Fixation stability and implication for multifocal electroretinography in patients with neovascular age-related macular degeneration after anti-VEGF treatment

Karen Bjerg Pedersen*, Anne Katrin Sjølie, Anders Højslet Vestergaard, S Andréasson, Flemming Møller

*Kontaktforfatter for dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

Purpose: To quantify fixation stability in patients with neovascular age-related macular degeneration (nAMD) at baseline, 3 and 6 months after anti-vascular endothelial growth factor (anti-VEGF) treatment and furthermore asses the implications of an unsteady fixation for multifocal electroretinography (mfERG) measurements. Methods: Fifty eyes of 50 nAMD patients receiving intravitreal anti-VEGF treatment with either bevacizumab or ranibizumab and eight eyes of eight control subjects were included. Fixation stability measurements were performed with the Eye-Link eyetracking system and the retinal area in degrees2 (deg2) containing the 68 % most frequently used fixation points (RAF68) was calculated. MfERG P1 amplitude and implicit time were analyzed in six concentric rings and as a summed response. Patients were examined at baseline, 3 and 6 months. Four different mfERG recordings were performed for the control subjects to mimic an involuntary unstable fixation: normal central fixation, 2.4°, 4.8°, and 7.1° fixation instability. Results: For control subjects, a fixation instability of 2.4° (corresponding to the central hexagon) did not reduce mfERG ring amplitudes significantly, whereas 4.8° and 7.1° fixation instability reduced the amplitudes significantly in rings 1 and 2 (p <0.001) as well as in the peripheral rings in the 7.1° instability condition (p <0.001). Fixation stability improved non-significantly for patients at 3 and 6 months. The size of the retinal area of fixation was at baseline, 3 and 6 months negatively correlated to visual acuity (VA) (rbaseline = −0.65, r3 months = −0.60, and r6 months = −0.66 respectively, p <0.001) and mfERG amplitudes of the three innermost rings (rbaseline = −0.29, p = 0.042, r3 months = −0.43, p = 0.003 and r6 months = −0.31, p = 0.042). The VA cutoff for a fixation area less than 5 deg2 (approximately the central hexagon) was 65, 77, and 68 ETDRS letters (corresponding a maximal Snellen equivalent of 0.31) at baseline, 3 and 6 months, respectively. Conclusions: MfERG amplitudes in recordings of nAMD patients are at substantial risk of being reduced due to poor fixation as a large number of patients may use a fixation area of more than 5 deg2. Fixation monitoring during recording as well as interpretation of results should be performed with care, especially in patients with poor visual acuity.

OriginalsprogEngelsk
TidsskriftGraefe's Archive for Clinical and Experimental Ophthalmology
Vol/bind254
Udgave nummer10
Sider (fra-til)1897-1908
ISSN0721-832X
DOI
StatusUdgivet - 14. apr. 2016

Fingeraftryk

Electroretinography
Macular Degeneration
Vascular Endothelial Growth Factor A
Visual Acuity
Equidae

