What are the typical presentation findings for a patient with a hemorrhage between the retinal pigment epithelium (layer D) and Bruch's membrane (layer G)?

Hemorrhage Between Retinal Pigment Epithelium and Bruch's Membrane

A bleed between the retinal pigment epithelium (RPE, layer D) and Bruch's membrane (layer G) presents as sudden, painless vision loss with a characteristic dark, dome-shaped subretinal lesion on fundoscopy, most commonly occurring in the context of age-related macular degeneration with choroidal neovascularization.

Clinical Presentation

Visual Symptoms

• Sudden, painless decrease in central vision is the hallmark presentation, with severity depending on the location and extent of hemorrhage 1
• Vision loss ranges from mild blurring to profound loss if the fovea is involved 1
• Metamorphopsia (distorted vision) commonly accompanies the hemorrhage 1
• Visual field defects correspond to the anatomic location of the subretinal blood 1

Fundoscopic Findings

• Dark red or reddish-brown dome-shaped elevation in the subretinal space is pathognomonic 1
• The hemorrhage appears darker than intraretinal or vitreous hemorrhage because blood is located beneath the neurosensory retina 1
• Overlying retinal vessels remain in focus and appear elevated, distinguishing this from deeper choroidal hemorrhage 1
• Associated findings may include drusen, pigmentary changes, or signs of choroidal neovascularization depending on the underlying etiology 1

Common Underlying Etiologies

Most Frequent Causes

• Age-related macular degeneration is the most common cause, particularly with choroidal neovascularization 1
• Presumed ocular histoplasmosis syndrome 1
• High myopia with lacquer cracks or choroidal neovascularization 1
• Retinal arterial macroaneurysm rupture 1
• Ocular trauma 1

Mechanism of Visual Loss

Pathophysiology

• Released toxins from blood breakdown products directly damage photoreceptors 1
• Outer retinal shear forces from the mass effect of accumulated blood cause mechanical injury 1
• The blood acts as a diffusion barrier, preventing normal metabolic exchange between the RPE and photoreceptors 1
• These combined mechanisms lead to rapid and potentially irreversible photoreceptor damage 1

Key Distinguishing Features from Other Hemorrhages

Differentiation from Vitreous Hemorrhage

• Subretinal hemorrhage appears as a well-demarcated, localized lesion rather than diffuse opacity 2, 1
• Retinal vessels remain visible and appear elevated over the hemorrhage, unlike vitreous hemorrhage where vessels are obscured 1
• No "boxcarring" of blood in vessels (which occurs in retinal artery occlusion) 3

Differentiation from Retinal Artery Occlusion

• No cherry red spot at the fovea (characteristic of central retinal artery occlusion) 3
• No diffuse retinal whitening from inner retinal edema 3
• No relative afferent pupillary defect unless extensive macular involvement 3
• Retinal arteries maintain normal caliber without segmentation 3

Differentiation from Retinal Vein Occlusion

• Absence of diffuse intraretinal hemorrhages throughout the affected vascular distribution 3
• No venous tortuosity or dilation 3
• No cotton-wool spots in the acute phase 3
• Hemorrhage is localized and subretinal rather than scattered and intraretinal 1

Critical Pitfalls to Avoid

Diagnostic Errors

• Failing to recognize that subretinal hemorrhage requires urgent evaluation for underlying choroidal neovascularization, which may be treatable with anti-VEGF therapy 1
• Mistaking subretinal hemorrhage for a choroidal melanoma, particularly when the blood is dark and dome-shaped 1
• Overlooking associated trauma history, as traumatic subretinal hemorrhage may indicate other serious ocular injuries 1

Management Considerations

• The location relative to the fovea is critical for prognosis—subfoveal hemorrhages have worse outcomes 1
• Thickness and duration of hemorrhage correlate with photoreceptor damage; thicker, older hemorrhages cause more irreversible damage 1
• Underlying etiology must be identified, as treatment differs dramatically (anti-VEGF for neovascularization vs. observation for macroaneurysm) 1