RESUMO
AIM: To compare the effective optical zone(EOZ)and corneal high order aberrations(HOAs)after small incision lenticule extraction(SMILE)among low, moderate, and high myopic patients.METHODS:A total of 134 patients who had undergone SMILE at the Second People's Hospital of Foshan from February 2019 to February 2021 were recruited, with all right eyes enrolled. The patients were divided into low myopia group(SE >-3.00 D), moderate myopia group(-6.00 D< SE ≤-3.00 D), and high myopia group(SE ≤-6.00 D)according to the spherical equivalent(SE). The total HOA(tHOA), spherical aberration, coma, and EOZ were measured by Pentacam preoperatively and 1 mo postoperatively, and differences in tHOA, spherical aberration, coma, and EOZ among the three groups were analyzed.RESULTS: EOZ was smaller than programmed EOZ in all groups at 1 mo after SMILE. With the increase in corrected refractive error, the EOZ decreased further(P<0.05); The tHOA, spherical aberration, and coma were significantly higher than their corresponding preoperative values in all groups at 1 mo after surgery, and there were statistical differences in the spherical aberration of all the groups at 1 mo after surgery(P<0.05), except for that of the mild myopia group(P>0.05). The tHOA, spherical aberration and coma increased with corrected refractive errors; the difference in tHOA and spherical aberration was statistically significant among the three groups(all P<0.05). Coma in the high myopia group was significantly greater than that in the moderate myopia group and the mild myopia group(P<0.05). In addition, the coma in the moderate myopia group and the mild myopia group was not statistically significant(P>0.05).CONCLUSION: With the increase of the refractive power corrected by surgery, the postoperative EOZ reduced more after surgery, and the HOA of the cornea is increased; corneal HOA increases at 1 mo after SMILE.
RESUMO
AIM: To investigate the effect of different preoperative corneal curvature on the size of optical deformation area after femtosecond laser small incision lens extraction(SMILE).METHODS:A prospective study was conducted on 108 consecutive patients who underwent SMILE surgery in our hospital from February 2021 to January 2022. Considering the association between both eyes, only the left eye of each patient was studied. According to the average anterior corneal surface curvature in preoperative, the patients were divided into three groups: Km<42.0D group(n=30), Km>47.0D group(n=26)and conventional corneal curvature group(n=52)with 42.0D≤Km≤47.0D. All patients underwent standardized SMILE surgery, and the laser ablation diameter was 6.5mm. The diameters of optical deformation areas in the three groups were compared at 6mo after operation.RESULTS:There was no significant difference in preoperative data among the three groups except for the mean curvature of the anterior corneal surface(all P>0.05), and there was no significant difference in uncorrected distance visual acuity(UDVA)and subjective refraction at 6mo after operation(all P>0.05). The diameters of the optical deformation zone in the Km<42.0D group, Km>47.0D group and the conventional corneal curvature group were 6.54±0.14, 6.32±0.13, 6.45±0.15mm respectively(F=19.238, P<0.05). The optical area diameter of the group with flat corneal curvature was larger than that of the group with conventional corneal curvature and the group with steeper corneal curvature(P<0.05). The diameter of optical zone in the conventional curvature group was larger than that in the Km>47.0D group(P<0.05).CONCLUSION: When the preset laser cutting diameter is the same, the steeper the corneal curvature before operation, the smaller the diameter of the optical deformation area after operation.