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Purpose: It has been previously demonstrated that the adaptive phase changes of steady-state pattern electroretinogram (SS-PERG), recorded during 4-minute presentation of patterned stimuli, are reduced in glaucoma suspects and patients compared to normal subjects. Our study aims at testing the hypothesis that adaptive changes of SS-PERG, recorded using the novel optimized Next Generation PERG (PERGx) protocol, differ between glaucoma patients and controls.Methods: In this pilot cross-sectional study, we included 28 glaucoma patients and 17 age-matched normal subjects. Both patients and controls underwent a full ophthalmologic examination, visual field testing, OCT and PERGx. The PERGx signal was sampled over 2 minutes (providing 1 noise and 9 signal packets) in response to alternating gratings generated on an OLED display. PERGx amplitude and phase were analyzed to quantify adaptive changes over recording time. Receiver operating characteristic (ROC) curves were used to study the diagnostic accuracy of PERGx parameters in distinguishing glaucoma patients from normal subjects.Results: PERGx amplitude and phase data showed declining trends in both groups. PERGx amplitude slope and grand-average vector amplitude were significantly lower in patients compared to controls (p < 0.01). The area under the ROC curves of PERGx amplitude slope and grand-average vector amplitude were 0.87 and 0.76, respectively.Conclusion: The PERGx paradigm resulted highly accurate in detecting the reduction of amplitude adaptive changes in glaucoma patients, presumably due to the loss of functional RGC autoregulation. Thus, PERG adaptation, recorded by this new protocol, might be helpful in the identification and diagnosis of early glaucomatous dysfunction.

Background To determine whether the functional effects of oral supplementation with Saffron, a natural compound that proved to be neuroprotective in early age-related macular degeneration, are influenced by complement factor H (CFH) and age-related maculopathy susceptibility 2 (ARMS2) risk genotypes. Methods Thirty-three early AMD patients, screened for CFH (rs1061170) and ARMS2 (rs10490924) polymorphisms and receiving Saffron oral supplementation (20 mg/day) over an average period of treatment of 11 months (range, 6–12), were longitudinally evaluated by clinical examination and focal electroretinogram (fERG)-derived macular (18°) flicker sensitivity estimate. fERG amplitude and macular sensitivity, the reciprocal value of the estimated fERG amplitude threshold, were the main outcome measures. Results After three months of supplementation, mean fERG amplitude and fERG sensitivity improved significantly when compared to baseline values (p < 0.01). These changes were stable throughout the follow-up period. No significant differences in clinical and fERG improvements were observed across different CFH or ARMS2 genotypes. Conclusions The present results indicate that the functional effect of Saffron supplementation in individual AMD patients is not related to the major risk genotypes of disease.

Objective: Sustained pattern stimulation in normal subjects induces adaptive changes in pattern electroretinogram (PERG), an effect that has been interpreted as a response of glial cells and retinal ganglion cells (RGC). The aim of this study was to compare the effect in normal subjects and in multiple sclerosis patients without previous optic neuritis. Methods: PERGs were elicited by a 7.5 Hz pattern stimulus, presented continuously over 152 s. Response cycles were averaged in 20 packets of 60 events each and amplitude and phase of the 2nd harmonic response was measured. Adaptive changes are expressed as amplitude reduction over the full examination time. Results: In normal subjects PERG amplitude declined progressively to a plateau (dA = � 0.46 lV, SE = 0.09 lV); in patients the effect size was severely reduced (dA = � 0.20 lV, SE = 0.04 lV). No significant difference was found in mean amplitude. Conclusions: The results show reduced RGC habituation in patients, suggesting an abnormal gain and sensitivity control in the inner retina, even in absence of clinical optic neuritis. Recent findings in astrocyte biology and indications drawn from a mathematical model point to a key role of glial cells in this process. Significance: The proposed methodology may have implications in the assessment of MS patients and in understanding the pathophysiology of neurological and retinal disorders.

PURPOSE: To evaluate macular focal cone ERG (fERG) as a tool for reliable and early detection of central retinal function decay in cone-rod dystrophy (CRD). METHODS: A retrospective study of the time course of fERG amplitude and its relation to visual acuity alterations was performed in 47 CRD patients followed yearly for 6.0 ± 3.1 years. Macular focal cone ERG was evoked by a flickering uniform red field overlaying the central 18° of visual field. RESULTS: Macular focal cone ERG follow-up allowed a clear-cut identification of CRD patients as stationary or progressive, in agreement with visual acuity follow-up. In all progressive patients, fERG declined whenever visual acuity declined, and--in 50% of the cases--fERG loss anticipated acuity loss of several years. CONCLUSIONS: Macular focal cone ERG represents a sensitive assay to detect, categorize, and follow the progression of central retinal dysfunction in CRD. Its use as a diagnostic tool in CRD may help anticipate, for an individual patient, the likelihood and rate of further disease progression before visual acuity loss has occurred.

