Skip to main content

Correlation of subfoveal choroidal thickness with axial length, refractive error, and age in adult highly myopic eyes



Subfoveal choroidal thickness (SFCT) in highly myopic eyes was found to be correlated with increasing age, refractive error (spherical equivalent), and axial length. Which factor is the most significant predictor of SFCT remains controversial.


A hospital-based cohort of highly myopic eyes (with spherical equivalent equal to or over 6.00 diopter) were retrospectively screened. Data from only right eye in those bilateral high myopia, and unilateral high myopia in any eye, were used for analysis. Correlations among the four biometric factors were analyzed. Linear correlation was performed to analyze the predictors of SFCT.


A cohort of 312 eyes from 312 adults (98 men) was enrolled. Statistical analysis showed that axial length (R = − 0.592), spherical equivalent (R = − 0.471), and age (R = − 0.296) were significantly correlated with SFCT (P < 0.001). No significant correlation was found between age and axial length, or age and spherical equivalent. Partial correlation with controlled age confirmed that axial length (R = − 0.628) was a more significant predictor of SFCT than spherical equivalent (R = − 0.507).


SFCT was inversely correlated with increasing age, spherical equivalent and axial length, with axial length as the most significant predictor of SFCT, in adult highly myopic eyes.

Peer Review reports


Myopia is a significant public health concern worldwide [1]. The prevalence of myopia in teenagers and young adults has reached up to 90% in East Asia, up to 50% in United States and Europe, and the overall prevalence of myopia is still increasing [1,2,3,4,5,6,7,8,9,10,11]. High myopia, featured by progressive elongation of the eyeball, is associated with potentially blinding complications such as retinal detachment, macular schisis, macular hole, chorioretinal atrophy, choroidal neovascularization, and peripapillary cavity [7, 8, 12,13,14,15]. It is estimated that 1–2% of the population in western countries exhibits high myopia, with a much higher prevalence in East Asian. Population-based studies showed high myopia to be the 1st to 3rd most frequent cause of blindness, and the prevalence of visual impairment attributable to high myopia ranged from 0.1 to 0.5% in European studies and from 0.2 to 1.4% in Asian studies [16].

The severity of myopic macular degeneration was found strongly associated with subfoveal choroidal thicknesses (SFCT) in a recent study [17]. Accurate measurement of choroidal thickness may provide some information about myopic pathologic conditions. The development of enhanced depth imaging (EDI) of spectral-domain optical coherence tomography (SD-OCT) allows for the evaluation of choroidal thickness in vivo [18,19,20].

Choroidal thickness in highly myopic eyes was reported to be correlated with increasing age, spherical equivalent, and axial length, and SFCT could be considered as a useful predictor of visual function [21,22,23,24,25], but which factor is the most significant predictor remains controversial in previous studies, and the data from different population might be variable according to literatures [21, 25]. The goal of this study was to estimate the correlation of SFCT with age, axial length and spherical equivalent in a hospital-based cohort of highly myopic eyes, and to find which factor was the most significant predictor of SFCT.


This is a retrospective cross-sectional study, by re-analysis of the project data of “high myopia cohort study in a tertiary eye center”. An informed consent was obtained from all of the included subjects for the project but not specifically for this study. Adult patients (age ≥ 18 years) with high myopia from December 2013 to April 2016 collected by high myopia research group at Fundus Disease Center of Zhongshan Ophthalmic Center were screened. The study followed the tenets of the Declaration of Helsinki and was approved by the Zhongshan Ophthalmic Center Institutional Review Board.

Inclusion criteria was spherical equivalent equal to or over 6.00 diopter (D); Exclusion criteria included poor OCT image quality and those choroid borderlines could not be clearly visualized; history of vitrectomy, sclera buckling, glaucoma, or retinal detachment. Data from only right eye were used for analysis in those with bilateral high myopia. Unilateral high myopia in any eye was also included.


All the participants underwent ophthalmic examinations including assessment of BCVA, intraocular pressure measurement, slit lamp examination, spherical equivalent, axial length, indirect dilated fundus ophthalmoscopy, fundus photography, and OCT for the mentioned project. Axial length was measured using IOL Master (Carl Zeiss Meditec, Jena, Germany). Spherical equivalent was measured by autorefractometry (Canon, Tokyo, Japan). Horizontal and vertical cross hair scans through central fovea were captured by an SD-OCT machine (Heidelberg, Germany) with EDI modality. Choroidal thickness was defined from the outer edge of the hyperreflective line corresponding to the retinal pigment epithelium to the inner surface of sclera [18, 25, 26]. The SFCT was manually measured and averaged by two independent observers from horizontal and vertical scans. Repeatability of SFCT measurements between the scans and observers were analyzed.


