Head-down Posture Induces PERG Alterations in Early Glaucoma

Ventura, Lori M.; Golubev, Iuri; Lee, William; Nose, Izuru; Parel, Jean Marie; Feuer, William J.; Porciatti, Vittorio

doi:10.1097/ijg.0b013e318232973b

Cited by 35 publications

(40 citation statements)

References 55 publications

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“…15 An additional group of 11 similarly-aged healthy controls (SAC, mean age 56.9 ± 13 years, difference with study subjects, P=0.3) originating from a previous study 15 was used to compare PERG, IOP, and hemodynamic parameters upon HDT with the study group.…”

Section: Methodsmentioning

confidence: 99%

“…7–12 Even a temporary head-down posture with small angle of tilt may induce reversible loss of neurophysiological function in normal subjects at both the retinal and cortical level. 13, 14 Ventura et al, 2003 15 using a head-down body tilt of minus 10 degrees below supine orientation for 8 minutes, reported reversible Pattern Electroretinogram (PERG) losses in a subpopulation of glaucoma suspects that was associated with IOP and systemic pressure elevation. 15 Thus, temporary, moderate head-down posture can be potentially used as provocative test to identify glaucoma suspects (GS) that may develop glaucoma earlier than those less susceptible to the procedure.…”

Section: Introductionmentioning

confidence: 99%

“…13, 14 Ventura et al, 2003 15 using a head-down body tilt of minus 10 degrees below supine orientation for 8 minutes, reported reversible Pattern Electroretinogram (PERG) losses in a subpopulation of glaucoma suspects that was associated with IOP and systemic pressure elevation. 15 Thus, temporary, moderate head-down posture can be potentially used as provocative test to identify glaucoma suspects (GS) that may develop glaucoma earlier than those less susceptible to the procedure. Here we show in a population of GS, longitudinally monitored with OCT over an average of 5 years, that baseline PERG and systemic/ocular pressures, together with their changes upon head-down posture, may predict future loss of nerve retinal fiber layer (RNFL) thickness.…”

Section: Introductionmentioning

confidence: 99%

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Head-down Posture in Glaucoma Suspects Induces Changes in IOP, Systemic Pressure, and PERG That Predict Future Loss of Optic Nerve Tissue

Porciatti¹,

Feuer

Monsalve

et al. 2017

Journal of Glaucoma

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Purpose To obtain pilot data on posture-induced changes of IOP, systemic pressure and pattern electroretinogram (PERG) predictive of future optic nerve tissue loss glaucoma suspects (GS). Methods Mean peripapillary retinal fiber layer thickness (RNFLT) was measured with OCT two times/year in 28 GS aged 58 ± 8.9 years over 5.0 ± 0.73 years. All patients had a baseline PERG, IOP and brachial blood pressure measurements in the seated and – 10 degrees head-down-body-tilt position (HDT). Outcome measures were seated/HDT PERG amplitude and phase, IOP, mean arterial blood pressure (MAP), and estimated ocular perfusion pressure (OPP). An additional group of 11 similarly-aged controls (SAC) aged 56.9 ± 13 years was tested for comparison. Results While all GS had initial RNFLT in the normal range, 9/28 of them developed significant (P < 0.05) loss of mean RNFLT (thinners, T) over the follow-up period as opposed to 19/28 who did not (non-thinners, NT). Significant (P<0.05) differences between SAC, NT and T were found in PERG amplitude, PERG phase, MAP, IOP, and OPP. A nominal logistic regression using baseline PERG and hemodynamic variables was able to distinguish T from NT with an AUROC of 0.89 (SE 0.07). Conclusions Baseline PERG, IOP, and systemic blood pressure, together with their changes upon HDT, may have predictive value for future loss of optic nerve tissue in GS. This study supports the rationale for a full-scale clinical trial to identify patients at high-risk of development of glaucoma.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Head-down Posture in Glaucoma Suspects Induces Changes in IOP, Systemic Pressure, and PERG That Predict Future Loss of Optic Nerve Tissue

Porciatti¹,

Feuer

Monsalve

et al. 2017

Journal of Glaucoma

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“…The PERGLA instrument provides a measure of within-test amplitude variability that was below 30% in all subjects. 17,22 Since the PERG was recorded in response to relatively fast alternating gratings, the response waveforms typically were sinusoidal-like, with a temporal period corresponding to the reversal rate (examples reported by Ventura et al 14 ). PERG waveforms were analyzed automatically in the frequency domain by discrete Fourier transform (DFT) to isolate the frequency component at the contrastreversal rate (16.28 Hz), and compute its amplitude in lV.…”

Section: Perg Recordingmentioning

confidence: 99%

Progressive Loss of Retinal Ganglion Cell Function Precedes Structural Loss by Several Years in Glaucoma Suspects

Banitt

Ventura

Feuer

et al. 2013

Invest. Ophthalmol. Vis. Sci.

