ObjectiveTo observe the clinical effect of subretinal injection and intravitreal injection of conbercept in the treatment of polypoid choroidal vasculopathy (PCV). MethodsA prospective, randomized double-blind controlled study. From June 2022 to January 2023, 35 patients of 35 eyes with PCV diagnosed at Affiliated Eye Hospital of Nanchang University were included in the study. All patients were first-time recipients of treatment. Best corrected visual acuity (BCVA), optical coherence tomography (OCT), and indocyanine green angiography (ICGA) were performed in all affected eyes. BCVA was performed using an international standard visual acuity chart and converted to logarithmic minimum resolved angle (logMAR) visual acuity for statistical purposes. Enhanced depth imaging with OCT instrument was used to measure the macular retinal thickness (MRT), subfoveal choroidal thickness (SFCT), and pigment epithelium detachment (PED) height. Randomized numerical table method was used to divide the patients into subretinal injection group (group A) and vitreous cavity injection group (Group B), 18 cases with 18 eyes and 17 cases with 17 eyes, respectively. Comparison of age (t=0.090), disease duration (t=?0.370), logMAR BCVA (t=?0.190), MRT (t=0.860), SFCT (t=0.247), and PED height (t=?0.520) between the two groups showed no statistically significant difference (P>0.05). The eyes of group A were given one subretinal injection of 10 mg/ml conbercept 0.05 ml (containing conbercept 0.5 mg), and subsequently administered on demand (PRN); eyes in group B were given intravitreal injection of 10 mg/ml conbercept 0.05 ml (containing conbercept 0.5 mg). The treatment regimen was 3+PRN. Lesions were categorized into active and quiescent according to the results of post-treatment OCT and BCVA. Active lesions were treated with intravitreal injection of conbercept at the same dose as before; stationary lesions were followed up for observation. BCVA and OCT were performed at 1, 2, 3, 6 and 9 months after treatment; ICGA was performed at 3, 6 and 9 months. BCVA, MRT, SFCT, and PED height changes before and after treatment were compared and observed in the affected eyes of the two groups. Independent sample t-test was used to compare between the two groups. ResultsWith the prolongation of time after treatment, the BCVA of the affected eyes in groups A and B gradually increased, and the MRT, SFCT, and PED height gradually decreased. Compared with group B, at 2, 3, 6, and 9 months after treatment, the BCVA of group A was significantly improved, and the difference was statistically significant (t=?2.215, ?2.820, ?2.559, ?4.051; P<0.05); at 1, 2, 3, 6, and 9 months after treatment, the MRT of the affected eyes in group A (t=?2.439, ?3.091, ?3.099, ?3.665, ?5.494), SFCT (t=?3.370, ?3.058, ?3.268, ?4.220, ?4.121), and PED height (t=?3.460, ?4.678, ?4.956, ?5.368, ?6.396) were significantly reduced, and the differences were statistically significant (P<0.05). No complications such as intraocular inflammation, high intraocular pressure, or vitreous hemorrhage occurred in any of the affected eyes during or after treatment. ConclusionCompared with the intravitreal injection of conbercept, the subretinal injection of conbercept can more effectively reduce the height of MRT, SFCT, PED height, and improve the visual acuity of the affected eyes with PCV.
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.