Statistical analyses were performed using SPSS 17.0 software. Pearson’s correlation was used to analyze the correlation between any two biometric factors. Analysis of multi-predictors (axial length/spherical equivalent and age) of SFCT were analyzed using stepwise method. Partial correlations with controlled factor were studied. Analysis of linear regression of SFCT with its predictors of axial length, spherical equivalent, and age was performed. P < 0.05 was considered statistically significant.


Correlations among biometric factors in high myopia

Our cohort comprised 312 eyes from 312 patients (98 men). Table 1 shows the demographic and clinical characteristics. The correlation between the measurements of SFCT performed by two independent observers was highly significant (r = 0.96; p < 0.001). The correlation between SFCT measurements from vertical scan and horizontal scan was also highly significant (r = 0.89, p < 0.001).

Table 1 Epidemiological data of included eyes

Correlation analysis among the four biometric factors showed that SFCT was significantly negative correlated with axial length (r = − 0.592, p < 0.001), negative correlated with spherical equivalent (r = − 0.471, p < 0.001), and negative correlated with age (r = − 0.296, p < 0.001), respectively, as shown in Table 2. With the increasing of axial length, spherical equivalence and age, the SFCT became gradually thinning. Among these three biometric factors, axial length showed the largest coefficient correlated to SFCT. Axial length and spherical equivalent was highly correlated, as commonly expected (r = 0.773, p < 0.001). There was no significant correlation between age and axial length. No significant correlation between age and spherical equivalent was found, either.

Table 2 Correlations among biometric factors in high myopia

Predictors of subfoveal choroidal thickness

Given that axial length, spherical equivalent, and age were all correlated significantly with SFCT. Multi-predictors of subfoveal choroidal thickness were analyzed. Adding all the three factors resulted in confounding results using stepwise method. The models of axial length plus age and spherical equivalent plus age were similar in the statistical fitness (Table 3). Partial correlation with controlled age further confirmed that axial length (R = − 0.628, p < 0.001) was a more significant predictor of SFCT than spherical equivalent (R = − 0.507, p < 0.001).

Table 3 Analysis of multi-predictors (axial length/ spherical equivalent and age) of subfoveal choroidal thickness

Linear regression of SFCT with predictors

The predictors of SFCT were analyzed using linear regression (Table 4). The distribution of SFCT values in eyes with different levels of predictors was shown in box plot, Fig. 1. The SFCT cohort was grouped by sectioned range of axial length (1 mm), age (1 decade), and spherical equivalent (3D). According to the distribution of data (Fig. 1), the speed of SFCT decrease seemed slowing down with the increasing axial length, age, and spherical equivalent, especially with axial length over 30 mm, age older than 50 years, and spherical equivalent over 15 D.

Table 4 Linear regression of SFCT with its predictors of axial length, spherical equivalent, and age
Fig. 1

Distribution of SFCT data associated with predictors. Left: SFCT data associated with axial length; Middle: SFCT data associated with refractive error; Right: SFCT data associated with age; о: Outlier values which were between 1.5 and 3 box lengths from either end of the box. *: Extreme values which are more than 3 box lengths from either end of the box


In this study, we found that axial length, rather than spherical equivalent, was the more important predictor of SFCT, different to previous reports from another cohort [21]. In a recent study, by comparing eyes with different degree of myopia and healthy eyes, axial length was found to be determining factor of choroidal thickness in some locations including subfoveal [25]. We suggest that axial length may be more accurate in predicting SFCT in high myopia due to the following reasons: 1) the sample size of our cohort was much larger; 2) the axial length may represent more accurately and directly the extent of choroidal stretch in the posterior pole of highly myopic eyes; 3) the refraction might be confused by development of nuclear cataract, which is very common in adult myopes and could result in further myopic shift; 4) for the eyes with cataract removed, spherical equivalent is not applicable to understanding the myopic status.

The choroidal thickness become gradually thinning with the extension of axial length. However, the SFCT seemed decrease faster in eyes with axial length in the range of 24 to 30 mm compared with those axial length over 30 mm (Fig. 1, left).

The second predictor of SFCT is spherical equivalent. The choroidal thickness become gradually thinning with the increasing of refraction. The speed of SFCT decrease looked much faster in eyes with a spherical equivalent from 6 D to 15 D, compared with those spherical equivalent greater than 15 D (Fig. 1, middle).

