Cataract surgery can increase the risk of postoperative cystoid macular edema (CME) for patients with retinitis pigmentosa (RP) more than 4 times that of patients without RP, according to research published in Ophthalmology Retina.

Researchers conducted a retrospective study using a large multi-year claims database to estimate the risk of CME after cataract surgery in patients with and without RP.

The team identified patients who underwent single-phase cataract surgery between January 1, 2010, and December 31, 2018. They evaluated baseline characteristics, outcomes, and estimated the hazard ratios (HR) using a multivariable model. The main outcome measure was incident postoperative CME in the same eye that underwent cataract extraction within 12 months of the procedure.


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The researchers identified 468,123 patients and 615,645 eyes for the study. Of those, 124 eyes were with RP (n=91 patients) and 615,521 were without RP (n=468,032 patients). The mean age at the time of surgery was significantly lower in patients with RP than patients without RP (50.5±9.8 vs 57.9±6.1 years; P <.001). The sex distribution also differed between the groups, with women comprising 44% of the group with RP and 57% of the group without RP (P =.013).

The team found that the cumulative CME incidence at 12 months was 5.8% (95% CI, 1.2-10.3%) in eyes with RP and 1.1% (95% CI, 1.1-1.2%), in eyes without RP. They also found that CME was reported an average of 3.9 weeks later in eyes with RP than eyes without RP (95% Cl, 2.04-6.5; P <.001), and patients with RP had a 4.83-times higher risk of CME than those without RP (95% CI, 2.13-10.92; P <.001). 

Using stratified analysis, the researchers demonstrated that presence of epiretinal membrane was associated with decreased CME risk in eyes with RP (HR, 0.12; 95% CI, 0.48-0.97; P =.004) and was associated with increased CME risk in eyes without RP (HR, 4.30; 95% CI, 3.12-5.93; P <.001).

“The cataract surgery-related risk of CME among RP patients may be more than 4 times that of people without RP. Males and patients aged 18 to 34 and 55 to 65 years may be at greatest risk, whereas ERM may lower the risk,” according to the researchers. “Further study is warranted to stratify risk by RP genotype and phenotype and illuminate the natural history, angiographic features, and functional consequences of postoperative CME.”

Limitations of the study included the retrospective design with data derived from administrative claims, reporting of conditions via ICD-9-CM diagnosis codes, potential ascertainment bias with postoperative optical coherence tomography potentially being conducted more often in RP eyes than eyes without RP (or vice-versa), and potential lag time between the event and report.

Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.  

Reference

Antonio-Aguirre B, Swenor B, Canner JK, Singh MS. Risk of cystoid macular edema following cataract surgery in retinitis pigmentosa: an analysis of United States claims from 2010 to 2018. Ophthalmol Retina. Published online May 2, 2022. doi:10.1016/j.oret.2022.04.018