RESEARCH Structure versus function in high myopia using optical coherence tomography and automated perimetry Clin Exp Optom 2019; 102: 335–340 DOI:10.1111/cxo.12836 Nasrin Moghadas Sharif* † MSc Nasser Shoeibi ‡ MD Asieh Ehsaei* † PhD David Atchison § DSc *Refractive Errors Research Center, Mashhad University of Medical Sciences, Mashhad, Iran † Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran ‡ Eye Research Center, Mashhad University of Medical Sciences, Mashhad, Iran § School of Optometry and Vision Science and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia E-mail: ehsaeia@mums.ac.ir Submitted: 21 February 2018 Revised: 11 August 2018 Accepted for publication: 13 August 2018 Background: To examine the structure–function relationship between retinal thickness using spectral-domain optical coherence tomography and standard automated perimetry in high myopia. Methods: The study population comprised 58 highly myopic individuals with no posterior abnormalities (mean spherical equivalent refraction ≤ -6.00 D and axial length ≥ 26.0 mm). All eyes underwent optical coherence tomography with the Spectralis spectral domain opti- cal coherence tomograph and visual field evaluation with the Humphrey Field Analyzer II-i. Average macular layer thicknesses in each quadrant were calculated in a 6 × 6 mm area centred on the fovea. The visual field was assessed from 17 central locations (10  ), approxi- mately the equivalent of the area tested by optical coherence tomography in the macular scan. Linear correlations were made between different macular layer thicknesses and peri- papillary retinal nerve layer thickness with their matched visual field sensitivities. Results: Participant ages were 28.2  6.4 years, mean spherical equivalent refractions were -8.20  1.40 D and axial lengths were 26.7  0.7 mm. There were significant positive correlations between layer thickness and corresponding visual field sensitivities as follows: ganglion cell layer in all quadrants, temporal quadrant of the nerve fibre layer with nasal quadrant of the visual field, inferior quadrant of the outer nuclear layer with superior visual field, and temporal-superior peripapillary nerve fibre layer with nasal-inferior visual field. Conclusion: The correlation between retinal layer thicknesses and visual field sensitivity could be explained by myopia-related losses due to lateral retinal stretching, with further research required to investigate this. Key words: high myopia, optical coherence tomography, retinal thickness, visual fields High myopia is characterised by abnormal axial elongation and thinning of the sclera. 1 It is often accompanied by ocular complica- tions such as glaucoma, 2 cataracts, 3 macu- lar degeneration, 4 and retinal detachment, 5 leading to blindness when the damage to the retina is severe. 6 The optic nerve fibre deformation following axial lengthening in high myopic eyes causes degenerative damages which impair vision. 7,8 In addition, myopic eyes can have more dramatic peripheral defocus than shorter eyes, which may be due to related fundus changes such as staphyloma. Defocus decreases retinal image quality by spread- ing the image over a larger area and leads to reduction of the luminous contrast and change of luminous gradient at the image margin. 9 These changes adversely affect the quality of life of individuals as well as being an economic burden on health care systems. 10 High myopia is a risk factor for visual field defects. 8,10,11 Visual field measurement by automated perimetry is one of the most commonly used methods to assess the severity of visual field loss. 12 The location of the visual field defect may correspond to the location of the ectatic retina following decreasing of retinal layer thicknesses. 13 Thickness changes in both the macula reti- nal layer and peripapillary nerve fibre layer have been reported in myopic eyes. 14–16 Detailed investigation of retinal layer thick- ness in high myopia and associated patho- logical changes is of great importance for early detection and treatment of degenera- tive eye diseases following myopia progres- sion. 6 Spectral-domain optical coherence tomography is a non-invasive technology that enables high-resolution cross-sectional imaging of the retinal structure in vivo and quantitative analysis of the macula retinal layers and peripapillary retinal nerve fibre layer thicknesses. 17–20 Potential artefacts (for example, pupil size, peripheral refractive defocus and individual differences in functional test and disc area, axial length, and segmentation errors in structural tests) may independently affect results of structural and functional tests. 21 Therefore, applying both structural and functional techniques can provide comple- mentary information. 21 As far as the authors are aware, there has been a limited number of studies on assess- ment of structure–function relationship in myopic eyes. 22,23 Wolsley et al. 22 investi- gated the correlation between retinal struc- ture using optical coherence tomography © 2018 Optometry Australia Clinical and Experimental Optometry 102.3 May 2019 335 CLINICAL AND EXPERIMENTAL