Our cohort was from a tertiary eye-care center based population, the myopic degree was probably much higher than other cohorts. The SFCT of our high myopia cohort was 83.77 ± 54.64 μm, much thinner than that in healthy subjects from literatures [27,28,29,30]. Our mean SFCT was even thinner than a similar study showing a SFCT of 113.8 ± 53.9 μm in a New York cohort (n = 35 eyes), 172.9 ± 72.8 μm in a Japanese cohort (n = 110 eyes) [21], 166 ± 88.7 μm in a Spain cohort [22] and 225.87 ± 5.51 μm from a case-control study of young Chinese men in Singapore [31].

Age is associated with SFCT in both high myopic and healthy eyes. In eyes without high myopia, age was found critical for evaluation of SFCT in two healthy Chinese cohorts, one from Guangzhou in southern China, and another from Beijing in northern China [28, 32]. SFCT in subjects older than 60 years of age was much thinner than that in younger subjects, and the SFCT after 60 years of age seemed to keep relatively stable in healthy cohorts [28, 29, 32]. The age of the patients in our cohort was from 18 to 88, but most of the cases were older than 30 years. The speed of SFCT decrease after 50 years of age looked much slower than that from 18 to 49 years of age (Fig. 1, right). Our study did not focus on young myopes. Choroidal thickness in young population [33, 34] might be quite different compared with in older ones.

Our study has several limitations: 1) it is a retrospective cross-sectional study, the data from a hospital-based cohort might represent more severe degree of myopia. 2) some eyes were excluded because of low image quality due to poor focus fixation, or the posterior scleral border was not clear; 3) the correlation of SFCT with other factors, such as gender, visual acuity, retinal thickness, intraocular pressure, ocular biometric parameters, or various maculopathy, was not analyzed, which might be worthy of further investigation; 4) Our cohort does not include patients younger than 18 years. 5) The SFCT may be also affected by other factors including the severity of posterior staphyloma, which was not included in this study.

We included only one eye from each patient to meet statistical requirement. From a recent study, there was larger absolute interocular differences in choroidal thickness of high myopic eyes compared with healthy control eyes [35]. Further study comparing the interocular difference in severity of pathological change and corresponding choroidal thickness and visual function might provide more information for understanding high myopia related changes.


In summary, SFCT in adult highly myopic eyes was inversely correlated with increasing age, spherical equivalent and axial length. Axial length was a more significant predictor of SFCT than spherical equivalent, or age.





Enhanced depth imaging


Spectral-domain optical coherence tomography


Subfoveal choroidal thickness


  1. 1.

    Dolgin E. The myopia boom. Nature. 2015;519(7543):276–8.

    Article  PubMed  CAS  Google Scholar 

  2. 2.

    Lyu Y, Zhang H, Gong Y, Wang D, Chen T, Guo X, Yang S, Liu D, Kang M. Prevalence of and factors associated with myopia in primary school students in the Chaoyang District of Beijing, China. Jpn J Ophthalmol. 2015;59(6):421–9.

    Article  PubMed  Google Scholar 

  3. 3.

    Wu LJ, You QS, Duan JL, Luo YX, Liu LJ, Li X, Gao Q, Zhu HP, He Y, Xu L, et al. Prevalence and associated factors of myopia in high-school students in Beijing. PLoS One. 2015;10(3):e0120764.

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  4. 4.

    Williams KM, Bertelsen G, Cumberland P, Wolfram C, Verhoeven VJ, Anastasopoulos E, Buitendijk GH, Cougnard-Gregoire A, Creuzot-Garcher C, Erke MG, et al. Increasing prevalence of myopia in Europe and the impact of education. Ophthalmology. 2015;122(7):1489–97.

    Article  PubMed  PubMed Central  Google Scholar 

  5. 5.

    Saxena R, Vashist P, Tandon R, Pandey RM, Bhardawaj A, Menon V, Mani K. Prevalence of myopia and its risk factors in urban school children in Delhi: the North India myopia study (NIM study). PLoS One. 2015;10(2):e0117349.

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  6. 6.

    Jones D, Luensmann D. The prevalence and impact of high myopia. Eye Contact Lens. 2012;38(3):188–96.

    Article  PubMed  Google Scholar 

  7. 7.

    Henaine-Berra A, Zand-Hadas IM, Fromow-Guerra J, Garcia-Aguirre G. Prevalence of macular anatomic abnormalities in high myopia. Ophthalmic Surg Lasers Imaging Retina. 2013;44(2):140–4.

    Article  PubMed  Google Scholar 

  8. 8.

    Chang L, Pan CW, Ohno-Matsui K, Lin X, Cheung GC, Gazzard G, Koh V, Hamzah H, Tai ES, Lim SC, et al. Myopia-related fundus changes in Singapore adults with high myopia. Am J Ophthalmol. 2013;155(6):991–9. e991

    Article  PubMed  Google Scholar 

  9. 9.

