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AIM:To investigate the effect of small incision lenticule extraction(SMILE)on the treatment of myopia patients, and the impact on corneal biomechanics.METHODS:Retrospective study. A total of 120 myopic patients(240 eyes)who were scheduled to undergo corneal refractive surgery in Anyang Eye Hospital from January 2020 to December 2021 were selected. The patients were divided into SMILE group(64 patients, 128 eyes)and transepithelial photorefractive keratectomy(TransPRK)group(56 patients, 112 eyes)according to the surgical treatment method. The two groups were compared in terms of uncorrected visual acuity, corneal biomechanics, corneal endothelial cell count, posterior corneal surface height and corneal surface regularity index at 1, 7 d, 1, 3, 6 mo and 1 a after surgery, and surgical complications.RESULTS:The uncorrected visual acuity of the SMILE group at 1, 7 d and 1 mo after surgery was better than that of the TransPRK group(all P<0.001), but there was no statistically significant difference between the groups at 3, 6 mo and 1 a after surgery(all P>0.05). Compared with preoperative values, corneal-compensated intraocular pressure, Goldmann-correlated intraocular pressure, corneal resistance factor, and corneal hysteresis in both groups showed a first decreasing and then increasing trend after surgery. The corneal-compensated intraocular pressure, Goldmann-correlated intraocular pressure, corneal resistance factor, and corneal hysteresis in the SMILE group at 1, 7 d and 1 mo after surgery were higher than those in the TransPRK group(all P<0.05), but there was no statistically significant difference between the groups at 3, 6 mo and 1 a after surgery(all P>0.05). There were no significant changes of corneal endothelial cell count and corneal posterior surface height in the two groups after surgery(all P>0.05). Furthermore, corneal surface regularity index of the two groups showed a first increasing and then decreasing trend after surgery, with no statistically significant difference between the groups(P>0.05), and there was no statistically significant difference in the incidence of postoperative complications between the groups(P>0.05).CONCLUSION:Compared with TransPRK, SMILE has less influence on corneal biomechanics, and better visual recovery in the early stage. There is no difference in long-term visual acuity between the two surgeries, and both have good safety and effectiveness.
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AIM:To observe the changes in corneal aberrations and the characteristics of visual quality after transepithelial photorefractive keratectomy(T-PRK)and femtosecond small incision lenticule extraction(SMILE)in the correction of low myopia.METHODS: Prospective cohort study. A total of 32 cases(32 eyes)with low myopia who underwent T-PRK surgery and 45 cases(45 eyes)of SMILE surgery at Weifang Eye Hospital from April 2021 to April 2022 were selected. The uncorrected visual acuity(UCVA), best corrected visual acuity(BCVA), spherical equivalent(SE), corneal higher-order aberrations(HOAs)and objective visual quality were compared between the two groups.RESULTS:All patients completed the surgery successfully without complications such as infection. At 3mo postoperatively, the safety index was 1.13±0.16 and 1.16±0.17(P=0.48)and the efficacy index was 1.10±0.20 and 1.15±0.18(P=0.27)in the T-PRK and SMILE groups, respectively. The percentage of UCVA(LogMAR)≤0 in the T-PRK and SMILE groups was 94% and 98%, respectively. The percentage of the residual SE within ±0.5D was 88% and 87% in the two groups, respectively. The HOAs and spherical aberration in both groups were significantly increased(P≤0.01), and the increase was not statistically significant between the two groups(P=0.31, 0.89). There was no significant change in horizontal coma, horizontal trefoil and vertical trefoil in both groups(P&#x003E;0.05). The vertical coma in SMILE group was significantly increased(P&#x003C;0.001), while there was no significant change in T-PRK group(P&#x003E;0.05), and the increase was significantly greater in SMILE group than in T-PRK group(P&#x003C;0.001). There was no significant difference in objective scattering index(OSI), modulation transfer function cut off frequency(MTFcut off), Strehl ratio(SR), visual acuity(VA)100%, VA20% and VA9% between the two groups(P&#x003E;0.05).CONCLUSION:Both T-PRK and SMILE showed good safety, efficacy, and visual quality in correcting low myopia, while SMILE induced more vertical coma than T-PRK.
