To compare the safety, efficacy, predictability, stability and complications of wavefront-guided laser-assisted subepithelial keratectomy ( LASEK ) in low myopia, myopic astigmatism and high myopia correction.METHODS: A retrospective analysis of 416 eyes were assigned to 3 groups:159 eyes with low myopia ( LM) and mean refractive spherical equivalent (MRSE) of-3. 68±1. 33 dioptre ( D ); 161 eyes with myopic astigmatism ( MA ) and MRSE of -5. 99 ± 2. 24D and mean cylinder of 2. 41 ± 1. 07D;and 96 eyes with high myopia (HM) and MRSE of- 7. 41 ± 0. 80D. After an epithelial flap creation, a wavefront-based excimer laser ablation was performed. Safety, efficacy, predictability and stability were evaluated at day 10, 2, 6 and 12mo postoperatively.RESULTS:At 12mo, the MRSE was -0. 36 ± 0. 31D in LM group, 0. 15 ± 0. 41D in MA group and 0. 58 ± 0. 68D in HM group. The uncorrected visual acuity ( UCVA) was 20/20 in 90. 60% of patients in LM group, 78. 90% in MA group and 67% in HM group. Efficacy indices were 0. 98, 1. 04 and 0. 92 in LM, MA and HM groups, respectively. Safety indices were 1. 00, 1. 07 and 1. 05 in LM, MA and HM respectively. Five eyes (3. 1%) in the LM group gained 1 line. Forty-four eyes (27. 3%) in MA gained 1-3 lines and eighteen eyes (19. 2%) of HM group gained 1-2 lines of BSCVA. Only 2 eyes in LM group developed corneal haze. There were not statistically significant differences in efficacy and safety indices amongst three groups.CONCLUSlON:Wavefront-guided LASEK is an effective and safe procedure for the treatment of LM, MA, and HM. although in myopic astigmatism the predictability, efficacy and safety indices had been better.

Objective To evaluate the effect of propofol,sevoflurane,and dexmedetomidine on respiratory complications in children undergoing fiberoptic bronchoscopy(FOB).Methods This double-blind randomized clinical trial was conducted among 120 children aged 1 month to 3 years undergoing FOB.The patients were randomized into 3 groups(n=40)for anesthesia induction with sevoflurane inhalation,1 mg/kg propofol,or 1 μg/kg dexmedetomidine before bronchoscopy,and the changes in hemodynamic parameters,sedation level,and respiratory complications during and after the procedure were assessed.Results The patients'heart rate during bronchoscopy was significantly lower and the mean arterial blood pressure significantly higher in dexmedetomidine group than in sevoflurane and propofol groups(P<0.05).Cough during bronchoscopy did not occur in any of the cases in propofol group,while the highest frequency of cough was recorded in dexmedetomidine group.The incidence of laryngospasm in the propofol group(12.5%)was significantly lower than those in sevoflurane and dexmedetomidine groups(30%and 32.5%,respectively)(P<0.05).Conclusion Sevoflurane and propofol are safe and suitable for anesthesia induction in children below 3 years of age undergoing diagnostic FOB and can achieve better sedative effect and lower the incidences of cough and respiratory complications as compared with dexmedetomidine.

Objective To evaluate the effect of propofol,sevoflurane,and dexmedetomidine on respiratory complications in children undergoing fiberoptic bronchoscopy(FOB).Methods This double-blind randomized clinical trial was conducted among 120 children aged 1 month to 3 years undergoing FOB.The patients were randomized into 3 groups(n=40)for anesthesia induction with sevoflurane inhalation,1 mg/kg propofol,or 1 μg/kg dexmedetomidine before bronchoscopy,and the changes in hemodynamic parameters,sedation level,and respiratory complications during and after the procedure were assessed.Results The patients'heart rate during bronchoscopy was significantly lower and the mean arterial blood pressure significantly higher in dexmedetomidine group than in sevoflurane and propofol groups(P<0.05).Cough during bronchoscopy did not occur in any of the cases in propofol group,while the highest frequency of cough was recorded in dexmedetomidine group.The incidence of laryngospasm in the propofol group(12.5%)was significantly lower than those in sevoflurane and dexmedetomidine groups(30%and 32.5%,respectively)(P<0.05).Conclusion Sevoflurane and propofol are safe and suitable for anesthesia induction in children below 3 years of age undergoing diagnostic FOB and can achieve better sedative effect and lower the incidences of cough and respiratory complications as compared with dexmedetomidine.