Observation And Analysis Of Changes In Retinal Ganglion Cell Complex Thickness Before And After Treatment Of Branch Retinal Vein Occlusion With Ranibizumab

Objective: To evaluate the changes in the macular retinal ganglion cell complex(GCC)and the retinal nerve fiber layer(RNFL)in patients with retinal branch vein occlusion(BRVO)secondary to macular edema(ME)after intravitreal injection of Ranibizumab.Methods: Patients diagnosed with BRVO-ME in the ophthalmology department of Dalian Municipal Central Hospital from May 2021 to December 2022 were retrospectively analyzed,and 25 patients(25 eyes)who met the inclusion criteria were set up as the experimental group.A total of 30 healthy patients(30 eyes)of the same age and sex without associated eye diseases who attended our department during the same period were selected as the control group.All patients in the experimental group were treated with intravitreal injection of Ranibizumab using the "3+PRN" protocol(i.e.,once a month for the first three months,followed by on-demand treatment).Macular and optic disc data were collected using spectral-domain optical coherence tomography(SD-OCT).The macular area images were automatically defined by the instrument’s own analysis software to divide the macular area into 3 concentric circles and 4 quadrants,forming a total of 9 partitions(e.g.,Figure 3).We combined the 9 subdivisions into(Figure 4)macular fovea(M0),macular superior(MS),macular nasal(MN),macular inferior(MI),and macular temporal(MT).temporal,MT).The images of the optic disc area were automatically divided into 4 quadrants(Figure 1 and Figure 2): superior(S),nasal(N),inferior(I),and temporal(T)by the instrument’s own analysis software.In the experimental group(25 eyes),patients with inferior temporal branch vein obstruction were set up as group A(15 eyes)and patients with superior temporal branch vein obstruction were set up as group B(10 eyes)according to the obstruction site,and the changes of GCC thickness in the macula were analyzed and compared in groups A,B and normal control group before and after the injection.The changes of peri-optic disc RNFL thickness in the experimental group and normal control group before and after the comparison of injection were analyzed.Results:1.Changes of GCC in macular area.1.1 Each zone was thicker than the control group before injection in both groups,and the difference was statistically significant(P < 0.05).The thickness of GCC decreased in each zone after 1,2 and 3 injections compared with that before injection,and the difference was statistically significant(P < 0.05).1.2 There was no statistically significant difference in GCC thickness between M0,MS,and MN zones in group A(inferior temporal BRVO)and M0 and MN zones in group B(superior temporal BRVO)after 2 injections compared with the control group(P > 0.05).1.3 The GCC thickness in MI and MT areas of group A(inferior temporal BRVO)and MS and MT areas of group B(superior temporal BRVO)was still thicker than that of the control group after 3 injections,and the difference was statistically significant(P <0.05).1.4 There was a tendency for the GCC thickness to become thinner after 3 injections in MS and MN areas of group A(inferior temporal BRVO)and M0 and MN areas of group B(superior temporal BRVO)compared with the control group,but the difference was not statistically significant(P > 0.05).2.Changes in the thickness of RNFL around the optic disc.2.1 There was no statistically significant difference in RNFL thickness between the experimental group before injection and the control group(P>0.05).2.2 There was no statistically significant difference between each quadrant of the peri-optical disc RNFL in the experimental group after 3 injections compared with the control group(P>0.05).2.3 There was a trend of decrease in the thickness of peripapillary RNFL in the experimental group after 3 injections compared with that before treatment,but the difference was not statistically significant(P > 0.05).Conclusion:1.The GCC thickness in the macula of BRVO-ME patients was significantly thicker than that of normal subjects.2.Intravitreal injection of Ranibizumab can rapidly reduce the GCC thickness in the macula of BRVO-ME patients and help restore the GCC structure.3.The degree of reduction of macular GCC thickness after intravitreal injection of Ranibizumab was related to the anatomical location of BRVO occurrence,and the GCC in the non-lesioned area had basically returned to normal after 2 injections of Ranibizumab.4.The GCC thickness in the area where BRVO lesion occurred did not return to normal after 3 injections of Ranibizumab,suggesting the need for continued treatment.5.The thickness of GCC(non-lesion-bearing area)and the thickness of RNFL around the optic disc tended to be thinner after 3 injections of Ranibizumab,but the difference was not statistically significant,suggesting that Ranibizumab had no significant negative impact on the inner retinal structure in the short term.