Evaluation of retinal ganglion cell function after intraocular pressure reduction measured by pattern electroretinogram in patients with primary open-angle glaucoma.

BACKGROUND: To evaluate retinal ganglion cell (RGC) function after intraocular pressure (IOP) reduction measured by pattern electroretinogram (PERG) in patients with newly diagnosed, non-treated preperimetric and early stages of primary open-angle glaucoma (POAG). METHODS: Twenty-four eyes from 24 patients with POAG: 11 eyes with preperimetric glaucoma and 13 eyes with early glaucoma received Ganfort ® (bimatoprost + timolol) once a day for a period of 1 month. Before and after the treatment, following measurements were analyzed: IOP, mean ocular perfusion pressure (MOPP), peak time of P50 and amplitude of P50 and N95 waves in PERG (ISCEV standard 2012). Correlations between PERG P50 and N95 waves, IOP and MOPP were calculated. RESULTS: After therapy, IOP significantly decreased in all eyes, on average 31%. Significant increase in MOPP in all eyes on average 14% was detected. PERG amplitude of P50 and N95 waves increased in 75 and 79% eyes, respectively, on average P50 by 28% and N95 by 38%. There were no significant interactions between the change of PERG parameters in time and stage of glaucoma. CONCLUSIONS: Significant IOP-lowering therapy can improve RGC function measured by PERG, in patients with preperimetric and early stages of POAG.

Photopic negative response of full-field electroretinography in patients with different stages of glaucomatous optic neuropathy.

PURPOSE: To evaluate photopic negative response (PhNR) discrimination ability between healthy and glaucomatous patients. METHODS: Ninety eyes of 50 patients with primary open angle glaucoma (POAG) and 45 eyes of 23 healthy age- and sex-matched controls were investigated. Based on European Glaucoma Society criteria, POAG patients were divided into three groups: early, moderate and advanced glaucoma. Following measurements were analysed: mean defect (MD) from Humphrey Visual Field Analyzer, SITA standard 24-2 white on white perimetry; nerve fibre index (NFI) obtained from scanning laser polarimetry; and GDx and PhNR amplitude and PhNR/b-wave ratio. PhNR was elicited by red stimuli with flash strength of 1.6 cd s/m(2) on blue background of 25 cd/m(2). Correlations between retinal ganglion cells function (PhNR), retinal sensitivity (MD) and structure (NFI) were calculated. Sensitivity and specificity of PhNR parameters were calculated with standard formulas. Receiver operating characteristic (ROC) curves were used to determine optimal cut-off values. The area under the curve (AUC) was used to compare the ROC curves results between PhNR amplitude and ratio. RESULTS: PhNR amplitude and ratio were significantly reduced in early, moderate and advanced glaucoma groups compared to controls. The sensitivity and specificity to detect glaucoma in early POAG were equal to 53.3 and 90.0% for PhNR amplitude and 60.0 and 70.0% for PhNR ratio; in moderate POAG 63.3 and 80.0% for PhNR amplitude and 60.0 and 86.7% for PhNR ratio; and in advanced POAG 76.6 and 80.0% for PhNR amplitude, 90.0 and 73.3% for PhNR ratio. There were no significant differences between AUC for PhNR amplitude (0.76-0.86) and PhNR ratio (0.78-0.86), p > 0.05. PhNR amplitudes and ratios correlated significantly with MD measured by SAP and NFI obtained from GDx (p < 0.05). PhNR amplitude significantly decreases with advancement of visual field defects in glaucoma patients. CONCLUSIONS: PhNR reveals dysfunction of RGCs in early, moderate and advanced stage of POAG. PhNR has good discrimination ability in detecting glaucomatous patients. PhNR might be a useful test in glaucoma diagnosis.

Visual evoked potentials in a diagnosis of a visual pathway dysfunction of a child with an arachnoid cyst.

PURPOSE: The aim of this case report was to demonstrate the usefulness of the flash visual evoked potentials in monitoring the effects of intracranial hypertension in a preterm-born child with a congenital arachnoid cyst. METHODS AND RESULTS: At baseline, abnormalities were found in the right eye: exotropia and lack of foveal fixation. Visual acuity was not achieved. Pupillary responses were normal in both eyes. There was no evidence of nystagmus. Flash visual evoked potentials were normal and equal in both eyes. When repeated one year later the signal had deteriorated in both eyes; the peak times of N2 and P2 had increased. The increased VEP latencies were the only ocular signs noted. After referral to neurosurgery, intracranial hypertension was found and a shunt was performed. CONCLUSIONS: Flash visual evoked potentials may be a valuable test in monitoring patients with arachnoid cysts.

