Black Race May Limit Choroidal Neovascularization in Pathologic Myopia

Black race may be a factor responsible for limiting the prevalence and incidence of choroidal neovascularization (CNV) in pathologic myopia (PM), according to research published in the Canadian Journal of Ophthalmology.

Investigators performed a retrospective chart review using data collected from the Wilmer Eye Institute at Johns Hopkins Hospital between 2005 and 2014. The team included 47 patients with International Classification of Diseases codes indicating PM with available 5-year follow-up data. Participants were stratified according to race including those self-reporting Black race (n=18; mean age, 58.1 years; 61%) and individuals reporting other ethnicities (n=29; mean age, 60.5 years; 59% women).

Baseline characteristics of participants who were Black included Snellen equivalents of 20/40 and 20/70, median central subfield thicknesses (CST) of 196 and 207 μm, and optical coherence tomography (OCT) volumes of 6.6 and 6.4 mm³ in the better- and worse-seeing eyes, respectively. Among individuals who did not report Black race, Snellen equivalents were 20/32 and 20/100, median CST was 225 and 194 μm, and OCT volume was 8.3 and 7.8 mm³ for the better- and worse-seeing eyes, respectively.

Baseline CNV prevalence was 3% and 34% among individuals with Black race and participants reporting other ethnicities, respectively. There were no bilateral CNV cases among individuals who were Black compared with 17% among individuals of other races.  

During a mean follow-up of 4.8 to 4.9 years, individuals who were Black experienced visual acuity changes of +0.04 and 0.00 logarithm of the minimum angle of resolution (logMAR) in the better- and worse-seeing eyes, respectively, compared with individuals of other races who experienced visual acuity changes of -0.05 and 0.10 logMAR in the better- and worse-seeing eyes, respectively. Overall, 66.7% to 72.7% of better-seeing eyes and 37.5% to 54.5% of worse-seeing eyes gained or lost fewer than 9 letters.

The prevalence of CNV remained stable in participants who identified as having Black race, whereas 15% of individuals of other races were diagnosed with CNV during follow-up — 8% of cases from baseline worsened and 12% improved.

“While it is unknown why there were differences in the presence or development of CNV in PM when comparing individuals who self-identified as black compared with white patients, the findings are consistent with differences in the presence or development of CNV in older individuals, wherein CNV typically develops in the setting of AMD,” according to the researchers.

This study was limited by a small sample size and retrospective nature.

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