Risk factors of refractive regression after 1 year femtosecond laser assisted in situ keratomileusis correction of moderate and high myopia and its prediction model construction / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the risk factors of refractive regression after correction of moderate and high myopia by femtosecond laser assisted in situ keratomileusis(FS-LASIK)for 1 a, and construct prediction model.METHODS: A retrospective analysis was performed on the clinical data of 400 patients(800 eyes)with moderate and high myopia undergoing FS-LASIK correction in Xi'an Gaoxin Hospital from June 2017 to November 2018, and the patients were randomly divided into modeling group(n=300)and verification group(n=100)according to a ratio of 3:1. The modeling group was divided into regression group and non-regression group according to the occurrence of refractive regression at 1 a after surgery. The changes of corneal curvature and corneal thickness were observed. Logistic regression analysis was used to screen the risk factors of refractive regression in patients with moderate and high myopia at 1 a after FS-LASIK correction, and the prediction model was built based on the regression coefficient. Receiver operating curve(ROC)was used to evaluate model differentiation.RESULTS:Refractive regression occurred in 44 eyes of the modeling group and 15 eyes of the verification group at 1 a after surgery. The anterior corneal surface curvature in the modeling group was lower than that in the regression group at 6 and 12 mo after surgery(all P<0.05). The degree of corneal hyperplasia in the regression group was greater than that in the non-regression group at 1, 3, 6 and 12 mo after surgery(all P<0.05). The regression equation of the probability value of refractive regression in patients with moderate and high myopia corrected by FS-LASIK at 1 a after surgery is as follows:P=1/[1+e-(-5.989+0.127×age+2.019×preoperative diopter-0.022×preoperative central corneal thickness+0.043×depth of cutting-1.569×diameter of cutting optical region)], Hosmer-Lemeshow detected the goodness of fit of the regression equation(P=0.818). Internal verification using the modeling group data showed that the area under ROC curve was 0.890(95%CI: 0.843-0.937), the sensitivity was 81.82%, and the specificity was 84.71%. The area under ROC curve was 0.838(95%CI: 0.717-0.959), the sensitivity was 80.00%, and the specificity was 87.57%.CONCLUSIONS:The established risk model has good discriminating validity and can be used to identify the high-risk group of refractive regression at 1 a after FS-LASIK in patients with moderate and high myopia.

Observation on the efficacy of moderate and high myopia patients with vault greater than 1 000 μm after implantation of phakic posterior chamber implantable contact lens / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To observe the efficacy of moderate and high myopia patients with vault greater than 1 000μm after implantation of phakic posterior chamber implantable contact lens(ICL).METHODS: A total of 42 patients(73 eyes)who received ICL implantation in the hospital and had postoperative vault greater than 1 000 μm between January 2014 and January 2017 were selected and retrospectively studied. Changes in visual acuity, intraocular pressure, corneal endothelial cell density, anterior chamber-related parameters(chamber angle, central anterior chamber depth, anterior chamber volume)and vault were compared among patients before surgery, at 1, 3, 6mo and 1a after surgery and at the last follow-up.RESULTS: The uncorrected visual acuity(UCVA)at 1, 3, 6mo and 1a after surgery and at the last follow-up was better than that before surgery(all P<0.05), and the chamber angle, central anterior chamber depth and anterior chamber volume were smaller or lower than those before surgery(all P<0.05), but there were no statistical differences in UCVA, chamber angle, central anterior chamber depth and anterior chamber volume at each time point after surgery(all P>0.05). The intraocular pressure at 1mo after surgery was lower than that before surgery(P<0.05), but the intraocular pressure at 3, 6mo and 1a after surgery and at the last follow-up was not statistically different from that before surgery(all P>0.05). There was no statistical significance in the corneal endothelial cell density at 1, 3, 6mo and 1a after surgery and at the last follow-up compared with that before surgery(all P>0.05). The vault at 1, 3, 6mo and 1a after surgery and at the last follow-up showed a decreasing trend, and the difference was statistically significant at each time point after surgery(all P<0.05).CONCLUSION: The short-term and long-term efficacy are better in moderate and high myopia patients with vault greater than 1 000 μm after ICL implantation, and there are no significant effects on the intraocular pressure and corneal endothelial cell. The postoperative anterior chamber structure is relatively stable and the vault tends to decrease over time. In most cases, close observation is sufficient and intraocular lens replacement is generally not required.