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Laser photocoagulation is one of the important methods for treating retinal diseases, and retinal laser technology continues to advance. For decades, researchers have been striving to find a laser treatment that can minimize tissue damage while achieving optimal results. With low toxicity, low scattering light, strong penetrating power, small compared with the traditional laser damage, light reaction and no pain, the 577 nm subthreshold micropulse laser(SML)turns this goal into reality and ushers in a new era of laser treatment for fundus diseases. This article reviews the concept, mechanism, related parameters and clinical application progress of 577 nm SML in a variety of retinal diseases, aiming to provide references for clinical treatments.
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Central serous chorioretinopathy(CSC)is a common macular degeneration that primarily affects young patients. While the disease may resolve on its own to some extent, delayed or inadequate treatment can result in recurrence and progression to chronic CSC. This can lead to complications such as retinal pigment epithelium(RPE)atrophy and choroidal neovascularization, ultimately causing irreversible damage to central vision. Subthreshold micropulse laser photocoagulation(SMLP)is a type of laser therapy that differs from traditional lasers in that it does not cause damage or thermal injury to RPE cells and photoreceptors. SMLP has become widely used in clinical treatment of CSC due to its effectiveness, safety, and reproducibility, particularly in cases where verteporfin is not available in photodynamic therapy(PDT). The purpose of this review is to explain the mechanism of SMLP in CSC and summarize the effector cells, cytokines, and mechanisms of action involved in its treatment. This will provide a theoretical basis for promoting and rationalizing the use of SMLP in clinical practice.
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AIM: To investigate the efficacy of micropulse laser combined with intravitreal injection of ranibizumab in the treatment of macular edema(ME)secondary to non-ischemic branch retinal vein occlusion(BRVO).METHODS: A total of 200 cases(200 eyes)of non-ischemic BRVO secondary to ME who were treated in our hospital from January 2020 to March 2022 were selected and divided into the control group(100 cases, 100 eyes)and the observation group(100 cases, 100 eyes)by random number table. The control group was given intravitreal injection of ranibizumab, and the observation group was given micropulse laser combined with intravitreal injection of ranibizumab. The best corrected visual acuity(BCVA), central macular thickness(CMT), subfoveal choroidal thickness(SFCT), total number of injections, macular leakage and complications were compared between two groups.RESULTS: After treatment, the BCVA of the two groups were improved, and the BCVA of the observation group was better than those in the control group at 1, 3, 6 and 12mo after treatment(all P<0.05). After treatment, the CMT and SFCT of the two groups decreased, and the CMT and SFCT of the observation group was lower than those in the control group at 1, 3, 6 and 12mo after treatment(all P<0.05). The total number of injections in the observation group during the treatment period was less than that in the control group [(4.06±1.12)times vs.(5.32±1.15)times](t=5.852, P<0.001). The leakage rates of the control group and the observation group after 12mo of treatment were 69.0% and 27.0% respectively, with statistical significance between the two groups(χ2=35.337, P<0.001). The incidence of complications in the control group and observation group were 11.0% and 5.0% respectively, with no statistical significance between the two groups(χ2=2.446, P=0.118).CONCLUSION: Micropulse laser combined with intravitreal injection of ranibizumab has a significant clinical efficacy in the treatment of ME secondary to non-ischemic BRVO, which is safe and can improve patients' vision and ME, reduce the total doses of ranibizumab without increasing the incidence of complications.
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Central serous chorioretinopathy (CSC) is a common macular disease, which can lead to the loss of central vision in young patients. Although the disease is self-limited to some extent, there is no shortage of patients with prolonged course and recurrent attacks, eventually leading to irreversible visual impairment. Therefore, taking reasonable treatment in a certain period is particularly important for the visual prognosis of patients. Although thermal laser photocoagulation of leakage points and photodynamic therapy (PDT) have achieved good effects, there are risks of retinal damage and retinal pigment epithelium atrophy. Subthreshold micropulse laser (SMLP) is a kind of subthreshold short pulse laser, which does not cause visible damage to the retina and is safer. In the era of lack of PDT drugs, SMLP has gradually become an important means of clinical treatment for CSC, especially for patients with no obvious leakage point or subfoveal leakage point. An in-depth understanding of the mechanism of action of SMLP and its efficacy and safety in the treatment of CSC is helpful for the promotion and application of SMLP in the clinical treatment of CSC.