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AIM: To compare the visual quality between smart pulse technology-assisted(SPT)transepithelial photorefractive keratectomy(TransPRK)of 1 050Hz ablation frequency and small incision lenticule extraction(SMILE)for myopia and astigmatism.METHODS: A total of 138 cases(248 eyes)who received corneal refractive surgery in the Eye Hospital of Chengdu University of TCM were enrolled from July 2020 to January 2021. The patients were divided into TransPRK group(64 cases, 123 eyes)and SMILE group(74 cases, 125 eyes)according to the surgical method. The follow-up duration was 6mo. Strehl ratio(SR)and high-order aberration at 6mm pupil diameter measured by Sirius anterior segment integrated analyzer and LogMAR visual acuity were recorded at different preoperative and postoperative time points.RESULTS: The uncorrected visual acuity(UCVA)of TransPRK group was worse than SMILE group at 1wk and 1mo after surgery(all P<0.05), but UCVA was better in TransPRK group at 6mo after surgery(P<0.05). SR in TransPRK group was lower than that in SMILE group at 1wk and 1mo after surgery(all P<0.05). There was no significant difference in SR between the two groups at 3 and 6mo after surgery(P=0.968, 0.433). At 1wk after surgery, there was no significant difference in coma between the two groups(P=0.554). At 1, 3, and 6mo after surgery, coma in the TransPRK group was lower than that in SMILE group(all P<0.05). At 1wk, 1 and 3mo after surgery, the trefoil aberration in TransPRK group was higher than that in SMILE group(all P<0.05). At 6mo after surgery, there was no significant difference in trefoil aberration between the two groups(P=0.167). At 6mo after surgery, UCVA of TransPRK group and SMILE group were -0.13±0.05 and -0.11±0.08, respectively, which were better than the best corrected visual acuity(BCVA)before surgery(-0.07±0.05 and -0.07±0.05; all P<0.05). Furthermore, the SR of both groups was higher than that before surgery(all P<0.05).CONCLUSION: Both SPT-assisted TransPRK of 1 050Hz ablation frequency and SMILE can achieve better visual acuity after refractive surgery, while SMILE has better visual quality at 1wk and 1mo after surgery. However, SPT-assisted TransPRK of 1 050Hz ablation frequency has better visual acuity at 6mo after surgery than SMILE, and the coma is smaller.
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AIM: To evaluate the effect of preoperative degrees of myopic astigmatism and anterior corneal curvature on the functional optical zone(FOZ)after transepithelial photorefractive keratectomy(TransPRK).METHODS: Retrospective study was conducted on 78 patients(130 eyes)with myopia and myopic astigmatism who underwent TransPRK, and they were divided into control group(cylinder 0D), moderate astigmatism group(-0.50～-2.00D)and high astigmatism group(>-2.00～<-6.00D). The FOZ was measured and compared among the three groups 6mo after operation. The correlations between attempted correction, anterior corneal curvature, corneal aberrations, Q value, and the FOZ were analyzed.RESULTS: At 6mo after operation, the mean FOZ was 5.16±0.12mm in the control group, 5.29±0.23mm in the moderate astigmatism group, and 5.49±0.23mm in the high astigmatism group(P<0.001), and the FOZ of the high astigmatism group was significantly higher than moderate astigmatism and control group(P<0.05, P<0.001); Pearson correlation analysis showed that the changes in spherical equivalent, total corneal higher-order aberrations(HOAs), coma, and spherical aberration were all negatively correlated with FOZ(all P<0.05); and FOZ positively correlated with changes in the steep curvature(K2), mean curvature(Km), corneal astigmatism, and Q value(all P<0.01). Multiple linear regression analysis showed that there was still positive correlation between preoperative K2 and FOZ after adjusting for other risk factors(P<0.001).CONCLUSION: Patients with high astigmatism can obtain a larger FOZ and less induced coma after TransPRK. A larger FOZ can be achieved in eyes with steeper keratometry.
