case_images: PMC10630022_01
case_images: (a) The patient right eye fundus photo. Three quadrants of retina are fully involved with central retinal vein occlusion (CRVO) features including retinal hemorrhages, retinal edema obscuring retinal details, and cotton wool spots while sparing inferior temporal quadrant. (b) Nasal quadrant full involvement. (c) The patient optic nerve head vascular anatomy from a closer view. There is not a single venular trunk visible, but instead of that, there is a superior branch that gives three vascular branches for superior temporal (ST), superior nasal (SN), and inferior nasal (IN) veins. There is also an inferior retinal vein without any branch that drains inferior temporal quadrant that is intact in this case, however showing a slight engorgement. (d) A normal subject fundus photo for comparison. There is a single arterial end of the central retinal artery (blue arrow), and it is divided into superior and inferior branches; the superior one gives superior nasal and superior temporal arteries. The inferior branch gives inferior nasal and inferior temporal arteries. There is also a single venular trunk of central retinal vein (white arrow) divided into superior (S) and inferior (I) branches; the superior one gives superior nasal (SN) and superior temporal (ST) veins. The inferior branch gives inferior nasal (IN) and inferior temporal (IT) veins.
case_images: CRIOPM2023-6648367.001.jpg
case_images: PMC10630022_01_CRIOPM2023-6648367.001.jpg
case_images: fig1
case_images: As evident in Figure 1(a), three quadrants of retina are fully involved with central retinal vein occlusion (CRVO) features including retinal hemorrhages, retinal edema obscuring retinal details, and cotton wool spots while sparing inferior temporal quadrant. Details of vascular supply in the optic disk (Figure 1) clear that inferior temporal retinal vein is not separated from main superior vein trunk. Unfortunately, to the best of our review, there is no published data regarding central retinal vein anatomical variations and their prevalence; however, in our experience, the most common variation for retinal artery and vein could be like the one shown in Figure 1(d).