AIM: To observe the changes in ocular surface and the dry eye symptoms following femtosecond laser-assisted cataract surgery(FLACS). METHODS: Patients with no eye signs or symptoms in Guangzhou Aier Eye Hospital betwe...AIM: To observe the changes in ocular surface and the dry eye symptoms following femtosecond laser-assisted cataract surgery(FLACS). METHODS: Patients with no eye signs or symptoms in Guangzhou Aier Eye Hospital between October 2017 and September 2018, who underwent FLACS and intraocular lens(IOL) implantation for age-related cataract were enrolled. Tear film stability assessed with OCULUS Keratograph 5 M, Schirmer’s I test(SIT), and corneal fluorescein staining(CFS) were evaluated before and after surgery at 1 d, 1 wk, 1, and 3 mo in order. Ocular Surface Disease Index scores(OSDI) and Subjective Symptom Questionnaires(SSQs) were recorded at the same time point.RESULTS: Thirty-eight eyes of 38 patients were enrolled. The noninvasive tear film break-up time(first break-up time and average break-up time) decreased in a peak at the 1 wk visit, and then increased to basic levels at 1 mo. The tear meniscus height(TMH) increased transiently at 1 d, and declined in the following 3 mo visits. The SIT had a transient increase at 1 d(P=0.357) and a decrease at 1 wk and 1 mo(both P<0.05) but returned to the preoperative levels at 3 mo after surgery(P=0.062). CFS scores were significantly improved compared with those before surgery, and had a statistical difference(P<0.05). OSDI scores and SSQs after surgery were obviously higher, and had a statistical difference(P<0.001) but didn’t return to the basic level by 3 mo. CONCLUSION: Dry eye signs and symptoms can occur immediately following FLACS and have a peak severity on day 7 postoperatively. Most signs of dry eye can return to preoperative basic levels within 3 mo postoperatively. However, all cases can not recover from CFS and dry eye symptoms at 3 mo postoperatively.展开更多
Surface of Al 2O 3 ceramic was processed by an excimer laser and the characteristics of topography were examined based on the application of the microelectromechanical system(MEMS). It is indicated that the statisti...Surface of Al 2O 3 ceramic was processed by an excimer laser and the characteristics of topography were examined based on the application of the microelectromechanical system(MEMS). It is indicated that the statistic parameters of surface topography processed by the excimer laser have an obvious regularity. The arithmetic-mean value R a and the root-mean square value R q change with the changing of processing parameters in the same step and trend, and there is a quantitative relation between them.A simplified model is proposed for the excimer laser processing surface profile, whose results of the analysis and calculation agree basically with the experimental data. Furthermore,the surfaces processed by excimer laser are greatly flat. Skewness root-mean-square value Z· q changed little with the change of the technological parameters. The above characteristics depend on the processing principle of excimer laser, quite different from the cutting processing.展开更多
Changes of surface morphology following XeCI excimer laser irradiation were investigated for three engineering ceramic materials (Al2O3, Al2O3-SiC nanocomposite and Si3N4). Al2O3 and AI2O3-SiC nanocomposite samples ex...Changes of surface morphology following XeCI excimer laser irradiation were investigated for three engineering ceramic materials (Al2O3, Al2O3-SiC nanocomposite and Si3N4). Al2O3 and AI2O3-SiC nanocomposite samples exhibit a smooth rapid melt layer on the surface, and the formation of the metastabfe γ-Al2Oa was observed. A silicon-rich layer on the surface was formed after laser irradiation of Si3N4. The toughness K1c of the materials was measured by the indentation fracture method. After laser irradiation, the toughness of Al2O3, Al2O3-SiC nanocomposite and Si3N4 was improved to various degrees: Al2O3-SiC nanocomposite, 60% (max.); AI203, 40% (max.); Si3N4, 12% (max.).展开更多