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AIM: To evaluate the effect of 0.02% mitomycin-C(MMC)on the corneal density after transepithelial photorefractive keratectomy(Trans-PRK). METHODS: Retrospective case analysis. Selected 28 patients with 56 eyes in moderate myopia who underwent Trans-PRK surgery from January 2021 to June 2021 in our hospital. They were divided into MMC group in 28 eyes with a combination of 0.02% MMC 20s during the surgery and the control group in 28 eyes was not use MMC during the surgery. The Pentacam anterior segment analyzer was used to measured the corneal density in different diameter ranges and different thickness layers before and after surgery at 14d, and after surgery at 1 and 3mo.RESULTS: The total corneal density value of MMC group was 16.60(15.70,17.10 )before the surgery, after the surgery at 14d was 16.63(15.90,17.50 ), at 1mo was 16.57(15.10,16.70 ), at 3mo was 16.04(14.60,16.60 ). The total corneal density value of control group was 16.30(15.50,17.30 )before the surgery, after the surgery at 14d was 16.20(15.20,17.10 ), at 1mo was 16.08(14.90,16.40 )and at 3mo was 15.60(14.60,16.40 ). In the zone of 0-2mm diameter was centered on the corneal vertex, the corneal density of the two groups at 14d after the surgery was higher than those before surgery(P<0.001 ). In the zone of 2-6mm diameter, the corneal density of the two groups at 1mo and 3mo after surgery was higher than those before the surgery(P<0.001). In the zone of 6-10mm, the corneal density of the two groups at 14d, 1 and 3mo after surgery was higher than those before the surgery(P<0.001). In the layer of anterior 120 μm, the corneal density of the two groups at 1mo and 3mo after the surgery was decreased than that before surgery(P<0.01). In the middle layer, the corneal density of the two groups at 1mo after the surgery was decreased than those before surgery(P<0.01).CONCLUSION:The use of 0.02% MMC during the operation can reduce the corneal density and increase the corneal light transmittance in the early postoperative period. The occurrence and prognosis of haze can be effectively quantified by observing the changes of corneal optical density in different ranges in different time periods after operation.
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Objective:To evaluate the effectiveness and safety of transepithelial photorefractive keratectomy (TransPRK) assisted by smart pluse technology (SPT) for the correction of high myopia.Methods:An observational case series study was conducted.Sixty high myopic patients (107 eyes) with spherical equivalent (SE)≥-6.0 D who received TransPRK assisted by SPT from January to December 2016 in Eye Hospital of Wenzhou Medical University were enrolled.Uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) of the patients were examined and recorded in logarithm of the minimum angle of resolution (LogMAR) units, and refraction was examined with a subjective refractometer.The healing of corneal epithelium and corneal haze was observed with a slit lamp.Intraocular pressure (IOP) was measured with the non-contact tonometer.Safety index (SI) and efficacy index (EI) were analyzed.The follow-up time was 12 months.This study protocol adhered to the Declaration of Helsinki and was approved by an Ethics Committee of Eye Hospital of Wenzhou Medical University (No.2019-197-k-177). Written informed consent was obtained from each patient prior to any medical examination.Results:The mean epithelial healing time was (3.77±1.02) days.There were statistically significant differences in UCVA and BCVA between before and after surgery ( Z=380.812, 267.313; both at P<0.001). And the 7-day, 6-month, and 12-month postoperative BCVA were better than preoperative BCVA, showing statistically significant differences (all at P<0.05). Mean SI was 1.10±0.12, and mean EI was 1.05±0.17 at 12 months after surgery.There was no significant difference between the attempted SE before surgery (-8.02±1.36)D and the achieved SE at 12 months after surgery (-8.04±1.51)D ( P=0.523). SE in the predictive range within ±0.50 D accounted for 79% (85/107) and that within ±1.0 D accounted for 92% (98/107). The IOP was slightly increased in 3 eyes at 7 days and 7 eyes at 1 month after surgery, respectively, which returned to normal after the use of ophthalmic solution for lowing IOP.The incidence of haze severer than grade 1 was less than 1% (1 eye), and haze gradually disappeared after application of drugs. Conclusions:TransPRK assisted by SPT for high myopia shows good safety, effectiveness and predictability.It is an ideal corneal surface surgery to correct high myopia.
