Allegretto Wave Eye-Q performs excellently after other kinds of surgical correction

1. Allegretto Wave Eye-Q performs excellently after other kinds of surgical correction Vjacheslav Kuznetsov Acu Mikroķirurģijas Centrs (Eye Microsurgery Center) Riga, Latvia

2. “Acu Mikroķirurģijas Centrs” Riga, www.lazer.lv • Founded in 1998, • Activity: • All kinds of vision correction • non-invasive (eyewear glasses, contact lenses) • microsurgery (RK, AK) • excimer laser techniques (LASIK, PRK group) • non-laser coagulative methods (CK) • implants (phakic IOL's, corneal rings) • Classical surgery (cataract, glaucoma) • Allegretto Wave Eye-Q since 2006

3. Rationale for combinations I • Excimer laser correction is now the world leader in the field of surgical correction. Nevertheless: • Sometimes cornea is too thin for reliable results • Large pupils present a problem • Decrease of the optical zone worsens the night vision • Risk of keratectasy/keratoconus is always present • Combining several kinds of correction could be beneficial for nonconforming patients.

4. Rationale for combinations II • Excimer laser correction: • causes decrease of corneal thickness • affects the optical zone. • RK and CK: • don't change the corneal thickness, • applied outside of the corneal optical zone • Thus, when correctly combined, methods could • eliminate each other’s shortcomings • and reinforce advantages

5. Rationale for combinations III • No method of surgical correction guarantees ideal outcome. • Thus, when one kind of correction fails or is insufficient, another kind could be used afterwards to improve results. • Hence the advantage of being familiar with different methods of refractive surgery

6. Our experience • Combinations currently used: • RK + LASIK and RK + PRK for myopia • CK + LASIK and CK + PRK for hypermetropia • We use specially devised nomograms and techniques that account for the eye condition and for the time after previous manipulations • FDA recommendations on the possible degree of ametropia correction are followed.

7. Equipment - surgery • Allegretto Wave Eye-Q • Near Vision REFRACTEC CK system • Leica M841 microsurgical microscope • Zyoptix XP microkeratome • Microkeratomes for radial keratotomy • both American and Russian styles

8. Equipment - diagnostics • ALLEGRO Topolyzer • ALLEGRO Analyzer • Pachymeters: • Humphrey ultrasonic • Qvantel Medical POCKET II • Heidelbeg Engineering

9. Patients 34 patients/64 eyes with combined correction using Allegretto Wave Eye-Q • 23 patients had RK + LASIK • 7 patients - RK +PRK • 3 patients - CK +LASIK • 1 patients - CK +PRK

10. Indications • In 13 patients the second step was planned initially (with 1 year interval) due to: • calculated residual stroma thickness with normal optical zone < 250μm (LASIK) • and/or pupil diameter ≥ 7 mm • In 21 patients postcorrection was performed (2 - 18 years after the first surgery)

11. Myopia (RK + LASIK/PRK),30 patients • Initial sphere from -5,5 to -13,0 • Initial astigmatism up to -3,0 • Initial cornea 470 - 510 μm • Pupilla 6,5 - 8,5 mm • Sphere after RK from -1,5 to -5,0 • Interval to laser 1 – 18 years • Stroma after LASIK 280 - 300 μm • Vision after laser Em in all patients

12. Hyperopia (CK + LASIK/PRK),4 patients • Initial sphere from 6,5 to 8,0 • Initial astigmatism up to 2,0 • Initial cornea 510 - 545 μm • Pupilla 5,0 - 6,5 mm • Sphere after CK from 4,0 to 5,5 • Interval to laser 1 - 2 years • Vision after laser 20/40 – 20/20

13. Results • Results were not different from planned. • Formation of corneal flap was adequate in all cases. • Rehabilitation period was analogous to usual manipulations.

14. Results in comparison • There are 11 patients who are being followed-up in our Center after the second laser postcorrection • performed elsewhere (mostly in Moscow) • by other excimer lasers • their results are significantly inferior • in vision quality • in rehabilitation/stabilisation

15. Overall results • Combined correction was particularly beneficial in patients with thin corneas and wide pupils, resulting in a more comfortable vision. • Resulting vision was subjectively better in patients with pre-planned second step if compared to postcorrected patients. • RK+excimer combination probably prevents the formation of keratoconus.

16. Conclusions

17. Combinations are useful! • Combined corrections may provide an eye surgeon with broader possibilities for ametropia correction • Combinations allow for safe compensation of insufficient results of previous manipulation

18. Benefits: • possibilities to treat thin cornea, even with LASIK, still preserving acceptable thickness • options for dealing with large pupils • increase of optical zone of excimer laser correction, thus alleviating the night vision problem • higher level of hypermetropia correction • possible prevention of keratectasia

19. “Acu Mikroķirurģijas Centrs” in Riga have been a supporter of microsurgical correction (RK) for many years • previous generation lasers being unable to provide postoperative adaptation comparable to our RK technique • Our experience with Allegretto Wave Eye-Q proved advantageous, including its great merit for complicated and pre-treated eyes and for combined correction

20. Thank you for attention!