.00D 58% 79% 4% 63%

RLE & multifocal IOL [4] +1.75 to +6.00D 88% 100% 0 100%

RLE Staar/Rayner IOL [5] +4.75 to +13.00 D 70% 90% 0 25%

Acrysoft RLE [2] +2.75 to +7.50 D 55% 91% 0 82%

LASIK – MEL80 +4.00 to +7.00 D 65% 93% 0% 95%

[1] Desai et al - Long-term results of the Artisan IOL for the correction of severe and extreme hyperopia in the United States: A prospective Multi-Center Study – ARVO 2008.[2] Pop M. Payette Y. Refractive lens exchange versus iris-claw Artisan Phakic Intraocular Lens for Hyperopia. J Refract Surg. 2004;20:20-24[3] Davidorf et al – Posterior chamber phakic intraocular lens for hyperopia +4 to +11 diopters. J Refract Surg. 1998; 14(3): 306-311[4] Dick et al – Refractive lens exchange with an array mutifocal IOL – J Refract Surg. 2002;18:509-518[5] Preetha et al – Clear lens extraction with intraocular lens implantation for hyperopia. J Cataract Refract Surg. 2003;29: 895-899


Conclusion• Equal or better outcomes than IOLs• Risks associated with IOLs avoided:

– No endothelial cell loss (4.3% over 3 years with Artisan IOL [1], 5.4% over 1 year with Kelman Duet Phakic IOL [2])

– No PCO (7.1% to 31.1% with monofocal IOLs [3], 48% with the Tetraflex lens [4])– No other complications associated with intra-ocular surgery

• Epithelial thickness better indicator than keratometry for preventing apical epitheliopathy

• Centration on corneal vertex (NB opposes convention!)• Contrast sensitivity: slight reduction but not clinically significant (cf.

Significant loss of CS with multifocal intraocular lenses [5,6])

• Stability: slight hyperopic shift over 2 years (+0.32D)

[1] Desai et al - Long-term results of the Artisan IOL for the correction of severe and extreme hyperopia in the United States: A prospective Multi- Center Study – ARVO 2008[2] Alio et al. The Kelman Duet Phakic Intraocular Lens: 1-year Results. J Refract Surg. 2007;23:868-878[3] Auffarth et al. Ophthalmic Epidemiol. 2004; 11(4) [4] Wolffsohn J. Two-year performance of the Tetraflex accommodative IOL. ARVO – May 2008[5] Alfonso et al. Prospective visual evaluation of apodized diffractive intraocular lenses. J Cataract Refract Surg. 2007;33: 1235-1243.[6] Schmidinger et al. Contrast sensitivity function in eyes with diffractive bifocal intraocular lenses. J Cataract Refract Surg. 2005;31:2076-2083

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One and two-year clinical outcomes of LASIK for high hyperopia