Treatment of Acute Zonal Occult Outer Retinopathy (AZOOR)
There is no proven effective treatment for AZOOR, and most cases stabilize spontaneously within 6 months, though immunomodulatory therapy may be considered in progressive cases based on emerging evidence of autoimmune mechanisms. 1
Initial Management Approach
AZOOR is a rare inflammatory retinal disease predominantly affecting young women (female:male ratio 3.2:1, average age 36.7 years) characterized by acute photopsias, scotomas, minimal funduscopic changes, and electroretinographic abnormalities. 1 The diagnosis requires multimodal imaging including fundus autofluorescence, optical coherence tomography (OCT) to detect outer retinal damage, and electroretinography which shows abnormalities in 99% of cases. 1, 2
Observation as Primary Strategy
- Most patients (74%) maintain visual acuity of 20/40 or better, and visual field loss typically stops progressing beyond 6 months without intervention. 1
- Central vision is often spared, providing a reasonable prognosis for functional vision. 3
- The fundus examination is unremarkable in 76% of eyes at presentation, though retinal pigment epithelial disturbances commonly develop over time. 1
Immunomodulatory Treatment Considerations
When to Consider Treatment
Progressive cases with continued visual deterioration beyond the typical 6-month stabilization period may warrant immunomodulatory therapy, particularly when anti-retinal antibodies are detected (enolase, arrestin, HSP27), suggesting secondary autoimmune retinopathy. 2
Treatment Options with Limited Evidence
Intravitreal sustained-release corticosteroids (Ozurdex) have shown benefit in isolated case reports, with documented improvement in visual acuity and recovery of photoreceptor inner/outer segment junction disruption on OCT. 4 This represents a more targeted approach than systemic steroids.
- Systemic corticosteroids have been attempted but lack proven efficacy in controlled studies. 1
- Combination therapy with mycophenolate mofetil, cyclosporine, and intravenous immunoglobulin has shown stabilization in cases with concurrent autoimmune retinopathy. 2
- Antiviral agents and calcium channel blockers have been tried without demonstrated benefit. 5, 4
Critical Prognostic Considerations
Long-Term Outcomes Require Caution
Contrary to earlier optimistic reports, long-term follow-up demonstrates that chorioretinal atrophy can progress significantly over years, leading to severe visual field loss. 5 A 13-year follow-up case showed progression from 20/60 and 20/25 to 20/60 bilaterally despite antiviral and immunomodulatory treatment. 5
Monitoring Strategy
- Visual field testing should document the characteristic blind spot enlargement (present in 75% of cases) and monitor for progression. 1
- Serial OCT imaging tracks outer retinal damage and photoreceptor loss over time. 2, 4
- Electroretinography provides objective documentation of outer retinal dysfunction. 3, 1
Key Clinical Pitfalls
Do not delay workup for other treatable conditions that mimic AZOOR, including acute idiopathic blind spot enlargement syndrome, paraneoplastic autoimmune retinopathy (which requires cancer screening), and infectious posterior uveitis. 2 The subtle and vague presentation makes diagnosis challenging, requiring high clinical suspicion. 3
Avoid aggressive systemic immunosuppression as first-line therapy given the lack of proven efficacy and the generally self-limited nature of the disease in most patients. 1 Reserve immunomodulatory therapy for documented progressive cases, particularly those with positive anti-retinal antibodies. 2
Counsel patients that despite initial stabilization, long-term visual prognosis should be guarded as chorioretinal atrophy may progress over years. 5 The dense visual field defects that develop typically remain permanent. 3