Thin metallic layers (~ 2 μm) of Ni were deposited on polycrystalline Al2O3. ZrO2 and (Ce-TZP)+Al2O3 ceramic substrates. and further irradiated with pulsed excimer (Xeno chloride) laser pulses. The laser energy densi...Thin metallic layers (~ 2 μm) of Ni were deposited on polycrystalline Al2O3. ZrO2 and (Ce-TZP)+Al2O3 ceramic substrates. and further irradiated with pulsed excimer (Xeno chloride) laser pulses. The laser energy density was varied from 0.21 to 0.81 J / cm2 to optimize bending strength. For ZrO2 ceramic, it was found that the strength increases from 530 to 753 MPa at 0.51 J / cm2 irradiation. For Al2O3 and (Ce-TZP)+ Al2O3 the fracture strength also increases in varying degree. The causes of strength increment were discussed.展开更多
Background: Individualized corneal refractive surgery requires an understanding of the basis of higher-order aberrations before surgery. To investigate the characteristics and distribution of anterior surface wavefron...Background: Individualized corneal refractive surgery requires an understanding of the basis of higher-order aberrations before surgery. To investigate the characteristics and distribution of anterior surface wavefront aberrations in patients suitable for corneal refractive surgery. Methods: A total of 121 myopic patients (121 eyes, 18 - 45 years old) who underwent corneal refractive surgery were recruited from January to May 2016 at Affiliated Hospital, Yanbian University. Patients were randomly selected by the Pentacam anterior segment analysis system with a spherical equivalent (SE) of -0.25 to -10.00 D. The corneal anterior aberrations (total higher-order aberration;spherical aberration;Coma;Trefoil) and Q and K values were detected, and a correlation analysis of the relevant parameters was carried out. Results: The root-mean-square (RMS) of the third to sixth order aberrations of the corneal anterior wavefront aberrations at a 6 mm analysis diameter showed a decreasing trend in patients suitable for the corneal refractive surgery, and the RMS of the third order aberrations accounted for 62.92% of the total HOAs. The coma ratio (coma/total cornea higher-order aberrations) was increased with the increasing diopters, while the spherical aberration ratio (spherical aberration/total cornea higher-order aberrations) was not changed. In addition, the spherical aberration was 0.203 ± 0.082 μm (range: 0.061 to 0.503 μm), and the Q30 was -0.19 ± 0.03 (range: -0.58 to 0.31). There were significant differences in the coma aberrations of preoperative corneal anterior surface (3, 1) between the low, middle and high myopia groups (P = 0.013). The spherical equivalent was positively correlated with the corneal coma of the anterior corneal surfaces (R =?-0.241, P = 0.009), and the Q value was positively correlated with the total higher-order aberrations (R = 0.326, P Conclusions: Individual wavefront aberrations on the anterior surfaces of the cornea are comparatively different, and the Zernike coefficients are related to the degree of myopia. Spherical aberrations are the most overriding aberrations of the cornea.展开更多
RECENTLY, excimer laser devices, which have higher-energy density output in pulsed ultravio-let (UV) light (193 or 248 nm), have been employed to generate some thin film struc-tures. The principle of this technique, w...RECENTLY, excimer laser devices, which have higher-energy density output in pulsed ultravio-let (UV) light (193 or 248 nm), have been employed to generate some thin film struc-tures. The principle of this technique, which is also called pulsed laser deposition (PLD)technique, is that the exposed material could be ablated out of the sample by the focusing laserbeam, and redeposit on a substrate to form thin-film structures under certain conditions. Onthe other hand, researchers have obtained high-quality Bragg gratings in photosensitive展开更多
