CHI3L1 and macular retinal edema: In a study evaluating the different morphological macular edema types, the levels of inflammatory factors in the aqueous humor - including interleukin 6 (IL-6), IL-8, IP-10, and platelet-derived growth factor-AA - were higher in the NSD group than in the diffuse retinal thickening (DRT) group [24]. Sonoda et al. reported that intravitreal IL-6 is the factor that was most significantly associated with NSD [25]. Moreover, Kaya et al. demonstrated that the serum chitinase-3-like protein 1 and IL-6 levels were significantly higher in DME with NSD than in patients with DRT and CME [26].