Since the retinal arterioles tend to mirror and parallel the arteriolar changes in other vital organs, routine ophthalmoscopy is essential in those pregnancies in which elevation of blood pressure or alterations in the renal and other studies indicate a possible deviation from the normal course of pregnancy.
A massive, and at times confusing, literature has arisen concerning the ocular findings in the toxemias of pregnancy; confusing because some authors have failed to differentiate between those changes in the ocular fundi that eventually occur in all patients with persistent hypertension and the ophthalmoscopic findings that occur purely by virtue of the existence of a toxic process in the course of pregnancy, with or without evidence of preceding cardiovascular-renal damage.
From an ophthalmoscopic point of view the patients with toxemia may be divided into two main groups: those with no evidence of prior vascular damage and those with such evidence. More simply
Gordon DM. ROUTINE EXAMINATION OF THE OCULAR FUNDI AS AN AID INN MANAGEMENT OF TOXEMIAS OF PREGNANCY. JAMA. 1951;146(9):810-813. doi:10.1001/jama.1951.03670090042012