OPTICAL COHERENCE TOMOGRAPHY IN PATIENTS WITH REFRACTIVE ERRORS. PART 3: THE THICKNESS OF THE GANGLION CELL-INNER PLEXIFORM LAYER

• Main Authors: A. A. Shpak, M. V. Korobkova
• Format: Article
• Language: Russian
• Published: Publishing house "Ophthalmology" 2018-07-01
• Series: Офтальмохирургия
• Subjects: optical coherence tomography; myopia; ganglion cell layer; inner plexiform layer; optical magnification; stretching of the posterior segment of the eyeball
• Online Access: https://www.ophthalmosurgery.ru/jour/article/view/426

Purpose. Investigation of the influence of the axial length of the eye on the thickness of the ganglion cell-inner plexiform layer (GCIPL) and the development of methods for its evaluation in patients with myopia in the age of over 40 years.Material and methods. The study involved 53 patients (53 eyes) over the age of 40 years, with medium- and high-degree myopia, as well as 80 healthy subjects (80 eyes) of the same sex and age with emmetropia (control group). OCT was performed on a Cirrus HD-OCT device (Carl Zeiss Meditec).Results. To assess the influence of the optical magnification effect on the average thickness of the GCIPL, the authors and the programmer A.A. Evsukov created a computer program. The average thickness of the GCIPL in the control group was 79.0±5.3 (68-90) μm. In the group of patients with myopia, the GCIPL thickness was lower by an average of 5.1 μm (73.9±5.2, 64 to 86 μm, P<0.000). Correction by the computer program reduced this difference by less than ⅓, to 3.5 μm (75.5±5.3, 65 to 88μm, difference from the controls and from the initial data: P<0.000). Theoretical calculations showed a significant increase in the surface area of the myopic eye. A table and normative database have been developed for correctly estimating the thickness of the GCIPL based on the axial length of the eye.Conclusion. Thinning of GCIPL in patients with medium- and highdegree myopia is only partially associated with the effect of optical magnification, and is more due to the stretching of the posterior segment of the eyeball. An original technique for assessing the thickness of the GCIPL in patients with myopia, adapted to the Cirrus HD-OCT device, is proposed.