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Objective:To compare the changes of corneal asphericity and higher-order aberrations after smart pulse technology-assisted transepithelial photorefractive keratectomy (Smart) for low and moderate myopia and to investigate the changes in the shape of the front corneal surface in patients with different diopters.Methods:A non-randomized controlled study design was used.Ninety-eight eyes of 54 patients with moderate or low myopia who underwent Smart surgery in Tianjin Medical University Eye Hospital from November 2018 to March 2019 were included.The 41 eyes of 23 patients with low myopia were set as the low-myopia group, and 57 eyes of 31 patients with moderate myopia were assigned as the moderate-myopia group.The Pentacam anterior segment analysis system was used to measure Q value, index of surface variance (ISV), corneal higher-order aberration (HOA), corneal vertical coma (Z 3-1), corneal horizontal coma (Z 31) and spherical aberration (Z 40) before surgery, 1 month and 3 months after surgery.The anterior surface morphology was compared between the low-myopia and moderate-myopia group.Pearson correlation analysis was used to analyze the correlations between measurement parameters.The study protocol was approved by an Ethics Committee of Tianjin Medical University Eye Hospital (No.2019KY-17). Written informed consent was obtained from each patient before surgery. Results:Corneal Q value, ISV, HOA and Z 40 were 0.445±0.191, 26.973±5.611, 0.671±0.142 and 0.384±0.188, respectively, in the low-myopia group at one month after surgery, which were significantly increased than corresponding preoperative values of -0.273±0.817, 13.784±2.376, 0.433±0.687 and 0.231±0.062 (all at P<0.05). Corneal Q value, ISV, HOA and Z 40 were 0.693±0.203, 34.038±5.773, 0.874±0.216 and 0.520±0.129, respectively, in the moderate-myopia group at one month after surgery, which were significantly increased than corresponding preoperative values of -0.309±0.104, 14.838±3.992, 0.409±0.081 and 0.228±0.089 (all at P<0.05). Corneal Q values, ISV, HOA and Z 40 in the moderate-myopia group were higher than those in the low-myopia group at different time points after surgery, showing significant differences between the two groups (all at P<0.05). There was no significant difference in postoperative 1-month and 3-month corneal Z 3-1 and Z 31 between the two groups (both at P>0.05). The results of correlation analysis showed that there were no significant differences in ΔQ value and ΔISV between the two groups, both of which were negatively correlated with spherical equivalent (ΔQ value: low-myopia group: r=-0.364, P=0.044; moderate-myopia group: r=-0.589, P<0.01; ΔISV: low-myopia group: r=-0.298, P=0.039; moderate-myopia group: r=-0.409, P=0.022). ΔQ value and ΔZ 40 were positively correlated in the moderate-myopia group ( r=0.348, P=0.009); there was no significant correlation between ΔQ value and ΔZ 40 in the low-myopia group ( r=0.180, P=0.266). Conclusions:The corneal high-order aberrations and ISV after Smart are increased in comparison with preoperative values in the low-myopia and moderate-myopia eyes, and the corneal Q values change from negative to positive.The effect of Smart on corneal asphericity is less in the low-myopia eyes.
