Posters

Laser-assisted in situ keratomileusis (LASIK): results in high astigmatism

Poster Details

First Author: M.Anticic CROATIA

Co Author(s):    M. Bohac   N. Gabric           

Abstract Details

Purpose:

To evaluate efficacy, safety, visual and refractive outcomes of LASIK in eyes with high myopic and mixed astigmatism (>2.0D).

Setting:

Special Eye Hospital Svjetlost, Zagreb, Croatia; School of Medicine University of Rijeka, Rijeka, Croatia

Methods:

Prospective consecutive observational nonrandomized case series on 230 eyes (127 patients) with myopic and mixed astigmatism between 2 and 7 diopters (D). There were 119 eyes (64 patients) with myopic astigmatism, and 111 eyes (63 patients) with mixed astigmatism. Aspheric ablation profile was used for excimer laser ablation on the Schwind Amaris 750S system. Ablation was centered on corneal vertex. Moria M2 mechanical microkeratome (90 µm head) was used for flap creation. Preoperative examination and postoperative follow up included measurements of sphere and cylinder refraction, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA) and aberrometry. The postoperative results at 1 year were compared to baseline values. For statistical analysis z test and Pearson correlation were used.

Results:

In myopic astigmatism group there were 36 men (56%) and 28 women (44%), average age (years±SD) of the patients was 32.41±6.9. In mixed astigmatism group there were 35 men (56%) and 28 women (44%), average age of the patients was 34.1±6.8 (range 20-59). In both groups postoperative UDVA showed improvement in comparison to preoperative CDVA, however the difference was not significant (p=0,06 in myopic group and p= 0,1153). In myopic astigmatism group average sphere decreased from -2,44±2,17D (-7,50 to 0,00) to -0,16±0,56D (-2,00 to +1,25), and average cylinder decreased from -3,21±0,87 (-6,50 to -2,00) to -0,43±0,36 (-1,50 to 0,00). In mixed astigmatism group average sphere decreased from +3,11±1,57 (+0,50 to +7,50) to +0,28±0,45 (-0,75 to +1,00), and average cylinder decreased from -3,66±1,16 (-7,00 to -2,00) to -0,58±0,38 (-1,50 to 0,00). Persons correlation revealed tendency toward undercorrection in both groups when comparing the attempted cylindrical correction with the postoperative cylinder (r=0.4701, p<0.01, n =119 for myopic and r=0.3257, p<0.01, n=111 for mixed astigmatism). Mean spherical aberration shifted from positive to negative values in mixed astigmatism (p<0.05). No other significant changes in higher order aberrations were observed on 5mm pupil (p>0,05). No eyes lost any line of CDVA. No complications were observed.

Conclusions:

LASIK in high astigmatism showed high safety, however tendency toward undercorrection was observed. FINANCIAL INTEREST: NONE FINANCIAL INTEREST: NONE