ObjectiveTo develop a simple and effective subretinal injection pipeline system to enhance the accuracy and precision of subretinal injection volume control. MethodsA retrospective case series study. From May to October 2023, 18 patients (18 eyes) with submacular hemorrhage (SMH) who continuously received modified subretinal injection treatment in Department of Ophthalmology of Peking Union Medical College Hospital were included in the study. Among them, there were 10 males and 8 females. The mean age was (60.00±7.41) years. The primary causes included polypoid choroidal vasculopathy (14 cases), retinal macroaneurysm (2 cases), traumatic retinopathy (1 case), and Valsalva retinopathy (1 case). Hemorrhage affected 14 eyes of the fovea centralis. All affected eyes underwent standard three-channel 25G vitrectomy via the flat part of the ciliary body combined with modified subretinal injection of recombinant tissue plasminogen activator. The improved injection system consisted of a 1 ml syringe, a Q-SyteTM connector, a 41G subretinal microinjection needle, a converter and a viscoelastic substance control pipeline. The drug preparation time for subretinal injection (i.e., the time consumed by the system connection step), the injection time, whether bubbles occur during the injection process, and the perioperative complications were recorded and analyzed. ResultsThe preparation time prior to drug injection ranged from 230 to 335 seconds, while the injection completion time varied between 43 and 75 seconds. Both times decreased progressively as operator proficiency improved. Among the treated eyes, five received a target injection dose of 0.05 ml and thirteen received 0.10 ml, with all eyes achieving the preset dose accurately. No subretinal bubbles were observed during the injection procedure. Additionally, no intraoperative complications such as retinal hemorrhage or tear secondary to mechanical trauma at the injection site were recorded. Postoperatively, one eye developed anterior chamber hemorrhage, which resolved following intraocular pressure-lowering treatment. No other postoperative complications, including hemorrhage, rhegmatogenous retinal detachment, or infection, were observed in the remaining eyes. ConclusionThe retinal drug injection system developed in this study has a simple structure, safe and stable operation, can achieve precise drug injection, and effectively avoid the formation of bubbles.
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 evaluate the therapeutic efficacy of vitrectomy with internal limiting membrane (ILM) peeling and subretinal injection of balance salt solution (BSS) for refractory diabetic macular edema (DME).MethodsA retrospective case series study. From November 2017 to August 2018, 24 eyes of 19 patients affected with DME resistant to anti-VEGF therapy [central macualar thickness (CMT) more than 275 μm despite undergoing anti-VEGF therapy at least 3 times] in Ophtalmology Department of Central Theater Command General Hospital of Chinese People's Liberation Army were enrolled in this study. All the patients underwent 25G pars plana vitrectomy with ILM peeling and subretinal injection of BSS. The BCVA was measured using the international standard visual acuity chart, and the results were converted to the logMAR visual acuity. The CMT and the macular volume (MV) were assessed with swept-source optical coherence tomography at baseline and each month postoperatively. The differences in BCVA, CMT and MV before and after surgery were analyzed.ResultsThe mean BCVA was 0.74±0.29 at baseline, which increased significantly to 0.62±0.28, 0.56±0.25, 0.47±0.26, 0.46±0.23 at 2 weeks, 1 month, 3 months and 6 months after treatment respectively (F=4.828, P=0.001). At 6 months, BCVA improved by more than 0.3 logMAR units in 16 eyes (66.7%). The mean CMT was 554.58±102.86 μm at baseline, which reduced to 338.17±58.09 μm, 299.42±52.66 μm, 275.75±41.24 μm and 270.96±38.33 μm at 2 weeks, 1 month, 3 months and 6 months after treatment respectively (F=84.867, P<0.001). The mean MV was 13.01±0.88 mm3 at baseline, which decreased to 11.50±0.73 mm3, 11.00±0.74 mm3, 10.68±0.61 mm3 and 10.52±0.56 mm3 at 2 weeks, 1 month, 3 months and 6 months after treatment respectively (F=47.364, P<0.001). Macular edema recurred in 5 eyes (20.8%) 6 months after surgery. No severe systemic or ocular side effect was reported during the follow-up.Conclusions25G vitrectomy with ILM peeling and subretinal injection of BSS for refractory DME can improve the visual acuity, facilitate a rapid resolution of macular edema.
