Retinopathy of prematurity (ROP) is a retinal vascular disease in preterm or low birth weight infants and a leading cause of childhood blindness. Anti-vascular endothelial growth factor (VEGF) therapy offers advantages such as minimal invasiveness and convenient intervention; however, it carries a relatively high risk of disease reactivation, necessitating long-term follow-up due to the potential for severe outcomes. Studies indicate that post-anti-VEGF reactivation rates vary regionally and are related with birth status, ROP severity, and the specific anti-VEGF agent used. Most reactivations occur 6-16 weeks after initial treatment, at a postmenstrual age of 37-60 weeks. Reactivated lesions often develop at the original ridge or the junction of vascularized and avascular retina, and may present with dilation and tortuosity of the posterior retinal vessels, peripheral vascular leakage, neovascularization, or retinal detachment. Fundus fluorescein angiography may reveal Plus disease, posterior arterial tortuosity, abnormal nondichotomous retinal vessel branching at the junction of vascularized and avascular retina, irregular circumferential vessels, vasoobliteration with capillary nonperfusion, neovascularization, and fluorescein leakage. The choice of retreatment (such as retinal laser photocoagulation, intravitreal anti-VEGF injection, or vitrectomy) should be decided by the timing and severity of reactivation, along with prognostic considerations. It is recommended to establish a standardized management protocol for reactivation after anti-VEGF treatment in ROP to enable early detection and intervention, thereby preventing severe visual impairment. Future studies should focus on the mechanisms underlying ROP reactivation, differences in reactivation rates and timing among various anti-VEGF agents, predictive models for reactivation risk, and long-term management of reactivated disease.
ObjectiveTo observe the efficacy and safety of vitrectomy combined with subretinal injection of alteplase (tPA) and intravitreal injection of Conbercept in the treatment of large area submacular hemorrhage (SMH) secondary to polypoidal choroidal vasculopathy (PCV). MethodsA retrospective clinical study. From January to September 2021, 32 eyes of 32 patients with massive SMH secondary to PCV diagnosed in the Affiliated Eye Hospital of Nanchang University were included in the study. Large SMH was defined as hemorrhage diameter ≥4 optic disc diameter (DD). There were 32 patients (32 eyes), 20 males and 12 females. The mean age was (72.36±8.62) years. All patients had unilateral disease.The duration from onset of symptoms to treatment was (7.21±3.36) days. All patients underwent best corrected visual acuity (BCVA) and optical coherence tomography (OCT) examination. BCVA examination was performed using the international standard visual acuity chart, which was converted to the logarithm of the minimum angle of resolution (logMAR) visual acuity during statistics. The central macular thickness (CMT) was measured by spectral domain-OCT. The average size of SMH was (6.82±1.53) DD. The logMAR BCVA 1.73±0.44; CMT was (727.96±236.40) μm. All patients were treated with 23G pars plana vitrectomy combined with subretinal injection of tPA and intravitreal injection of Conbercept. At 1, 3, 6 and 12 months after treatment, the same equipment and methods were used for relevant examinations before treatment. The changes of BCVA and CMT, the clearance rate of macular hemorrhage, and the complications during and after surgery were observed. BCVA and CMT before and after treatment were compared by repeated measures analysis of variance. ResultsCompared with before treatment, BCVA gradually increased at 1, 3, 6 and 12 months after treatment, and the differences were statistically significant (F=77.402, P<0.001). There was no significant difference in BCVA between any two groups at different time points after treatment (P>0.05). Correlation analysis showed that BCVA at 12 months after treatment was negatively correlated with the course of disease (r=-0.053, P=0.774). One week after treatment, macular hemorrhage was completely cleared in 30 eyes (93.75%, 30/32). The CMT was (458.56±246.21), (356.18±261.46), (345.82±212.38) and (334.64±165.54) μm at 1, 3, 6 and 12 months after treatment, respectively. Compared with before treatment, CMT decreased gradually after treatment, and the difference was statistically significant (F=112.480, P<0.001). There were statistically significant differences in different follow-up time before and after treatment (P<0.001). The number of treatments combined with Conbercept during and after surgery was (4.2±1.8) times. At the last follow-up, there was no recurrence of SMH, retinal interlamellar effusion and other complications. Conclusion Subretinal injection of tPA combined with intravitreal injection of Conbercept is safe and effective in the treatment of large SMH secondary to PCV, and it can significantly improve the visual acuity of patients.
