Lesson 7: Retinopathy of Prematurity

Retinopathy of Prematurity (ROP)

  • ROP causes abnormal vascular development in the retina, leading to risks of vasoconstriction, hemorrhage, and potential retinal detachment and blindness.

  • Key Risk Factors:

    • Prematurity

    • Hyperoxia

  • Management of Oxygen:

    • Minimize supplemental oxygen before retinal maturation (up to 44 weeks post-conception).

    • Maintain SpO2 levels between 89% - 94%, preferably monitored preductally (RUE).

Pathophysiology

  • Vasculogenesis Timeline:

    • Begins at week 16 and continues to week 44 post-conception, starting at the macula and spreading outward.

  • ROP Phases:

    • Phase 1: Inhibited growth of retinal vessels

    • Phase 2: Overgrowth of abnormal vessels with potential for retinal detachment.

  • Normal PaO2 Values:

    • In utero: 20 - 30 mmHg

    • After delivery: 55 - 85 mmHg

  • Higher PaO2 in premature neonates may lead to hyperoxia, disrupting normal vascular growth and leading to complications including retinal detachment.

Incidence and Risk Factors

  • ROP incidence inversely proportional to post-conceptual age and birth weight; affects up to 70% of infants weighing <1000 g at birth.

  • Most Significant Risk Factor: Prematurity

  • Modifiable Risk Factors: Hyperoxia (controllable oxygen administration).

  • Additional Risk Factors:

    • Mechanical ventilation

    • Blood transfusion

    • Intraventricular hemorrhage

    • Sepsis

    • Vitamin E deficiency

Anesthetic Management

  • Continue to monitor SpO2 and maintain levels carefully until retinal maturation is achieved.

  • Surgical options for late-stage ROP include:

    • Cryotherapy

    • Laser therapy

    • Scleral buckle

    • Vitrectomy