Electrophysiological tests in evaluation of glaucoma and ocular hypertension treatment--up to date knowledge. A review.

PURPOSE: On the basis of the literature data to assess the efficacy of the electrophysiological tests (pattern electroretinogram, multifocal electroretinogram and multifocal visual evoked potentials) in evaluation of retinal ganglion cells function in glaucomatous and ocular hypertension eyes, after intraocular pressure reduction. MATERIAL AND METHODS: Data published in the literature available at the Pub Med library between 1964-2012. RESULTS: Several results of studies suggest, that steady-state pattern electroretinogram reveals significant improvement of retinal ganglion cells function after treatment with timolol, acatazolamide, beta-blockers and prostaglandin analogues. Multifocal electroretinograms' changes, after lowering the intraocular pressure by trabeculectomy, were confirmed in only one study, There were no statistically significant correlations between changes in intraocular pressure reduction and multifocal visual evoked potentials. CONCLUSIONS: Steady state pattern electroretinogram is the most commonly used electrophysiological test in evaluating the results of glaucoma and ocular hypertension treatment.

Topical dorzolamide treatment of macular cysts in the enhanced S-cone syndrome patient.

PURPOSE: The purpose of the study was to evaluate the efficacy of a topical form of a carbonic anhydrase inhibitor (dorzolamide) on the foveal function and thickness in the eye of a patient with enhanced S-cone syndrome (ESCS) associated with macular cysts. METHODS: Twenty-eight-year-old Polish man with ESCS and macular cysts appearance in the right eye was treated 3 times daily with 2.0 % dorzolamide drops for the period time equal to 6 months. Monthly controls included: best corrected distance visual acuity (BCDVA-logMAR), foveal thickness (optical coherence tomography, OCT) and foveal function (multi-focal electroretinography, mfERG). RESULTS: Before treatment, BCDVA in the right eye was equal to 0.26 logMAR, improved to 0.1 logMAR during the first 3 months and remained stable for the next 3 months. After 6 months, foveal thickness decreased (from 482 to 224 µm) and foveal function improved (the amplitude of P1-wave density increased from 34.8 to 107.3 nV/deg(2)) and was between the ranges of normal values. Implicit time of P1-wave remained prolonged. CONCLUSIONS: The results of our short-term study suggest potential efficacy of topical dorzolamide treatment in ESCS patients with macular cysts.

The photopic negative response as a promising diagnostic tool in glaucoma. A review.

PURPOSE: Based on the available literature, the clinical usefulness of Photopic Negative Response (PhNR) of flash Electroretinogram (ERG) in detecting glaucoma has been described. MATERIALS AND METHODS: Data published in the literature available at the Pub Med library between 1999-2011. Different techniques of eliciting, assessing and measuring PhNR have been analyzed. Relations between results of static automated perimetry (SAP), Gdx, optical coherence tomography (OCT), pattern electroretinogram (PERG) and PhNR in glaucomatous patients have been described. RESULTS: 1. The most frequent method of PhNR recording has been brief (< 6 ms), red stimulus against the blue background with thread active DTL electrodes. 2. There has been a significant decrease of PhNR amplitude and PhNR/b-wave ratio in patients with different stages of glaucoma field defect. 3. Curvilinear and linear correlation between retinal sensitivity (SAP), retinal nerve fibre layer thickness (RNFLT), PhNR amplitude and PhNR/b-wave ratio has been found. 4. A significant correlation occurred between PhNR and PERG amplitudes. 5. Focal PhNR seems to be a more specific and sensitive tool in comparison to full field PhNR. CONCLUSIONS: PhNR is a promising tool in glaucoma neuropathy assessment. Up to date the value of PhNR has not been definitely proved. More research is necessary to con rm the usefulness of PhNR in diagnosing glaucoma.

Evaluation of treatment efficacy of intravitreal ranibizumab injections in patients with wet type of AMD.

