Retinal photoreceptor functions are compromised in patients with resistance to thyroid hormone syndrome (RTHb)

Irene Campi, Gabriella Cammarata, Stefania Bianchi Marzoli, Paolo Beck-Peccoz, Diletta Santarsiero, Davide Dazzi, Alessandra Bottari De Castello, Elena Giuliana Taroni, Francesco Viola, Caterina Mian, Sara Watutantrige-Fernando, Carla Pelusi, Marina Muzza, Maria Antonia Maffini, Luca Persani

Research output: Contribution to journalArticle


Context: In animalmodels, disruption of thyroid hormone (TH) receptor-b (TRb) reduces the long/medium wavelength (L/M) and increases the short-wavelength (S) cones. Retinal photoreceptor (RP) functions are unknown in patients with resistance to TH syndrome (RTHb) with dominant-negative TRb mutations. Objective: To investigate RP functions in RTHb. Design, Setting, and Participants: Case-control study involving 27 RTHb patients and 31 age/sexmatched controls, conducted in two tertiary referral centers in Italy. Main Outcome Measures: Color vision sensitivity assessed by Farnsworth; central macular thickness (CMT) of the outer retinal layer measured by spectral-domain optical coherence tomography; and retinal function tested by full-field electroretinogram (ERG) and S-cone ERG. Results: Color sensitivity was worse in RTHb patients than controls (P = 0.002). CMT was overlapping between the study groups but directly correlated with sex hormone-binding globuline levels in RTHb.We found a significant reduction in amplitude of the cone (P = 0.024) and of the rod response (P = 0.006) in the ERG of RTHb patients compared with controls. The response of the L/M cones measured by a specialized ERG test was lower in RTHb than controls (P = 0.027), whereas no differences were found in the S-cone response. No correlations were found between TH levels, total error score, or electrophysiological results. Furthermore, no differences were found between patients with maternal or de novo/paternal inheritance. Conclusions: We report, to our knowledge, the first in vivo evidence of functional defects of RP in RTHb. These changes occur independently of endogenous TH levels or the prenatal exposure to high or normal maternal TH.

Original languageEnglish
Pages (from-to)2620-2627
Number of pages8
JournalJournal of Clinical Endocrinology and Metabolism
Issue number7
Publication statusPublished - Jul 1 2017


ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Biochemistry
  • Endocrinology
  • Clinical Biochemistry
  • Biochemistry, medical

Cite this

Campi, I., Cammarata, G., Marzoli, S. B., Beck-Peccoz, P., Santarsiero, D., Dazzi, D., De Castello, A. B., Taroni, E. G., Viola, F., Mian, C., Watutantrige-Fernando, S., Pelusi, C., Muzza, M., Maffini, M. A., & Persani, L. (2017). Retinal photoreceptor functions are compromised in patients with resistance to thyroid hormone syndrome (RTHb). Journal of Clinical Endocrinology and Metabolism, 102(7), 2620-2627.