To quantify the level of disorder, two hundred ommatidia per image were analyzed at 550× magnification, and the results revealed a significantly higher level of disorder in the AD-like model (GMR-Gal4;UAS-Aβ) than in the GMR-Gal4/+ (p < 0.0001) and UAS-Aβ/+ (p = 0.0004) controls (Fig. 1d). This evidence concerns the gene LGALS4 and Alzheimer disease.