Laser in Situ Keratomileusis (LASIK) using the Zeiss VisuMax- MEL80 Platform for the Correction of Myopia

Victoria S. Chang, BS Richard M. Awdeh, MD Takeshi Ide, MD, PhD William W. Culbertson, MD Sonia H. Yoo, MD

Bascom Palmer Eye Institute, Miami, FL

* The first author has no financial or proprietary interest in any materials or methods described herein. WWC and SHY have received speaker's honoraria from Carl Zeiss Meditec.

VisuMax Femtosecond System

  10 ^-15s optical pulse (ultra-short pulse duration) •   zone of collateral damage Spherical corneal interface:  IOP elevation No vision loss during suction • Internal fixation target  Auto centration during docking  surgeon choice in flap parameters     Submicron tissue disruption 0.2 uJ Repetition rate 200kHz Precise focusing 1.0 um 2

MEL 80 Excimer Laser

Fast Ablation and Eye Tracker

• 250 Hz repetition rate • Automatic lock on pupil center • Additional limbus tracking • Corrects for asymmetrical pupil shift • Gaussian beam – 0.7mm

• Optimized beam fluence/shot distribution pattern • Additional peripheral pulses based on corneal curvature and RX 3

Purpose

• To report the visual acuity outcomes, predictability, and safety of the Zeiss VisuMax-MEL80 platform for the treatment of myopia.

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Methods

• Retrospective review of initial series of 46 eyes of 26 patients treated for myopia using the Zeiss Visumax-MEL80 platform • All eyes had a treatment goal of emmetropia. • All data was analyzed using JMP (SAS, Cary, NC) and SPSS (SPSS Inc, Chicago, Illinois) • All Snellen visual acuities were converted to a logMAR scale based on a logMAR conversion table • • • Individual letter adjustments where accounted for as 0.02 logMAR per letter. A Snellen acuity was rounded down one Snellen line if the logMAR score was >0.04 for that respective line. LogMAR scores were converted back to Snellen fractions for the purposes of categorizing the results 5

Demographics

Patient Characteristics

Characteristic Age mean (SD) All Patients (N=46) 33.13 (8.97) Female N (%) Preoperative UCVA mean (range) Preoperative MRSE mean (range) Time to post-operative month one visit 25 (54.3) 1.11 logMAR (0.21 – 1.34) -3.97 D (-0.875- -6.75) 43.8 days( 28 – 90) 6

Preoperative MRSE & UCVA

MRSE

• -3.97 (SD: 1.67; Range: 0.875 - -6.75).

UCVA

• 1.11 logMAR (SD: 0.29; Range: 0.21 – 1.34) 7

Post-operative Day 1 and Month 1

• • •

POD 1 UCVA

• 73.9% of eyes had UCVA of 20/20 or better • 91.3% of eyes had UCVA of 20/25 or better

POM 1 UCVA

• -0.029 logMAR (SD: 0.09, Range: -0.18 – 0.28) • • 87.0% had UCVA of 20/20 or better 97.9% of eyes had UCVA of 20/25 or better

POM 1 BCVA

• -0.0726 (SD: 0.078; Range: -0.3 – 0.04) • 100% of eyes had BCVA of 20/20 or better 8

Pre-op and Post-op UCVA

Distribution of UCVA preoperatively and 1 day and 1 month postoperatively after Myopic LASIK using VisuMax- MEL80 (Efficacy)

Preop (86 eyes) Postop day 1 (86 eyes) Postop month 1 (46 eyes) 100 90 80 70 60 50 40 30 20 10 0 20/16 20/20 or better 20/25 or better 20/32 or beter

UCVA

20/32 or better 20/40 or better 20/50 or better worse than 20/50 9

POM 1 MRSE

• 89.1% of eyes were within +/- 0.50 D of emmetropia • 97.8% were within +/- 1.00 D of emmetropia

Achieved Correction 1 month postoperative LASIK using the VisuMax- MEL80 for 46 myopic eyes (Predictability)

100 90 30 20 10 0 80 70 60 50 40 6,5 minus 0.51 to 1.0D

89,1 2,2 plus/minus 0.5D

0.51 to 1.0D

Diopters from Emmetropia

2,2 1.01D to 1.5D

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POM 1 Attempted vs. Achieved SE

r 2 = 0.945 11

Conclusion

• Our results show that LASIK using the VisuMax- MEL80 platform is effective, predictable, and safe in the treatment of myopia.

• • References Holladay JT.

Visual acuity measurements

. J Cataract Refract Surg 2004; 30(2): 287- 90. Shen N, Schaffer CB, Datta D, Mazur E.

Surface and bulk photodisruption in turbid tissue using femtosecond laser pulses.

Dept. of Physics. Harvard University.

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