Prospective comparison of two excimer laser platforms in treatment of high astigmatism with laser in situ keratomileusis [Prospektivna usporedba dvije laserske platforme u tretiranju visokog astigmatizma laser in situ keratomijeluzom]

Biščević, Alma (2019) Prospective comparison of two excimer laser platforms in treatment of high astigmatism with laser in situ keratomileusis [Prospektivna usporedba dvije laserske platforme u tretiranju visokog astigmatizma laser in situ keratomijeluzom]. PhD thesis, Sveučilište u Zagrebu.

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Abstract

PURPOSE: Comparison of Wavelight Allegretto Eye-Q and Schwind Amaris 750S excimer laser groups after performed LASIK procedure regarding functional parameters – uncorrected (UDVA) and corrected distant visual acuity (CDVA), residual refractive error, astigmatism outcomes by means of vector analysis and high order aberrations in patients with high astigmatism (more than 2 diopters (D)). ----- METHODS: 135 patients with myopic astigmatism (246 eyes) and 102 patients with mixed astigmatism (172 eyes) underwent LASIK correction (some of the patients had only one eye operated – the eye that met the criteria for the study, while the other eye had no diopter at all) and were divided in 4 groups: 1 – myopic astigmatism corrected with Allegretto, 2 – myopic astigmatism corrected with Amaris, 3 – mixed astigmatism corrected with Allegretto and 4 – mixed astigmatism corrected with Amaris. Data were analysed to determine significance of change in spherical correction, astigmatism, UDVA, CDVA, high order aberrations, and also vector analysis by Thibos (J0 and J45) and Alpins method was performed. ----- RESULTS: Visual acuity improvement for group 1 was statistically significant (p=0.017); for group 2, 3 and 4 was not statistically significant (p=0.06, p=0.406, p=0.115). None of the eyes lost any lines of CDVA. Regarding refractive results, for all groups there was almost complete elimination of spherical and cylindrical refractive error. High-order aberrations results for groups 1 and 2 showed no significant change between preoperative and postoperative high-order aberrations, while in groups 3 and 4 spherical aberrations changed. Vector analysis by Thibos showed statistically significant difference between J0 preop and J0 postop for both platforms (p<0.001). There was statistically significant difference for J45 postoperatively between the platforms (p=0.012). Correlation between ΔJ0 and preop J0 values (groups 1 and 2) showed that the difference between these two correlation coefficients was significant (z=−3.086, p=0.002). There was statistically significant difference in preoperative mean values for J0 (p<0.001) between the groups 3 and 4. There was a statistically significant difference between J0 preop and J0 postop for both platforms (p<0.001). Correlation between ΔJ0 and preop J0, and between ΔJ45 and preop J45 for groups 3 and 4 showed that difference between these two correlation coefficients was significant (z=−3.533, p=0.0004; z=−2.886, p=0.004). Vector analysis by Alpins showed that negative SIA power (y1) was significantly correlated with negative TIA power (x1) and sine of the TIA axis (x2) as follows: [a] i, y1=0.829X1–0.403X2–0.325 (F=87.76, R=0.804, P<0.001, N=127); ii, y1=0.891X1–0.037X2-0.192 (F=240.06, R=0.901, P<0.001, N=119) and [b] i, y1=1.063X1+0.233X2+0.411 (F=990.99, R=0.881, P<0.001, N=61); ii, y1=1.029X1– 0.115X2+0.322 (F=270.12, R=0.908, P<0.001, N=111). The sine of negative SIA axis (y2) was significantly correlated with negative TIA power (x1) and TIA axis (x2) as follows: [A] I, y2=0.951x2–0.007x1+0.008 (F=446.58, r=0.950, p<0.001, n=127); II, y2=0.856x2+0.007x 1+0.105 (F=277.18, r=0.912, p<0.001, n=119) and [B] I, y2=0.953x2 +0.009x1+0.075 (F=362.6, r=0.963, p<0.001, n=61); II, y2=0.977x2–0.004x1+0.002 (F=2910.9, r=0.990, p<0.001, n=111). ----- CONCLUSIONS: Both lasers showed effective in terms of UDVA, CDVA, spherical correction, and preservation of high-order aberrations. However, Amaris was more effective in cylinder correction. There was no genuine difference post-operatively between groups treated on two different laser platforms according to the vector analyses by Thibos. By using Alpins method, we revealed that both platforms were similar in tending to undercorrect astigmatism; axis rotational errors were apparent, although overall the two platforms differed in terms of direction; and the predicted angle between the SIA and TIA tended to increase when the astigmatic correction was against-the-rule.

