Spontaneous Pathologic Myopia and Contributing Factors in Nonhuman Primate Models

To characterize the fundus changes associated with spontaneous pathologic myopia (PM) in non-human primates (NHPs).

A total of 82 highly myopic eyes from 48 macaques, with an average age of 18.73 ± 2.74 years, were included in this study. High myopia was defined as spherical equivalent of -5.00 D or less. The 45° fundus images and optical coherence tomography (OCT) images centered on the macula and optic disc were utilized to assess the fundus tessellation, parapapillary atrophy (PPA), and other fundus characteristics.

The mean spherical equivalent (SE) was -8.91 ± 3.45 D, and the average axial length measured 20.03 ± 0.99 mm. The SE had a negative correlation with axial length (r = -0.380, P < 0.001). Here, we identified fundus lesions associated with PM in 23 eyes (28.05%), including diffuse chorioretinal atrophy, patchy chorioretinal atrophy, macular atrophy, and lacquer cracks on fundus images, as well as photoreceptor atrophy, retinal pigment epithelium atrophy, focal choroidal excavation, retinoschisis, and retinal detachment on OCT. PM eyes exhibited higher rates of PPA and more serious tessellation than highly myopic eyes (P = 0.001 and P < 0.001, respectively). The binary logistic regression further indicated that axial elongation and aging were independent risk factors for PM.

PM in macaques exhibits analogical fundus changes and contributing factors similar to those of human beings.

This study revealed the fundus characteristics and contributing factors associated with spontaneous PM in macaques and suggests that NHPs serve as optimal animal models for PM studies.