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Central serous chorioretinopathy (CSC) is a common macular disease, mainly manifested as a plasma detachment of the macula. Photodynamic therapy (PDT) is an effective treatment for CSC, but with the shortage of the photosensitizer Verteporfin, the effective treatment of CSC has become a common concern for ophthalmologists. In this paper, based on the latest research results on the relationship between the changes in the thickness of the outer nuclear layer and the natural course of the disease and PDT therapy, we propose that patients with CSC should receive effective treatment as early as possible to prevent irreversible damage to visual function due to the thinning of the outer nuclear layer. In addition to PDT, it is recommended that laser photocoagulation or subthreshold micropulse laser treatment of the leaking spot should be considered first, depending on the presence of the leaking spot and its location in relation to the macula center. Anti-vascular endothelial growth factor therapy can be considered if there is a combination of choroidal neovascularization and/or polypoidal choroidal vasculopathy. Other treatments that have not been demonstrated to be effective in evidence-based medicine are not recommended.
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Central serous chorioretinopathy (CSC) is a primary disease that affects the vision of young and middle-aged people.Its treatment is difficult because of its high incidence and easy recurrence.Currently, the commonly used clinical treatment methods for CSC include photodynamic therapy, traditional laser photocoagulation, subthreshold micropulse laser photocoagulation (SDM), anti-vascular endothelial growth factor therapy, and so on.SDM is a high-frequency, short, subthreshold and selective laser, which is preferred by many clinicians because of its low energy, good safety, small trauma and so on.Different wavelengths of laser can be absorbed by different pigments in the eye, so the therapeutic wavelengths of SDM for different sites of CSC are also different.In SDM treatment, it is necessary to determine the effective treatment range and parameters to avoid undertreatment or overtreatment.In this article, the mechanism of SDM in the treatment of CSC, the difference of SDM under different wavelengths, the selection of treatment site and parameters, the efficacy and safety were reviewed, and the prospect of SDM in the future was envisioned.
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AIM: To analyze the clinical effect of 577nm subthreshold micropulse laser(SML)photocoagulation combined with intravitreal injection of Conbercept in the treatment of diabetic macular edema(DME)after vitrectomy in patients with proliferative diabetic retinopathy(PDR).METHODS:A retrospective analysis was performed on 29 cases(30 eyes)of PDR patients who had DME after vitrectomy in our hospital from January 2019 to June 2021. They were divided into two groups according to different treatment methods: 14 cases(14 eyes)in the single injection group received intravitreal injection of Conbercept, and 15 cases(16 eyes)in the combined treatment group received 577nm SML photocoagulation in the macular area combined with intravitreal injection of Conbercept. The changes in best corrected visual acuity(BCVA)and central macular thickness(CMT)before and at 6 and 12mo after treatment, as well as the changes of multifocal electroretinogram(mfERG)before and at 12mo after treatment were compared between the two groups.RESULTS: The BCVA(LogMAR)of patients in both groups improved and CMT decreased after treatment for 6 and 12mo(all P<0.001). There were no significant differences in BCVA(LogMAR)and CMT before treatment and 6mo, 12mo after treatment between single injection group and combined treatment group(all P>0.05). Compared with the combined treatment group, the amplitude was slightly lower(23.02±3.13 vs. 26.50±3.33 μV/deg2)and the latency time was prolonged(38.75±1.62 vs. 34.21±3.06ms)in single injection group at 12mo(all P≤0.001). The average injection times in single injection group was 8.14±1.46, and 5.05±1.51 in combined treatment group at 12mo after treatment(P<0.05).CONCLUSION: 577nm SML photocoagulation combined with intravitreal injection of conbercept can effectively relieve macular edema, improve BCVA and visual function of macular area and reduce the injection times of conbercept for DME patients.
