Intraocular scatter introduced by refractive surgery may induce high-order aberrations

Purpose： To investigate whether intraocular scatter introduced by refractive surgery will induce high-order aberrations (HOAs). Method： Intraocular scatter and HOAs (measured at a pupil diameter of 5mm) of 130 myopic eyes (67 patients) were analyzed and compared before surgery and at 1 week, 6 and 12 months after surgery, while 40 normal eyes were set as a control group. Autocorrelation analysis of intraocular scatter and HOAs were performed to confirm the variation trend of ocular scatter and HOAs, respectively. The causal relationship (based on eight criteria: temporal order, strength of association, correlation, exclusion of other explanations, reproducibility, evidence from experimental studies, biological plausibility, and specificity) between intraocular scatter changes and HOAs was analyzed. Result： Intraocular scatter significantly increased during the refractive surgery and then gradually decreased. HOAs decrease slightly during the refractive surgery, and then gradually increased. The results about the causal relationship analysis: (1) There was a significant correlation between the changes of intraocular scatter during refractive surgery and the HOAs at 6 months after refractive surgery (correspond to the temporal order and correlation). (2) The correlations were also found between the changes of intraocular scatter at 6 months after refractive surgery and HOAs at 12 months after refractive surgery (correspond to the reproducibility). (3) The strong correlation within the experimental group did not exist in the control group (correspond to the exclusion of other explanations). (4) The proportion of individuals in the experimental and control groups who match the conclusions drawn from the analysis was calculated and used to calculate relative ratio (RR) of 4.769 (99.0% CI: 1.790~12.706). The z-test (z=4.106, p=0.000) indicates a high strength of causal association, and the proportion of matches in the experimental group is 4.769 times that of the control group. (5) The data collected in this study were based on clinical trials, which meet the requirements for evidence from experimental studies. Conclusions： Intraocular scatter introduced by refractive surgery would induce HOAs.