ObjectiveTo observe and analyze the influencing factors for the prognosis of anti-vascular endothelial growth factor (VEGF) drug treatment in patients with macular neovascularization (MNV) under 45 years old. MethodsA retrospective clinical case study. A total of 89 MNV patients with 96 eyes who were diagnosed and treated with anti-VEGF drugs in Department of Ophthalmology of The Second Hospital of Lanzhou University from January 2020 to January 2024 were included in the study. The ages of all patients were <45 years old. All patients underwent best corrected visual acuity (BCVA) and optical coherence tomography (OCT) examinations; 49 eyes underwent OCT angiography (OCTA) examination. The BCVA examination was carried out using the international standard visual acuity chart and was converted into the logarithm of the minimum angle of resolution (logMAR) visual acuity for statistics. The macular foveal thickness (CMT) was measured using an OCT instrument. The size of the MNV lesion was measured using the software of the OCTA self-contained device. The affected eyes were given intravitreal injection of anti-VEGF drugs once, and then the drugs were administered as needed after evaluation. The follow-up time after treatment was ≥6 months. During the follow-up, relevant examinations were performed using the same equipment and methods as before treatment. The last follow-up was taken as the time point for efficacy evaluation. According to the OCT image characteristics of the MNV lesions, the affected eyes were divided into the fibrous scar group and the non-fibrous scar group, with 52 (54.16%, 52/96) and 44 (45.83%, 44/96) eyes respectively. Comparing the CMT and BCVA at the last follow-up with those at the baseline, the affected eyes were divided into the CMT reduction group, the CMT increase group, the BCVA improvement group and the BCVA reduction group, with 66 (68.75%, 66/96), 30 (31.25%, 30/96) eyes and 74 (77.08%, 74/96), 22 (22.92%, 22/96) eyes respectively. The Mann-Whitney U test was used for the comparison of non-normally distributed measurement data between groups. Logistic regression analysis was used to analyze the independent factors affecting the prognosis of MNV patients. ResultsThere were no statistically significant differences in the age (Z=?0.928) and gender composition ratio (χ2= 0.123) between the fibrous scar group and the non-fibrous scar group (P>0.05); there were statistically significant differences in the number of eyes with a follow-up time of ≥36 months and <36 months (χ2= 3.906, P=0.048); there were statistically significant differences in the size of the MNV lesions (Z=?2.385, P=0.017); there were statistically significant differences in the number of eyes with different vascular network morphologies (χ2=12.936, P=0.001). Before treatment and at the last follow-up, the CMT of the affected eyes was 267.50 (237.25, 311.75) μm and 242.00 (217.25, 275.75) μm respectively; logMAR BCVA was 0.20 (0.10, 0.50) and 0.35 (0.16, 0.60) logMAR respectively. There were statistically significant differences in the CMT and logMAR BCVA before treatment and at the last follow-up (Z=?3.311,?1.984; P=0.001, 0.047). There were statistically significant differences in different ages (Z=?2.284), myopic diopter (χ2=7.437), etiology (χ2=6.956), and disease course (Z=?1.687) between the CMT reduction group and the CMT increase group (P<0.05). There were statistically significant differences in the number of eyes with different subjective feelings between the BCVA improvement group and the BCVA reduction group (χ2=10.133, P<0.05). The results of logistic regression analysis showed that the etiology was an independent risk factor for CMT thickening. ConclusionsAge, etiology, myopic diopter, disease course, follow-up time, lesion size and the morphology of the neovascular network are the influencing factors for the prognosis of anti-VEGF drug treatment in MNV patients under 45 years old. The etiology is an independent risk factor for CMT increase.
