Hypertensive Disorders Complicating Pregnancy has been used to be called as Pregnancy-Induced Hypertension Syndrome and shortened to PIHS. Generally speaking, it always happens after 20 weeks of the pregnancy with the pathophysiological changes of systemic small vessel spasm, endothelium injury and ischemia. With previous experience, the PIHS patients’ fundus changes have close connection to the patients’ general clinical manifestation. For example, the higher the blood pressure and proteinuria level are, which are the indicators for the severity of PIHS, the more obvious the fundus changes are [3]. Besides, since the retinal vessels in fundus is the only part for directly observing the vessel changes in living people, the fundus detection result is always a vital indicator for PIHS diagnosis. For patients with fundus change in early stage, if their blood pressure could be lowered accordingly, in which case they are clear on the fundus changes, after taking rest, being tranquillised, releasing spasm, taking hypotensor and diuretics etc., they could continue the pregnancy with the intensive monitor on the maternal-fetal status. Otherwise, if the patients are failed to respond to these medical treatments, especially when, after the treatments, they have the symptoms such as retinal oedema, exudation or haemorrhage, which means there is organic damage to the retina and general small artery, the pregnancy should be terminated accordingly to avoid any severe complication afterwards. Therefore, the diagnosis results on fundus change, especially on the severe retinopathy, should be a vital reference for the necessity of conducting pregnancy termination [4]. However, some of the severe retinal diseases, such as retinal oedema and limited retinal detachment etc., especially for the latter one, might be missed in the fundus detection by the eye ultrasound examination, for the contrast medium used in which are not suitable for the pregnant women. On the contrary, OCT, with its non-invasive and reproducible characteristic, high solution and cross section imaging technique, could be used for the ocular tissue micro-imaging, especially for the imaging of retina and its neighbouring tissues. There are some studies have found that the retinal disease is correlated to optic disc peripheral, the thickness of retinal nerve fibre layer at the central fovea of macula, and the continuity change in the outer retinal structure [5, 6, 7]. Our study also finds that the OCT examination results for healthy pregnant women are normal, but the results are abnormal for the PIHS patients, which could be summarised into three phenotypes related to the patients’ general system status, especially to the patients’ blood pressure, oedema and proteinuria. The higher the blood pressure is, the severer the oedema and proteinuria will be. Also, the higher the blood pressure is, the more possible the patients will be diagnosed with retinal haemorrhage and optic disc oedema, which are seconded only to retinal epithelium oedema, in OCT. Besides, our study also finds that the OCT phenotypes will not be impacted by the patients’ gestational age, age and the number of times for being pregnant, but by the patients’ disease progress, in which case the patients with short disease progress will be more possible to be diagnosed with epithelium oedema, while the ones with long disease progress will be more possible to be in the middle of recovering from the fundus changes, for some of them have get the blood pressure under control.
With fundus angiography, some studies find that it is quite common among the early stage PIHS patients that they have the symptom, in varied degrees, of slow choroid filling or without reperfusion, in other words, choroid ischemia, which are shown as faint or dark areas, indicating pigment epithelium change with damage and dysfunction caused by choroid ischemia, in the fundus angiography. [8, 9, 10] This change is often diagnosed in the patients’ optic disc peripheral and the macular area, for which are areas most of the choroid artery watershed and vein vertical watershed are distributed around. With the comparatively poor blood circulation here, the optic disc peripheral and the macular area are also the areas with the greatest occurrence of dysfunctional choroid circulation and pigment epithelium damage, complicating with fluid filled in the retina here, where OCT could detect properly, by ischemia and hypoxia. According to our study, the main OCT phenotypes for PIHS patients are neurosensory serous retinal detachment 84 eyes (56.76%), which is mainly diagnosed in the optic disc peripheral and the macular area, pigment epithelium and the IS / OS layer change 38 eyes (25.68%), optic disc oedema and retinal haemorrhage and other changes of 26 eyes (17.56%) respectively. Moreover, according to the patients’ self-claim, the retinopathy in the macular and optic disc peripheral area has the predominant impact on their visual acuity. Our study also finds the OCT phenotypes are correlated to the patients’ corrected visual acuity, the severity of the fundus changes and the patients’ self-claimed symptoms, which not only proves the coherence between OCT and fundus detection, but also the advantage that OCT has for observing the retinal microstructure changes.
According to our study, for patients, who are diagnosed with neurosensory oedema retinal detachment by OCT, they are always in the middle of the disease progress with the severe fundus change and poor systemic health condition so that they are required to be taken care of by intensive monitoring on their eye and systemic health condition with positive medical treatment. The relevant medical solution of necessity, such as pregnancy termination, should be conducted in accordance with the monitoring. While, for patients, who are diagnosed with pigment epithelium and IS/OS layer change, they are always in the end of the disease progress, a recovering or stabilized period for the fundus changes, so that they should continue current treatment along with health condition observation. With OCT examination on their fundus recovering status when they visit our department, we find that although some of the patients’ health condition have been stabilised by getting blood pressure under control, the pigment epithelium and IS/OS layer change has not recovered yet.