AIM:To evaluate the feasibility of promoting genetic detection for granular corneal dystrophy type 2(GCD2)by a questionnaire conducted among citizens in five cities in China.METHODS:The data were collected by question...AIM:To evaluate the feasibility of promoting genetic detection for granular corneal dystrophy type 2(GCD2)by a questionnaire conducted among citizens in five cities in China.METHODS:The data were collected by questionnaire,and analyzed by Chi-square test and one-tailed t test in IBM SPSS statistics.RESULTS:Based on the survey data on the awareness of GCD2 genetic detection in this study and the positive predictive analysis report of the citizens in five cities in China,the vast majority(84.2%)of respondents had never heard of it and did not know that GCD2 patients have been prohibited from performing excimer surgery that can deteriorate GCD2 patients’condition even leading to blindness.Though 3.4%of patients understood GCD2 very much,they have no idea that GCD2 could not be 100%accuracy diagnosed by the conventional inspection methods.CONCLUSION:It is feasible and necessary to use GCD2 genetic detection as an excimer preoperative examination project.In order to promote the development of detection project,a few improvements should be carried out in terms of the promoting efforts,costs,and research progress.展开更多
基金Supported by Medical Science and Technology Research Foundation Project of Guangdong Province(No.C2017029)Science and Technology Project of Yuexiu District,Guangzhou(No.2017-WS-013)
文摘AIM: To observe the changes in ocular surface and the dry eye symptoms following femtosecond laser-assisted cataract surgery(FLACS). METHODS: Patients with no eye signs or symptoms in Guangzhou Aier Eye Hospital between October 2017 and September 2018, who underwent FLACS and intraocular lens(IOL) implantation for age-related cataract were enrolled. Tear film stability assessed with OCULUS Keratograph 5 M, Schirmer’s I test(SIT), and corneal fluorescein staining(CFS) were evaluated before and after surgery at 1 d, 1 wk, 1, and 3 mo in order. Ocular Surface Disease Index scores(OSDI) and Subjective Symptom Questionnaires(SSQs) were recorded at the same time point.RESULTS: Thirty-eight eyes of 38 patients were enrolled. The noninvasive tear film break-up time(first break-up time and average break-up time) decreased in a peak at the 1 wk visit, and then increased to basic levels at 1 mo. The tear meniscus height(TMH) increased transiently at 1 d, and declined in the following 3 mo visits. The SIT had a transient increase at 1 d(P=0.357) and a decrease at 1 wk and 1 mo(both P<0.05) but returned to the preoperative levels at 3 mo after surgery(P=0.062). CFS scores were significantly improved compared with those before surgery, and had a statistical difference(P<0.05). OSDI scores and SSQs after surgery were obviously higher, and had a statistical difference(P<0.001) but didn’t return to the basic level by 3 mo. CONCLUSION: Dry eye signs and symptoms can occur immediately following FLACS and have a peak severity on day 7 postoperatively. Most signs of dry eye can return to preoperative basic levels within 3 mo postoperatively. However, all cases can not recover from CFS and dry eye symptoms at 3 mo postoperatively.
文摘Surface of Al 2O 3 ceramic was processed by an excimer laser and the characteristics of topography were examined based on the application of the microelectromechanical system(MEMS). It is indicated that the statistic parameters of surface topography processed by the excimer laser have an obvious regularity. The arithmetic-mean value R a and the root-mean square value R q change with the changing of processing parameters in the same step and trend, and there is a quantitative relation between them.A simplified model is proposed for the excimer laser processing surface profile, whose results of the analysis and calculation agree basically with the experimental data. Furthermore,the surfaces processed by excimer laser are greatly flat. Skewness root-mean-square value Z· q changed little with the change of the technological parameters. The above characteristics depend on the processing principle of excimer laser, quite different from the cutting processing.
文摘Changes of surface morphology following XeCI excimer laser irradiation were investigated for three engineering ceramic materials (Al2O3, Al2O3-SiC nanocomposite and Si3N4). Al2O3 and AI2O3-SiC nanocomposite samples exhibit a smooth rapid melt layer on the surface, and the formation of the metastabfe γ-Al2Oa was observed. A silicon-rich layer on the surface was formed after laser irradiation of Si3N4. The toughness K1c of the materials was measured by the indentation fracture method. After laser irradiation, the toughness of Al2O3, Al2O3-SiC nanocomposite and Si3N4 was improved to various degrees: Al2O3-SiC nanocomposite, 60% (max.); AI203, 40% (max.); Si3N4, 12% (max.).