PURPOSE: To evaluate foveal function, retinal circulation and foveal thickness before and after intravitreal ranibizumab injections in eyes with wet type of age-related macular degeneration (AMD). MATERIAL AND METHODS: The study group consisted of 21 eyes (20 patients) with choroidal neovascularisation (CNV) due to AMD. Inclusion criteria were based on fluorescein angiography (FA) and distance best corrected visual acuity (DBCVA)--log MAR scale. In each eye, 3 consecutive injections of ranibizumab every 4 weeks were administered and then individual course for re-injections according to DBCVA and optical coherence tomography (OCT) up to 12 months was applied. At baseline, 3, 6 and 12 months follow-up, the following tests were performed: DBCVA, multifocal electroretinogram (mfERG) and OCT. Additionally, FA was carried out before the treatment, 3 and 12 months from the baseline. RESULTS: At baseline, FA revealed mainly minimally occult choroidal neovascularisation--57% (12/21) of eyes. At 3 months choroidal neovascularisation diameter was stable; no leakage from active choroidal neovascularisation was seen in 76% (16/21) of eyes. After 12 months follow-up, increase in choroidal neovascularisation diameter was seen in 43% (9/21) of eyes and no leakage in 57% (12/21) of cases. The mean DBCVA significantly improved only after 3 months (p < 0.02). Significant decrease of mean foveal thickness was observed in each follow-ups (p < 0.01). The mfERG data from the macular region remained stable or improved slightly in some cases. CONCLUSIONS: In our series of patients with the wet type of AMD after intravitreal injections of ranibizumab in 12 months follow-up, the reduction of foveal thickness was noted while DBCVA and the bioelectrical function from the macular region measured by the mfERG remained stable.

[Functional improvement of injured retina following the adjuvant stem cell-based therapy. Preliminary report]. / Poprawa funkcji bioelektrycznej uszkodzonej siatkówki oka po zastosowaniu wspomagajacej terapii komórkowej. Doniesienie wstepne.

PURPOSE: The purpose of this study was to appraise the functional response of damaged retina to the stem cell-based therapy in mice. The majority of disorders leading to the irreversible vision loss in the developed world is caused by retinal degeneration. Since, recent reports emphasized regenerative potential of bone marrow stem marrow stem/progenitor cells (SPCs), we investigated here the beneficial effect of intravenously administrated SPCs on regeneration of acutely injured retina. MATERIAL AND METHODS: Selective chemical injury of murine retinas was induced by intravenous administration of sodium iodate (NalO3) in its toxic dose. Flash electroretinogram (ERG), was performed in different time points after infusion of bone marrow-derived and negative for linage antigens population of SPCs. RESULTS: Stem cell-based therapy resulted in gradual increase of b-wave amplitude in ERG recordings starting from the 3rd day after NalO3 administration, what confirmed the improvement of retinal function in long-term observation. CONCLUSIONS: Our preliminary findings revealed that the selected stem cell-based therapy employed in the adjuvant mode has been shown to be effective in supporting the retinal function recovery after acute retinal damage.

Sodium iodate selectively injuries the posterior pole of the retina in a dose-dependent manner: morphological and electrophysiological study.

Sequential morphological and functional features of retinal damage in mice exposed to different doses (40 vs. 20 mg/kg) of sodium iodate (NaIO(3)) were analyzed. Retinal morphology, apoptosis (TUNEL assay), and function (electroretinography; ERG) were examined at several time points after NaIO(3) administration. The higher dose of NaIO(3) caused progressive degeneration of the whole retinal area and total suppression of scotopic and photopic ERG. In contrast, the lower dose induced much less severe degeneration in peripheral part of retina along with a moderate decline of b- and a-wave amplitudes in ERG, corroborating the presence of regions within retina that retain their function. The peak of photoreceptor apoptosis was found on the 3rd day, but the lower dose induced more intense reaction within the central retina than in its peripheral region. In conclusion, these results indicate that peripheral area of the retina reveals better resistance to NaIO(3) injury than its central part.

A 43-year-old man with reduced visual acuity and normal fundus: occult macular dystrophy--case report.

PURPOSE: Occult macular dystrophy (OMD) is an unusual, inherited macular dystrophy characterized by a slowly progressive decline of visual acuity with normal fundus and fluorescein angiography (FA). The authors present a 43-year-old man who was diagnosed as having OMD because of the results of electrophysiological, psychophysical, optical coherence tomography (OCT) tests. METHODS: Routine ophthalmological evaluation, FA, visual field tests, electroretinographic examinations (EOG, ERG, PERG and mfERG recordings according to ISCEV standards) and foveal thickness measurements (OCT) were performed. RESULTS: Funduscopic examinations, FA, full field ERG as well as PERG results were all normal. In both eyes, the abnormalities were observed in static perimetry (relative central scotomas), mfERG (significant reduction of P1 amplitude in the central retinas) and OCT (significantly thinner foveal thickness). CONCLUSIONS: A new case with OMD is added to preceding reports. The mfERG and OCT tests are important in detection of OMD patients. It can help in differential diagnosis of amblyopia, optic nerve diseases and non-organic visual disorders.

