Myopia is on the rise, especially in certain Asian populations. As such, Chinese researchers developed a new myopia grading system that suggests certain types of myopic maculopathy have different risk factors.

Their study in the American Journal of Ophthalmology used the new system to look at three forms of the condition—myopic atrophy maculopathy, myopic tractional maculopathy and myopic neovascular maculopathy—in older adult Chinese patients. Known as “ATN,” the classification system’s inclusion of traction and neovascular maculopathy was unique in comparison with existing atrophy-centered grading systems.

The study included 820 eyes of 496 patients with high myopia and 266 normal control eyes. The researchers analyzed patients’ fundus photography and OCT to measure the three maculopathy types. The study also measured the peripapillary atrophy area, tilt ratio and macular choroidal thickness.

The investigators found highly myopic eyes were more likely to progress to myopic atrophy maculopathy and myopic neovascular maculopathy, and those with greater macular choroidal thickness were less likely to have myopic atrophy maculopathy and myopic neovascular maculopathy.

Additionally, the researchers noted highly myopic eyes with a lower tilt ratio were more likely to have myopic tractional maculopathy, and they found the pathogens of myopic tractional maculopathy were different from myopic atrophy maculopathy and myopic neovascular maculopathy.

The investigation is the first population-based study to research the distribution, mergers and associated factors of the three types of myopic maculopathy in an older adult Chinese high myopia cohort using the new classification, the researchers noted.