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Purpose: To study the effect of subthreshold micropulse yellow laser treatment on central serous chorioretinopathy (CSC) and to compare two laser protocols. As per our knowledge, there are no studies comparing the two protocols of subthreshold laser. Methods: Twenty-three patients with non-resolving CSC of at least three months duration were treated with subthreshold laser (577 nm). Ten patients were treated with 5% duty cycle (group A) and 13 patients with 10% duty cycle (group B). At one month, best corrected visual acuity (BCVA), central macular thickness (CMT), subretinal fluid (SRF), choroidal thickness (CT) and choroidal vascularity index (CVI) were evaluated. Results: In group A, BCVA improved from 0.508 ± 504 to 0.174 ± 0.171 (P = 0.0058), CMT improved from 349.8 ± 168.9 micrometers (mm) to 183.3 ± 70.312 mm (P = 0.0093) and SRF reduced from 202.4 ± 158.024 to 43.8 ± 46.599 mm (P = 0.0069). In group B, BCVA improved from 0.437 ± 0.426 to 0.289 ± 0.470 (P = 0.0026), CMT improved from 280.846 ± 72.668 to 196.769 ± 72.62 mm (P = 0.0002) and SRF reduced from 110.385 ± 57.687 mm to 52.538 ± 52.111 mm (P = 0.0064). No significant difference was found in BCVA and CMT between the groups (P = 0.8716 and P = 0.8523, respectively). CSC completely resolved in 50% of cases in group A and in 69.2% of cases in group B. This difference was not statistically significant (0.423); however, the odds ratio of resolution was 2.25 times more with 10% duty cycle. No change was observed on fundus autofluorescence (FAF) following laser. Conclusion: Subthreshold micropulse laser can lead to resolution of SRF in 60.87% of cases (groups A and B combined). Ten per cent duty cycle had higher odds of resolution without causing any RPE damage.
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AIM:To observe the clinical effect of ranibizumab combined with 577nm micropulse laser in the treatment of severe diabetic macular edema(DME). METHODS:There were 52 eyes of 52 patients diagnosed with severe DME who admitted to the People's Hospital of Guangxi Zhuang Autonomous Region from June 2016 to September 2019. The patients were randomly divided into the observation group(26 patients with 26 eyes, treated with ranibizumab combined with 577nm micropulse laser)and the control group(26 patients with 26 eyes, treated with ranibizumab alone). Patients in both groups received intravitreal injection of ranibizumab with “3+PRN” regimen. Followed up at 9mo after treatment to observe the central macular thickness(CMT), the best corrected visual acuity(BCVA)and the times of intravitreal injection of ranibizumab in the two groups.RESULTS:Compared with before treatment, the CMT and BCVA of the two groups were significantly improved at each time point after treatment(all P<0.001), but there was no difference between the two groups(P>0.05). During the follow-up period, the times of vitreous injection of ranibizumabin the observation group was significantly less than that in the control group(5.88±1.24 times vs 7.12±1.24 times, P=0.001). CONCLUSION:Both ranibizumab combined with 577nm micropulse laser and ranibizumab alone are effective in reducing edema and improving vision in patients with severe DME, but the combination therapy reduces the times of injection.
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AIM: To comparatively analyze the efficacy of subthreshold laser photocoagulation with the NAVILAS&#xAE; Laser system and subthreshold micropulse laser for patients with chronic central serous chorioretinopathy(cCSC).METHODS: A retrospective clinical study. A total of 36 patients(40 eyes)with cCSC were recruited from January 2020 to January 2021 diagnosed at the Affiliated Eye Hospital of Nanjing Medical University. There were 19 patients(23 eyes)treated with subthreshold navigated laser photocoagulation(the Navilas group), and 17 patients(17 eyes)treated with subthreshold micropulse laser(SML)(the SML group). There was no significant difference in baseline data between the two groups(P>0.05). The best corrected visual acuity(BCVA, LogMAR), central macular thickness(CMT), subretinal fluid(SRF)height, vessel densities of the superficial capillary plexus(SCP), the deep capillary plexus(DCP)and area of the foveal avascular zone(FAZ)were collected at 2wk, 1, 3 and 6mo before and after treatment.RESULTS: The BCVA of the two groups were significantly higher than that before treatment at 3 and 6mo after surgery(P<0.05),which was significantly reduced at 2wk after treatment in the Navilas group and was reduced at 1mo after treatment in the SML group(P<0.05). In both groups, there was significant decrease compared with that before treatment at 3 and 6mo after treatment(P<0.05),but there was no significant difference between the two groups(P>0.05). The difference in SRF absorption between the two groups was statistically significant(P<0.05), and the complete absorption rate of SRF in the Navilas group was higher than that in the SML group. SCP, DCP, the area of the FAZ were not significantly different from each time ofbaseline in the two groups(P >0.05).CONCLUSION: Subthreshold laser photocoagulation with the NAVILAS&#xAE; Laser system can rapidly improve the retinal morphology and shorten the course of cCSC to improve the recovery of visual function with its rapid effect, high cost-effectiveness, non-invasiveness and high repeatability, which can be a new clinical method for patients with cCSC.
