To Flush or Not to Flush the Interface in Small-Incision Lenticule - - PowerPoint PPT Presentation

To Flush or Not to Flush the Interface in Small-Incision Lenticule Extraction

First Results of a Prospective Randomized Paired-Eye Multicenter Study

• Sekundo W, Kind R, Bechmann M, Kiraly L, Langenfeld S, Meyer B, Taneri S,

Troeber L, Wiltfang R SMILEEYES:) Group & Philipps-University of Marburg

Aim and Methods

Purpose: to investigate the outcome differences in uncomplicated bilateral simultaneous SMILE with and without interface flushing with BSS after the removal of the refractive lenticule

• Single blinded prospective study at 6 Laser Refractive Centers of the SMILEEYES :) group
• Approved by the Ethics Committee of the Philipps University
• Randomization for flushing left or right eye using envelope method

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Background and Methods (2)

• Surgeries performed by 9 different surgeons of the SMILEEYES group
• Analysis was performed comparing flushed and not-flushed eye of the

same patient (paired t-test) by an independent investigator (Ralph Kind)

• In planned cases of under-correction (mini-monovision for presbyopia)

 the target refraction was put in front of the under-corrected eye to get a comparable “UDVA”

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Study demographics and data (1)

• Requirement

– MRSE: -1 to -12 D – Maximum difference between both eyes < 2 D – CDVA before surgery at least 20/25 (0.8 decimal) for both eyes – Laser (VisuMax) settings

• Lenticule and cap diameter of same size in both eyes
• Cap thickness between 120 and 130 µm
• Flushing of the pocket using 1ml of BSS via a single use 27 G cannula

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Study demographics and data (2)

• 264 patients were enrolled at 6 study centers
• Excluded:

– 7 patients with complications during surgery – 22 patients with an incomplete follow up –

• 470 eyes of 235 patients for final analysis

– Age: mean 32.8y, range (18y-56y) – Refraction:

• Sphere: mean -3.97 D ± 1.99 D
• Cylinder: mean -0.89 D ± 0.77 D
• Low myopia (-3 D <): 66 Patients
• Moderate myopia (-3 to -6 D): 114 Patients
• High myopia (> -6 D): 55 Patients

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Results: decimal UDVA for all 470 eyes

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0,60 0,70 0,80 0,90 1,00 1,10 1,20 1d 1w 3m

UDVA Time after surgery

Results (235 Patients)

Not-flushed Flushed

p-value: 1d: 0.1329 1w: 0.2079 3m: 0.1719

20/25 20/20

Results: subgroups

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0,60 0,70 0,80 0,90 1,00 1,10 1,20 1d 1w 3m

UDVA Time after surgery

Slight myopia (66 patients)

Not-flushed Flushed 0,60 0,70 0,80 0,90 1,00 1,10 1,20 1d 1w 3m

UDVA Time after surgery

Moderate myopia (114 patients)

Not-flushed Flushed 0,60 0,70 0,80 0,90 1,00 1,10 1,20 1d 1w 3m

UDVA Time after surgery

Severe myopia (55 patients)

Not-flushed Flushed

• Low myopia

0,2 0,4 0,6 0,8 1 1,2 1,4 Not-flushed UDVA Flushed UDVA Not-flushed CDVA Flushed CDVA

visual acuity

3-month follow-up

Decimal UDVA & CDVA for all 470 eyes @ 3/12

• 1.04

1.06 1.15 1.17

Complications intraoperative

• Relevant intra-operative complications (excluded from follow-up): 7

patients – 4 patients: multiple or both sided flushing due to stuck parts of lenticule – 2 patients: conversion to PRK due to suction loss at one eye – 1 patient: conversion to PRK because conjunctiva was pulled into interface at both eyes

• Minor intra-operative complications: 23 eyes

– Cap tear at the incision site: 4 eyes – Epithelial defects: 8 eyes – Difficult dissection, minor remaining lenticule’s edge, bleeding at the incision site

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Complications (postoperative)

• 19 eyes with minor postoperative complications

– haze, – dry eye symptoms, – superficial punctate keratitis, – diffuse lamellar keratitis stage 1

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Conclusion & Outlook

• No statistical difference between the flushed and unflushed eyes
• Tendency for a better UDVA/CDVA for flushed eyes regardless of preop

refraction, but never reached statistical significance (p ≥ 0.05)

• Maybe larger group of patients (> 2000) would get p<0.05
• Overall high efficacy (UDVA @ 3 month follow-up with average > 1.0)

– The UDVA better in low myopias (< -3D)

• To-do:

– Check for relationship between UDVA and minor complications – Compare OCT-data with UDVA – Compare, if flushing/non-flushing has any impact on refractive predictability

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Special thanks to the surgeons and their teams

• Cologne: Dr. B. Meyer
• Leipzig: Dr. L. Kiraly
• Marburg: Prof. Dr. W. Sekundo
• Munich: Dr. R. Wiltfang & Dr. M. Bechmann
• Munster: Dr. S. Taneri
• Trier: Dr. L. Troeber

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0,00 0,20 0,40 0,60 0,80 1,00 1,20 1,40 1d 1w 3m

visual acuity

Not-flushed UDVA Flushed UDVA Not-flushed CDVA Flushed CDVA

Results: decimal UDVA and CDVA for all 470 eyes

• CDVA

UDVA

0,8 0,85 0,9 0,95 1 1,05 1,1 1,15 1,2 not-flushed UDVA flushed UDVA not-flushed CDVA flushed CDVA

Comparison between difference of CDVA and UDVA for flushed and not-flushed eyes

visual acuity difference between CDVA and UDVA