Abstract in Croatian

CILJ: Usporedba Wavelight Allegretto Eye-Q 400 Hz i Schwind Amaris 750S excimer laser grupa nakon obavljene LASIK procedure analizirajući sljedeće funkcionalne parametre – nekorigirana (UDVA) i korigirana daljinska vidna oštrina (CDVA), ostatna refrakciona greška, rezultati korigiranog astigmatizma uz pomoć vektorske analize te okularne aberacije višeg reda kod pacijenata sa visokim astigmatizmom (više od 2 dioptrije (D)). ----- METODE: 135 pacijenata s miopskim astigmatizmom (246 očiju) i 102 pacijenta s miješanim astigmatizmom (172 oka) su podvrgnuta korekciji dioptrije LASIK metodom (kod nekih pacijenata operirano je samo jedno oko koje je ispunjavalo kriterije za studiju, dok drugo oko nije imalo dioptriju) te podijeljena u 4 grupe: 1 – miopski astigmatizam korigiran Allegrettom, 2 – miopski astigmatizam korigiran Amarisom, 3 – miješani astigmatizam korigiran Allegrettom i 4 – miješani astigmatizam korigiran Amarisom. Podaci su analizirani da bi se utvrdio značaj promjene sferne korekcije, astigmatizma, nekorigirane (UDVA) i korigirane vidne oštrine na daljinu (CDVA), okularnih aberacija višeg reda, a vektorska analiza Thibosovom (J0 and J45) i Alpinsovom metodom je također primijenjena. ----- REZULTATI: Poboljšanje vidne oštrine za grupu 1 je bilo statistički značajno (p=0.017), a za grupe 2, 3 i 4 nije bilo statistički značajne razlike (p=0.06, p=0.406, p=0.115). Niti jedan pacijent (oko) nije izgubio jedan ili više redova korigirane vidne oštrine nakon obavljenog zahvata. Što se tiče refrakcijskih rezultata, sve četiri grupe su imale skoro potpuno otklanjanje sferne i cilindrične refrakcijske pogreške. Rezultati okularnih aberacija višeg reda za grupe 1 i 2 su pokazali statistički neznačajnu promjenu poslijeoperacijskih u odnosu na prijeoperacijske vrijednosti, dok su se u grupama 3 i 4 sferne aberacije promijenile. Vektorska analiza Thibosovom metodom je pokazala statistički značajnu razliku između prijeoperacijskog J0 i poslijeoperacijskog J0 za obje platforme (p<0.001). Za vektor J45 se pokazala statistički značajna poslijeoperacijska razlika između platformi (p=0.012). Međusobna povezanost između ΔJ0 i prijeoperacijskih J0 vrijednosti (grupe 1 i 2) je pokazala da je razlika između ova dva koeficijenta povezanosti bila statistički značajna (z=−3.086, p=0.002). Postojala je statistički značajna razlika u prijeoperacijskim srednjim vrijednostima J0 (p<0.001) između grupa 3 i 4. Pokazala se i statistički značajna razlika između prijeoperacijskog J0 i poslijeoperacijskog J0 za obje platforme (p<0.001). Međusobna povezanost između ΔJ0 i prijeoperacijskog J0 te ΔJ45 i prijeoperacijskog J45 za grupe 3 i 4 je dokazala da je razlika između ovih koeficijenata povezanosti bila značajna (z=−3.533, p=0.0004; z=−2.886, p=0.004). Vektorska analiza Alpinsovom metodom je pokazala da negativna SIA vrijednost (kirurški izazvani astigmatizam) (y1) je bila značajno povezana sa negativnom TIA vrijednosti (ciljani astigmatizam) (x1) i sinusom TIA osi (x2) na sljedeći način: [A] I, y1=0.829x1–0.403x2–0.325 (F=87.76, r=0.804, P<0.001, N=127); II, y1=0.891x1– 0.037x2–0.192 (F=240.06, r=0.901, P<0.001, N=119) i [B] I, y1=1.063x1+0.233x2+0.411 (F =990.99, r=0.881, P<0.001, N=61); II, y1=1.029x1– 0.115x2+0.322 (F=270.12, r=0.908, P<0.001, N=111). Sinus negativne SIA osi (y2) je bio značajno povezan sa negativnom TIA vrijednosti (x1) i TIA osi (x2) što pokazuje sljedeće: [A] I, y2=0.951x2– 0.007x1+0.008 (F =446.58, r=0.950, P<0.001, N=127); II, y2 = 0.856x2+0.007x1+0.105 (F=277.18, r=0.912, p<0.001, N=119) and [B] I, y2=0.953x2+0.009x1+0.075 (F=362.6, r=0.963, p<0.001, n=61); II, y2=0.977x2–0.004x1+0.002 (F =2910.9, r=0.990, p<0.001, n=111). ----- ZAKLJUČAK: Oba lasera su se pokazala učinkovitim po pitanju nekorigirane (UDVA) i korigirane vidne oštrine na daljinu (CDVA), sferne korekcije i očuvanja aberacija višeg reda. Međutim, Amaris se pokazao učinkovitiji u korekciji cilindara. Nije bilo značajne poslijeoperacijske razlike između grupa korigiranih na dvije različite laser platforme po pitanju vektorske analize po Thibosu. Koristeći Alpinsovu metodu otkrili smo da su se obje platforme ponašale slično hipokorigirajući astigmatizam; bile su očite osne rotacijske pogreške, iako su se u cjelini obje platforme razlikovale po pitanju smjera; a predviđeni kut između SIA i TIA bio je sklon povećanju kada je astigmatska korekcija bila “protiv pravila”.

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