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@#AIM: To analyze changes in objective visual quality before and after femtosecond laser <i>in situ</i> keratomileusis(FS-LASIK)and smart pulse technology-assisted transepithelial photorefractive keratectomy(SMART).<p>METHODS: Prospective study. We collected 50 cases(100 eyes)treated with FS-LASIK(FS-LASIK group)and another 50 cases(100 eyes)treated with SMART(SMART group)from the Ophthalmology Department of our hospital between October 2018 and December 2018 using Optical Quality Analysis System(OQAS)to measure objective scatter index(OSI), modulation transfer function cut off frequency(MTF cut off), strehl ratio(SR)before and after surgery.<p>RESULTS: In the FS-LASIK and SMART groups, the OSI values were higher in the 1 and 3mo after surgery, whereas the MTF cut off and SR were lower in the 1 and 3mo after surgery(<i>P</i><0.05). There was no statistical difference between the two groups in the objective visual quality index before and after 1mo(<i>P</i>>0.05). However, after 3mo, the OSI value of the FS-LASIK group was higher than the SMART group(0.88±0.28 <i>vs</i> 0.70±0.27, <i>P</i><0.001), whereas the SR was lower than SMART group(0.21±0.05 <i>vs</i> 0.24±0.05, <i>P</i>=0.002).<p>CONCLUSION: Both FS-LASIK and SMART caused an increase in the intraocular scattering index and a decrease in objective visual quality. However, the visual quality of the SMART group was generally better than that of the FS-LASIK group, and long-term visual quality was more dominant.
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@#AIM: To observe the effect of transepithelial photorefractive ketatectomy(TPRK)on corneal curvature, asphericity and aberrations. <p>METHODS: Twenty-nine patients(58 eyes)were enrolled. The 1mm-8mm zone curvature, target curvature and 3mm ring curvature, corneal asphericity(Q value)and corneal aberration was measured and analyzed before and 6mo after TPRK surgery. <p>RESULTS: In the 1mm-8mm zone, the corneal curvature all had significant decrease after TPRK surgery. The curvature 3mm ring after operation was 39.20±1.99D, and the curvature target was 39.51±1.99D. And both values had a significant correlation(<i>r</i>=0.98). The Q values before and after operation were -0.44 to -0.30, 0.34-0.66 respectively <i>(P</i><0.05). The total high-order aberration, spherical aberration and vertical coma of cornea before and after operation were 0.41±0.10, 0.17±0.08, -0.07±0.23 and 0.72±0.23, 0.41±0.17, -0.24±0.32, respectively, and these differences were significant. The pre-and postoperative horizontal coma was -0.03±0.12, and -0.03±0.30 respectively(<i>P</i>>0.05).<p>CONCLUSION: After TPRK operation, corneal curvature decreased significantly, and the change in zone of 3mm was the largest. The Q value, total high-order aberration, spherical aberration and vertical coma increased significantly after TPRK operation.
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@#AIM: To evaluate the early postoperative efficacy of SMART for myopia and compare it with TransPRK.<p>METHODS: Retrospective non-randomized controlled study. Totally 120 eyes of 60 patients with myopia who underwent SMART and TransPRK in our hospital from January to August 2018 were selected respectively. The uncorrected visual acuity(UCVA), visual quality, pain score, corneal epithelial healing and subepithelial haze were compared between two groups.<p>RESULTS: There was no statistical differences between two groups regarding the proportion of UCVA reaching or exceeding 1.0 at 5d, 1mo and 3mo after operation(<i>P</i>>0.05), but the visual quality of SMART group was better than that of TransPRK group at 5d after operation(<i>P</i><0.05), and with the prolongation of time, the visual quality of the two groups gradually improved. There was a significant difference in pain scores between the TransPRK group and SMART group(3.56±0.96 <i>vs</i> 3.07±1.07; 1.22±0.61 <i>vs</i> 0.84±0.59)on the 1st day and 3rd day after operation(<i>P</i><0.01). 5d after operation, the complete recovery rate of corneal in TransPRK group was lower than that in SMART group(69.2% <i>vs</i> 83.3%, <i>P</i><0.05). At 1st and 3 mo after operation, there was no difference in haze between the two groups(5.0% <i>vs</i> 5.0% and 8.3% <i>vs</i> 10.0%; <i>P</i>>0.05).<p>CONCLUSION: There is no significant difference between SMART and TransPRK in the speed and stability of visual acuity recovery, but the early postoperative pain of SMART is lighter, the corneal epithelium is healed faster, and the visual quality is better.