ObjectiveTo observe the clinical features of high myopia domed-shaped macula (DSM) complicated with choroidal neovascularization (CNV) and the efficacy of intravitreal injection of anti-vascular endothelial growth factor (VEGF). MethodsA retrospective clinical study. A total of 23 eyes of 23 patients with high myopia DSM combined with CNV diagnosed by ophthalmology examination in Department of Ophthalmology of The Second People's Hospital of Foshan from January 2019 to December 2023 were included in the study.Best corrected visual acuity (BCVA), intraocular pressure, optical coherence tomography (OCT) were performed in all eyes. BCVA tests are performed using the international standard visual acuity chart, which was statistically converted to logarithm of the minimum angle of resolution (logMAR) visual acuity. DSM height, central macular thickness (CMT) and choroidal thickness (ChT) were measured by OCT. According to OCT image features, DSM was divided into horizontal and vertical elliptic bulges and circular bulges. According to the literature standard, CNV was divided into subfoveal CNV and parafoveal CNV. All patients were treated with 0.05 ml intravitreal injection of ranibizumab or conbercept (IVR or IVC). The treatment regimen was 1+ on-demand treatment. The first IVR and IVC treatment were performed on 17 eyes and 6 eyes, respectively, and were divided into IVR group and IVC group. Follow-up time ≥1 month after treatment. The clinical features of the patients and the changes of BCVA, intraocular pressure, CMT and ChT after treatment were observed. Independent sample t test was used for comparison between groups. ResultsThere were 23 eyes in 23 cases, 7 males had 7 eyes and 16 females had 16 eyes. There were 11 and 12 eyes in the right and left eyes respectively. Age were (49±16) years old; logMAR BCVA was 0.94±0.39. Shapes of DSM were in 13 (56.52%, 13/23), 6 (26.09%, 6/23), and 4 (17.39%, 4/23) eyes, respectively. The dome height was (97.83±46.14) μm. CMT and ChT were (276.39±98.35) and (49.48±31.66) μm, respectively. There were 17 eyes in the IVR group, including 4 males and 13 females. There were 6 cases in the IVC group, 3 cases were male and 3 cases were female. At the last follow-up, logMAR BCVA and CMT were 0.60±0.39 and (209.96±71.38) μm, respectively. BCVA was significantly increased and CMT was significantly decreased compared with before treatment, with statistical significance (t=2.98, 2.62; P=0.005, 0.010). One month after treatment and at the last follow-up, there were no significant differences in the degree of BCVA improvement (t=1.47, 1.35), intraocular pressure change (t=?0.20, ?0.56) and ChT reduction thickness (t=0.80, ?0.62) between IVR group and IVC group (P>0.05). At 1 month after treatment and last follow-up, the CMT of patients in IVR group and IVC group was decreased by (57.94±67.61), (83.17±78.37) μm and (13.33±9.73), (18.17±17.88) μm compared with that before treatment, respectively, and the differences were statistically significant (t=2.64, 3.21; P<0.05). ConclusionsIVR or IVC in the treatment of high myopia DSM combined with CNV can effectively improve BCVA. The reduction of CMT with ranibizumab is better than conbercept.
Retinal vein occlusion (RVO) is a closely related disease of ophthalmology and systemic diseases. The Expert consensus on clinical diagnosis and treatment path of retinal vein occlusion in China (consensus) emphasizes that etiological diagnosis and treatment should be paid primary attention to, and etiological exploration should be placed in an important position in the diagnosis and treatment path. In addition to etiological treatment, the consensus emphasizes that clinical attention should be paid to the management of anterior segment neovascularization, neovascular glaucoma and macular edema. Especially for patients with short course of central retinal vein occlusion, the occurrence of 100-day glaucoma should be vigilant, and active anti-vascular endothelial growth factor (VEGF) drugs, laser photocoagulation and intraocular pressure treatment should be taken. For the treatment of macular edema, the consensus points out that anti-VEGF drugs and intraocular glucocorticoid sustained-release agents are effective, but the latter should be used cautiously to avoid problems such as high intraocular pressure glaucoma and accelerated cataract formation. For deficient RVO, the consensus defines its concept, defines the time point of treatment when combined with macular edema, and clarifies the applicable conditions of laser therapy.
