The use of optical coherence tomography angiographic (OCTA) parameters is inadequate for the prediction of disease severity in patients with hereditary transthyretin amyloidosis (hATTR), according to the results of a retrospective study published recently in the journal PLoS One.

hATTR is an autosomal dominant form of amyloidosis caused by an abnormality in transthyretin and is associated with a variety of ocular manifestations. Among these, ocular amyloid angiopathy has been linked to serious complications, including visual impairment and neovascular glaucoma.

The researchers of the current analysis hypothesized that OCTA parameters would be useful biomarkers of systemic severity among patients with amyloidosis. They conducted a retrospective investigation of the relationship between OCTA parameters and disease severity in patients with hATTR.

The primary outcome was the correlation between systemic severity score and mean choriocapillaris flow deficit percentage (CC FD%). Secondary study outcomes included the correlations between the systemic severity score and retinal OCTA parameters, such as foveal avascular zone (FAZ) size, FAZ circularity, and superficial/deep/total retinal perfusion and vessel densities.

A total of 36 eyes from 36 patients were included in the study. In all participants, the diagnosis was confirmed by the Department of Medicine (Neurology and Rheumatology) at Shinshu University School of Medicine (SUSM) in Matsumoto, Nagano, Japan. All patients were referred to the SUSM Department of Ophthalmology for the evaluation of ocular amyloidosis.

Learn more about hATTR 

The mean CC FD% was 28.6±9.2, which was not statistically significantly associated with the systemic severity score (P =.863). In a similar fashion, FAZ size, FAZ circularity, and superficial/deep/total retinal perfusion and vessel densities all were not significantly correlated with the systemic severity score.

According to the authors, “These results may indicate that optical coherence tomography angiographic parameters are not sufficient to predict amyloidosis severity.”

The mean systemic severity score reported in the study was 6.97±2.85. Regarding ocular measurements, the mean signal strength was 8.69±0.86 (range, 7 to 10). The mean logarithm of the minimum angle of resolution, best-corrected visual acuity was –0.127±0.09; the mean axial length was 24.33±1.07 mm.

Overall, 10 of the eyes had undergone prior treatment with pars plana vitrectomy. Systemic therapies included liver transplantation in 17 individuals, administration of tafamidis in 10 individuals (7 eyes), and administration of patisiran in 7 patients.

The mean patient age was 51.8±12.1 years and the mean duration from onset of disease was 13.4±6.2 years. Among the 36 participants, 30 had the TTR Val30Met variant; the remaining 6 participants had other variants (ie, Ser50Arg, Asp38Ala, Tyr114His, Ser50Ile, Arg54Thr, and Phe53Val).

Reference

Kakihara S, Hirano T, Kitahara J, et al. Application of optical coherence tomography angiography to assess systemic severity in patients with hereditary transthyretin amyloidosis. PLoS One. 2022;17(9): e0275180. doi:10.1371/journal.pone.0275180