scholarly journals Effect of axial length on full-field and multifocal electroretinograms

2017 ◽  
Vol 100 (6) ◽  
pp. 668-675 ◽  
Author(s):  
Ramya Sachidanandam ◽  
Priya Ravi ◽  
Parveen Sen
Keyword(s):  
Axial Length ◽  
Full Field ◽  
Multifocal Electroretinograms

Effect of Axial Length on Full-Field and Multifocal Electroretinogram

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Noura S Hamzawy ◽  
Tarek A El-Zarakany ◽  
Amany A El-Shazly ◽  
Sameh H Mohamed
Keyword(s):  
Visual Acuity ◽  
Negative Correlation ◽  
Axial Length ◽  
Multifocal Electroretinogram ◽  
Case Series ◽  
Length Measurement ◽  
Peripheral Retina ◽  
Full Field ◽  
Case Series Study ◽  
Four Quadrant

Abstract Background The Electroretinogram is a mass potential, which reflects the summed electrical activity of the retina. Full-field ERG measures the electrical signals from the whole retina in response to a light stimulus. The weakness of the full-field ERG is that it cannot provide topographical information regarding the functional integrity of the retina and cannot detect subtle functional defects. The response is dominated by the peripheral retina due to its predominance of retinal cells. Aim of the Work to investigate the effect of axial length on fullfield (ffERG)and multifocal ERG (mfERG). Subjects and Methods Forty-four eyes of 44 healthy subjects were included in this case series study which has been conducted at Ain shams university hospitals after the approval of the research ethical committee in the faculty of medicine, Ain Shams University between July 2018 and September 2019. Full ophthalmologic examination was performed for all participants, including visual acuity assessment (Best corrected visual acuity) using Snellen chart, calculation of spherical equivalent (SE), slit Lamp biomicroscopy examination with IOP measurement via Goldmann applanation tonometry (GAT), and fundus examination by indirect ophthalmoscope or via 90 D VOLK lens to assess macular area. Axial length measurement, ffERG & mf-ERG. Results; We found that in the absence of fundus changes, mfERG parameters showed decreased amplitudes with increase in axial length. The Six- Rings Response Densities showed negative correlation with AL while there is no significant correlation between Six- Rings Response Densities and SE. The Six- Rings P1 Amplitude showed negative correlation with AL while there is no significant correlation between P1 Amplitude and SE. The Six- Rings N1 Amplitude showed negative correlation with AL while there is no significant correlation between P1 Amplitude and SE. The four- quadrant Response Densities showed negative correlation with AL while there is no significant correlation between four- quadrant Response Densities and SE. The four- quadrant P1 Amplitude showed negative correlation with AL while there is no significant correlation between P1 Amplitude and SE. The four- quadrant N1 Amplitude showed negative correlation with AL while there is no significant correlation between P1 Amplitude and SE. There is no significant correlation between full-field clinical ERG parameters and both AL and SE. Conclusion In the absence of fundus changes, mfERG parameters showed decreased amplitudes with increase in axial length. For correct interpretation of ERG responses in clinical practice, we recommend consideration of axial length measurement when evaluating mfERG responses.

scholarly journals Effect of short-term peripheral myopic defocus on ocular biometrics using Fresnel “press-on” lenses in humans 

2021 ◽  
Author(s):  
Ryo Kubota ◽  
Nabin R Joshi ◽  
Inna Samandarova ◽  
Maksud Oliva ◽  
Arkady Selenow ◽  
...  
Keyword(s):  
Axial Length ◽  
Choroidal Thickness ◽  
Fresnel Lens ◽  
Short Term ◽  
Full Field ◽  
Before And After ◽  
The Mean ◽  
The Difference ◽  
The Right ◽  
And Control

Abstract This study assessed axial length and choroidal thickness changes following short-term peripheral myopic defocus in normal adult subjects. Twenty subjects underwent defocus sessions by viewing a full-field projected movie 4 meters away for 4 hours in the morning, while wearing spectacle lenses, corrected for distance vision in both eyes. The right eye, serving as the test eye, was peripherally defocused using a Fresnel lens overlay of + 3.50D with a central aperture of 11.5 mm, while the left eye served as the control. A subset of 10 subjects from the same cohort also underwent additional defocus sessions with + 5.00D of peripheral defocus. Axial length was measured and radial sub-foveal choroidal scans were obtained before and after the defocus sessions. The mean increase in axial length of the test eyes was 8 µm (p < 0.05) less than that of the control eyes with + 3.50D peripheral defocus condition and 14 µm (p < 0.05) less than the control eyes with + 5.00 D peripheral defocus condition. The difference in mean changes for choroidal thickness between test and control eyes were not significant for both dioptric conditions. Our results demonstrated that short-term peripheral myopic defocus significantly inhibited axial elongation in adult humans, without significant changes in choroidal thickness.

Foveal amplitudes of multifocal electroretinograms are larger following full-field electroretinograms

2018 ◽  
Vol 137 (3) ◽  
pp. 143-149 ◽  
Author(s):  
Wendy Harrison ◽  
Kaila Osmotherly ◽  
Nathan Biancardi ◽  
Jamison Langston ◽  
Russell Gray ◽  
...  
Keyword(s):  
Full Field ◽  
Multifocal Electroretinograms

scholarly journals Effect of short-term peripheral myopic defocus on ocular biometrics using Fresnel “press-on” lenses in humans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryo Kubota ◽  
Nabin R. Joshi ◽  
Inna Samandarova ◽  
Maksud Oliva ◽  
Arkady Selenow ◽  
...  
Keyword(s):  
Axial Length ◽  
Choroidal Thickness ◽  
Fresnel Lens ◽  
Short Term ◽  
Central Visual Field ◽  
Full Field ◽  
Before And After ◽  
The Difference ◽  
The Right ◽  
And Control

AbstractThis study assessed axial length and choroidal thickness changes following short-term peripheral myopic defocus in normal adult subjects. Twenty subjects underwent defocus sessions by viewing a full-field projected movie 4 m away for 4 h in the morning, while wearing spectacle lenses, corrected for distance vision in both eyes. The right eye, serving as the test eye, was peripherally defocused using a Fresnel lens overlay of + 3.50 D with a central clear aperture of 11.5 mm (correlating to a clear central visual field of approximately 23°), while the left eye served as the control (with no Fresnel lens overlay). A subset of 10 subjects from the same cohort also underwent additional defocus sessions with + 5.00 D of peripheral defocus. Axial length was measured and radial sub-foveal choroidal scans were obtained before and after the defocus sessions. The increase in axial length of the test eyes were significantly less than the control eyes under both peripheral defocus conditions (p < 0.05). The difference in mean change for choroidal thickness between test and control eyes was not significant for either dioptric condition. Our results demonstrated that short-term peripheral myopic defocus significantly inhibited axial elongation in adult humans, without significant changes in choroidal thickness.

Full-Field Approach for Modeling of Microstructural Evolutions During Forming Processes

2019 ◽  
Author(s):  
S. Andrietti ◽  
M. Bernacki ◽  
N. Bozzolo ◽  
L. Maire ◽  
P. De Micheli ◽  
...  
Keyword(s):  
Full Field ◽  
Field Approach
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