In this cross-sectional study of asymptomatic clinic-based individuals, we found that 11.67% of the subjects had posterior staphyloma, and more than 50% had one or more peripheral retinal changes. The most common peripheral retinal changes were white without pressure and frost degeneration. Retinal hole and lattice degeneration are considered important risk factors for retinal detachment in 1.67% and 15.00% of eyes. The most common posterior retinal changes were optic nerve crescents, followed by posterior staphyloma.
Optic nerve crescents are generally considered to be relatively stable fundus changes and do not lead to severe lesions for an extended time. We showed a higher prevalence of optic nerve crescents in our study than in previous studies. Cheng et al.6 reported that 52.5% of eyes had optic nerve crescents in 12–18-year-old ethnic Chinese adolescents with myopia ranging from − 6.00 to -17.13 D. In that study, optic nerve crescents were associated with the family history of myopia and longer axial length. Bansal4 reported that 38.8% of eyes had optic nerve crescent in children less than 10 years of age, with myopia ranging from − 6 to -25 D. In our study, the eyes with optic nerve crescents had a higher degree of myopic and thinner choroidal thickness compared with eyes without optic nerve crescents. However, these differences, which are significantly associated with the occurrence of optic nerve crescent, were not found in the binary logistic analysis.
In this study, we evaluated the association of posterior staphyloma with spherical equivalent refractive error, axial length, and choroidal thickness. Eyes with posterior staphyloma had a significantly higher magnitude of myopia, longer axial length, and thinner choroidal thickness than those without posterior staphyloma. Similar findings have been reported in previous studies. Lai et al.7 found that 11% of eyes had posterior pole lesions, longer axial lengths, and a higher degree of myopia was associated with the presence of posterior pole lesions. Around 25% of the subjects were observed to have posterior retinal changes in the Blue Mountain Eye Study, which only included subjects aged 49 years or older, while we included subjects aged 7 to 16 years.
Staphyloma has been considered a hallmark of pathologic myopia and is associated with myopic macular retinoschisis or choroidal neovascularization3,12,13. In this study, we also found that the choroid was markedly thinned. Similar findings were reported in previous studies14,15. It has been hypothesized that choroidal thinning may lead to posterior scleral thinning because the inner scleral might be nourished by the choroid, and an attenuation of the choroidal vessels may cause scleral thinning. However, this hypothesis has not yet been proven.
We also demonstrated strong associations of peripheral retinal changes with spherical equivalent refractive error, axial length, choroidal thickness, and age of the subjects. This was consistent with previous studies by Chen et al. 16 in which eyes increasing axial length was associated with lattice degeneration and retinal holes. The prevalence of lattice degeneration observed in our study was 14.88%, which was in agreement with a Hong Kong ethnic Chinese study7, but it was slightly higher or comparable with those reported in other ethnic2,17. Furthermore, after adjusting for axial length, we also found that age and spherical equivalent refractive error were independent factors for the presence of peripheral retinal changes. High myopic-related lattice degeneration was an essential risk factor for retinal detachment. Close follow-up of highly myopic patients with lattice degeneration might be warranted with ageing.
This study has several limmitations. First, subjects of the study were recruited from clinic-based practices which may lead to selection bias, even though we select the consecutive cases. Second, we excluded the patients with previous history of retinal detachment. It may have led to underestimation of the prevalence of retinal changes in our study. In addition, the sample size was relatively small. Strengths of our study is that we comprehensive evaluate the association of ocular and general parameters with retinal changes in subjects aged 7 to 16 years old which was not yet have been well characterized by previous studies.
In conclusion, most peripheral retinal and posterior pole changes were found in our children and adolescent subjects. Some of these changes, such as the retinal hole and lattice degeneration, have been associated with retinal detachment in previous studies. Therefore, for 7 to 16 years old children and adolescents with highly myopia, a thorough fundus examination should be performed at a regular intervals.