In High Myopia, Structural Anomalies Can Point to Polypoidal Choroidal Vasculopathy

Polypoidal choroidal vasculopathy (PCV) in eyes with high myopia eyes is characterized by a predominance in women, a lower incidence of subretinal hemorrhage, and a thin choroid with a focal pachychoroid phenotype, according to research published in Eye.

Researchers conducted a retrospective cohort study comparing the characteristics and treatment responses of PCV between highly myopic and non-highly myopic eyes.

Adult patients (≥18 years) diagnosed with PCV at a single center between 2013 and 2019 were included in the study. The researchers grouped the eyes with PCV according to refractive error and axial length at diagnosis (high, moderate, low, and none). They collected PCV characteristics using imaging data and treatment responses from electronic medical records.

The study included 116 eyes of 104 patients, with 11 eyes of 10 patients qualifying as having high myopia. These patients had an average age of 59.0±8.8 years. Most (70.0%) of the patients with high myopia were women, while most (71.3%) of the patients without high myopia were men. 

The researchers found that highly myopic eyes presented with a thin subfoveal choroid (high, 124.0 μm; moderate, 302.8 μm; low, 272.9 μm; none, 287.2 μm; P =.001), greater central retinal thickness (348.7 μm; 266.2 μm; 260.3 μm; 304.3 μm, respectively; P =.043), and less subretinal hemorrhage (9.1%; 30.8%; 11.1%; 37.5%, respectively; P =.017) than in the other refractive groups. They also found that 27.6% of highly myopic eyes had a pachychoroid phenotype with significant focal choroidal thickening.

After treatment with either intravitreal anti-vascular endothelial growth factor (VEGF) injections, photodynamic therapy (PDT), or both, the researchers observed improvement in best-corrected visual acuity (BCVA) at 1 year in the high-myopia group (at presentation, 0.59±0.60 logMAR; at 1 year, 0.33±0.28 logMAR; change from baseline, -0.25±0.37; P=.093). 

Using a multivariate model to analyze 100 treated eyes, the study shows pre-treatment BCVA was the strongest predictor for BCVA changes (Coefficient [Coeff], −0.330; P <.001) and that subretinal hemorrhage was predictive of worse initial visual acuity (Coeff, 0.357; P =.002). They also found that the presence of feeder vessels was a predictor of worse outcome at both the 1-year follow-up (Coeff, 0.241; P =.035) and final follow up (Coeff, 0.252; P =.048). 

“Female predominance, less subretinal hemorrhage, and a thin choroid with a focal pachychoroid phenotype were found to characterize highly myopic PCV cases. With either anti-VEGF monotherapy or combination therapy with PDT, highly myopic eyes showed an improved visual outcome at the 1-year follow-up, which carries implications for treatment recommendations,” according to the study authors.

Limitations of the study included the retrospective design, rarity of PCV in highly myopic eyes, and change in the treatment protocol over time.