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Objective:To observe the clinical efficacy and safety of full macular coverage micropulse laser in the treatment of refractory macular edema secondary to Irvine-Gass syndrome.Methods:A retrospective case study. From April 2018 to November 2019, 21 cases of Irvine-Gass syndrome patients with 24 eyes were included in the study. Among them, there were 11 females with 12 eyes and 10 males with 12 eyes; the average age was 54.5±10.1 years. All the affected eyes underwent best corrected visual acuity (BCVA) and optical coherence tomography (OCT) examination. BCVA was performed using a standard logarithmic visual acuity chart, and the results were converted into the logarithmic minimum angle of resolution (logMAR) visual acuity when recording. The frequency domain OCT instrument was used to measure the foveal retinal thickness (CMT) and the retinal volume (MRV) of the macular area with a diameter of 1, 6 mm. All the affected eyes were treated with a micropulse laser under the threshold of 577 nm, with a spot diameter of 200 μm, an exposure time of 200 ms, a power of 400 mW, and a 5% duty cycle. The treatment scope was in the upper and lower vascular arches of the macula, covering the entire macula (including the fovea). One or 3 months after treatment, the eyes with macular edema were treated twice with micropulse laser, the method was the same as before. 1, 3, and 6 months after the treatment, the same equipment and methods as before the treatment were used for related inspections. The changes of BCVA, CMT, MRV and the occurrence of complications in the affected eye were observed.Results:The average logMAR BCVA of the eyes before treatment and 1, 3, and 6 months after treatment were 0.440±0.320, 0.333±0.286, 0.250±0.245, 0.166±0.184, and the average CMT were 395.88±79.21, 349.17±78.07, 317.67±53.72, 285.29±37.03 μm, respectively; the average MRV of diameter 1, 6 mm were 0.310±0.063, 0.275±0.060, 0.245±0.035, 0.221±0.219 mm 3 and 9.866±0.846, 9.494±1.002, 9.005±0.885, 8.190±0.850 mm 3. Compared with before treatment, the BCVA of the eyes at 1, 3, and 6 months after treatment was significantly increased ( t=5.060, 5.564, 6.466), and CMT was significantly decreased ( t=4.854, 5.777, 7.349), and the differences were statistically significant ( P<0.01); the average MRV of diameters 1, 6 mm decreased significantly, and the difference was statistically significant (1 mm diameter: t=4.527, 5.394, 7.380; P<0.01; diameter 6 mm: t=4.577, 7.980, 11.209; P<0.01). The average number of micropulse laser treatments for the affected eye was 1.25 times. Conclusion:Full macular coverage micropulse laser can safely and effectively treat refractory macular edema secondary to Irvine-Gass syndrome and can be used as an alternative treatment.
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@#AIM: To analyze the morphological changes of macular soft drusen and drusenoid pigmental epithulium detachment(DPED)after subthreshold micropulse laser treatment(SMLT).<p>METHODS: Fourteen patients(20 affected eyes)with soft drusen and DPED clinically confirmed from August 2016 to October 2018, were included in this study. 577 nm yellow laser of SMLT was applied for soft drusen and DPED. The changes of soft drusen and DPED in best corrected visual acuity(BCVA)(LogMAR)and height, diameter and cross-sessional area according to fundus autofluorescence and SD-OCT examinations were observed after SMLT.<p>RESULTS: BCVA was not significant difference after treatment of soft drusen(<i>P</i>=0.260), and the DPED(<i>P</i>=0.736)than that of the baseline. Compared with the baseline values, the height and cross-sessional area of soft drusen were reduced at the 6mo after treatment(<i>P</i>=0.008, <i>P</i>=0.034). Compared with the baseline values, the differences were not statistically significant in height, diameter and cross-sectional area of DPED after treatment.<p>CONCLUSION: BCVA was not reduced for drusen and DPED after SMLT, however, the height and cross-sessional area of soft drusen was reduced compared with those before treatment, and the differences were not statistically significant in height, diameter and cross-sectional area of DPED before and after treatment. The results indicated that SMLT was effective for soft drusen, but was not effective for short-term treatment of DPED. SMLT caused no damage to the visual acuity in treatment of soft drusen and DPED, but prospective, controlled, large sample and long-term follow-up studies should be required.
