Measuring of the fovea and foveola using line scans and 3D Macular scans obtained with spectral domain optical coherent tomography.

Transcription

1 Measuring of the fovea and foveola using line scans and 3D Macular scans obtained with spectral domain optical coherent tomography. Vakhrameeva O.A. 1, Moiseenko G.A. 1, Maltsev D.S. 2, Sukhinin M.V. 2, Koskin S.A. 2, Shelepin Y.E. 1 Pavlov Institute of Physiology, Russian Academy of Sciences. 2 Department of ophthalmology; S. M. Kirov Military Medical Academy, St. Petersburg, Russia

2 Central retina structures

3 Layers of the human retina Spectral domain optical coherence tomography (Spectralis, Heidelberg) image of a normal individual. The multilayered retinal architecture can be observed and each retinal layer can be identified. NFL, nerve fiber layer; GCL, ganglion cell layer; IPL, inner plexiform layer; OPL, outer plexiform layer; ONL, outer nuclear layer; ELM, external limiting membrane; IS/OS, junction of the inner and outer segments of the photoreceptors; RPE, retinal pigment epithelium. (RETINA, 2013)

4 Different animals have different retina structure in the central visual field. Macaque monkeys have very similar to human foveal depression. Some of the animals don t have fovea, some of them have tiny foveal depression, but it differs from human (cat). Some monkeys (f.e. macaque) has very similar to human fovea structure.

5 Comparing the geometrical characteristics of the fovea with morphological structures of the retina (FAZ).

6 Variations of anatomical structures dimensions (FAZ) across different studies Reference Method n Area (mm 2 ) Mean (SD) Diameter (mm) Bresnick et al.[1] FFA * Wolf et al.[2] FFA (0.06) Mansour et al.[3] FFA (0.559) Arend et al.[4] FFA (0.062) 0.255

7 Line scan of the retina, obtained by time domain OCT (TD-OCT) Fovea distance between nerve fiber layer ends. Foveola distance between inner nuclear layer ends Vakhrameeva O.A., Sukhinin M.V., Moiseenko G.A., Muraviova S.V., Pronin S.V., Pronin S.V. Volkov V.V., Shelepin Yu.E. Investigatin of the perception depending on the geometry of the fovea // Sencory Systems, 2013, V. 27, 2, pp

8 Modified Landolt C optotype, without noise and with different percent of noise. Vakhrameeva O.A., Sukhinin M.V., Moiseenko G.A., Muraviova S.V., Pronin S.V., Pronin S.V. Volkov V.V., Shelepin Yu.E. Investigatin of the perception depending on the geometry of the fovea // Sencory Systems, 2013, V. 27, 2, pp

9 Correct answer dependence on the size of the Landolt C optotype Number of the correct answers Different curves for different noise levels (from 0 to 50, see plot) Size of the object (deg) Vakhrameeva O.A., Sukhinin M.V., Moiseenko G.A., Muraviova S.V., Pronin S.V., Pronin S.V. Volkov V.V., Shelepin Yu.E. Investigatin of the perception depending on the geometry of the fovea // Sencory Systems, 2013, V. 27, 2, pp

10 Probability of the correct answer Correct answer dependence on the diameter of the foveola Noise 10 % Noise 40 % Different markers are for different object size. Each dot particular subjects eye Foveola diameter (μm) Vakhrameeva O.A., Sukhinin M.V., Moiseenko G.A., Muraviova S.V., Pronin S.V., Pronin S.V. Volkov V.V., Shelepin Yu.E. Investigatin of the perception depending on the geometry of the fovea // Sencory Systems, 2013, V. 27, 2, pp

11 Correct answer dependence on the diameter of the fovea Probability of the correct answer Noise 30 % Different markers are for different object size. Each dot particular subjects eye Fovea diameter (μm) Vakhrameeva O.A., Sukhinin M.V., Moiseenko G.A., Muraviova S.V., Pronin S.V., Pronin S.V. Volkov V.V., Shelepin Yu.E. Investigatin of the perception depending on the geometry of the fovea // Sencory Systems, 2013, V. 27, 2, pp

12 Line scan and 3D macular images of the retina, obtained by spectral domain OCT (SD-OCT) SD-OCT is faster than TD-OCT, which allows to obtain more B-scans per 1 second. Using this method researcher can obtain one averaged across hundreds line scan with good resolution or many slices, which allow to reconstruct the 3D structure of the macula region.

13 Dependence of contrast sensitivity on the foveola diameter (p 0.05) Each dot particular subjects eye Vakhrameeva O.A., Moiseenko G.A., Maltsev D.S., Sukhinin M.V., Pronin, S.A., Koskin S.A., Shelepin Yu.E Role of the optical and morphological characteristics of the eye in detection of small objects // Boook of abstracts, VII all Russia seminar Macula 2016, Rostov-on-Don, May 20-22, 2016

14 Interaction between diameter of the foveola and latency of the evoked potentials in response to chessboard pattern. Oz ВП рисунок Moiseenko G.A., Vakhrameeva O.A., Maltsev D.S., Sukhinin M.V., Koskin S.A., Shelepin Yu.E. Investigation of correlation between electrophysiological, morphological and optical characteristics of the human eye and recognition of objects in the fovea region // Boook of abstracts, VII all Russia seminar Macula 2016, Rostov-on-Don, May 20-22, 2016

15 Correlation between foveola diameter and latency of the P100 component in response to chessboard pattern. (p<0,05) Moiseenko G.A., Vakhrameeva O.A., Maltsev D.S., Sukhinin M.V., Koskin S.A., Shelepin Yu.E. Investigation of correlation between electrophysiological, morphological and optical characteristics of the human eye and recognition of objects in the fovea region // Boook of abstracts, VII all Russia seminar Macula 2016, Rostov-on-Don, May 20-22, 2016

16 Number of letters per fixation Eye movements during reading Number of letters per fixation p<0,001 p<0,001 Reading time (sec) Number of saccades There was tendency of negative correlations between fovea diameter and fixation duration. Lamminpia A. Moiseenko G.A., Vakhrameeva O.A., Shelepin Yu.E. Influence of fovea dimension on the eye movement during reading // Boook of abstracts, VII all Russia seminar Macula 2016, Rostov-on-Don, May 20-22, 2016

17 Conclusions: Foveola diameter affects the ability to recognize small objects (smaller than 1 deg) This influence has been approved by the use of visual ERP Foveola diameter affects maximum of the contrast sensitivity Fovea diameter influence the eye movements during reading

18 General conclusion: Anatomical characteristics of the fovea region (particularly, diameter of the foveola and fovea) measured in vivo plays an important role in visual performance. Supported by grant of Russian Science Foundation