Bibliografisk note

First Online: 14 April 2016

Citer dette

@article{f342967daa384df9bbc60fb5f8e9bdef,
title = "Fixation stability and implication for multifocal electroretinography in patients with neovascular age-related macular degeneration after anti-VEGF treatment",
abstract = "Purpose: To quantify fixation stability in patients with neovascular age-related macular degeneration (nAMD) at baseline, 3 and 6 months after anti-vascular endothelial growth factor (anti-VEGF) treatment and furthermore asses the implications of an unsteady fixation for multifocal electroretinography (mfERG) measurements. Methods: Fifty eyes of 50 nAMD patients receiving intravitreal anti-VEGF treatment with either bevacizumab or ranibizumab and eight eyes of eight control subjects were included. Fixation stability measurements were performed with the Eye-Link eyetracking system and the retinal area in degrees2 (deg2) containing the 68 {\%} most frequently used fixation points (RAF68) was calculated. MfERG P1 amplitude and implicit time were analyzed in six concentric rings and as a summed response. Patients were examined at baseline, 3 and 6 months. Four different mfERG recordings were performed for the control subjects to mimic an involuntary unstable fixation: normal central fixation, 2.4°, 4.8°, and 7.1° fixation instability. Results: For control subjects, a fixation instability of 2.4° (corresponding to the central hexagon) did not reduce mfERG ring amplitudes significantly, whereas 4.8° and 7.1° fixation instability reduced the amplitudes significantly in rings 1 and 2 (p <0.001) as well as in the peripheral rings in the 7.1° instability condition (p <0.001). Fixation stability improved non-significantly for patients at 3 and 6 months. The size of the retinal area of fixation was at baseline, 3 and 6 months negatively correlated to visual acuity (VA) (rbaseline = −0.65, r3 months = −0.60, and r6 months = −0.66 respectively, p <0.001) and mfERG amplitudes of the three innermost rings (rbaseline = −0.29, p = 0.042, r3 months = −0.43, p = 0.003 and r6 months = −0.31, p = 0.042). The VA cutoff for a fixation area less than 5 deg2 (approximately the central hexagon) was 65, 77, and 68 ETDRS letters (corresponding a maximal Snellen equivalent of 0.31) at baseline, 3 and 6 months, respectively. Conclusions: MfERG amplitudes in recordings of nAMD patients are at substantial risk of being reduced due to poor fixation as a large number of patients may use a fixation area of more than 5 deg2. Fixation monitoring during recording as well as interpretation of results should be performed with care, especially in patients with poor visual acuity.",
keywords = "Age-related macular degeneration, Anti-VEGF, Electrophysiology, Fixation stability, Multifocal ERG, Retinal area of fixation (RAF68)",
author = "Pedersen, {Karen Bjerg} and Sj{\o}lie, {Anne Katrin} and Vestergaard, {Anders H{\o}jslet} and S Andr{\'e}asson and Flemming M{\o}ller",
note = "First Online: 14 April 2016",
year = "2016",
month = "4",
day = "14",
doi = "10.1007/s00417-016-3323-0",
language = "English",
volume = "254",
pages = "1897--1908",
journal = "Graefe's Archive for Clinical and Experimental Ophthalmology",
issn = "0721-832X",
publisher = "Heinemann",
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Fixation stability and implication for multifocal electroretinography in patients with neovascular age-related macular degeneration after anti-VEGF treatment. / Pedersen, Karen Bjerg; Sjølie, Anne Katrin; Vestergaard, Anders Højslet; Andréasson, S; Møller, Flemming.

I: Graefe's Archive for Clinical and Experimental Ophthalmology, Bind 254, Nr. 10, 14.04.2016, s. 1897-1908.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Fixation stability and implication for multifocal electroretinography in patients with neovascular age-related macular degeneration after anti-VEGF treatment

