[Comparison of the visual quality at 1 year following femtosecond laser-assisted LASIK, wavefront-guided femtosecond LASIK and small incision lenticule extraction for myopia and astigmatism]

Association between Fundus Tessellation and Contrast Sensitivity in Myopic Eyes

PURPOSE

To assess the association of fundus tessellation with contrast sensitivity, Quality of Vision questionnaire, and other factors at five years postcorneal refractive surgery.

METHODS

This is a cross-sectional study. Both eyes of 98 subjects (196 eyes) who received femtosecond laser in situ keratomileusis (FS-LASIK) or small incision lenticular extraction (SMILE) five years prior were enrolled in this study. Fundus tessellation was imaged using wide-angle fundus photographs and graded into four categories with the assistance of the ETDRS grid. Photopic and mesopic contrast sensitivity were measured under the best correction. The Quality of Vision (QoV) questionnaire was used to assess visual symptoms.

RESULTS

Fundus tessellation was classified as follows: 19 eyes were grade 0 (9.7%), 28 eyes were grade 1 (14.3%), 59 eyes were grade 2 (30.1%), and 90 eyes were grade 3 (45.9%). Higher degrees of fundus tessellation were associated with lower photopic contrast sensitivity, a significant difference was observed at spatial frequencies of 6cpd (p = 0.030, grade 1 >grade 3 p = 0.011). Higher degrees of fundus tessellation were also associated with lower mesopic contrast sensitivity, a significant difference was observed at spatial frequencies of 18cpd (p = 0.011, grade 0 >grade 3 p = 0.012). The preoperative degree of myopia was positively associated with fundus tessellation grade (p < 0.001). However, in linear mixed-effect model analysis, no significant influence of parameters (contrast sensitivity, preoperative myopia, and QoV scores) upon different tessellation grades was found (p > 0.05).

CONCLUSIONS

Patients with moderate and high myopia were more likely to have higher grades of fundus tessellation. Higher degree of fundus tessellation associates with lower contrast sensitivity. Patients with moderate and high myopia should be concerned with retinal-choroidal changes. Contrast sensitivity could be a clinical sign for progression of tessellation and used to screen for early retinal-choroidal changes to prevent pathologic myopia.

Comparison of correcting myopia and astigmatism with SMILE or FS-LASIK and postoperative higher-order aberrations

AIM

To compare the effect of myopia and astigmatism correction and postoperative change in higher-order aberration as results of receiving small-incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK).

METHODS

A prospective and non-randomized controlled study was conducted. The subjects are divided into two groups according to different operations received: 229 eyes of 116 patients in the SMILE group and 168 eyes of 86 patients in the FS-LASIK group. All subjects were followed up for 3mo by monitoring their uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical equivalent, higher-order aberrations, and the preoperative and postoperative complications.

RESULTS

At 1wk, 1, and 3mo post-surgery, 224 eyes (97.8%), 227 eyes (99.1%) and 229 eyes (100%) had UCVA≥20/20 in the SMILE group, while 165 eyes (98.2%), 167 eyes (99.4%) and 167 eyes (99.4%) had UCVA≥20/20 in the FS-LASIK group, respectively (χ ²=0.146, 2.135, and 1.124; all P>0.05). BCVA reduction was not observed in both groups at 1 and 3mo of post-surgery (χ ²=0.734 and 1.898, P>0.05). There was no statistically significant difference in the spherical equivalent between the two groups at 1 and 3mo post-surgery, though the percentage of the spherical equivalent within ±0.50 D at 3mo post-surgery was 98% in the SMILE group, which was higher than that of the FS-LASIK group (92%, χ ²=1.872, P>0.05). The root mean square (RMS) values of total high-order aberration, coma, and spherical aberration of the two groups increased significantly in the early postoperative period and decreased after 3mo, but the values were still higher than the preoperative levels (P<0.05); there was no significant difference between the two groups in the RMS values of total higher-order aberrations and specific higher-order aberrations (P>0.05). The incidence of complications in the SMILE group was lower than that in the FS-LASIK group (χ ²=14.52, P<0.05).

CONCLUSION

SMILE and FS-LASIK can effectively treat myopia, significantly improve visual acuity, and increase the total high-order aberration, spherical aberration, and coma. The incidence of complications after SMILE is relatively low.