Objective To observe the clinical effect of vitrectomy, inner limiting membrane (ILM) peeling, subretinal injection of compound electrolyte intraocular irrigation solution (CEIIS) and conbercept in the treatment of diabetic macular edema (DME) with hard exudate (HE) (DME-HE). MethodsA prospective clinical study. Thirty-three patients with DME-HE diagnosed by examination in Weifang Eye Hospital from June 2020 to February 2022 were included in the study. Among them, there were 15 males (16 eyes) and 18 females (20 eyes), with the mean age of (62.00±6.54) years. All patients underwent the examinations of best corrected visual acuity (BCVA), scanning laser ophthalmoscope, optical coherence tomography (OCT), and multifocal electroretinography (mf-ERG). Snellen visual acuity chart was used for BCVA examination, which was converted into logarithm of the minimum angle of resolution (logMAR) BCVA for statistic analysis. Macular foveal retinal thickness (CMT) and macular volume (MV) were measured by OCT. The 1 ring P1 wave amplitude density was measured by mf-ERG. The patients were randomly divided into group A and group B, with 17 patients (18 eyes) and 16 patients (18 eyes), respectively. There were no significant differences in age, logMAR BCVA, HE area, CMT, MV, and 1 ring P1 wave amplitude density between the two groups (t=0.403, 0.972, 0.291, 0.023, -0.268, -0.206; P>0.05). Group A was treated with vitrectomy, ILM peeling, and subretinal injection of CEIIS and conbercept (combined therapy). Group B was treated with intravitreal injection of conbercept (IVC). Follow-up was 12 months after treatment. The changes of BCVA, HE area, CMT, MV, 1 ring P1 wave amplitude density were compared between groups and groups after treatment. The times of injection and complications after treatment were observed. Independent sample t test was used for comparison between the two groups. ResultsAt 12 months after treatment, compared to before treatment, there were significant differences in logMAR BCVA (F=14.837), HE area (χ2=94.522), CMT (χ2=199.212), MV (χ2=81.914) and 1 ring P1 wave amplitude density (F=8.933) in group A (P<0.05); there were significant differences in CMT (F=5.540) and MV (F=7.836) in group B (P<0.05). Compared between the two groups, logMAR BCVA: 1 week and 6 and 12 months after treatment, the difference was statistically significant (t=2.231, -2.122, -3.196; P<0.05); HE area: except 1 week after treatment, there were statistically significant differences at other times after treatment (t=-2.422, -3.107, -3.540, -4.119; P<0.05). CMT, MV, 1 ring P1 wave amplitude density: 12 months after treatment, the differences were statistically significant (t=-2.653, -2.455, 2.204; P<0.05). During the follow-up period, the injection times of group A and group B were (3.06±1.89) and (5.56±2.04), respectively, and the difference was statistically significant (t=-3.815, P<0.05). Macular hole and vitreous hematoma were found in 1 eye in group A and 1 eye in group B. ConclusionVitrectomy, ILM peeling, subretinal injection of CEIIS and conbercept to treat DME-HE can effectively remove HE, alleviate macular edema, improve BCVA, and reduce CMT and MV. Combination therapy can reduce the number of IVC re-treatments.
