(A) ELISA of soluble Trem2 (sTrem2) in vitreous fluid and retinal fluid from naïve WT mice, WT and Trem2 cKO mice subjected to LD. (B) Fundus images of mice treated with isotype control or 4D9 anti-Trem2 in LD. Four individual mice per group are shown. (C) Representative OCT images of mice treated with isotype or 4D9 in LD. (D) Quantifications of outer nuclear layer (ONL) thickness by OCT (n=13 per group). ONL thickness was measured at both nasal and temporal sides. (E and F) Scotopic a-waves and b-waves of ERG data among mice treated with isotype or 4D9 in naïve or LD setting (n=5 per group). (G) Fundus images of Gal3 cKO mice treated with isotype or 4D9 in LD. Four individual mice per group are shown. (H) Representative OCT images of Gal3 cKO mice treated with isotype control or 4D9 anti-Trem2 in LD. (I) Quantifications of average ONL thickness by OCT between control and Gal3 cKO mice treated with either isotype or 4D9 (n=13 per group). (J) Images of phalloidin staining of control and Gal3 cKO RPE treated with isotype or 4D9 in LD. (K) Quantifications of dysmorphic RPE cells (n=15, 13, 11 and 13, respectively). Scale bars: 100μm. Data were collected from 2-4 independent experiments. *: p<0.05; **: p<0.01; ***: p<0.001. Unpaired Student’s t-test (F-H). One-way ANOVA with Tukey’s post hoc test (A); two-way ANOVA with Tukey’s post hoc test (D-F, I and K).