[Improvement of the PERG parameters measurement accuracy in the continuous wavelet transform coefficients domain]. / Poprawa dokladnosci pomiaru parametrów PERG w dziedzinie wspólczynników ciaglej transformaty falkowej.

PURPOSE: To determine parameters of the pattern electroretinogram (PERG) waveforms in the continuous wavelet transform (CWT) coefficients domain important in more precise clinical assessment of the recordings. MATERIAL AND METHODS: 102 normal PERG recordings were studied in two age groups (< or = 50 years, > 50 years). Continuous wavelet transform analysis was performed using the MatLab 7.0 software. Various wavelets were used in the experiments. Mother wavelets selection was optimized with the criterion based on minimal scatter of the results for normal PERG waveforms. RESULTS: Comparison with traditional, time-domain based analysis showed that determining the PERG parameters in CWT domain was achieved with better accuracy. Normal values for the test showed much less scatter. It was shown on some clinical examples (glaucomatous patients) that the sensitivity of the test was improved. CONCLUSIONS: The CWT-based method of the PERG signal analysis is useful in clinical differentiation between normal and abnormal waveforms, particularly in objective early detection of glaucoma.

[Computer fusion of the mfVEP and HVF images]. / Komputerowa fuzja obrazów mfVEP i HVF.

INTRODUCTION: The purpose of this paper is to show a method of data fusion from two different tests: the multifocal visual evoked potentials (mfVEP) and humphrey visual field (HVF). Fusing the results may lead to a better diagnosis of various diseases associated with changes of patient's field-of-view. MATERIAL AND METHODS: Two methods were used: mfVEP and HVF. MatLab environment was used for computer fusion of the images obtained in the mfVEP and HVF tests. RESULT: The two methods results' fusion was achieved during computer experiments. CONCLUSIONS: Achieved results will allow more precise and objective analysis of patient's field-of-view.

Retinal dysfunction in eyes of patients with BRCA1 gene mutation.

PURPOSE: To assess the retinal function in BRCA1 gene mutation carriers. MATERIAL AND METHODS: Thirty unaffected patients (60 eyes) with constitutional BRCA1 gene mutation were studied. Flash ERG recordings were performed in accordance with the International Society for Clinical Electrophysiology of Vision (ISCEV) standards. RESULTS: In ERGs, in the maximal response, amplitude of a-wave (p<0.02) was reduced. In the cone single- flash response, the amplitude of a-wave (p<0.04) was also reduced. In the scotopic oscillatory potentials (OPs), we noted: increased amplitude of OP2 (p<0.0006), increased index of OP amplitude (01+02+03+04) (p<0.04), and increased latencies of OP1 (<0.05) and OP3 (p<0.004) and OP4 (p<0.03). CONCLUSIONS: Slight dysfunction of rods, cones and inner retinal layers is present in asymptomatic carriers of BRCA1 gene mutation.

Supernormal electro-oculograms in patients with neurofibromatosis type 1.

PURPOSE: To asses the retinal pigment epithelium (RPE) function measured by EOG testing in patients with neurofibromatosis type 1 (NF-1). Our preliminary EOG results suggested dysfunction of the RPE in individuals with NF-1. In order to confirm our initial results we performed EOG examination on a larger group of NF-1 patients. PATIENTS: Studies were performed on 36 patients with clinically diagnosed NF-1 and compared to normal healthy controls. METHODS: Standard EOG recordings were performed in accordance with the International Society for Clinical Electrophysiology of Vision (ISCEV) standards. RESULTS: In NF-1 patients the Arden indexes of the EOG test were significantly higher primarily due to the lower values of dark troughs. Supernormal EOGs (exceeding the value of the mean + 2 SD from the control group) were present in 58% of NF-1 patients. CONCLUSIONS: Dysfunction of the RPE is a characteristic feature of individuals with NF-1.

Electro-oculographic and electroretinographic studies in HNPCC gene mutation carriers.