Objective To observe the efficacy and safety of subretinal injection of Aflibercept for the treatment of refractory or recurrent polypoidal choroidal vasculopathy (PCV). MethodsA prospective clinical research. From January to June 2022, 18 patients of 18 eyes with PCV diagnosed in The Affiliated Eye Hospital of Nanchang University were included in the study. All patients underwent best corrected visual acuity (BCVA), indocyanine green angiography and optical coherence tomography (OCT). The BCVA examination was performed using the international standard visual acuity chart, which was converted to logarithm of the minimum angle of resolution (logMAR) visual acuity during statistics. The large choroidal vessel thickness (LVCT), central retinal thickness (CRT), sub-foveal choroidal thickness (SFCT) and retinal pigment epithelium detachment (PED) height were measured by enhanced depth imaging technique of OCT. The choroidal vascular index (CVI) was calculated. There were 18 patients of 18 eyes, 11 males of 11 eyes and 7 females of 7 eyes. The age was (64.22±3.86) years old. The disease duration was (5.22±1.80) years. The patient had received intravitreal injection of anti-vascular endothelial growth factor (VEGF) drugs for (7.72±1.36) times. The logMAR BCVA of the affected eyes was 1.28±0.25. The SFCT, CRT, LVCT, PED height were (436.56±9.80), (432.44±44.29), (283.78±27.10), (342.44±50.18) μm, respectively, and CVI was 0.65±0.01. All eyes were treated with a single subretinal injection of 40 mg/ml Aflibercept 0.05 ml (including Aflibercept 2.0 mg). According to the results of OCT and BCVA after treatment, the lesions were divided into active type and static type. The active lesions were treated with intravitreal injection of Aflibercept at the same dose as before. Quiescent lesions were followed up. Examinations were performed 1-3, 6, 9 and 12 months after treatment using the same equipment and methods before treatment. The BCVA, LVCT, CRT, SFCT, PED height, CVI, interretinal or subretinal fluid, lesion regression rate, injection times, and complications during and after treatment were observed. The BCVA, SFCT, CRT, LVCT, PED height and CVI before and after treatment were compared by repeated measures analysis of variance. ResultsEighteen eyes received subretinal and/or intravitreal injection of Aflibercept (1.61±0.85) times (1-4 times). At the last follow-up, the polypoid lesions regressed in 4 eyes and PED disappeared in 1 eye. Compared with before treatment, BCVA (F=50.298) gradually increased, CRT (F=25.220), PED height (F=144.16), SFCT (F=69.77), LVCT (F=136.69), CVI (F=72.70) gradually decreased after treatment. The differences were statistically significant (P<0.001). Macular hole occurred in 1 eye after treatment, and the hole closed spontaneously 3 months after treatment. No serious complications such as retinal tear, retinal detachment, endophthalmitis and vitreous hemorrhage occurred during and after treatment. ConclusionSubretinal injection of Aflibercept is safe and effective in the treatment of refractory PCV.
Objective To observe and evaluate the safety and efficacy of anti-vascular endothelial growth factor (VEGF) in the treatment of eyes with macular edema (ME) secondary to branch retinal vein occlusion (BRVO) in Lhasa, Tibet. MethodsA retrospective case series. From September 2018 to January 2022, a total of 41 patients (41 eyes) with BRVO-ME, who were diagnosed in Department of Ophthalmology of Tibet Autonomous Region People’s Hospital, were included in this study. There were 21 eyes in 21 males and 20 eyes in 20 females. The median age was 53 (31,75) years. There were 24 patients with hypertension (58.8%, 24/41). Best corrected visual acuity (BCVA), ocular pressure, fundus color photography and optical coherence tomography (OCT) were performed in all eyes. The BCVA was performed using the international standard logarithmic visual acuity chart, which was converted into logarithm of the minimum angle of resolution (logMAR) BCVA for record. The foveal macular thickness (CMT) was measured by OCT. All eyes were treated with intravitreous injection of anti-VEGF drugs, once a month, among which 23 eyes (56.1%, 23/41) received intravitreous injection of ranibizumab (IVR), and 18 eyes (43.9%, 18/41) received intravitreous injection of conbercept (IVC), and were grouped accordingly. There was no significant difference in age (Z=-0.447), gender composition (Z=-0.485), logMAR BCVA (t=-1.591), intraocular pressure (t=-0.167) and CMT (t=-1.290) between two groups (P>0.05). During the follow-up, the same devices and methods were used at baseline to perform relevant examinations, and the changes of BCVA, intraocular pressure, CMT and new cardiovascular and cerebrovascular events were compared between baseline and the last follow-up. logMAR BCVA, intraocular pressure and CMT were compared between baseline and last follow-up using Student t test. The comparison of injection times and follow-up time between IVR group and IVC group was conducted by Mann-Whitney U test. ResultsAt baseline, logMAR BCVA, intraocular pressure, and CMT were 0.852±0.431, (12.5±2.5) mm Hg (1 mm Hg= 0.133 kPa), and (578.1±191.1) μm, respectively. At the last follow-up, the number of anti-VEGF drug treatments was (2.7±1.2) times; logMAR BCVA and CMT were 0.488±0.366 and (207.4±108.7) μm, respectively, with CMT > 250 μm in 14 eyes (34.1%, 14/41). Compared with baseline, BCVA (t=4.129) and CMT (t=-0.713) were significantly improved, with statistical significance (P<0.001). The injection times of IVR group and IVC group were (2.6±0.9) and (3.0±1.5) times, respectively. There were no significant differences in the number of injection times (t=-1.275), logMAR BCVA (t=-0.492), intraocular pressure (t=0.351) and CMT (t=-1.783) between the two groups (P>0.05). No new hypertension, cardiovascular and cerebrovascular events occurred in all patients during follow-up. At the last follow-up, there were no eye complications related to treatment modalities and drugs. ConclusionShort-term anti-VEGF treatment can improve the visual acuity of BRVO secondary ME patients and alleviate ME in Lhasa, Tibet. The safety and efficacy of ranibizumab and conbercept were similar.
