Transient Blindness Associated with Hypertensive Disorders in Pregnancy

EDITORIAL COMMENT": Readers will enjoy this paper, especially those who have had to care for a woman who suddenly became blind during pregnancy. The authors quote a wide range of reported incidences yet who could forget such a case or fail to code the history appropriately? The Editor can remember seeing only 3 such women in 38 years of obstetric practice. The first in 1963, at the Royal Women's Hospital, Melbourne, was in a woman already in hospital with severe preeclampsia. Ophtha‐Imological assessment showed only bilateral retinal pallor. Her vision returned within days of delivery after receiving magnesium sulphate, paraldehyde and sodium phenobarbitone prior to induction of labour and delivery. The second unforgettable case, at the Mercy Hospital for Women in 1975, was of a 20‐year‐old nullipara who presented to an ophthalmologist because of sudden blindness. This doctor fortunately measured her blood pressure (220/160), examined her urine (solid'on boiling i.e. proteinuria 24 g/L) and then diagnosed that she was about 16 weeks' pregnant. Examination of the fundi showed retinal haemorrhages and exudates. A misdiagnosis of hydatidiform mole with fetus was made, since this was the only condition that we believed could explain this presentation at 16–17 weeks' gestation. Hysterotomy was performed of a normal fetus and placenta after the severe preeclampsia was controlled with magnesium sulphate and heavy sedation. The vision improved after delivery and became normal over the course of the next 2 months. This woman subsequently was shown to have chronic renal disease and in her next pregnancy had a surviving infant, birth‐weight 1,745 g, delivered at 34 weeks'gestation because the cardiotocograph showed loss of beat to beat variation and late decelerations. The third case was seen in 1990 in Munster, West Germany, where the Editor was guest lecturer. This woman was at term but did not have the signs of severe preeclampsia. Her vision returned to normal within 24 hours after treatment with magnesium sulphate, sedation and delivery. In both cases reported by the authors the patients had severe preeclampsia and in Case 2 the coagulation failure and abnormal hepatic function were indicative of the HELLP syndrome. The moral of this story and of these important cases is that sudden onset of blindness during pregnancy is usually a complication of preeclampsia, and requires control of the disease and delivery of the patient. This complication may be more likely when severe preeclampsia is treated conservatively i.e. without heavy sedation and prompt delivery. There have been 115,396 deliveries at the Mercy‐Hospital for Women from February. 1971 to April, 1995 and although the incidence of preeclampsia is 8.1% in this institution, we have seen only I case of blindness, transient or otherwise, associated with hypertensive disorders of pregnancy, in addition to the case summarized above.