Pupillometry: An objective test to assess endocular hereditary transthyretin amyloidosis

Abstract

Objective: To automatically study the pupillary light reflex in patients with hereditary transthyretin-associated amyloidosis (hATTR). Methods: Prospective cross-sectional observational study in patients with hATTR with unilateral scalloped iris. Pupillary light reflex of scalloped iris eyes (21 eyes) were compared with non-scalloped iris eyes (21 eyes, paired eyes of the same patients) and also with a control group of 20 healthy eyes, using static and dynamic pupillometry with the Metrovision® MonPack One. Results: No patient presented evident neurological involvment of the cranial nerves. No significant differences were found in the pupillary diameters under standardized lighting conditions (static pupillometry) among groups. In dynamic pupillometry, the amplitude of contraction, the velocity of contraction and the velocity of dilation were statistically significantly lower in eyes with scalloped iris, comparing both with the contralateral non-scalloped iris eyes ( p < 0.001 for all) and with eyes from healthy subjects ( p < 0.05 for all). Conclusion: A scalloped iris reflects a more advanced endocular hATTR and it is associated with an altered pupillary light reflex. Pupillometry may be a quick, simple, and portable test to objectively evaluate ocular amyloid deposition in hATTR eyes. Pupillary light reflex may not be reliable to evaluate neurological dysfunction in these patients.

Comments on pupillometry: An objective test to assess endocular hereditary transthyretin amyloidosis

“…However, there were statistically significant differences in contraction velocity and dilation velocity (Mann-Whitney U test; two-tailed p < 0.05). Our results are consistent with those reported by Marques et al 1 After reading the article, we further analyzed this data by retrospectively stratifying hATTR patients into two groups, based on the presence of scalloped pupils: group 0 (normal eyes of healthy subjects; n = 23), group 1 (hATTR eyes without scalloped pupil; n = 18), and group 2 (hATTR eyes with scalloped pupils; n = 9). The mean values of contraction and dilation velocities decreased stepwise from group 0 to 2.…”

“…We read with great interest the article published by Marques et al 1 on the objective assessment of pupillary response using pupillometry in patients with hereditary transthyretin amyloidosis (hATTR). We have also recorded pupillary responses using an automatic pupillometer (NPi-100; NeurOptics Inc., Irvine, CA, USA) 2 to investigate the utility of pupillometry in this rare disease because autonomic neuropathy occurs in hATTR, and pupillary response is controlled by autonomic nerves.…”

Ocular Involvement in Hereditary Amyloidosis

“…Peculiar pupillary indentations ( Figure 9 ) are considered a pathognomonic sign of ocular amyloidosis and are due to amyloid deposition at the inner pupillary margin [ 75 ].…”

“…Peculiar pupillary indentations (Figure 9) are considered a pathognomonic sign of ocular amyloidosis and are due to amyloid deposition at the inner pupillary margin [75]. Pupillary abnormalities, such as anisocoria and pupillary light-near dissociation, are additional frequent findings, but their pathogenesis remains unclear.…”

Response to the letter “Comments on ‘Pupillometry: An objective test to assess endocular hereditary transthyretin amyloidosis’”, by Shinji Kakihara, Takao Hirano, Akira Imai, Teruyoshi Miyahara and Toshinori Murata

“…The letter by Kakihara et al corroborates our results regarding the presence of reduced pupil contraction and dilation velocities in hATTR patients with a scalloped pupil. 1 When analyzing automatic pupillometry, it is essential to consider inter-device variability and to standardize ambient light conditions. Interestingly, each study used a different automatic pupillometry device (Metrovision ® MonPack One in ours and NeurOptics NPi-100 in theirs) but both reached similar results.…”