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@#AIM: To compare the clinical effects and safety of single subthreshold micropulse(STMP)yellow laser and combined ranibizumab intravitreal injection on the treatment of diabetic macular edema(DME).<p>METHODS: Totally 33 patients(58 eyes)with DME were divided into two groups. Group A(laser group)received STMP yellow laser, and group B(combined treatment group)received ranibizumab intravitreal injection combined with STMP yellow laser. The best corrected visual acuity(BCVA), intraocular pressure(IOP), central macular thickness(CMT), total macular volume(TMV), fluorescein fundus angiography(FFA), multifocal ERG(MERG), autofluorescence(AF)and macular pigment optical density(MPOD)were compared before and after the treatments. And treatment times were counted. <p>RESULTS:Compared with those before treatment, there were significant differences in BCVA and TMV 6, 9, 12mo after treatment in the laser group(<i>P</i><0.05). And there were significant differences in BCVA and TMV 3, 6, 9, 12mo after treatment in the combined treatment group(<i>P</i><0.05). For both groups, there were significant differences in CMT before and 3, 6, 9, 12mo after treatment(<i>P</i><0.01). Compared with the P1 amplitude of MEG, Max OD and Mean OD before treatment, there were significant differences for the two groups 12mo after treatment(<i>P</i><0.01). And the differences were significant in TMV and P1 amplitudes between the two groups after 12mo of treatment(<i>P</i><0.01). During the follow-up period, the laser times was 3.32±1.09 in the laser group and 3.30±1.18 in the combined treatment group(<i>P</i>=0.943).<p>CONCLUSION:Both single STMP laser and combined with intravitreal injection of ranibizumab can effectively reduce macular edema, improve vision and safety in DME patients. And the combined treatment group has faster and better effect.
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?AIM:To analyze the morphological changes of macular soft drusen and drusenoid pigmental epithulium detachment ( DPED ) after subthreshold micropulse laser treatment ( SMLT) .?METHODS: Fourteen patients ( 20 affected eyes ) with soft drusen and DPED clinically confirmed from August 2016 to October 2018, were included in this study. 577 nm yellow laser of SMLT was applied for soft drusen and DPED. The changes of soft drusen and DPED in best corrected visual acuity ( BCVA ) ( LogMAR ) and height, diameter and cross-sessional area according to fundus autofluorescence and SD - OCT examinations were observed after SMLT.?RESULTS: BCVA was not significant difference after treatment of soft drusen (P=0.260), and the DPED (P=0. 736 ) than that of the baseline. Compared with the baseline values, the height and cross-sessional area of soft drusen were reduced at the 6mo after treatment ( P=0. 008, P=0.034) . Compared with the baseline values, the differences were not statistically significant in height, diameter and cross - sectional area of DPED after treatment.?CONCLUSION: BCVA was not reduced for drusen and DPED after SMLT, however, the height and cross -sessional area of soft drusen was reduced compared with those before treatment, and the differences were not statistically significant in height, diameter and cross -sectional area of DPED before and after treatment. The results indicated that SMLT was effective for soft drusen, but was not effective for short-term treatment of DPED. SMLT caused no damage to the visual acuity in treatment of soft drusen and DPED, but prospective, controlled, large sample and long-term follow-up studies should be required.