ObjectiveTo evaluate the efficacy and safety of 41G ultramicroneedle subretinal injection of balanced salt solution (BSS) in the treatment of large diameter macular holes (MH). MethodsA prospective clinical intervention study. A total of 22 eyes of 22 large-diameter full-layer MH patients diagnosed by examination in Tianjin Eye Hospital from March to June 2024 were included in the study. The minimum diameter of MH in the affected eyes was all greater than 400 μm. The affected eyes received 25G pars plana vitrectomy combined with internal limiting membrane peeling and 41G ultramicroneedle subretinal injection of BSS. The affected eyes underwent best-corrected visual acuity (BCVA), microperimetry, fundus autofluorescence, and optical coherence tomography (OCT) examinations before and 1 and 3 months after surgery. BCVA was measured using the standard logarithmic visual acuity chart and converted to logarithm of the minimum angle of resolution (logMAR) visual acuity for statistical analysis. The minimum and base diameter of MH were measured using OCT. Microperimetry was performed using a macular integrity assessment device, recording the macular integrity index (MII) and macular threshold (MT) within 10° of the macular. The changes in BCVA, MII, MT, and the closure of MH and the occurrence of complications were compared and analyzed before and after surgery. For the comparison of the same continuous indicators before and after surgery, Student's t-test was used if the data were normally distributed and had equal variances, and the Mann-Whitney U test was used if the data were not normally distributed; the correlation between different indicators was analyzed using Pearson correlation analysis. ResultsAmong the 22 cases (22 eyes), there were 4 males and 18 females; all were unilaterally affected. The age was 66 (60, 71) years. The duration of the disease was 5 (2.5, 12.0) months. The logMAR BCVA of the affected eyes was 1.24±0.57, and the MII and MT were 100.0 (99.53, 100.00) and 19.0 (13.23, 21.78) dB, respectively. One month after surgery, all MH were closed, with 20 (90.91%, 20/22) and 2 (9.09%, 2/22) eyes classified as typeⅠand Ⅱ closure, respectively. At the last follow-up, the logMAR BCVA was 0.62±0.58, and the MII and MT were 99.9 (59.45, 100.00) and 23.6 (19.33, 26.25) dB, respectively; compared with before surgery, the BCVA (t=3.579), MII (Z=-2.374), and MT (Z=-2.997) were significantly improved, and the differences were all statistically significant (P<0.05). Correlation analysis showed that postoperative BCVA was significantly positively correlated with preoperative BCVA (r=0.41), the minimum and base diameter of MH (r=0.64, 0.58), disease duration (r=0.63), and age (r=0.50) (P<0.05). No surgery-related complications occurred in all affected eyes during the follow-up period. Conclusion41G ultramicroneedle subretinal injection of BSS can effectively improve the hole closure rate of large diameter MH-affected eyes in the short term, improve visual function, and has good safety.
Objective To observe the efficacy and safety of pars plana vitrectomy (PPV) combined with subretinal injection of dexamethasone in treating refractory diabetic macular edema (DME). MethodsA prospective case study. From January 2024 to March 2024, 9 cases with 10 eyes of refractory DME diagnosed at Tianjin Eye Hospital were included in the study. All eyes had a central macular thickness (CMT) of greater than 275 μm despite receiving intravitreal injection of anti-vascular endothelial growth factor (VEGF) drug at least 5 times. All eyes underwent 25G PPV combined with internal limiting membrane (ILM) peeling and subretinal injection of dexamethasone sodium phosphate. Best-corrected visual acuity (BCVA), microperimetry, and optical coherence tomography examinations were performed on all eyes before and 1 and 3 months after surgery. BCVA was assessed using an international standard visual acuity chart and converted to logarithm of the minimum angle of resolution (logMAR) for statistical analysis. Paired t-tests were used to compare changes in BCVA, mean macular sensitivity (MS), and CMT before and after surgery. The intraoperative and postoperative complications were recorded. ResultsAmong the 9 cases with 10 eyes, there were 4 males with 5 eyes and 5 females with 5 eyes. Age ranged from 43 to 79 (65.3±10.8) years. Preoperative and postoperative logMAR BCVA at 1 and 3 months were 0.84±0.25, 0.72±0.31, and 0.63±0.22, respectively. MS was (16.48±5.03), (16.6±6.31), and (18.0±5.33) dB, respectively. CMT was (437.5±90.4), (306.9±87.4), and (288.7±87.3) μm, respectively. Compared with data before surgery, BCVA: the difference was not statistically significant at 1 month (t=2.025, P=0.074), but was statistically significant at 3 months (t=5.161, P=0.001), MS: the differences at 1 and 3 months were not statistically significant (t=-0.078, -1.022, P=0.940, 0.334), CMT: the differences were of statistical significance at both 1 and 3 months (t=2.892, 3.175, P=0.018, 0.011), and the difference between 1 and 3 months post-surgery was also statistically significant (t=2.427, P=0.038). No complications such as macular hole, vitreous hemorrhage, or retinal detachment occurred during or after surgery in any eyes. No cases of increased intraocular pressure or cataracts were reported during the follow-up period. ConclusionPPV combined with ILM peeling and subretinal injection of dexamethasone can effectively reduce CMT in refractory DME eyes and improve visual acuity, with good safety.
