Peng Ji

AIM: To investigate the changes in corneal densitometry (CD) after small incision lenticule extraction combined with accelerated corneal cross-linking (SMILE Xtra) for correcting moderate to high myopia and to analyze their correlation. METHODS: In this non-randomized retrospective comparative study, participants who underwent surgery were enrolled in the standalone SMILE group and SMILE Xtra group, respectively. Preoperative and postoperative uncorrected visual acuity, spherical equivalent (SE), and CD values were recorded at 1, 3, 6, and 12mo. Measurements were taken in the central (0–2 mm), paracentral (2–6 mm), and peripheral (6–10 mm) zones, as well as in the anterior 120 μm, central, and posterior 60 μm layers of the cornea. A generalized linear mixed model (GLMM) was used to compare CD values between groups and at different time points, and the correlation between postoperative CD values and residual bed thickness (RBT) was analyzed. RESULTS: Totally 31 participants (62 eyes, mean age 20.32±2.76y) were in the standalone SMILE group and 28 participants (53 eyes, mean age 20.45±2.08y) in SMILE Xtra group. At 12mo postoperatively, there were no statistically significant differences in uncorrected visual acuity or SE between the two groups (P>0.05). Preoperative CD values in all regions showed no significant differences between groups (all P>0.05). In the central (0–2 mm) and paracentral (2–6 mm) zones, and the anterior, central, and total stromal layers, group, time, and interaction effects were all significant (all P<0.001). At 1, 3, and 6mo postoperatively, CD values in the SMILE Xtra group were significantly higher than those in the SMILE group within the 0–2 mm and 2–6 mm diameter ranges, as well as in the anterior, central, and total layers (all P0.05). Correlation analysis revealed that at 12mo postoperatively, CD values in all regions of both groups showed a significant positive correlation with RBT (all P<0.05), except for the anterior layer in the SMILE group, which showed no significant correlation with RBT (r=0.114, P=0.380). CONCLUSION: SMILE Xtra induces transient early increase in CD, primarily in the anterior and central layers. Although values stabilize or decline by 12mo postoperatively, the clinical significance of these long-term patterns requires cautious interpretation, considering the potential influence of post-surgical structural changes. Further research is necessary to fully elucidate the underlying contributions to these densitometric changes.

The aim is to evaluate the agreement and accuracy of refraction using a binocular wavefront optometer with the autorefractor and phoropter. To do this, 1 month after corneal refractive surgery, the right eyes of 125 subjects were enrolled in this cross-sectional study. Objective and subjective refractions were measured using a binocular wavefront optometer, an autorefractor, and a phoropter in a noncycloplegic condition. The differences and agreement of refractive data were analyzed using the Wilcoxon signed-rank test and Bland-Altman plots. The differences between sphere (Z=-0.872, p=0.38), J0 (Z=-0.065, p=0.95), J45 (Z=-1.199, p=0.23), and SE (Z=-1.316, p=0.19), objectively detected by binocular wavefront optometer and autorefractor, were not statistically significant. The differences between J0 (Z=-0.533, p=0.59), J45 (Z=-0.724, p=0.47), and SE (Z=-0.933, p=0.35), subjectively detected by binocular wavefront optometer and phoropter, were not statistically significant, whereas sphere (Z=-3.699, p<0.0001) had statistically significant differences. The Bland-Altman plots showed agreement between binocular wavefront optometer objective refraction and autorefractor in sphere (95% LoA: -1.00 D to 0.89 D), J0 (95% LoA: -0.47 D to 0.47 D), J45 (95% LoA: -0.55 D to 0.58 D), and SE (95% LoA: -0.89 D to 0.96 D). The Bland-Altman plots also showed agreement between binocular wavefront optometer subjective refraction and phoropter in sphere (95% LoA: -0.59 D to 0.82 D), J0 (95% LoA: -0.47 D to 0.43 D), J45 (95% LoA: -0.47 D to 0.43 D), and SE (95% LoA: -0.66 D to 0.74 D). Conclusively, the binocular wavefront optometer is an effective instrument, demonstrating good agreement between its objective and subjective refraction results and those obtained from autorefractor and phoropter, its smaller refractive intervals presenting a high accuracy in refractive error detection.