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@#AIM: To analyze the morphological changes of macular soft drusen and drusenoid pigmental epithulium detachment(DPED)after subthreshold micropulse laser treatment(SMLT).<p>METHODS: Fourteen patients(20 affected eyes)with soft drusen and DPED clinically confirmed from August 2016 to October 2018, were included in this study. 577 nm yellow laser of SMLT was applied for soft drusen and DPED. The changes of soft drusen and DPED in best corrected visual acuity(BCVA)(LogMAR)and height, diameter and cross-sessional area according to fundus autofluorescence and SD-OCT examinations were observed after SMLT.<p>RESULTS: BCVA was not significant difference after treatment of soft drusen(<i>P</i>=0.260), and the DPED(<i>P</i>=0.736)than that of the baseline. Compared with the baseline values, the height and cross-sessional area of soft drusen were reduced at the 6mo after treatment(<i>P</i>=0.008, <i>P</i>=0.034). Compared with the baseline values, the differences were not statistically significant in height, diameter and cross-sectional area of DPED after treatment.<p>CONCLUSION: BCVA was not reduced for drusen and DPED after SMLT, however, the height and cross-sessional area of soft drusen was reduced compared with those before treatment, and the differences were not statistically significant in height, diameter and cross-sectional area of DPED before and after treatment. The results indicated that SMLT was effective for soft drusen, but was not effective for short-term treatment of DPED. SMLT caused no damage to the visual acuity in treatment of soft drusen and DPED, but prospective, controlled, large sample and long-term follow-up studies should be required.
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@#Subthreshold micropulse laser(SML)consists of short repetitive pulses of laser. This kind of treatment is safe and cheap, and contrary to conventional laser photocoagulation(LPC), SML doesn't involve destruction of retinal cells and leave no scars. The possible mechanism of SML is to stimulate retinal pigment epithelium(RPE)cells for the production of heat shock proteins(HSPs)and regulate its metabolism and improve its function. The clinical indication of SML includes central serous chorioretinopathy(CSC), diabetic retinopathy edema(DME), nonproliferative diabetic retinopathy(NPDR)and proliferative diabetic retinopathy(PDR)and macular edema(ME)secondary to retinal vein occlusion(RVO). This article discussed the mechanism and safety of SML and reviewed the updates of its application.
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@#AIM: To compare the efficacy and safety of 577nm subthreshold micropulse laser(SML)and photodynamic therapy(PDT)in patients with chronic central serous chorioretinopathy(cCSC).<p>METHODS: Thirty patients(30 eyes)with cCSC were treated in our hospital from February 2015 to April 2018. And 15 patients(15 eyes)were treated with SML(577 nm)while the others were treated by PDT. The BCVA and CMT as well as complications were observed at 1, 3, 6mo after treatment.<p>RESULTS: At 1mo after treatment, BCVA was increased to 0.37±0.13 in SML group and 0.20±0.11 in PDT group(<i>t</i>=-3.93, <i>P</i><0.001); CMT was decreased to 382.80±76.54μm in SML group and 247.60±28.46μm in PDT group(<i>t</i>=-6.41, <i>P</i><0.001). Although improvements of BCVA and CMT were both achieved in two groups, improvements in PDT group were better than those in SML group. At 3mo and 6mo after treatment, both BCVA and CMT were no significant difference between the two groups(<i>P</i>>0.05). During the follow-up period, there were no obvious complications or recurrence observed.<p>CONCLUSION: Both SML(577nm)and PDT were effective and safe in the treatment of cCSC, but the theraputic effects of PDT was slightly quicker than SML. Further, with the prolongation of recovery time, the curative effects of these treatments were similar. Additionally, SML(577nm)costs was much cheaper than PDT and had no risk of injury or allergy for patients, and patients with cCSC could also be treated repeatedly using it.