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@#AIM: To observe the early clinical effects of smart pulse technology(SPT)-assisted transepithelial photorefractive keratectomy(TPRK).<p>METHODS: This was a retrospective non-randomized research. There were 260 patients(508 eyes)who were underwent SPT-assisted TPRK surgery. The best corrected visual acuity(BCVA)was recorded at 1 to 2wk before surgery. The uncorrected visual acuity(UCVA)was recorded at 1mo and 3mo after surgery. Corneal epithelial growth status and haze grade were recorded after surgery. Record the degree of pain within 3d after surgery and satisfaction surveys in all patients.<p>RESULTS: After 1mo and 3mo, UCVA(-0.080±0.0798, -0.108±0.089)achieved or even better than preoperative BCVA(-0.050±0.0561). Corneal epithelial wounds were completely repaired in all patients during 5d after operation. In the follow-up of 1mo and 3mo after operation, the corneas of most patients are clear except for 3 cases who had haze in 0-1 grade. Very satisfied patients accounted for 93.0%.<p>CONCLUSION: SPT-TPRK surgery is safe. The average postoperative UCVA can reach or even exceed the preoperative average BCVA.
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@#AIM:To compare dry eye symptoms and signs before and after three kinds surgery, femtosecond laser-assisted laser <i>in situ</i> keratomileusis(FS-LASIK), transepithelial photorefractive keratectomy(T-PRK), small incision lenticule extraction(SMILE)using ocular surface analyzer(Oculus Keratograph). <p>METHODS:Totally 98 patients(196 eyes)undergoing corneal refractive surgery from January 2017 to May 2017 were recruited. They were divided into three groups, namely, FS-LASIK group, T-PRK group and SMILE group. All patients underwent observation and assessment in the following order: ocular surface disease index(OSDI), tear meniscus height(TMH), measure using the infrared pattern of Oculus Keratograph. The first tear film break-up time(FBUT)and average tear break-up time(ABUT)measure using the infrared pattern of Oculus Keratograph, corneal fluorescein staining(FL), Schirmer Ⅰ test(SⅠt). <p>RESULTS:1)OSDI index: There was statistically significant difference between the three groups(<i>F</i><sub>groups</sub>=2.799, <i>P</i><sub>groups</sub><0.05). However, the difference in the OSDI values of different time points in each group was statistically significant(<i>F</i><sub>time</sub>=85.942, <i>P</i><sub>time</sub><0.001). The OSDI index were significantly increased at 1wk, 1 and 3mo after operation in each group. All groups recovered to the preoperative level at 6mo after operation. After 3mo, there was an inter-group difference in the OSDI values(<i>P</i>=0.019), and the OSDI values of the T-PRK group were higher than those of the other two groups. 2)TMH: There was statistically significant difference among the three groups postoperatively(<i>F</i><sub>groups</sub>=1.720, <i>P</i><sub>groups</sub><0.05). The TMH values of different time points in each group were significantly different(<i>F</i><sub>time</sub>=11.202, <i>P</i><sub>time</sub><0.001). The TMH values of each group were significantly reduced after 1wk and 1mo and were restored to preoperative levels after 3 and 6mo. After 3mo, there was a difference TMH among the three groups(<i>P</i>=0.004), and the inferior TMH in the SMILE group was higher than that of the other two groups. 3)FBUT: There was statistically significant difference among the three groups after surgery(<i>F</i><sub>groups</sub>=1.428, <i>P</i><sub>groups</sub>=0.245). The difference in FBUT values between different time points in each group was statistically significant(<i>F</i><sub>time</sub>=4.511, <i>P</i><sub>time</sub>=0.001). The FBUT values of each group were significantly reduced after 1wk and 1mo, and recovered to preoperative levels after 3mo and 6mo. There was no significant difference in FBUT between different groups at each time points(<i>P</i>>0.05). 