What is Irvine‑Gass syndrome?

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Irvine-Gass Syndrome

Irvine-Gass syndrome (IGS) is pseudophakic cystoid macular edema (CME) that develops following cataract surgery, representing one of the most common causes of postoperative visual impairment. 1

Clinical Definition and Epidemiology

  • IGS is characterized by cystoid macular edema occurring after cataract surgery, typically presenting with blurred or cloudy vision in the postoperative period 1, 2
  • The condition remains one of the most common complications following uneventful cataract surgery, despite modern surgical techniques 1
  • Most cases are benign and self-limiting, resolving spontaneously without permanent visual impairment 1
  • However, persistent edema and refractory cases can occur, potentially causing deterioration of visual function 1

Typical Clinical Presentation

  • Patients typically present with blurred or cloudy vision weeks to months after cataract surgery 2, 3
  • The condition can occur bilaterally, even after uncomplicated phacoemulsification 3
  • Acute bilateral presentation has been documented, with CME developing 25-32 days after surgery in sequential operations 3
  • Visual acuity is typically reduced, with best corrected visual acuity commonly in the 6/12 to 6/18 range during active disease 2

Diagnostic Evaluation

  • Optical coherence tomography (OCT) is the primary diagnostic tool, demonstrating characteristic cystoid spaces in the macula 1, 2, 4
  • Spectral-domain OCT reveals intraretinal cystic fluid with increased central macular thickness (mean baseline thickness approximately 530 μm in documented cases) 4
  • Fluorescein angiography shows characteristic petaloid pattern of fluorescein leakage in the macular region 5
  • Photoreceptor inner segment/outer segment junction abnormalities on OCT correlate with incomplete visual recovery and serve as prognostic indicators 4

Natural History and Prognosis

  • In most cases, macular edema resolves spontaneously within 3-6 months without intervention 1
  • Complete resolution can occur by 6-12 months with appropriate treatment 2, 3, 4
  • Eyes with interruption of the inner segment/outer segment junction at baseline (approximately 20% of cases) show persistent photoreceptor damage and incomplete visual recovery 4
  • Macular thickness changes correlate positively with visual acuity changes (r = 0.75), making OCT useful for monitoring treatment response 4

Risk Factors and Recurrence

  • Patients who develop CME following their first cataract operation have increased risk of developing the condition in the contralateral eye 3
  • This risk persists despite prophylactic measures including topical NSAIDs and corticosteroids 3
  • Bilateral presentation can occur even in healthy individuals without systemic comorbidities 2

Important Differential Diagnosis

  • Central serous chorioretinopathy can occur simultaneously or sequentially with IGS, though this association is exceptional 5
  • The presence of focal fluorescein leakage on angiography distinguishes central serous chorioretinopathy from pure IGS 5
  • Posterior capsule opacity may initially be suspected but can be ruled out with OCT imaging 2

Common Clinical Pitfalls

  • Failing to perform OCT imaging in patients with persistent visual complaints after cataract surgery delays diagnosis 2, 4
  • Assuming all post-cataract visual complaints are due to posterior capsule opacity without macular imaging misses IGS 2
  • Not counseling patients about contralateral eye risk before second-eye surgery in those who developed IGS after first-eye surgery 3
  • Overlooking photoreceptor junction abnormalities on OCT that predict incomplete visual recovery 4

References

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This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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