Short Term Changes in Anterior Segment and Retina After Small Incision Lenticule Extraction

Abstract

Purpose: To analyze changes of the anterior segment and retina after small incision lenticule extraction (SMILE) in the short term.Methods: Myopia patients scheduled for SMILE were recruited in Ruijin Hospital, Shanghai, China. Basic information of patients such as age, gender, and refractive errors was recorded. Ocular measurements were taken before surgery, 1 day and 1 week after surgery, including axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), white to white (WTW), pupil diameter (PD), macular thickness (MT), ganglion cell layer thickness (GCL), retinal nerve fiber layer thickness (RNFL), choroidal thickness (CT), macular vessel density, optic disc vessel density. Results of postoperative were compared to baseline, respectively, with paired student t test, and the results were considered statistically significant when p<0.05. Correlations between sphere and changes of ACD (𝜟ACD) and LT (𝜟LT) were analyzed with the Pearson correlation coefficient.Results: 61 eyes of 31 patients were selected for this study. AL, CCT, ACD, and PD postoperative were significantly reduced (p<0.05), while LT was thickened after surgery (p<0.05). MT at the fovea decreased on 1 day and 1 week after surgery (p<0.05). GCL was no statistical changes after surgery. RNFL was unchanged 1 day after surgery, but the inferior sector was thickened 1 week after surgery. CT was observed thicker at fovea 1 day after surgery and 1.0mm from the fovea in nasal 1 week after surgery. Macular vessel density was significantly decreased on 1 day after surgery and most recovered in 1 week. Optic disc vessel density decreased at the peripapillary part on 1 day after surgery and recovered in 1 week. 𝜟ACD and 𝜟LT were found no significant correlation on 1 day after surgery. 𝜟ACD was negatively correlated with 𝜟LT and sphere on 1 week after surgery (r=-0.847, p<0.000; r=-0.398, p=0.002). 𝜟LT was positively correlated with the sphere on 1 week after surgery (r=0.256, p=0.048).Conclusion: Anterior segment was the most influenced while the retina was also impacted in MT, RNFL, CT, macular vessel density, and peripapillary vessel density.

Changes in Anterior Chamber Dimensions Following Small Incision Lenticule Extraction (SMILE)

“…In this study, CCT, and ACD signi cantly decreased at postoperative 6-month, similar to previous studies with other tomography systems (p < 0.05 for both) [6,9,13]. In addition, we observed a signi cant decrease at HACD (p < 0.05), but no change at ICA (p = 0.54).…”

“…In our study, the population consisted almost exclusively by young patients, which might explain the difference. Chen et al found that despite the lack of correlation after 1 day, Δ-LT and Δ-ACD had a negative correlation following SMILE after 1 week [13]. However, this follow-up time is also shorter than ours, and this might have been a temporary outcome until the accommodative process adopts to the changes due to procedure.…”