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1.

Purpose

We have monitored retinal function in patients treated for retinoblastoma (primarily, but not exclusively by intra-arterial chemotherapy infusion) by electroretinography (ERG) recordings for the past 7 years. We here present data from 599 ERG studies of 108 patients, in which a complete ERG protocol including both photopic and scotopic recordings was performed, in justification of our frequent practice of reporting primarily 30-Hz photopic flicker amplitude data.

Methods

Patients referred for treatment of retinoblastoma underwent ERG recordings during examination under anesthesia whenever possible: at baseline and following most treatment sessions. Correlations were calculated for the complete datasets between the four primary amplitude response parameters: photopic single flash b-wave, photopic 30-Hz flicker peak-to-trough, scotopic rod-isolating b-wave, and scotopic maximal flash b-wave.

Results

Using our adaptation of the International Society for Clinical Electrophysiology of Vision-recommended standard ERG protocol, ERG responses of eyes of patients with untreated retinoblastoma or following traditional or intra-arterial treatment for retinoblastoma show very high correlations between 30-Hz flicker amplitude responses and three other standard photopic and scotopic ERG response amplitudes. Reductions in ERG amplitudes seen in these eyes following treatment show no significant difference between retinal dysfunction estimated using rod- or cone-dominated responses.

Conclusion

These observations support the use of photopic response amplitudes (especially in response to 30-Hz flicker) as the primary ERG outcome measure in studies of treated and untreated eyes with retinoblastoma when more complete ERG protocols may be impractical.  相似文献   

2.

Purpose

In murine disease models, particularly in cases when retinal electrical activity is reduced, an event-related component becomes apparent that does not change with the stimulus intensity in electroretinogram (ERG) recordings. In this work, we show that this electric component is evoked by the sound of the flash discharge rather than the light flash itself.

Methods

Wild-type mice (C57BL/6), mice with rod function only (Cnga3 ?/?), mice lacking any photoreceptor function (Cnga3 ?/? rho ?/?), and mice with no auditory function (Cdh23 vAlb/vAlb ) were examined with Xenon flash ERG systems. An acoustic noise generator was used to mask discharge sounds.

Results

ERG recording modalities were identified where usually no discernible response can be elicited. These include photopic conditions in Cnga3 ?/? mice, photopic conditions together with very low stimulus intensities in C57BL/6 mice, and both scotopic and photopic conditions in Cnga3 ?/? rho ?/? mice. However, in all of these cases, small signals, featuring an initial a-wave like deflection at about 20 ms and a subsequent b-wave like deflection peaking at about 40 ms after the flash, were detected. In contrast, such signals could not be detected in deaf Cdh23 vAlb/vAlb mice. Furthermore, masking the Xenon discharge sound by continuous acoustic noise led to a loss of the event-related signals in a reversible manner.

Conclusions

We could identify an auditory event-related component, presumably resembling auditory evoked potentials, as a major source of ERG signals of non-visual origin in mice. This finding may be of particular importance for the analysis and interpretation of ERG data in mice with reduced visual responses.  相似文献   

3.

Background

Electroretinographic measurement instruments allow the variation of several stimulation parameters enabling to study a wide range of retinal processes. The purpose of the present study was to measure human flicker electroretinograms (ERGs) varying temporal modulation, temporal frequency and mean luminance in the photopic and higher mesopic ranges where the change from cone to rod dominance occurs.

Methods

Fourteen healthy subjects (mean age = 31 ± 6) participated in this study. ERG recordings were performed with the RetiPort system (Roland Consult, Germany). The stimuli were ON and OFF sawtooth waves, square wave and sine wave. The temporal frequencies were 4 and 8 Hz. The mean luminance varied from 1 to 60 cd/m2.

Results

The results confirmed the possibility to distinguish between rod- and cone-dominated retinal responses when using the flicker ERG at different temporal frequencies and luminances. We have also evaluated the responses at luminance levels at which the transition between rod- and cone-dominated responses occurs. This transition between rod- and cone-dominated flicker ERG responses is indicated by a significant change in the response characteristics between 4 and 8 cd/m2 (between 200 and 400 phot Td).

Conclusions

The findings on the transition between rod- and cone-dominated ERGs along with the demonstration of ERG responses to different temporal flicker modulations might be informative for the electrophysiologists when setting up the stimulus at mesopic and photopic luminance levels.  相似文献   

4.

Background

The aims of this study were to determine the longitudinal effects of myopia on full-field electroretinogram (ffERG) in children, and whether there were any effects due to atropine treatment.

