https://doi.org/10.31288/oftalmolzh201361216

New approach to morphometric assessment of the optic nerve disc in high axial myopia according to the data of spectral optic coherent tomography

Ulyanova NA, Venger LV

Odessa National Medical University 

E-mail: ulyanova@ukr.net

Introduction. The enlargement of the anterior — posterior size (APS) of the eye in high axial myopia influences the architectonics of the nervous fibres in the area of the optic nerve disc (OND) and is accompanied by the morphometric indices.

Purpose. Improvement of morphometric analysis of OND and peripapillar retina in patients with high axial myopia according to a spectral optical coherent tomography (SOCT).

Materials and methods. There were examined 46 patients (88 eyes). 1 group consisted of 7people (14 eyes) with emmetropia and average APS of up to 24 mm (23.89+0.05). II group comprised 10 patients (20 eyes) with average spherical equivalent (-2.5D+0.15), APS — 25.02+0.03 mm. IIIgroup included 12patients (21 eyes) with average spherical equivalent (-4.0o+0.04), APS — 26.1+0.21 mm. IVgroup was of9 patients (18 eyes) with average spherical equivalent (-8.75°+0.05), APS — 27.05+0.24mm. V group consisted of 8patients (15 eyes) with average spherical equivalent (-10.5°+0.05), APS — 28.03+0.11 mm. All patients were made SOCTof OND («SoctCopernicusOptopol») in the mode «Asterisk scanningprogram» and «3D scannings.

Results. There was revealed OND deformation in patients with high axial myopia manifested by changes of the OND sizes and form, oblique entrance of the nervous fibres into the scleral ring and non-uniform thickness of the layer of the nervous fibres in the peripapillar zone. In high axial myopia the increase in thickness of the nervous fibres layer in the temporal sector is on the average by 55.5 % in comparison with emmetropia, decrease in the thickness of the layer of the nervous fibers in the upper and lower sectors is on an average by 12.9 and 13.4 % accordingly (p<0.05). For qualitative assessment of the oblique entrance of the nervous fibers into spectral ring there was suggested the angle index of APS deformation, which was calculated by the angle between two beams passed from the APS edges to the deepest point of the physiological excavation on optic tomogram of APS.

Key words: high degree myopia, optic nerve disc, spectral optical coherence tomography.

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