ObjectiveTo explore the related risk factors of vitreous macular interface abnormalities (VMIA) in eyes with diabetic macular edema (DME) after receiving anti-vascular endothelial growth factor (VEGF) drug treatment, and to evaluate the influence of VMIA on the best corrected visual acuity (BCVA) and central retinal thickness (CRT) of the affected eyes. MethodsA retrospective cohort study. From January 2021 to January 2023, 285 DME patients (285 eyes) who received anti-VEGF drug treatment at Tianjin Medical University Eye Hospital and had no VMIA at baseline were included in the study. All affected eyes underwent BCVA examination, and CRT was measured by optical coherence tomography. The treatment plan was a monthly stress therapy for the initial three months, followed by treatment as needed. According to whether VMIA was formed 12 months after treatment, the affected eyes were divided into the VMIA formation group and the non-VMIA formation group, that was further subdivided based on the VMIA classification. Logistic regression model was used to analyze the risk factors for VMIA formation and its influence on BCVA and CRT 12 months after treatment. ResultsTwelve months after treatment, among 285 eyes, 111 eyes (38.9%) developed VMIA (VMIA formation group), and 174 eyes (61.1%) did not develop VMIA (non-VMIA formation group). Logistic regression analysis showed that a thinner baseline CRT [odds ratio (OR=0.99, 95% confidence interval (CI) 0.98-0.99, P=0.04] was associated with a higher number of anti-VEGF drug injections (OR=1.12, 95%CI 1.02-1.23, P=0.02) was a risk factor for the formation of VMIA. However, the formation status of VMIA itself was not an influencing factor for BCVA (OR=1.89, 95%CI 0.98-3.67, P=0.06) or CRT (OR=1.34, 95%CI 0.30-0.83, P=0.40) at 12 months after treatment. The intergroup comparison showed that at 12 months after treatment, the improvement degrees of BCVA and CRT in the VMIA formation group were both worse than those in the non-VMIA formation group (t=2.99, 2.07; P<0.00, 0.05). Furthermore, in the VMIA subtype analysis, the improvement degree of CRT in the affected eyes with epiretinal membrane (ERM) was significantly lower than that in the affected eyes without ERM (t=4.31, P<0.001). ConclusionsThinner baseline CRT and more injection times are associated with the occurrence of VMIA; compared with the eyes without VMIA formation, the improvement of BCVA and CRT in the eyes with VMIA formation is less during the 12-month follow-up period after treatment. The formation of VMIA has no significant effect on BCVA or CRT at 12 months after treatment. The improvement effect of CRT is the poorest in patients with ERM.
