An analysis of recent literature indicates disparate definitions—and subsequently, the lack of a uniform classification system—for pachychoroid spectrum disorders, a research paper in Retina reports.

The review examined pachychoroid-related investigations published from 2013 to 2020 and found 18 unique definitions for pachychoroid, six for pachychoroid pigment epitheliopathy, 12 for pachychoroid neovasculopathy and eight for pachyvessels. An additional 39 studies offered no definition associated with pachychoroid disease.

Even in instances where the disease was defined, the criteria—such as dilated vessels or thickened choroid—were often vague, the investigator noted.

In several papers, choroidal thickness abnormality parameters weren’t given, while others listed thresholds ranging from at least 200μm to more than 300μm. In the latter, none of the thresholds were correct for age or refractive status, and the ranges of specified thicknesses were either below normal or normal and, oftentimes, consistent with those found in the general population.

“By examining the definitions and reported prevalence of characteristics in the general population, the present study found most people would meet the diagnostic criteria of at least one of the subset diseases, and, therefore, nearly everyone would be considered to have a pachychoroid spectrum disease,” the researcher wrote.

To remedy the current investigation’s findings, an international group of experts could map out potential pachychoroid disorders and provide concise definitions to be tested in terms of sensitivity, specificity and clinical utility, the author suggests.

Until then, the pachychoroid spectrum appears to be a diagnostic group of entities that may or may not be linked and is similar to terms such as “white-dot syndrome” or “pachyderm,” the study noted.

Spaid RF. The ambiguity of pachychoroid. Retina. December 7, 2020. [Epub ahead of print].