4)ABUT: There was statistically significant difference in ABUT among the three groups after surgery(<i>F</i><sub>groups</sub>=1.290, <i>P</i><sub>groups</sub><0.05). However, the difference in ABUT values between different time points in each group was statistically significant(<i>F</i><sub>time</sub>=10.294, <i>P</i><sub>time</sub><0.001). The ABUT values of each group were significantly reduced after 1wk and 1mo, and recovered to preoperative levels after 3mo and 6mo. There was a statistical difference in ABUT values between different groups after 1mo(<i>P</i>=0.008); among them, the ABUT value of the SMILE group was higher than that of the T-PRK group and the FS-LASIK group. 5)FL: There was no statistical difference in the FL score between the three groups(<i>F</i><sub>groups</sub>=0.816, <i>P</i><sub>groups</sub>=0.445). The differences in the FL scores at different points in each group were statistically significant(<i>F</i><sub>time</sub>=5.539, <i>P</i><sub>time</sub>=0.004). The FL score of each group was significantly higher than before surgery at 1wk and 1mo, and recovered to preoperative levels at 3mo and 6mo after surgery. There was no statistical difference in the FLs between different groups at different points in time(<i>P</i>>0.05). 6)SⅠt: There was no statistically significant difference in SⅠt values among the three groups after surgery(<i>F</i><sub>groups</sub>=0.225, <i>P</i><sub>groups</sub>=0.799). The difference in SⅠt values between different time points in each group was statistically significant(<i>F</i><sub>time</sub>=4.604, <i>P</i><sub>time</sub>=0.003). The SⅠt values of each group were slightly higher than the preoperative values afyer 1wk and 3mo, but they were all within normal values. There was no significant difference between the SⅠt values of 1mo or 6mo after operation and the preoperative level. There was no statistical difference in SⅠt values between different groups at each points in time(<i>P</i>>0.05).<p>CONCLUSION:The three types of corneal refractive surgery FS-LASIK, T-PRK, and SMILE all cause different degrees of dry eyes within a certain period of time after surgery, but they can gradually recover later. After SMILE surgery, the stability of the tear film recovered faster, while the symptoms after T-PRK surgery improved the least.
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PURPOSE: To compare the results of transepithelial photorefractive keratectomy (trans PRK) and brush-assisted photorefractive keratectomy (brush PRK) for the treatment of myopia. METHODS: A total of 146 eyes from 78 patients who received brush PRK or trans PRK with the Schwind Amaris laser platform were included in the present study. Uncorrected distance visual acuity (UDVA) and manifest refraction spherical equivalent (MRSE) at postoperative 1 week, 1, 3, 6, and 12 months were compared between the 2 groups as well as epithelial healing time. RESULTS: The mean time to complete epithelial healing was 3.27 +/- 0.75 days in the trans PRK group and 3.67 +/- 0.93 days in the brush PRK group (P < 0.05). At 1 week after surgery, UDVA recovered more rapidly after trans PRK than brush PRK (brush PRK: 0.13 +/- 0.12 log MAR units, trans PRK: 0.09 +/- 0.08 log MAR units, P < 0.05), however, UDVA was not significantly different at 1, 3, 6, and, 12 months postoperatively between the 2 groups. CONCLUSIONS: Re-epithelialization and visual recovery were faster in the trans PRK group while visual outcome and postoperative complications were equivalent to the brush PRK group.