Oclusões Vasculares da Retina

Anatomia

• A artéria carótida interna entra no crânio através do canal carotídeo e ramifica-se para a artéria oftálmica, a qual se ramifica em:
  • Artéria central da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy; irriga os ⅔ internos da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy)
  • Artérias ciliares posteriores (ramo da artéria retiniana); irriga o ⅓ externo da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy
• A veia central da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy
  • Drena para a veia oftálmica superior ou diretamente para o seio cavernoso

Etiologia

Oclusão da artéria central da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy/oclusão do ramo arterial da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy

• Embolia (causa mais MAIS Androgen Insensitivity Syndrome comum de OACR ipsilateral)
  • Cardiogénica (abaixo dos 40 anos) ou aterosclerótica (após os 40 anos e mais MAIS Androgen Insensitivity Syndrome frequentemente de origem carotídea)
    • Os fatores de risco incluem:
      • Hipertensão arterial
      • Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus mellitus
      • Fibrilhação auricular
      • Problemas valvulares cardíacos/forame oval (libertação de coágulos para a corrente sanguínea)
  • Embolia de colesterol; ocorre geralmente após cateterização vascular
  • Embolia séptica, por endocardite infecciosa
• Condições inflamatórias como, por exemplo, a arterite temporal e outras formas de vasculite

Oclusão da veia central da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy/oclusão do ramo venoso da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy

As causas exatas são desconhecidas, porém, está associada com as seguintes condições:

• Aterosclerose
  • Hipertensão arterial
  • Hipercolesterolemia
  • Hábitos tabágicos
  • Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus mellitus
  • Obesidade
• Estado de hipercoagulabilidade
  • Anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types falciforme
  • Síndrome dos anticorpos antifosfolipídicos
  • Mieloma múltiplo
• Estados inflamatórios crónicos (por exemplo, lúpus eritematoso sistémico (LES))
• Determinados fármacos (por exemplo, contraceção oral)
• OVCR é classificada em 2 tipos clínicos com base na etiologia: OVCR isquémica (retinopatia hemorrágica) e OVCR não isquémica (retinopatia de estase).

Apresentação Clínica e Diagnóstico

Apresentação clínica

Oclusão da artéria central da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy

• Perda repentina, indolor e completa da visão monocular
• Podem existir episódios prévios transitórios semelhantes (por exemplo, amaurose fugaz)
• A fundoscopia revela:
  • Palidez do disco ótico devido à atrofia arterial
  • Mácula vermelho-cereja (na fóvea central)

Oclusão da veia central da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy

• Pode ser súbita ou gradual, indolor, com perda monocular de visão
  • Escotoma ou outro defeito parcial do campo visual
  • Pode ser precedida por sintomas visuais de alarme chamados “escotomas cintilantes”
• A fundoscopia revela
  • Edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema do disco ótico (papiledema) e dilatação das veias da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy com hemorragia
  • Aspeto do tipo “sangue” e “trovão” resultado de uma hemorragia extensa (tipo isquémico)
  • Manchas algodonosas: depósitos brancos na retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy devido ao edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema do nervo da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy (tipo isquémico)

Diagnóstico

O diagnóstico de ambas as situações é geralmente clínico, embora possam ser necessários exames adicionais.

• Angiofluoresceinografia (para diferenciar os tipos de OVCR, isquémico e não isquémico)
• Tomografia de coerência ótica (utilizada para avaliar a progressão da oclusão da veia da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy ou a resposta ao tratamento)
• Ecocardiografia com Doppler Doppler Ultrasonography applying the doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. Ultrasound (Sonography) da carótida
• Velocidade de Sedimentação (VS) e proteína C reativa ( PCR PCR Polymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules. Polymerase Chain Reaction (PCR)): para exclusão de vasculites

Diagnóstico Diferencial

• Hemorragia vítrea: hemorragia intraocular dentro ou em redor do corpo vítreo geralmente resultado de trauma, de uma laceração da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy ou de qualquer doença que cause neovascularização. Os doentes apresentam-se com miodesópsias e visão nublada. O tratamento inclui cirurgia e a suspensão de qualquer terapêutica anticoagulante. A hemorragia vítrea pode ser distinguida da oclusão de um vaso da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy pelo seu início mais MAIS Androgen Insensitivity Syndrome insidioso e pela presença de miodesópsias.
• Descolamento da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy: separação da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy neurosensorial do epitélio pigmentar da retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy. Classicamente, esta condição apresenta-se como uma cortina que desce sobre o olho e que causa uma perda de visão indolor. Sintomas como miodisópsias e fotopsias também podem estar presentes no início do curso da doença. As causas mais MAIS Androgen Insensitivity Syndrome comuns são o envelhecimento, a hipertensão arterial, e o trauma. O diagnóstico é feito com o exame oftalmológico direto e uma ecografia. O tratamento consiste na cirurgia a laser ou crioterapia.
• Cataratas: opacificação da lente no olho, o que leva a uma diminuição da visão. Frequentemente as cataratas desenvolvem-se insidiosamente num ou em ambos os olhos. Os fatores de risco são idade avançada e lesões oculares. Os sintomas incluem visão desfocada ou dupla, maior sensibilidade ao brilho, observação de halos em torno das luzes, cores desbotadas e diminuição da visão noturna. No exame oftalmológico, as cataratas podem ser visualizadas como uma lente nublada. O tratamento é a substituição cirúrgica da lente.