[Retinal tomography features of thrombotic microangiopathy associated with atypical hemolytic-uremic syndrome]

To evaluate structural and morphological changes in the retina using optical coherence tomography (OCT) in patients with thrombotic microangiopathy (TMA) associated with atypical hemolytic-uremic syndrome (aHUS).

The study analyzed OCT data of 14 patients (28 eyes) with an established diagnosis of aHUS including such indicators as central retinal thickness (CRT), thickness of the retinal nerve fiver layer (RNFL), ganglion cell layer (GCL), retinal pigment epithelium (RPE), etc.

Patients with aHUS were noted to have an increase in CRT, paracentral acute middle maculopathy in the form of a hyperreflective defect primarily of the inner nuclear layer of paracentral localization, as well as disorganization of the RPE, which was observed statistically significantly more often compared to healthy persons (p=0.0001, p=0.001 and p=0.009 respectively). In the subgroup with thrombotic retinopathy (6 people) a statistically significant increase in CRT and peripapillary RNFL was found (p=0.004 and p=0.001) compared to patients without thrombotic retinopathy, as well as the presence of paracentral acute middle maculopathy and transudative macular retinoschisis (p=0.0001 and p=0.004). A statistically significant thinning of the peripapillary RNFL was revealed (p=0.0001) in the subgroup with symptoms of Purtscher-like retinopathy (PLR) found retrospectively (4 people) compared to patients without retrospective PLR symptoms. A statistically significant decrease in CRT was revealed (p=0.018) in the subgroup of patients receiving systemic therapy with eculizumab (5 people) compared with patients not receiving this therapy. Statistically significant correlations were recorded between the studied OCT indicators, laboratory indicators, and the level of systolic blood pressure (p<0.05).

According to OCT, paracentral acute middle maculopathy is a biomarker of thrombotic retinopathy and the activity of systemic TMA associated with aHUS. Arterial hypertension is an additional aggravating factor in the development of paracentral acute middle maculopathy and transudative macular retinoschisis. Targeted therapy with eculizumab leads to an effective decrease in CRT, which is potentially associated with regression of ischemic edema. The outcome of PLR involves thinning of peripapillary RNFL.