PURPOSE: To assess subfoveal choroidal blood flow (ChBF) in patients with early manifest glaucoma (EMG) and to compare blood flow with functional measures of central retinal integrity, standard automated perimetry (SAP) and pattern electroretinogram (PERG). METHODS: Subfoveal ChBF was determined by confocal, real-time laser Doppler flowmetry in 24 patients with EMG [>-6 dB mean deviation (MD), age range: 29-77 years, visual acuity: 20/25-20/20] and 23 age-matched control subjects. All patients had a therapeutically (topical beta-blockers with or without prostaglandin analogues) controlled intraocular pressure (IOP < 20 mmHg). Subfoveal choroidal blood volume (ChBVol), velocity (ChBVel) and ChBF were determined as the average of three 60 second recordings. In all patients and controls, the PERG and SAP (Humphrey 30-2), following standardized protocols, were also recorded. RESULTS: In patients with EMG, reductions in average ChBVel and ChBF were roughly equal, respectively, by 30% and 33.4% (p < 0.01), when compared to control subjects, so that there was no significant difference in ChBVol between the two groups. Pattern electroretinogram amplitudes were reduced by 46% (p < 0.01) in patients compared to controls. No correlation was found between any of the ChBF parameters and PERG amplitude, or Humphrey 30-2 MD and pattern standard deviation. CONCLUSION: The results suggest a significant alteration of both ChBVel and ChBF in EMG, which does not appear to be associated with the severity of central retinal dysfunction. These findings may contribute to a better understanding of the pathophysiology of early glaucomatous damage in EMG and have implications for the treatment of this pathologic condition.

""Two major susceptibility genes, complement factor H (CFH) and age-related maculopathy susceptibility 2 (ARMS2), have been. implicated in age-related macular degeneration (AMD) pathogenesis. We analyzed the association between CFH rs1061170 and\\\/or ARMS2. rs10490924 polymorphisms with central retinal function properties, as evaluated by focal electroretinogram (fERG). Forty early AMD. patients, with preserved visual acuity and typical macular lesions, underwent fERG recording (in response to 41 Hz flicker stimuli presented. to the central 18 degrees) and CFH\\\/ARMS2 genotyping. Mean fERG amplitude and sensitivity decreased in patients carrying CFH. rs1061170 polymorphism (p 0.01), compared with wild type ones, although visual acuity and funduscopic features were similar across. the 2 groups. No significant fERG phase changes were observed. No association was detected between ARMS2 (rs10490924) polymorphism. and fERG parameters. Our findings indicate that CFH (rs1061170) polymorphism impacts significantly on retinal function in early AMD. patients, and support the hypothesis that dysfunctional CFH might result in early retinal function loss due to a reduction in the immune. antioxidant defense mechanism.. © 2012 Elsevier Inc. All rights reserved.. Keywords: Age-related macular degeneration; Complement factor H; Early diagnosis; Electroretinography; Flicker sensitivity; Gene polymorphisms""

PURPOSE: To determine whether subfoveal choroidal blood flow is altered in retinitis pigmentosa (RP) and whether this alteration is associated with central cone-mediated dysfunction. METHODS: In 31 RP patients (age range, 15-72 years) with preserved visual acuity (range: 20/30-20/20), subfoveal choroidal blood flow was measured by real-time, confocal laser Doppler flowmetry, and focal macular (18°) electroretinograms (FERGs) were elicited by 41 Hz flickering stimuli. Twenty normal subjects served as controls. The following average blood flow parameters were determined based on three 60-second recordings: volume (ChBVol), velocity (ChBVel), and flow (ChBF), the last being proportional to blood flow if the hematocrit remains constant. The amplitude and phase of the FERG first harmonic component were measured. RESULTS: On average, ChBF and ChBVel were reduced by 26% (P ≤ 0.02) in RP patients compared to controls, whereas ChBVol was similar in the two groups. FERG amplitudes were reduced by 60% (P < 0.01) in patients compared with controls. FERG phases of patients tended to be delayed (P < 0.08) compared with their values in the controls. In patients, FERG phase delays were correlated (r = 0.50, P < 0.01) with ChBF and ChBVel values. FERG amplitudes were correlated (r = 0.49, P < 0.01) with ChBVol values. CONCLUSIONS: These data indicate significant alterations of subfoveal choroidal hemodynamic in RP and suggest a link between the alteration of ChBF and the RP-associated central cone-mediated dysfunction as assessed by the FERG