OcuLearning › Retina

Wet Age-Related Macular Degeneration

URGENT — Retina

Symptoms

  • metamorphopsia: straight lines (like door frames or blinds) appearing wavy or distorted
  • central scotoma: a gray, black, or "fuzzy" spot in the center of the vision
  • decreased vision: rapid or subacute drop in the ability to read or recognize faces
  • photopsias: brief flashes of light in the central visual field

Clinical Findings

Clinical presentation

  • subretinal fluid (srf): pockets of clear fluid under the retina causing a "dome" elevation
  • intraretinal hemorrhage: small "dots" or "blotches" of blood within the retinal layers
  • retinal exudates: yellowish lipid deposits (hard exudates) from leaking vessels
  • rpe detachment (ped): a localized elevation of the pigment layer (RPE)
  • disciform scar: a late-stage white/gray fibrous scar resulting in permanent vision loss

Risk factors

  • demographics: age >55, Caucasian ancestry, and light-colored eyes (blue/green)
  • lifestyle: smoking is the strongest modifiable risk factor
  • fellow-eye risk: 10–12% annual risk of the second eye "turning wet"

Etiology

Pathophysiology

  • choroidal neovascularization (cnv): abnormal, fragile blood vessels grow from the choroid through Bruch’s membrane into the retina
  • vegf drive: damaged retinal cells release Vascular Endothelial Growth Factor (VEGF) which triggers this "leaky" vessel growth
  • genetics: high association with complement pathway dysregulation (CFH Y402H and ARMS2 genes)

Red Flags

  • sudden distortion: any new waviness on an Amsler grid is an emergency—refer to retina the same day
  • submacular hemorrhage: a large pool of blood under the fovea can cause rapid, irreversible damage
  • non-responders: if fluid persists after 3 monthly "loading" injections, a switch in medication may be needed
  • rpe tear: a physical rip in the pigment layer following an injection; requires careful monitoring

Investigations

OCT (the gold standard)

  • used at every visit to detect microscopic fluid and track response to injections

Fluorescein angiography (FA)

  • an injected dye test used to classify the CNV as "classic" (bright/distinct) or "occult" (fuzzy/leaky)

OCTA

  • a newer, non-invasive "no-needle" way to visualize the abnormal blood vessel network

ICG angiography

  • helpful for seeing through blood or detecting specific variants like Polypoidal Choroidal Vasculopathy (PCV)

Treatment

Intravitreal anti-VEGF (mainstay)

  • agents: Aflibercept (Eylea), Ranibizumab (Lucentis), Bevacizumab (Avastin), or Brolucizumab (Beovu)
  • protocol: typically starts with 3 monthly "loading" doses, followed by a "Treat-and-Extend" schedule

Support measures

  • smoking cessation: essential to slow disease progression
  • areds2 supplements: reduces the risk of the "dry" eye turning "wet"
  • low vision aids: magnifiers and high-contrast tools for those with permanent scarring

Clinical Pearl

Metamorphopsia (wavy lines) = wet AMD until proven otherwise. The Amsler grid is the best home screening tool. Every month of delay before anti-VEGF costs the patient central vision.

Differential Diagnosis

  • • ocular histoplasmosis (presents with CNV but also peripheral "punched-out" spots)
  • • angioid streaks (cracks in Bruch’s membrane that can bleed)
  • • central serous chorioretinopathy (cscr) (fluid in younger patients, usually no blood)
  • • myopic CNV (bleeding caused by high nearsightedness, not age)

Related Retina Conditions