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Objective To evaluate the efficiency and safety of micropulse laser trabeculoplasty (MLT) for open angle glaucoma ( OAG) patients and ocular hypertension ( OHT) patients. Methods A prospective self-controlled study was designed. Fifty-six eyes of 56 OAG and OHT patients in Peking University Third Hospital were recruited from June 2016 to June 2017,including 32 males and 24 females with the age of (50. 4±19. 0) years old. The diagnosis included 48 eyes of primary open angle glaucoma (POAG),3 eyes of normal tension glaucoma and 5 eyes of OHT. The best corrected vision acuity ( BCVA) was 0. 7 ±0. 3 before treatment. The intraocular pressure (IOP) before MLT was (20.4±5.8) mmHg,the average types of antiglaucoma medications was 1.7,including systemic medication and local drug use. The general information, BCVA, IOP and antiglaucoma medication were recorded. Only one eye of each patient was treated by MLT. The IOP at different follow-up time points (2 hours, 1 day,1 week, 1 month, 3 months post-treatment) and the number of antiglaucoma medication before and after treatment were compared. This study protocol was approved by Ethic Committee of Peking University Third Hospital (No. 2014166). Written informed consent was obtained from each subject prior to any medical examination. Results The IOP after MLT was (20. 2±6. 7),(17. 6±4. 4),(18. 1±4. 5),(17. 4±3. 4) and (17. 0±2. 1)mmHg at 2 hours, 1 day,1 week,1 month and 3 months,respectively,with significant difference among the different time points ( F=7. 320,P<0. 001). Compared with the IOP before treatment,the IOP at 1 day,1 week,1 month and 3 months after treatment were significantly decerased,with significant differences between them (all at P<0. 05). Three months after treatment,the average number of glaucoma medications used was 1. 5, and only local administration was used. Infection,hyphema,cornea injury,burns and other complications were not seen in all the patients. Conclusions MLT is effective and safety for OAG and OHT patients,and reduce the use of glaucoma drugs.
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Objective To investigate the effects of subthreshold micropulse yellow laser (577 nm) on vascular endothelial growth factor (VEGF),nerve growth factor (NGF) and Chemerin expressions in retina of early stage diabetic rats.Methods A total of 40 Brown Norway rats were treated with streptozocin (65 mg · kg-1) to establish the diabetic model.20 diabetic BN rats' right eyes were received subthreshold micropulse yellow laser (577 run) therapy after 2 weeks.The left eyes were used as control group.At 3 days,7 days,14 days,28 days after laser therapy,5 BN rats were randomly chosen to perform RT-PCR and Weston-blot.The expressions of mRNA and protein of VEGF,NGF and Chemerin were analyzed.Results The expression of VEGF mRNA and protein increased in control group at 3 days,7 days,14 days and 28 days (all P ＜ 0.05).Compared with the control group,VEGF mRNA and protein decreased in the subthreshold micropulse yellow laser (577 nm) group (all P ＜ 0.05).The expression of NGF mRNA and protein decreased in the control group at 3 days,7 days,14 days and 28 days (all P ＜ 0.05),however,the difference was not statistically significant between 3 days and 7 days(P ＞0.05).Compared with control group,NGF mRNA and protein increased in the subthreshold micropulse yellow laser (577 nm) group (all P ＜ 0.05),with maximum expression at 14 days.The expression of chemerin mRNA and protein increased at 3 days,7 days,14 days and 28 days in the control group (all P ＜0.05).Compared with the control group,chemerin mRNA and protein decreased in the subthreshold micropulse yellow laser (577 urn) group (all P ＜ 0.05).Conclusion Subthreshold micropulse yellow laser (577 urn) can suppress VEGF,Chemerin expression and upregulate NGF expression in early stage diabetic rats.
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AIM: To observe the changes of MMP-9 expression in rabbit retina after laser irradiation at different thresholds of 577nm.METHODS: Twenty-six pigmentation rabbits were randomly divided into normal control group(n=2), conventional photocoagulation group (n=6) and subliminal micropulse laser photocoagulation group (n=18).The conventional photocoagulation group was treated with 577nm laser photocoagulation, subcutaneous micro-pulsed laser photocoagulation at a working loading rate of 9%, 12% and 15%, respectively.Eighteen rabbits were again divided into three subgroups according different powers of subthreshold working loading rate of 9%(n=6), 12%(n=6) and 15%(n=6) that undertook, respectively.The expression of MMP-9 on the retina of rabbit eyes was detected by immunohistochemistry.RESULTS: In the conventional photocoagulation group, the expression of MMP-9 in the RPE layer and the visual cell layer was strongly positive, which was significantly higher than that in the sub-micro pulse group(P0.05).CONCLUSION: The 577nm subliminal micro-pulsed photocoagulation has high selectivity to retinal pigment epithelium at working load rate of 9%, 12% and 15%, and no damage to retinal nerve fiber layer, which is safer than conventional 577nm laser photocoagulation.