APAO 2023: Diffuse atrophy in children: Key to development of pathologic myopia in adults

Kyoko Ohno-Matsui, MD, PhD, Tokyo Medical and Dental University, Tokyo, provided a close look at the ocular signs of myopia in children that help predict the evolution to pathologic myopia as adults.

She theorized that the ocular appearance in these children who later develop pathologic myopia may be distinctive at an early age and provided ophthalmologists with guideposts on what to look for at the 2023 Asia-Pacific Academy of Ophthalmology Congress in Kuala Lumpur, Malaysia.

“Diffuse atrophy is the most common lesion in patients with pathologic myopia. It is a yellowish, ill-defined lesion and classified as category 2 maculopathy according to the META-PM Study Group. Category 2 diffuse atrophy is the gateway to pathologic myopia,” she said.

This is followed by categories 3 and 4, respectively, patchy atrophy and choroidal neovascularization macular atrophy.

Imaging findings of diffuse atrophy

Optical coherence tomography (OCT) shows extreme abrupt choroidal thinning. Almost the entire choroid disappears besides sporadically-remaining large choroidal vessels. The retina and sclera also are thin; however, the hallmark of the pathology is the extreme choroidal thinning, she explained.

She and her colleagues conducted an observational study¹ that included 29 adults with pathologic myopia, in which fundus photos were analyzed retrospectively when the patients were evaluated before age 15 years. The results showed that 83% of these patients already had diffuse atrophy in childhood.

Imaging shows that the sudden transition from relatively normal choroid around the fovea to almost absent choroid. Because it is not generalized thinning, a circulatory disturbance is not the cause.

“The pathogenesis is unclear, however, a sudden loss of peripapillary choroid is the cause of diffuse atrophy in children,” she said.

A second lesion of concern is posterior staphyloma, an outpouching of the eye wall and another hallmark of pathologic myopia. Ohno-Matsui explained that while staphyloma generally is considered to develop later in life; however, it is unclear at what age that development begins.

She suggested that staphyloma can be detected precisely by identifying staphyloma edges based on their typical OCT features.

“We think that staphyloma formation occurs in synchronicity with scleral curvature changes of a wide area,” she said.

She and her colleagues conducted a longitudinal study of 47 eyes to examine the changes in thescleral curvature patterns and the process of staphyloma formation in highly myopic children and adolescents showed that scleral curvature patterns changed either in horizontal or vertical section in 57.4% of eyes.²

Staphyloma was found in 4 eyes at baseline and newly developed in 6 among 43 eyes (14%) that had no baseline staphyloma. All staphyloma edges were found at and around the optic nerve in a horizontal direction. During a follow-up, staphyloma edge formation accompanied more posterior bowing of the macular sclera and changes in the scleral curvature patterns in a wide area in some cases.

The following findings in children are clues to the possible development of pathologic myopia in adults.

• Diffuse atrophy is seen in children who become pathologic myopia in adults.
• Scleral curvature patterns significantly change in highly myopic children/adolescents.
• Staphyloma occurs at a much earlier age than previously thought.
• Staphyloma newly developed in 14% of this age group.
• Staphyloma edges preferentially developed around the optic nerve and are obvious in horizontal section.
• Scleral curvature changes from symmetry to asymmetry in vertical direction were correlated with increased axial length.
• Changes of scleral curvature and staphyloma edge development may occur in synchronicity, and this combination etches the eventual eye shape in myopes.

The conclusion to consider is that children who ultimately develop pathologic myopia may have a different retinal appearance at an early age.

References

1. Yokoi T, Jonas JB, Shimada N, et al. Peripapillary diffuse chorioretinal atrophy in children as a sign of eventual pathologic myopia in adults. Ophthalmology. 2016;123:1783-1787. doi:10.1016/j.ophtha.2016.04.029.

2. Chen C. Du R, Xie S, et al. Longitudinal study of changes in inner scleral curvature patterns and development of posterior staphylomas in highly myopic eyes of children and adolescents.Retina. 2022 Nov 29. doi:10.1097/IAE.0000000000003681. Online ahead of print.