ObjectiveTo observe changes in peripapillary blood flow before and after combined treatment with anti-vascular endothelial growth factor (VEGF) drugs and Dexamethasone intravitreal implant (DEX) in patients with central retinal vein occlusion (CRVO). MethodsA prospective clinical study. Thirty-three eyes of 33 patients with newly diagnosed non-ischemic CRVO and macular edema (ME) were enrolled from Shanxi Eye Hospital between April 2023 and April 2024. All patients underwent best-corrected visual acuity (BCVA) and swept-source optical coherence tomography angiography (SS-OCTA) examinations. The treatment regimen consisted of three intravitreal injections of ranibizumab and one DEX implant. SS-OCTA was used to scan a 3 mm×3 mm area centered on the optic disc to measure peripapillary retinal nerve fiber layer (RNFL) thickness and blood flow density in the superficial vascular complex (SVC), deep vascular complex (DVC), and radial peripapillary capillaries (RPC). Changes in SVC, DVC, and RPC blood flow density and RNFL thickness were evaluated at 3 and 6 months post-treatment. Shapiro-Wilk test was used to assess normality, and Spearman's rank correlation coefficient was applied for correlation analysis. ResultsCompared with before treatment, the blood flow density changes of SVC and RPC showed a downward trend at 3 and 6 months after treatment. Among them, the difference was statistically significant at 6 months after treatment (Z=?2.592, ?2.070, P=0.012, 0.042), while there was no statistically significant difference at 3 months after treatment (P>0.05). The blood flow density of DVC showed an upward trend at 3 and 6 months after treatment, but the differences were not statistically significant (P>0.05). The results of the correlation analysis showed that the thickness of RNFL was negatively correlated with the blood flow density of DVC (r=?0.768, P<0.001). It was positively correlated with the blood flow densities of SVC and RPC (r=0.288, 0.398; P=0.040, 0.004). ConclusionAnti-VEGF drugs combined with DEX treatment can significantly improve the perioptic disc blood flow distribution in eyes with CRVO, manifested as a decrease in blood flow density of SVC and RPC, while a compensatory increase in blood flow of DVC. The thickness variation of RNFL is closely related to the blood flow density of different vascular layers.
Objective To compare the outcomes of ranibizumab and conbercept adjunct for pars plana vitrectomy (PPV) in the treatment of proliferative diabetic retinopathy (PDR). MethodsA prospective randomized case-control study. From June 2022 to December 2023, 90 cases (90 eyes) of PDR patients diagnosed through ophthalmic examination at Department of Ophthalmology of Gansu Provincial Hospital were included in the study. All patients underwent the best corrected visual acuity (BCVA), intraocular pressure, B-mode ultrasound, and optical coherence tomography (OCT) examinations. The central macular thickness (CMT) was measured using an OCT instrument. The patients were randomly divided into a intravitreal injection of ranibizumab group (monoclonal-antibody group) and a intravitreal injection of conbercept group (fusion-protein group) using a random number table method, with 45 cases (45 eyes) in each group. Two groups of patients were intravitreal injected with 10 mg/ml ranibizumab or conbercept 0.05 ml, respectively. A standard 23G PPV was performed through the flat part of the ciliary body 3-7 days after intravitreal injection. Relevant examinations were performed using the same equipments and methods as before surgery at postoperative 1 week, 1, 3, 6, and 12 months. The PPV time, intraoperative use of intraocular electrocoagulation, incidence of iatrogenic retinal breaks, and sterile air or silicone oil tamponade rate in the vitreous cavity, the postoperative changes of BCVA and CMT, and incidence of complications were compared between two groups. Independent sample t test was used for inter group comparison. ResultsThe intraoperative utilization rate of intraocular electrocoagulation in the monoclonal-antibody group was higher than that in the fusion-protein group, and the difference was statistically significant (χ2=3.876, P<0.05). There were no statistically significant differences in the PPV time (t=0.152), intraoperative bleeding rate (χ2=0.800), incidence of iatrogenic retinal breaks (χ2=1.975), and sterile air and silicone oil tamponade rate in the vitreous cavity (χ2=1.607, 1.553) between the two groups (P>0.05). There were no statistically significant differences in early and late postoperative vitreous hemorrhage (χ2=1.235, 2.355), and re-PPV (χ2=2.355) between two groups (P>0.05). The BCVA of the fusion-protein group was significantly better than that of the monoclonal-antibody group at postoperative 3 months, and the difference was statistically significant (t=2.428, P<0.05). The CMT of the fusion-protein group was lower than that in the monoclonal-antibody group at postoperative 1 week, and the difference was statistically significant (t=2.739, P<0.05). None of the patients experienced endophthalmitis, retinal artery occlusion, or severe cardiovascular events after surgery. ConclusionCompared with intravitreal injection of ranibizumab before PPV, intravitreal injection of conbercept before PPV in PDR patients can shorten the surgical time, reduce intraoperative bleeding rate, lower the rate of electrocoagulation and intraocular tamponade, and incidence of iatrogenic retinal breaks, and improve the visual acuity.