    Cheng SC, Lam CS, Yap MK. Prevalence of myopia-related retinal changes among 12-18 year old Hong Kong Chinese high myopes. Ophthalmic Physiolog Opt. 2013;33(6):652–60.

    Article  Google Scholar 

  10. 10.

    Morgan IG. What public policies should be developed to deal with the epidemic of myopia? Optom Vis Sci. 2016;93(9):1058–60.

    Article  PubMed  Google Scholar 

  11. 11.

    Warner N. Update on myopia. Curr Opin Ophthalmol. 2016;27(5):402–6.

    Article  PubMed  Google Scholar 

  12. 12.

    Lichtwitz O, Boissonnot M, Mercie M, Ingrand P, Leveziel N. Prevalence of macular complications associated with high myopia by multimodal imaging. J Fr Ophtalmol. 2016;39(4):355–63.

    Article  PubMed  CAS  Google Scholar 

  13. 13.

    Rey A, Jurgens I, Maseras X, Carbajal M. Natural course and surgical management of high myopic foveoschisis. Ophthalmologica. 2014;231(1):45–50.

    Article  PubMed  Google Scholar 

  14. 14.

    Ripandelli G, Parisi V, Friberg TR, Coppe AM, Scassa C, Stirpe M. Retinal detachment associated with macular hole in high myopia: using the vitreous anatomy to optimize the surgical approach. Ophthalmology. 2004;111(4):726–31.

    Article  PubMed  Google Scholar 

  15. 15.

    Shimada N, Ohno-Matsui K, Nishimuta A, Tokoro T, Mochizuki M. Peripapillary changes detected by optical coherence tomography in eyes with high myopia. Ophthalmology. 2007;114(11):2070–6.

    Article  PubMed  Google Scholar 

  16. 16.

    Wong TY, Ferreira A, Hughes R, Carter G, Mitchell P. Epidemiology and disease burden of pathologic myopia and myopic choroidal neovascularization: an evidence-based systematic review. Am J Ophthalmol. 2014;157(1):9–25. e12

    Article  PubMed  Google Scholar 

  17. 17.

    Wong CW, Phua V, Lee SY, Wong TY, Cheung CM. Is choroidal or scleral thickness related to myopic macular degeneration? Invest Ophthalmol Vis Sci. 2017;58(2):907–13.

    Article  PubMed  Google Scholar 

  18. 18.

    Fujiwara A, Shiragami C, Shirakata Y, Manabe S, Izumibata S, Shiraga F. Enhanced depth imaging spectral-domain optical coherence tomography of subfoveal choroidal thickness in normal Japanese eyes. Jpn J Ophthalmol. 2012;56(3):230–5.

    Article  PubMed  Google Scholar 

  19. 19.

    Shao L, Xu L, Chen CX, Yang LH, Du KF, Wang S, Zhou JQ, Wang YX, You QS, Jonas JB, et al. Reproducibility of subfoveal choroidal thickness measurements with enhanced depth imaging by spectral-domain optical coherence tomography. Invest Ophthalmol Vis Sci. 2013;54(1):230–3.

    Article  PubMed  Google Scholar 

  20. 20.

    Spaide RF, Koizumi H, Pozzoni MC. Enhanced depth imaging spectral-domain optical coherence tomography. Am J Ophthalmol. 2008;146(4):496–500.

    Article  PubMed  Google Scholar 

  21. 21.

    Nishida Y, Fujiwara T, Imamura Y, Lima LH, Kurosaka D, Spaide RF. Choroidal thickness and visual acuity in highly myopic eyes. Retina. 2012;32(7):1229–36.

    Article  PubMed  Google Scholar 

  22. 22.

    Flores-Moreno I, Ruiz-Medrano J, Duker JS, Ruiz-Moreno JM. The relationship between retinal and choroidal thickness and visual acuity in highly myopic eyes. Br J Ophthalmol. 2013;97(8):1010–3.

    Article  PubMed  Google Scholar 

  23. 23.

    Zaben A, Zapata MA, Garcia-Arumi J. Retinal sensitivity and choroidal thickness in high myopia. Retina. 2015;35(3):398–406.

    Article  PubMed  Google Scholar 

  24. 24.

    Fujiwara T, Imamura Y, Margolis R, Slakter JS, Spaide RF. Enhanced depth imaging optical coherence tomography of the choroid in highly myopic eyes. Am J Ophthalmol. 2009;148(3):445–50.

    Article  PubMed  Google Scholar 

  25. 25.