文摘Thin metallic layers (~ 2 μm) of Ni were deposited on polycrystalline Al2O3. ZrO2 and (Ce-TZP)+Al2O3 ceramic substrates. and further irradiated with pulsed excimer (Xeno chloride) laser pulses. The laser energy density was varied from 0.21 to 0.81 J / cm2 to optimize bending strength. For ZrO2 ceramic, it was found that the strength increases from 530 to 753 MPa at 0.51 J / cm2 irradiation. For Al2O3 and (Ce-TZP)+ Al2O3 the fracture strength also increases in varying degree. The causes of strength increment were discussed.
文摘Background: Individualized corneal refractive surgery requires an understanding of the basis of higher-order aberrations before surgery. To investigate the characteristics and distribution of anterior surface wavefront aberrations in patients suitable for corneal refractive surgery. Methods: A total of 121 myopic patients (121 eyes, 18 - 45 years old) who underwent corneal refractive surgery were recruited from January to May 2016 at Affiliated Hospital, Yanbian University. Patients were randomly selected by the Pentacam anterior segment analysis system with a spherical equivalent (SE) of -0.25 to -10.00 D. The corneal anterior aberrations (total higher-order aberration;spherical aberration;Coma;Trefoil) and Q and K values were detected, and a correlation analysis of the relevant parameters was carried out. Results: The root-mean-square (RMS) of the third to sixth order aberrations of the corneal anterior wavefront aberrations at a 6 mm analysis diameter showed a decreasing trend in patients suitable for the corneal refractive surgery, and the RMS of the third order aberrations accounted for 62.92% of the total HOAs. The coma ratio (coma/total cornea higher-order aberrations) was increased with the increasing diopters, while the spherical aberration ratio (spherical aberration/total cornea higher-order aberrations) was not changed. In addition, the spherical aberration was 0.203 ± 0.082 μm (range: 0.061 to 0.503 μm), and the Q30 was -0.19 ± 0.03 (range: -0.58 to 0.31). There were significant differences in the coma aberrations of preoperative corneal anterior surface (3, 1) between the low, middle and high myopia groups (P = 0.013). The spherical equivalent was positively correlated with the corneal coma of the anterior corneal surfaces (R =?-0.241, P = 0.009), and the Q value was positively correlated with the total higher-order aberrations (R = 0.326, P Conclusions: Individual wavefront aberrations on the anterior surfaces of the cornea are comparatively different, and the Zernike coefficients are related to the degree of myopia. Spherical aberrations are the most overriding aberrations of the cornea.
文摘RECENTLY, excimer laser devices, which have higher-energy density output in pulsed ultravio-let (UV) light (193 or 248 nm), have been employed to generate some thin film struc-tures. The principle of this technique, which is also called pulsed laser deposition (PLD)technique, is that the exposed material could be ablated out of the sample by the focusing laserbeam, and redeposit on a substrate to form thin-film structures under certain conditions. Onthe other hand, researchers have obtained high-quality Bragg gratings in photosensitive
基金Supported by National Natural Science Foundation of China(No.81570870)Natural Science Foundation of Fujian Province(No.2016J01375)Innovation and Entrepreneurship Training Program of Fujian Medical University(No.C4015,No.C19067,No.S202010392022X)。
文摘AIM:To evaluate the feasibility of promoting genetic detection for granular corneal dystrophy type 2(GCD2)by a questionnaire conducted among citizens in five cities in China.METHODS:The data were collected by questionnaire,and analyzed by Chi-square test and one-tailed t test in IBM SPSS statistics.RESULTS:Based on the survey data on the awareness of GCD2 genetic detection in this study and the positive predictive analysis report of the citizens in five cities in China,the vast majority(84.2%)of respondents had never heard of it and did not know that GCD2 patients have been prohibited from performing excimer surgery that can deteriorate GCD2 patients’condition even leading to blindness.Though 3.4%of patients understood GCD2 very much,they have no idea that GCD2 could not be 100%accuracy diagnosed by the conventional inspection methods.CONCLUSION:It is feasible and necessary to use GCD2 genetic detection as an excimer preoperative examination project.In order to promote the development of detection project,a few improvements should be carried out in terms of the promoting efforts,costs,and research progress.