AU - Pedersen, Karen Bjerg

AU - Sjølie, Anne Katrin

AU - Vestergaard, Anders Højslet

AU - Andréasson, S

AU - Møller, Flemming

N1 - First Online: 14 April 2016

PY - 2016/4/14

Y1 - 2016/4/14

N2 - Purpose: To quantify fixation stability in patients with neovascular age-related macular degeneration (nAMD) at baseline, 3 and 6 months after anti-vascular endothelial growth factor (anti-VEGF) treatment and furthermore asses the implications of an unsteady fixation for multifocal electroretinography (mfERG) measurements. Methods: Fifty eyes of 50 nAMD patients receiving intravitreal anti-VEGF treatment with either bevacizumab or ranibizumab and eight eyes of eight control subjects were included. Fixation stability measurements were performed with the Eye-Link eyetracking system and the retinal area in degrees2 (deg2) containing the 68 % most frequently used fixation points (RAF68) was calculated. MfERG P1 amplitude and implicit time were analyzed in six concentric rings and as a summed response. Patients were examined at baseline, 3 and 6 months. Four different mfERG recordings were performed for the control subjects to mimic an involuntary unstable fixation: normal central fixation, 2.4°, 4.8°, and 7.1° fixation instability. Results: For control subjects, a fixation instability of 2.4° (corresponding to the central hexagon) did not reduce mfERG ring amplitudes significantly, whereas 4.8° and 7.1° fixation instability reduced the amplitudes significantly in rings 1 and 2 (p <0.001) as well as in the peripheral rings in the 7.1° instability condition (p <0.001). Fixation stability improved non-significantly for patients at 3 and 6 months. The size of the retinal area of fixation was at baseline, 3 and 6 months negatively correlated to visual acuity (VA) (rbaseline = −0.65, r3 months = −0.60, and r6 months = −0.66 respectively, p <0.001) and mfERG amplitudes of the three innermost rings (rbaseline = −0.29, p = 0.042, r3 months = −0.43, p = 0.003 and r6 months = −0.31, p = 0.042). The VA cutoff for a fixation area less than 5 deg2 (approximately the central hexagon) was 65, 77, and 68 ETDRS letters (corresponding a maximal Snellen equivalent of 0.31) at baseline, 3 and 6 months, respectively. Conclusions: MfERG amplitudes in recordings of nAMD patients are at substantial risk of being reduced due to poor fixation as a large number of patients may use a fixation area of more than 5 deg2. Fixation monitoring during recording as well as interpretation of results should be performed with care, especially in patients with poor visual acuity.

AB - Purpose: To quantify fixation stability in patients with neovascular age-related macular degeneration (nAMD) at baseline, 3 and 6 months after anti-vascular endothelial growth factor (anti-VEGF) treatment and furthermore asses the implications of an unsteady fixation for multifocal electroretinography (mfERG) measurements. Methods: Fifty eyes of 50 nAMD patients receiving intravitreal anti-VEGF treatment with either bevacizumab or ranibizumab and eight eyes of eight control subjects were included. Fixation stability measurements were performed with the Eye-Link eyetracking system and the retinal area in degrees2 (deg2) containing the 68 % most frequently used fixation points (RAF68) was calculated. MfERG P1 amplitude and implicit time were analyzed in six concentric rings and as a summed response. Patients were examined at baseline, 3 and 6 months. Four different mfERG recordings were performed for the control subjects to mimic an involuntary unstable fixation: normal central fixation, 2.4°, 4.8°, and 7.1° fixation instability. Results: For control subjects, a fixation instability of 2.4° (corresponding to the central hexagon) did not reduce mfERG ring amplitudes significantly, whereas 4.8° and 7.1° fixation instability reduced the amplitudes significantly in rings 1 and 2 (p <0.001) as well as in the peripheral rings in the 7.1° instability condition (p <0.001). Fixation stability improved non-significantly for patients at 3 and 6 months. The size of the retinal area of fixation was at baseline, 3 and 6 months negatively correlated to visual acuity (VA) (rbaseline = −0.65, r3 months = −0.60, and r6 months = −0.66 respectively, p <0.001) and mfERG amplitudes of the three innermost rings (rbaseline = −0.29, p = 0.042, r3 months = −0.43, p = 0.003 and r6 months = −0.31, p = 0.042). The VA cutoff for a fixation area less than 5 deg2 (approximately the central hexagon) was 65, 77, and 68 ETDRS letters (corresponding a maximal Snellen equivalent of 0.31) at baseline, 3 and 6 months, respectively. Conclusions: MfERG amplitudes in recordings of nAMD patients are at substantial risk of being reduced due to poor fixation as a large number of patients may use a fixation area of more than 5 deg2. Fixation monitoring during recording as well as interpretation of results should be performed with care, especially in patients with poor visual acuity.

KW - Age-related macular degeneration

KW - Anti-VEGF

KW - Electrophysiology

KW - Fixation stability

KW - Multifocal ERG

KW - Retinal area of fixation (RAF68)

UR - http://www.scopus.com/inward/record.url?scp=84963743676&partnerID=8YFLogxK

U2 - 10.1007/s00417-016-3323-0

DO - 10.1007/s00417-016-3323-0

M3 - Journal article

C2 - 27080862

VL - 254

SP - 1897

EP - 1908

JO - Graefe's Archive for Clinical and Experimental Ophthalmology

JF - Graefe's Archive for Clinical and Experimental Ophthalmology

SN - 0721-832X

IS - 10

ER -