Objective To compare and observe the efficacy and safety of pars plana vitrectomy (PPV) combined with 41G ultrafine needle injection of balanced salt solution (BSS) and internal limiting membrane inversion and coverage in the treatment of large-diameter macular hole (MH). MethodsA prospective study. From April 2023 to April 2024, 42 patients (42 eyes) diagnosed with large-diameter MH at The Affiliated Eye Hospital of Nanchang University were included in the study. The substrate diameters (BD) of MH are all greater than 1 000 μm. All affected eyes underwent best corrected visual acuity (BCVA), microvisual field, optical coherence tomography (OCT), and OCT angiography (OCTA) examinations before surgery. BCVA examination was conducted using the international standard logarithmic visual acuity chart, and the statistics were converted to the logarithm of the minimum angle of resolution (logMAR) visual acuity. Microfield-of-view examination records the mean retinal sensitivity (MS) within a 12° range of the fovea. The minimum diameter (MD) and BD of the hole were measured by OCT and the MH index (MHI) was calculated. OCTA measures the area and perimeter (PERIM) of the foveal avascular zone (FAZ) in the fovea centralis, as well as the retinal vessel length density (VLD) and vessel perfusion density (VPD) in the central area. The affected eyes were divided into the observation group (22 eyes, treated with PPV combined with 41G ultra-micro needle subretinal injection of BSS and the control group (20 eyes, treated with PPV combined with internal limiting membrane inversion and coverage) according to the random number table method. The patients were followed up for 6 months after the operation, and the above indicators were reexamined at 1, 3 and 6 months. The changes of BCVA, MS, FAZ parameters, VLD, VPD before and after the operation, as well as the closure of the hole and the occurrence of complications were compared between the two groups. The independent sample t test was used for comparison between groups. The correlation between postoperative indicators and preoperative structural parameters was analyzed using Pearson analysis. ResultsIn the 22 eyes of the observation group, the hole closure rate was 100.0% (22/22) 6 months after the operation, and the complete closure rate was 90.9% (20/22). In the control group of 20 eyes, the closure rate was 95.0% (19/20), and the complete closure rate was 90.0% (18/20). The hole closure rate of the affected eyes in the observation group was better than that in the control group, but the difference was not statistically significant (χ2=1.736, P=0.420). The logMAR BCVA, MS, FAZ area, PERIM, VLD and VPD at each time point after the operation in both groups were significantly improved compared with those before the operation, and the differences were statistically significant (P<0.05). The results of Pearson correlation analysis showed that in the observation group, logMAR BCVA at 6 months after surgery was positively correlated with BD before surgery (r=0.340, P=0.029), and negatively correlated with MHI before surgery (r=?0.350, P=0.023). Six months after the operation, MS was positively correlated with the preoperative hole height and MHI (r=0.330, P=0.034). In the control group, 6 months after the operation, MS was negatively correlated with BD before the operation (r=?0.480, P=0.032), and positively correlated with MHI before the operation (r=0.510, P=0.027). Six months after the operation, the FAZ area of the affected eyes in the observation group [(0.17±0.09) mm2] was larger than that in the control group [(0.12±0.07) mm2], and the difference was statistically significant (t=?0.340, P=0.025). No complications such as abnormal intraocular pressure, retinal pigment epithelium injury or retinal detachment occurred in all the affected eyes after the surgery. ConclusionsPPV combined with 41G ultra-micro needle subretinal injection of BSS for the treatment of large-diameter MH has a high rate of hole closure and good safety. Larger BD and MD, lower MHI and hole height before surgery may affect the recovery of visual function after surgery.
