Rainbow halos occur less following implantation of extended range of vision one-piece intraocular lenses vs diffractive bifocal intraocular lenses

AIM:To evaluate clinical outcomes following implantation of an extended range of vision intraocular lens(IOL),the ZXR00,and a diffractive multifocal IOL with+2.75 diopters(D)add power,the ZKB00.METHODS:Totally 30 patients who underwent either bilateral implantation of the ZXR00 IOL with intended emmetropia(ZXR00 emmetropia group:20 eyes)and intended micromonovision(ZXR00 monovision group:20 eyes),or bilateral implantation of the ZKB00 IOL with intended emmetropia(ZKB00 group:20 eyes)were included in this study.Visual acuity at 4 m,80,and 40 cm;and the types of halos(misty,fine,and rainbow)were analyzed at one and three months after surgery.RESULTS:There were no significant differences in distance visual acuity among the three groups.The mean uncorrected intermediate visual acuity was better in the ZXR00 emmetropia and monovision groups(0.02 logMAR and 0.02 logMAR,respectively)than in the ZKB00 group(0.14 logMAR).The mean uncorrected near visual acuity was worse in the ZXR00 emmetropia group(0.26 logMAR)than in the ZXR00 monovision and ZKB00 groups(0.12 logMAR and 0.10 logMAR,respectively).There was an increased incidence of rainbow halos in the ZKB00 group vs in either ZXR00 group(P=0.033).CONCLUSION:Implantation of the ZXR00 IOL with intended micromonovision provide superior visual acuity than implantation of the ZXR00 IOL with intended emmetropia.The ZXR00 IOLs tend to show a lower incidence of rainbow halos than did the ZKB00 IOL.

Visual outcomes after three different surgical procedures for correction of refractive error in patients with thin corneas

AIM:To investigate and compare the visual and refractive outcomes of small incision lenticule extraction(SMILE),laser assisted sub-epithelial keratomileusis(LASEK),and LASEK combined with corneal collagen cross-linking(LASEKCXL)surgery in patients with less than 500μm of central corneal thickness(CCT).METHODS:The retrospective medical records review was conducted on the patients with CCT less than 500μm treated with SMILE,LASEK,and LASEK-CXL.There was a total of 172 eyes,76 eyes were in the SMILE group,53 eyes in the LASEK group,and 43 eyes in the LASEK-CXL group.Uncorrected distance visual acuity(UDVA),spherical equivalent refraction(SE),and corneal haze were followed up in the three groups for 12 mo.RESULTS:At 12 mo postoperatively,there were no statistically significant differences in UDVA and in the absolute value of SE between the three groups.The predictability within±0.50 D in the SMILE group(85.5%)was significantly higher than in both the LASEK group(64.2%,P<0.01)and the LASEK-CXL group(69.8%,P=0.04).The efficacy index and safety index were not significantly different among the three groups.Corneal haze at 12 mo postoperatively was higher in the LASEK-CXL group(27.9%)than in the SMILE group(2.6%,P<0.01)and in the LASEK group(7.5%,P<0.01).CONCLUSION:In patients with CCT less than 500μm,SMILE,LASEK,and LASEK-CXL appear to be effective for myopic correction.Among them,SMILE surgery shows the highest predictability.

Simple method of measuring ocular rotation in supine position during small incision lenticule extraction

AIM:To introduce a novel measurement method of static cyclotorsion in small incision lenticule extraction(SMILE)and to investigate the effect of preoperative parameters on cyclotorsion and the effect of cyclotorsion on postoperative outcomes.METHODS:The medical records of 242 patients and 484 eyes who under went SMILE surger y were retrospectively reviewed.Preoperative intraocular pressure,refractive error,and corneal thickness were investigated.Refractive values and visual acuity were measured at 1d,1,3,and 6mo.Ocular cyclotorsion in the supine position was measured by calculating the location and angle of the incision site of the cornea in the anterior slit photograph taken after surgery.RESULTS:Of the total 484 eyes in 242 patients,preopera tive means phericale quivalent(SE)was-4.10±1.64 D,and the mean astigmatism was-0.82±0.74 D.Uncorrected distance visual acuity(UCVA)and SE improved significantly after the surgery.Moreover,219(45.2%)eyes had excyclotorsion,235(48.6%)eyes had incyclotorsion,and 30(6.2%)eyes had no torsion.The right eyes tended to be excyclotorted,and the left eyes tended to be incyclotorted(P<0.01).The mean cyclotorsion was 1.18°±3.69°,and the mean absolute value of cyclotorsion was 3.14°±2.26°.The range of cyclotorsion was 0.5°–11.4°.It was found that the smaller the preoperative sphere,the higher the amount of cyclotorsion(r=0.11,P=0.016).There was no significant association between the amount of cyclotorsion and preoperative astigmatism.There was no correlation between sex,preoperative corneal thickness,preoperative intraocular pressure,amount of cyclotorsion,and direction of cyclotorsion.The ratio of right eye excyclotorsion and left eye incyclotorsion on 1d was higher than that at 1,3,and 6mo(all P<0.01).There was no difference between the 1,3,and 6mo results in the right and left eyes(P=0.15,P=0.16,respectively).CONCLUSION:The newly devised ocular cyclotorsion measurement method can be used to evaluate ocular cyclotorsion after SMILE.Preoperative SE is associated with the amount of cyclotorsion,however,cyclotorsion doesn't have a significant effect on the results of SMILE surgery.

Effect of transcranial direct current stimulation on supernumerary phantom limb pain in spinal cord injured patient:A case report

BACKGROUND Supernumerary phantom limb(SPL)sensation is the experience of additional limbs,either single or a pair of limbs.Unique to traumatic spinal cord injuries,we report effect of transcranial direct current stimulation(tDCS)on SPL pain in a patient with cervical cord injury.CASE SUMMARY The subject was a 57-year-old man who was diagnosed with complete spinal cord injury(C6/C5,motor level;C5/C5,sensory level;AIS-A)approximately three months ago.After a period of 2 wk,we administered anodal tDCS over the motor cortex for 15 minutes at an intensity of 1.5 mA.Following that treatment,the patient experienced a decrease of SPL pain intensity and frequency,which lasted for 1 week after the end of treatment.CONCLUSION Targeting the motor cortex through neuromodulation appears to be a promising option for the management of SPL pain.

Study for the Gas Flow through a Critical Nozzle

In the present study, computational work using the axisymmetric, compressible, Navier-Stokes equations is carded out to predict the discharge coefficient and critical pressure ratio of gas flow through a critical nozzle. The Reynolds number effects are investigated with several nozzles with different throat diameter. Diffuser angle is varied to investigate the effects on the discharge coefficient and critical pressure ratio. The computational results are compared with the previous experimental ones. It is known that the discharge coefficient and critical pressure ratio are given by functions of the Reynolds number and boundary layer integral properties. It is also found that diffuser angle affects the critical pressure ratio.