The aim is to evaluate the agreement and accuracy of refraction using a binocular wavefront optometer with the autorefractor and phoropter. To do this, 1 month after corneal refractive surgery, the right eyes of 125 subjects were enrolled in this cross-sectional study. Objective and subjective refractions were measured using a binocular wavefront optometer, an autorefractor, and a phoropter in a noncycloplegic condition. The differences and agreement of refractive data were analyzed using the Wilcoxon signed-rank test and Bland-Altman plots. The differences between sphere (Z=-0.872, p=0.38), J0 (Z=-0.065, p=0.95), J45 (Z=-1.199, p=0.23), and SE (Z=-1.316, p=0.19), objectively detected by binocular wavefront optometer and autorefractor, were not statistically significant. The differences between J0 (Z=-0.533, p=0.59), J45 (Z=-0.724, p=0.47), and SE (Z=-0.933, p=0.35), subjectively detected by binocular wavefront optometer and phoropter, were not statistically significant, whereas sphere (Z=-3.699, p<0.0001) had statistically significant differences. The Bland-Altman plots showed agreement between binocular wavefront optometer objective refraction and autorefractor in sphere (95% LoA: -1.00 D to 0.89 D), J0 (95% LoA: -0.47 D to 0.47 D), J45 (95% LoA: -0.55 D to 0.58 D), and SE (95% LoA: -0.89 D to 0.96 D). The Bland-Altman plots also showed agreement between binocular wavefront optometer subjective refraction and phoropter in sphere (95% LoA: -0.59 D to 0.82 D), J0 (95% LoA: -0.47 D to 0.43 D), J45 (95% LoA: -0.47 D to 0.43 D), and SE (95% LoA: -0.66 D to 0.74 D). Conclusively, the binocular wavefront optometer is an effective instrument, demonstrating good agreement between its objective and subjective refraction results and those obtained from autorefractor and phoropter, its smaller refractive intervals presenting a high accuracy in refractive error detection.

The study aims to evaluate visual acuity and objective visual quality before and after the monocular bi-aspheric ablation profile for correction of ... Jove

AIM: To observe the effects of femtosecond laser-assisted excimer laser in situ keratomileusis combined with accelerated corneal cross-linking (FS-LASIK Xtra) on corneal densitometry after correcting for high myopia. METHODS: In this prospectively study, 130 patients underwent FS-LASIK or FS-LASIK Xtra for high myopia. Their right eyes were selected for inclusion in the study, of which 65 cases of 65 eyes in the FS-LASIK group, 65 patients with 65 eyes in the FS-LASIK Xtra group. Patients were evaluated for corneal densitometry at 1, 3, and 6mo postoperatively using Pentacam Scheimpflug imaging. RESULTS: Preoperative differences in corneal densitometry between the FS-LASIK and FS-LASIK Xtra groups in different ranges were not statistically significant (P>0.05). Layer-by-layer analysis revealed statistically significant differences in the anterior (120 μm), central, and total layer corneal densitometry between the FS-LASIK and FS-LASIK Xtra groups at 1 and 3mo postoperatively (all P<0.05), the FS-LASIK Xtra group is higher than that of the FS-LASIK group. Analysis of different diameter ranges showed statistically significant differences between the FS-LASIK group and the FS-LASIK Xtra group at 1mo postoperatively in the ranges of 0–2, 2–6, and 6–10 mm (both P<0.05); At 3mo postoperatively, the FS-LASIK Xtra group is higher than that of the FS-LASIK group in the ranges of 0–2 and 2–6 mm (P0.05). CONCLUSION: There is an increase in internal corneal densitometry during the early postoperative period after FS-LASIK Xtra for correction of high myopia. However, the densitometry values decreased to the level of conventional FS-LASIK at 6mo after surgery, with the most significant changes observed in the superficial central zone.