Retinopathy of Prematurity

ROP Basics - Preemie Eye Peril

• Retinopathy of Prematurity (ROP): A developmental vascular proliferative disorder affecting the incompletely vascularized retina of premature infants, potentially leading to blindness.
• Primary risk factors:
  • Extreme prematurity: Gestational age often ≤ 30 weeks.
  • Very low birth weight: Typically ≤ 1500 grams.
  • Unregulated oxygen supplementation.
• Pathophysiology: A biphasic disease process.
  • Phase 1 (Hyperoxia): Suppressed VEGF, delayed retinal vessel growth, vaso-obliteration.
  • Phase 2 (Hypoxia): Relative hypoxia triggers VEGF surge, leading to abnormal neovascularization.

⭐ ROP is a biphasic disease: Phase 1 (hyperoxia-mediated) involves delayed physiological retinal vascularization and vaso-obliteration, and Phase 2 (hypoxia-mediated) involves neovascularization.

Risk & Rules - Spotting Trouble Early

• High-Risk Infants (NNF India):
  • Birth Weight (BW) ≤ 1700g
  • Gestational Age (GA) ≤ 34 weeks
  • BW 1700-2000g or GA >34 wks with major risk factors (prolonged O₂, sepsis).
• Key Additional Risks:
  • Uncontrolled O₂ therapy. 📌 ROP = Risk from O₂ & Prematurity.
  • Sepsis, IVH, Apnea, RDS, Anemia requiring transfusion.
• Screening Timing (First Exam):
  • GA <28 wks: 2-3 wks postnatal age.
  • GA ≥28 wks: 4 wks postnatal age (or 31 wks PCA, whichever is later).

⭐ Supplemental oxygen, while life-saving, is a major modifiable risk factor for ROP due to its impact on retinal vascular development (the 'oxygen paradox').

ROP Staging - Zone & Stage Showdown

Zones (Posterior → Anterior):

• Zone I: Posterior pole; circle (radius 2x disc-macula, 30°). Poorest prognosis.
• Zone II: Zone I edge to nasal ora.
• Zone III: Remaining anterior temporal crescent. Best prognosis.

Stages (Severity):

• Stage 1: Demarcation Line (flat, white).
• Stage 2: Ridge (elevated).

  ⭐ Plus disease, characterized by venous dilatation and arteriolar tortuosity in at least two quadrants in the posterior pole, signifies active and aggressive ROP requiring urgent attention.

• Stage 3: Ridge + Extraretinal Fibrovascular Proliferation (EFVP).
• Stage 4: Partial Retinal Detachment (RD).
  • 4A: Extrafoveal.
  • 4B: Foveal.
• Stage 5: Total RD (funnel).

Key Concepts:

• Plus Disease: Vascular tortuosity/dilatation (≥2 quadrants).
• AP-ROP: Aggressive Posterior ROP (Zone I/posterior II, severe Plus).

ROP Rescue - Laser & Later Worries

• Goal: Prevent retinal detachment & blindness.
• Treatment Indicated (Type 1 ROP):

  ⭐ Treatment (laser photocoagulation or anti-VEGF) is typically indicated for Type 1 ROP: Zone I any stage ROP with plus disease; Zone I stage 3 ROP without plus; Zone II stage 2 or 3 ROP with plus disease.

• Modalities:
  • Laser Photocoagulation: Peripheral retinal ablation. Gold standard.
  • Anti-VEGF (e.g., Bevacizumab): For Zone I or Aggressive Posterior ROP (APROP). ⚠️ Systemic absorption, late recurrence risk.
  • Surgery (Vitrectomy): For Stage 4 (subtotal RD) or Stage 5 (total RD).
• Flowchart: ROP Management Approach

• Later Worries (Long-term): Myopia (most common), strabismus, amblyopia, glaucoma, cataracts, late retinal detachment. Lifelong follow-up essential.

High‑Yield Points - ⚡ Biggest Takeaways

• Key Risk Factors: Prematurity (<32 weeks), low birth weight (<1500g), supplemental oxygen.
• Pathophysiology: Biphasic process; initial vaso-cessation then VEGF-driven neovascularization.
• Location: Primarily avascular peripheral retina, often temporal side.
• ICROP Classification: Defines Zones (I, II, III), Stages (1-5), and Plus disease (vascular tortuosity/dilation).
• Screening: Crucial for at-risk infants (e.g., <31 weeks GA or <1250g birth weight).
• Treatment: Laser photocoagulation is mainstay; Anti-VEGF agents for aggressive posterior ROP.
• Major Complications: High myopia, strabismus, retinal detachment, potential blindness.