    El-Shazly AA, Farweez YA, ElSebaay ME, El-Zawahry WMA. Correlation between choroidal thickness and degree of myopia assessed with enhanced depth imaging optical coherence tomography. Eur J Ophthalmol. 2017;27(5):577–84.

  26. 26.

    Moussa M, Sabry D, Soliman W. Macular choroidal thickness in normal Egyptians measured by swept source optical coherence tomography. BMC Ophthalmol. 2016;5(16):138.

  27. 27.

    Ikuno Y, Kawaguchi K, Nouchi T, Yasuno Y. Choroidal thickness in healthy Japanese subjects. Invest Ophthalmol Vis Sci. 2010;51(4):2173–6.

    Article  PubMed  Google Scholar 

  28. 28.

    Ding X, Li J, Zeng J, Ma W, Liu R, Li T, Yu S, Tang S. Choroidal thickness in healthy Chinese subjects. Invest Ophthalmol Vis Sci. 2011;52(13):9555–60.

    Article  PubMed  Google Scholar 

  29. 29.

    Kim M, Kim SS, Koh HJ, Lee SC. Choroidal thickness, age, and refractive error in healthy Korean subjects. Optom Vis Sci. 2014;91(5):491–6.

    Article  PubMed  Google Scholar 

  30. 30.

    Ruiz-Medrano J, Flores-Moreno I, Pena-Garcia P, Montero JA, Duker JS, Ruiz-Moreno JM. Macular choroidal thickness profile in a healthy population measured by swept-source optical coherence tomography. Invest Ophthalmol Vis Sci. 2014;55(6):3532–42.

    Article  PubMed  Google Scholar 

  31. 31.

    Gupta P, Saw SM, Cheung CY, Girard MJ, Mari JM, Bhargava M, Tan C, Tan M, Yang A, Tey F, et al. Choroidal thickness and high myopia: a case-control study of young Chinese men in Singapore. Acta Ophthalmol. 2015;93(7):e585–92.

    Article  PubMed  Google Scholar 

  32. 32.

    Wei WB, Xu L, Jonas JB, Shao L, Du KF, Wang S, Chen CX, Xu J, Wang YX, Zhou JQ, et al. Subfoveal choroidal thickness: the Beijing eye study. Ophthalmology. 2013;120(1):175–80.

    Article  PubMed  Google Scholar 

  33. 33.

    Gupta P, Cheung CY, Saw SM, Koh V, Tan M, Yang A, Zhao P, Cheung CM, Wong TY, Cheng CY. Choroidal thickness does not predict visual acuity in young high myopes. Acta Ophthalmol. 2016;94(8):e709–15.

    Article  PubMed  Google Scholar 

  34. 34.

    Gupta P, Thakku SG, Saw SM, Tan M, Lim E, Tan M, Cheung CMG, Wong TY, Cheng CY. Characterization of choroidal morphologic and vascular features in young men with high myopia using spectral-domain optical coherence tomography. Am J Ophthalmol. 2017;177:27–33.

    Article  PubMed  Google Scholar 

  35. 35.

    Alzaben Z, Cardona G, Zapata MA, Zaben A. Interocular asymmetry in choroidal thickness and retinal sensitivity in high myopia. Retina; 2017. [Epub ahead of print]

Download references


The authors thank Mr. Jun Chen from Guangzhou Women and Children’s Medical Center for statistical assistant, Mrs. Xiaofang Li, Shaofen Lin, and Qiufen Yang from Zhongshan Ophthalmic Center for OCT imaging support.


This study was supported by National Natural Science Foundation of China (81570862), Natural Science Foundation of Guangdong Province (2014A030313197), Guangzhou Science and Technology Project (2014Y2–00064), and Young Teacher Training Program of Sun Yat-sen University (15ykpy32).

Availability of data and materials

The datasets used and analyzed during the current study are available from the corresponding author on reasonable request.

Author information




BL participated in the design of the study and drafted the manuscript; YW, XC and CL collected and analyzed the data; TL and YLin carried out critical review and revised the manuscript; LL and YLi conceived of the study and revised the manuscript, and contributed as co-corresponding authors. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Lin Lu.

Ethics declarations

Ethics approval and consent to participate

The study was conducted in compliance with the principles of the Declaration of Helsinki and approved by the Ethics Committee of Zhongshan Ophthalmic Center. An informed consent was obtained from all of the included subjects.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Liu, B., Wang, Y., Li, T. et al. Correlation of subfoveal choroidal thickness with axial length, refractive error, and age in adult highly myopic eyes. BMC Ophthalmol 18, 127 (2018).

Download citation


  • High myopia
  • Subfoveal choroidal thickness
  • Axial length
  • Age
  • Refractive error
  • Correlation analysis