Comparison of Changes in Number of Hyperreflective Dots After İntravitreal Ranibizumab or Dexamethasone İmplant in Patients with Branch Retinal Vein Occlusion

Abstract

\n Purpose: To compare the effect of intravitreal ranibizumab (IVR) or intravitreal dexamethasone implants (IVD) on regression of hyperreflective dots (HRDs) on optical coherence tomography (OCT) B-scan in patients with branch retinal vein occlusion (BRVO). Methods: 37 eyes of 37 patients with cystoid macular edema who received IVR or IVD and followed up for at least 12 months were included in this study. The patients were divided into three groups according to intravitreal treatment. Group 1 consisted of 12 eyes who received only IVD, group 2 consisted of 10 eyes who received only IVR on a pro re nata and group 3 consisted of 15 eyes who received both IVD and IVR. OCT parameters (CMT, number of HRDs, status of external limiting membrane (ELM) and ellipsoid zone (EZ)) and best-corrected visual acuity (BCVA) were compared between the groups over the follow-up time. HRDs were categorized as HRD in inner retinal layers (from the internal limiting membrane to the inner nuclear layer) or HRD in outer retinal layers (from the outer plexiform layer to the outer border of the photoreceptor layer).Results: There was no significant difference between groups in terms of BCVA, CMT, HRDs in the inner and the outer retinal layers at baseline visit. (p˃0.05 for all) Comparing the baseline values in all groups, a significant decrease was observed in CMT in the first year. (For group 1; p=0.013, group 2; p=0.010; group 3, p<0.001) The BCVA was significantly increased after 1 year in all groups. (p=0.001, p=0.006, p<0.001) The mean number of HRDs in inner and outer retinal layers were significantly decreased in group 1 and group 3. (For group 1; p<0.001, p=0.001, for group 3; p<0.001, p<0.001) However, there was no significant difference in terms of the mean number of HRDs in inner and outer retinal layers for group 2. (p=0.134, p=0.477) At the first year, the number of HRDs in inner and outer retinal layers was significantly lower in group 1 and group 3 than group 2. (For inner HRDs; group 1 vs. group 2 p=0.007, group 2 vs. group 3 p<0.001. For outer HRDs group 1 vs. group 2 p<0.001, group 2 vs. group 3 p<0.001.) The BCVA was higher in group 3 than group 2 at 1year. (p=0.048). There was no significant difference in terms of post-treatment CMT and the number of HRDs between group 1 and group3 in posthoc tests (p=0.621, p=0.876, and p=0.632).Conclusion: The reduction in HRDs at 12 months and better BCVA after IVD intimates that the HRDs should be considered as inflammatory markers in the follow-up of CME in BRVO. Thus, IVD injection could be more appropriate for patients with higher HRDs after BRVO.