PURPOSE: To assess retinal function in HNPCC gene mutation carriers. PATIENTS: 19 carriers (38 eyes) of HNPCC genes and controls. METHODS: Electro-oculogram, standard flash electroretinogram and pattern electroretinogram (PERG) recordings were performed. RESULTS: In the total group of HNPCC gene mutation carriers examined by oscillatory potentials, reduced amplitude (p < 0.0004) and increased latency (p < 0.04) of the O3 wave and increased latency (p < 0.02) of the O4 wave were found. In the subgroup of carriers with hMLH1 gene mutation, reduced amplitudes of the O3 (p < 0.0005) and O4 (p < 0.04) waves were identified. In the total group of HNPCC gene mutation carriers examined by PERG, reduced amplitudes of the P50 (p < 0.003), N95 (p < 0.02) and abnormal N95/P50 ratio (p < 0.02) were revealed. In the subgroup of hMLH1 gene mutation carriers, reduced amplitude of the P50 (p < 0.04) and abnormal N95/P50 ratio (p < 0.02) were observed, whereas in the hMSH2 gene mutation carrier subgroup, reduced amplitude (p < 0.03), shortened latency of the P50 wave (p < 0.02) and reduced amplitude of the N95 wave (p < 0.03) were found. CONCLUSION: Constitutional dysfunction of the inner retina appears to be a characteristic feature of HNPCC gene mutation carriers.

Retinal function in the von Hippel-Lindau disease.

PURPOSE: To assess the retinal function in patients with von Hippel-Lindau disease (VHL). PATIENTS: Studies were undertaken in 12 patients (17 eyes) with detected VHL gene mutation and 12 normal healthy controls (17 eyes). METHODS: Pattern ERG (PERG), standard flash electroretinogram (ERG) recordings were performed in accordance with the International Society for Clinical Electrophysiology of Vision (ISCEV) standards. RESULTS: In VHL patients, electrophysiological statistically significant changes were found. In PERG examination, increased latency of P50 was found in the total VHL group (p < 0.02) and in the VHL subgroup with retinal angiomas (p < 0.04). In ERG examination, photopic b-wave latency was increased in the total VHL group (p < 0.03) and also in the VHL subgroup without retinal angiomas (p < 0.05). In OPs, latency increase of OP2, OP3 waves and reduced amplitude of OP3 wave in the total VHL group (OP2 latency, p < 0.05; OP3 latency, p < 0.01; OP3 amplitude, p < 0.03) and in the VHL subgroup with retinal angiomas (OP2 latency, p < 0.02; OP3 latency, p < .008; OP3 amplitude, p < 0.02) were obtained. CONCLUSIONS: It can be hypothesized that dysfunction of the inner retinal layer is present in individuals with VHL disease even in patients without retinal angiomas.

Electroretinographic changes in eyes of patients with BRCA1 gene mutation.

AIM: To assess the retinal function in BRCA1 gene mutation carriers and to evaluate the clinical significance of its potential alterations. PATIENTS AND METHODS: Flash electroretinogram (ERG) was studied in 15 unaffected patients (30 eyes) with constitutional BRCA1 gene mutation. Routine ophthalmological examination was additionally performed in the oldest, unaffected 15 patients and in 15 breast cancer patients being carriers of BRCA1 mutation. RESULTS: In ERGs, in the maximal response, a-wave (p < 0.03) and b-wave (p < 0.05) amplitudes were reduced. In the cone single-flash response, the amplitude of a-wave (p < 0.007) was also reduced. In the oscillatory potentials (OPs), increased amplitude of OP2 (p < 0.03), and increased latencies of OP3 (p < 0.0009) and OP4 (p < 0.03) were obtained. BRCA1 carriers even at old age or after treatment of breast cancer have not presented increased frequency of abnormalities detectable by routine ophthalmological examination. CONCLUSION: It can be hypothesized that dysfunction of rods, cones and inner retinal layers is present in asymptomatic carriers of BRCA1 gene mutation; however, this does not have clinical consequences.

Electroretinographic changes in the inner retinal layers of the retained eyes of patients with sporadic unilateral retinoblastoma.

PURPOSE: Examination of retinal function as measured by flash electroretinogram (ERG) including oscillatory potentials (OPs) and pattern electroretinogram (PERG) in a series of patients with unilateral sporadic retinoblastoma. PATIENTS: Studies were undertaken in the retained eye (without clinical evidence of retinoblastoma) of 13 patients with sporadic unilateral retinoblastoma and in 13 healthy controls. METHODS: Standard flash ERG including scotopic OPs and PERG recordings were performed in accordance with the International Society for Clinical Electrophysiology of Vision (ISCEV) standards. RESULTS: Statistically significant differences between the studied and the control groups were observed with flash ERG (OP1 amplitude increase, p < 0.003; photopic flicker amplitude increase, p < 0.05) and PERG (P50 latency increase, p < 0.008). CONCLUSIONS: Inner retinal layer dysfunction may be a characteristic feature of individuals with unilateral sporadic retinoblastoma.