Banca de DEFESA: MARCOS VINICIUS DIAS ROSA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : MARCOS VINICIUS DIAS ROSA
DATE: 13/11/2025
TIME: 09:00
LOCAL: online
TITLE:

Investigation of Vitiligo and Its Potential Association with Immune-Mediated Ocular Disease in Equines

KEY WORDS:

Immunopathogenesis; Retinal hypopigmentation; T lymphocytes

PAGES: 80
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Patologia Animal
SPECIALTY: Anatomia Patologia Animal
SUMMARY:

Vitiligo is an autoimmune disease described in horses of different breeds,
characterized by the destruction of melanocytes and the consequent formation of
depigmented areas on the skin. The immune system plays a central role in its
pathogenesis. This study investigated the possible association between vitiligo and
immune-mediated ocular diseases in horses, with an emphasis on clinical and
morphological manifestations. In a population of 539 animals, 120 were evaluated
and divided into two groups: animals with a clinical or histopathological diagnosis of
vitiligo (n = 60) and a control group without dermatological alterations. Ophthalmic
analysis included ocular physical examination, biomicroscopy, fundoscopy, and
neurosensory testing. Most individuals showed functional preservation of the optic
pathways, with normal pupillary response and intact corneal and palpebral reflexes in
most cases. Biomicroscopy alterations were observed in 10.8% of the animals,
predominantly in the vitiligo group. Fundoscopy revealed pigmentary alterations in
23% of individuals, particularly peripapillary retinal hypopigmentation, whose
association with vitiligo was statistically significant (p = 0.0394). Six horses presented
conditions consistent with immune-mediated keratitis and uveitis, reinforcing the
hypothesis of autoimmune involvement. The results indicate that vitiligo in horses
may share immunopathogenic mechanisms with autoimmune ocular diseases,
especially processes mediated by cytotoxic T lymphocytes. The correlation between
skin depigmentation and retinal hypopigmentation suggests cross-expression of
melanocytic antigens between the skin and retina. This study contributes to the
understanding of the pathophysiology of vitiligo in horses and highlights the
importance of detailed ophthalmic evaluations in carrier animals for the early
diagnosis of possible associated ocular manifestations.

COMMITTEE MEMBERS:
Presidente - 2181699 - PAULO DE TARSO LANDGRAF BOTTEON
Interno - 387015 - FERNANDO QUEIROZ DE ALMEIDA
Interna - 2606155 - VIVIAN DE ASSUNCAO NOGUEIRA CARVALHO
Externo à Instituição - MICHEL JOSÉ SALES ABDALLA HELAYEL - UFF
Externo à Instituição - FLÁVIO AUGUSTO SOARES GRAÇA - UENF
Externa à Instituição - ERICA CRISTINA ROCHA ROIER - UV
Externo à Instituição - DANIEL AUGUSTO BARROSO LESSA - UFF