Greater Risk of Cystoid Macular Edema Observed in Patients with Retinitis Pigmentosa

Mandeep S. Singh, MD, PhD

The cataract surgery-related risk of cystoid macular edema (CME) among patients with retinitis pigmentosa (RP) may be four times greater than people without RP.

Study data suggest that men, individuals aged 18 to 34 years, and individuals aged 55 to 65 years may be at the greatest risk, while epiretinal membrane (ERM) may decrease the risk.

“Further study is warranted to stratify the risk by RP genotype and phenotype and illuminate the natural history, angiographic features, and functional consequences of postoperative CME,” wrote study author Mandeep S. Singh, MD, PhD, Assistant Professor of Ophthalmology, Wilmer Eye Institute, Johns Hopkins Medicine.

The retrospective multicenter cohort included patients aged 18 to 65 years who underwent single-phase cataract surgery between January 2020 and December 2018. This population was identified using the IBM MarketScan claims database, according to investigators.

Singh and colleagues evaluated the baseline characteristics and outcomes and estimated the hazard ratio (HR) using a multivariable mixed-effects approach. Eyes of patients with RP were categorized as group R1, and those without diagnoses of RP by the time of surgery were categorized as group R0.

The main outcomes measured were incident postoperative CME in the same eye that underwent cataract extraction within 12 months of the procedure. The study included 468,123 patients and a total of 615,645 eyes.

Overall, this included 124 eyes with RP (R1) and 615,521 eyes without RP (R0). The R1 population had a mean age of 50.5 ± 9.8 years and the R0 population had a mean age of 57.9 ± 6.1 years.

Data show the cumulative incidence of CME at 12 months was 5.8% (95% confidence interval [CI], 1.2% – 10.3%) in R1 and 1.1% (95% CI, 1.1% - 1.2%) in R0. Then, on average, CME was reported in R1 subjects 3.9 weeks later than in R0 subjects (95% CI, 2.04 – 6.5 weeks; P <.001).

Moreover, the subjects in R1 had 4.83 (95% CI, 2.13 – 10.93; P <.001) times the risk of CME compared to the subjects in R0. A stratified analysis indicated that ERM decreased the risk of CME in R1 (HR, 0.12 [95% CI, 0.48 - 0.97; P = .004]), but increased it in R0 (HR, 4.32 [95% CI, 3.13 - 5.95; P <.001]).

The study, “Risk of Cystoid Macular Edema after Cataract Surgery in Retinitis Pigmentosa: An Analysis of United States Claims from 2010 to 2018,” was published in Ophthalmology Retina.