ObjectiveTo compare the efficacy of pars plana vitrectomy (PPV) combined with subretinal or intravitreal injection of Conbercept for the treatment of refractory diabetic macular edema (DME). MethodsA retrospective case control study. From June 2022 to March 2024, 32 eyes of 32 patients with refractory DME diagnosed at The Affiliated Eye Hospital of Nanchang University were included in the study. There were 17 male cases with 17 eyes and 15 female cases with 15 eyes. Age was (57.44±8.99) years old; The duration of diabetes was (12.72±6.11) years. All patients had received regular treatment with anti-vascular endothelial growth factor (VEGF) drugs or corticosteroid drugs for at least 5 times, and had undergone focal retinal laser photocoagulation or panretinal laser photocoagulation, the central macular thickness (CMT) persisted or decreased by less than 50 μm. All affected eyes underwent best-corrected visual acuity (BCVA), intraocular pressure, optical coherence tomography (OCT), microperimetry, and laboratory glycated hemoglobin (HbA1c) testing. BCVA was measured using a standard logarithmic visual acuity chart, and converted to the logarithm of the minimum angle of resolution (logMAR) for statistical analysis. CMT was measured using an OCT device. Microperimetry was performed using an MP-3 microperimeter, recording the mean sensitivity (MS) of the retina within a 12° range of the fovea. The affected eyes were treated with 23G PPV combined with internal limiting membrane peeling and either macular subretinal or intravitreal injection of Conbercept, and were divided into subretinal injection group and the intravitreal injection group, each consisting of 16 cases and 16 eyes. The same equipment and methods as before surgery were used for related examinations at 1, 3, and 6 months post-surgery. Changes in BCVA, CMT, and MS were observed and compared, as well as the number of additional anti-VEGF treatments required within 6 months after surgery. Intergroup comparisons were made using independent samples t tests, and repeated measures data were analyzed using repeated measures analysis of variance. ResultsThe age (t=-0.271), gender composition (χ2=0.001), duration of diabetes (Z=-0.868), HbA1c (t=-0.789), intraocular pressure (t=1.689), logMAR BCVA (t=1.393), CMT (t=-0.613), MS (Z=-0.132), and the number of anti-VEGF injections (t=-0.752) between the subretinal injection group and the intravitreal injection group showed no statistically significant differences (P>0.05). The within-subject effects comparison of BCVA, CMT, and MS at 1, 3, and 6 months post-surgery compared to pre-surgery for all affected eyes showed statistically significant differences (F=8.060, 125.722, 39.054; P<0.05). The overall comparison of logMAR BCVA between the subretinal and intravitreal injection groups post-surgery showed no statistically significant difference (F=0.662, P=0.422), however, comparisons of CMT (F=4.540) and MS (F=6.066) showed statistically significant differences (P<0.05). At 1, 3, and 6 months post-surgery, comparisons of logMAR BCVA between the two groups showed no statistically significant differences (t=-0.123, 0.239, 1.087; P>0.05), comparisons of CMT showed statistically significant differences (t=-3.474, -4.832, -2.482; P<0.05), comparisons of MS showed statistically significant differences at 1 and 3 months (t=-2.940, -2.545; P<0.05), but not at 6 months (t=-1.527, P>0.05). At 6 months post-surgery, the number of additional intravitreal anti-VEGF injections required in the subretinal and intravitreal injection groups showed a statistically significant difference (Z=-2.033, P=0.042). During the follow-up period and at the final follow-up, no complications such as injection site bleeding, retinal detachment, vitreous hemorrhage, macular hole, or retinal pigment epithelial tear or atrophy occurred in all affected eyes. ConclusionCompared with intravitreal injection, subretinal injection of Conbercept for the treatment of refractory DME has more advantages in reducing macular edema and improving visual function in the macular area, and also reduces the number of postoperative anti-VEGF drug treatments.