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. 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.
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.