Association Between Hyperreflective Dots on Spectral-Domain Optical Coherence Tomography in Macular Edema and Response to Treatment.

Purpose To investigate the association between hyperreflective dots (HRDs) on spectral-domain optical coherence tomography (SD-OCT) and response to intravitreal bevacizumab (IVB) or dexamethasone injection in eyes with diabetic macular edema (DME) or macular edema due to retinal vein occlusion (RVO). Methods A retrospective review was conducted involving patients with DME or macular edema due to RVO. Patients with treatment-naïve macular edema were initially treated with three consecutive IVB injections and classified based on the treatment response to bevacizumab. After three consecutive IVB injections, bevacizumab nonresponders were treated using dexamethasone implants and reclassified based on the treatment response. The best-corrected visual acuity, number of HRDs, and outer plexiform layer (OPL) disruptions were analyzed according to the treatment response. Results Eighty-two eyes with DME and 68 eyes with RVO were included in this study. Thirty-six (43.9%) eyes with DME and 22 (32.4%) eyes with RVO were bevacizumab nonresponders. The number of baseline HRDs in bevacizumab nonresponders (16.06 ± 6.60 in DME, 14.23 ± 4.09 in RVO) was significantly greater than that in responders (11.26 ± 3.64, P < 0.001 in DME, 11.17 ± 4.83, P = 0.013 in RVO), and it did not decrease after IVB injections. Unlike the response to bevacizumab, eyes that responded to dexamethasone implant but not to IVB had significantly more HRDs (19.56 ± 6.75) than eyes that did not respond (11.50 ± 3.78, P = 0.006). The OPL disruption rate was significantly higher in bevacizumab nonresponders than in responders (P < 0.001 in DME and P = 0.001 in RVO). Conclusions In patients with DME or macular edema due to RVO, the number of HRDs on SD-OCT may be a predictive indicator of the response to IVB injection or dexamethasone implant. In bevacizumab responders, the number of HRDs on SD-OCT was small. In contrast, more HRDs, which might reflect increased inflammation in the retina, were observed in dexamethasone responders. Therefore, dexamethasone implants might be more effective in DME or RVO eyes with multiple HRDs and OPL disruption on SD-OCT.