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PURPOSE. We determined the time lag between loss of retinal ganglion cell function and retinal nerve fiber layer (RNFL) thickness.METHODS. Glaucoma suspects were followed for at least four years. Patients underwent pattern electroretinography (PERG), optical coherence tomography (OCT) of the RNFL, and standard automated perimetry testing at 6-month intervals. Comparisons were made between changes in all testing modalities. To compare PERG and OCT measurements on a normalized scale, we calculated the dynamic range of PERG amplitude and RNFL thickness. The time lag between function and structure was defined as the difference in time-to-criterion loss between PERG amplitude and RNFL thickness.RESULTS. For PERG (P < 0.001) and RNFL (P ¼ 0.030), there was a statistically significant difference between the slopes corresponding to the lowest baseline PERG amplitude stratum ( 50%) and the reference stratum (>90%). Post hoc comparisons demonstrated highly significant differences between RNFL thicknesses of eyes in the stratum with most severely affected PERG ( 50%) and the two strata with least affected PERG (>70%). Estimates suggested that the PERG amplitude takes 1.9 to 2.5 years to lose 10% of its initial amplitude, whereas the RNFL thickness takes 9.9 to 10.4 years to lose 10% of its initial thickness. Thus, the time lag between PERG amplitude and RNFL thickness to lose 10% of their initial values is on the order of 8 years.CONCLUSIONS. In patients who are glaucoma suspects, PERG signal anticipates an equivalent loss of OCT signal by several years. (Invest Ophthalmol Vis Sci. 2013;54:2346-2352 DOI: 10.1167/iovs.12-11026 A n issue central to the treatment of glaucoma is determining the onset of the disease. The current understanding is that early signs of glaucoma often manifest as permanent atrophic changes in the optic nerve, which are detected by characteristic visual field defects. Structural changes can be observed directly by examining the optic nerve, but also by measuring the optic nerve and retinal nerve fiber layer (RNFL) thickness with imaging devices. It is likely that these clinically manifest structural-functional changes are preceded by subclinical stages, at which retinal ganglion cells (RGC) have lost their autoregulatory ability in response to a chronically stressful biomechanical, vascular, or molecular environment, and become increasingly dysfunctional over time until they die and are eliminated from the neuronal pool.1 The transition between normal and abnormal homeostasis may be considered the true time of disease onset, whereas the stage of RGC dysfunction preceding death represents the ideal stage during which therapeutic strategies to prevent cell death and visual loss should be initiated.The electrical responsiveness of RGC to contrast-reversing visual stimuli can be monitored noninvasively in human and experimental models of glaucoma with the pattern electroretinogram (PERG).2-7 Recent studies in human and mouse models of glaucoma have shown that in the early stages of the disease the m...

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“…Por outro lado, alguns estudos relataram atraso no tempo de pico em olhos com glaucoma (13,98,(107)(108)(109)(110)(111) . Além disto, enquanto nossos pacientes com SG não diferiram significativamente dos controles no tempo de pico do PERGmf, nossos pacientes com GH apresentaram uma latência prolongada no hemicampo superior.…”

Section: Resultsunclassified

Eletrorretinograma de padrão reverso macular e multifocal e tomografia de coerência óptica em olhos suspeitos de glaucoma e glaucomatosos com perda de hemicampo

Kreuz¹

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Head-down Posture Induces PERG Alterations in Early Glaucoma

Cited by 35 publications

References 55 publications

Head-down Posture in Glaucoma Suspects Induces Changes in IOP, Systemic Pressure, and PERG That Predict Future Loss of Optic Nerve Tissue

Head-down Posture in Glaucoma Suspects Induces Changes in IOP, Systemic Pressure, and PERG That Predict Future Loss of Optic Nerve Tissue

Progressive Loss of Retinal Ganglion Cell Function Precedes Structural Loss by Several Years in Glaucoma Suspects

Eletrorretinograma de padrão reverso macular e multifocal e tomografia de coerência óptica em olhos suspeitos de glaucoma e glaucomatosos com perda de hemicampo

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