June 2019

CATARACT

Research Highlight
Higher risk of post-cataract persistent anterior uveitis for African Americans


by Rich Daly EyeWorld Contributing Writer


Mild peripheral vascular leakage indicative of retinal vasculitis in a patient with persistent anterior chamber
inflammation following cataract surgery
Source: Akshay Thomas, MD

New research found African Americans have a higher risk of developing persistent anterior uveitis (PAU) following uncomplicated phacoemulsification cataract extraction.
The retrospective cohort study examined risk factors for the development of PAU following uncomplicated cataract extraction in patients without histories of uveitis or autoimmune diseases.1
The PAU patients were identified according to the Standardization of Uveitis Nomenclature Working Group, which found 61 eyes (2.0%) from 48 patients developed PAU. It found African Americans were more likely than Caucasians to develop PAU (relative risk=11.3, p<0.0001).
“The mechanism leading to this is unclear,” the study authors wrote. “While requiring prolonged treatment, PAU does not appear to lead to worse visual outcomes.”
Age, sex, surgery length, and cumulative dissipated energy were not found to be risk factors.
Patients with PAU did not have worse visual acuity (VA) compared to those without PAU, and African Americans with PAU did not have worse VA or IOP compared to other races with PAU.
Eighteen of the 61 eyes (29.5%) also developed cystoid macular edema (CME).
Akshay Thomas, MD, said the study was well powered to meet its goal of identifying risk factors for PAU following uncomplicated cataract surgery.
“There are limitations to the study design inherent to any single-center retrospective analysis and the authors have acknowledged this,” Dr. Thomas said. “The authors clearly defined the SUN diagnostic criteria for PAU but did not elaborate on whether all patients with suspected PAU underwent an evaluation for alternate causes of uveitis. If so, was the workup standardized across patients? For example, did all patients get a chest x-ray?”

Study needed

Dr. Thomas agreed with the authors that there is a need for a better understanding of PAU following uncomplicated phacoemulsification cataract extraction in patients without a history of uveitis or autoimmune disease.
“In my own experience, I have seen numerous patients with suspected PAU, some of whom have a negative laboratory workup and some of whom are subsequently diagnosed with an underlying autoimmune condition,” Dr. Thomas said. “It is well documented in the literature that some of our patients with idiopathic uveitis may actually have sarcoidosis-related uveitis, and this discrepancy is due to a lack of standardized imaging/lab protocols for patients with uveitis.2
Dr. Thomas cited the example of patients not necessarily having clear evidence of sarcoidosis on chest x-rays but possibly suggestive findings on a CT scan of the chest.
Additionally, Dr. Thomas warned that the extent of inflammation in a postop uveitis may be underestimated; if OCT is not being routinely performed, prevalence of CME may be underestimated. Additional imaging may reveal inflammation beyond the anterior chamber and macula.
For example, a patient with PAU who Dr. Thomas recently evaluated also was found to have mild retinal vasculitis.

Significance of the findings

The finding that African Americans have a higher risk of developing PAU following uncomplicated phacoemulsification cataract extraction was “quite significant,” Dr. Thomas said.
Equally significant was the percentage of African American patients that had bilateral PAU.
“While the hypothesis of the role of melanin in the pathogenesis of PAU is appropriate, I wonder whether patients with bilateral PAU and those with inflammation exceeding 12 months following cataract surgery have some underlying predisposition to autoimmunity,” Dr. Thomas said. “Given the greater prevalence of sarcoidosis in African American patients and the challenges with diagnosis that I mentioned previously, it would be interesting to investigate this point further.”
Also important was the finding that there was no association with worse VA or IOP compared to others who also developed PAU. Such information should be available for patients.
“It is important, however, to note that OCT was not routinely performed on all patients with PAU,” Dr. Thomas said. “Thus, is it plausible that the prevalence of CME, and its effect on VA outcomes, was underestimated.”
The findings should impact ophthalmologists’ clinical approach.
“I would implore any ophthalmologist assessing a patient with suspected PAU to have a standardized approach to the diagnosis of this condition,” Dr. Thomas said. “That is, first rule out any lens-related uveitides, then consider a standard panel of laboratory and radiographic tests.”
Additionally, it would be worthwhile for anterior segment surgeons to consider waiting for resolution of anterior chamber inflammation and/or CME in the first eye prior to performing cataract surgery on the fellow eye, especially in African American patients, Dr. Thomas said.

About the doctor

Akshay Thomas, MD
Tennessee Retina
Nashville, Tennessee

Contact information

Thomas: akshaysthomas@gmail.com

References

1. Reddy AK, et al. Risk factors associated with persistent anterior uveitis after cataract surgery. Am J Ophthalmol. 2019. Epub ahead of print.
2. Han YS, et al. Distinguishing uveitis secondary to sarcoidosis from idiopathic disease: cardiac implications. JAMA Ophthalmol. 2018;136:109–115.

Financial interests

Thomas: None

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