Methods

Fifty children, enrolled in the atropine treatment for myopia study, were randomly selected and 35 children consented to undergo ffERG at baseline (prior to atropine treatment), 24 months (at end of treatment) and 32 months (8 months after cessation of treatment). An extended ISCEV ffERG protocol was used for all recordings. The relationship between axial length (AL) and the following scotopic and photopic ffERG responses was analyzed: a- and b-wave amplitude and implicit time, saturated amplitude (V max), and retinal sensitivity (logK).

Results

Reliable ffERG recordings with acceptable level of noise were obtained on all 3 visits from 29 children (mean age: 9.5 ± 0.8 years and mean spherical equivalent: ?5.0 ± 1.6 D). At baseline, the correlation detected between AL and logK was 0.37 (p = 0.047). There was no significant correlation between AL and V max or any scotopic and photopic ffERG amplitude and implicit time measures. Longitudinal data suggested a reduction in photopic a- and b-wave and 30 Hz flicker response amplitudes over time. Multivariate analysis showed that the change in 30 Hz flicker response amplitude was likely to be associated with AL change. There was no evidence that changes in other responses were associated with age, baseline AL, or atropine dose used.

Conclusion

Retinal sensitivity was reduced in myopic children. There was a gradual decline in cone function over time which was not influenced by atropine treatment.  相似文献   

5.

Background

This study aimed to identify the pre-adapting light intensity that generated the maximum separation in the parameters of dark adaptation between participants with early age-related macular degeneration (AMD) and healthy control participants in the minimum recording time.

Methods

Cone dark adaptation was monitored in 10 participants with early AMD and 10 age-matched controls after exposure to three pre-adapting light intensities, using an achromatic annulus (12° radius) centred on the fovea. Threshold recovery data were modelled, and the time constant of cone recovery (τ), final cone threshold, and time to rod-cone-break (RCB) were determined. The diagnostic potential of these parameters at all pre-adapting intensities was evaluated by constructing receiver operating characteristic (ROC) curves.

Results

There were significant differences between those with early AMD and healthy controls in cone τ and time to RCB (p < 0.05) at all pre-adapting ‘bleaching’ intensities. ROC curves showed that the diagnostic potential of dark adaptometry was high following exposure to all three pre-adapting intensities, generating an area under the curve in excess of 0.87 ± 0.08 for cone τ and time to RCB for all conditions.

Conclusions

Dark adaptation was shown to be highly diagnostic for early AMD across a range of pre-adapting light intensities, and therefore, the lower pre-adapting intensities evaluated in this study may be used to expedite dark adaptation measurement in the clinic without compromising the integrity of the data obtained. This study reinforces the suggestion that cone and rod dark adaptation are good candidate biomarkers for early AMD.  相似文献   

6.

Background

The current study aimed to investigate retinal function during exposure to normobaric hypoxia.

Methods

Standard Ganzfeld ERG equipment (Diagnosys LLC, Cambridge, UK) using an extended ISCEV protocol was applied to explore intensity–response relationship in dark- and light- adapted conditions in 13 healthy volunteers (mean age 25?±?3 years). Baseline examinations were performed under atmospheric air conditions at 341 meters above sea level (FIO2 of 21 %), and were compared to hypoxia (FIO2 of 13.2 %) by breathing a nitrogen-enriched gas mixture for 45 min. All subjects were monitored using infrared oximetry and blood gas analysis.

Results

The levels of PaCO2 changed from 38.4?±?2.7 mmHg to 36.4?±?3.0 mmHg, PaO2 from 95.5?±?1.9 mmHg to 83.7?±?4.6 mmHg, and SpO2 from 100?±?0 % to 87?±?4 %, from baseline to hypoxia respectively. A significant decrease (p?<?0.05) was found for saturation amplitude of the dark-adapted b-wave intensity–response function (Vmax), dark-adapted a- and b-wave amplitudes of combined rod and cone responses (3 and 10 cd.s/m2), light-adapted b-wave amplitudes of single flash (3 and 10 cd.s/m2), and flicker responses (5–45 Hz) during hypoxia compared to baseline, without changes in implicit times. The a-wave slope of combined rod and cone responses (3 and 10 cd.s/m2) and the oscillatory potentials were significantly lower during hypoxia (p?<?0.05). A isolated light-adapted ON response (250 ms flash) showed a reduction of amplitudes at hypoxia (p?<?0.05), but no changes were observed for the OFF response.

Conclusions

The results show significant impairment of retinal function during simulated normobaric short-term hypoxia affecting specific retinal cells of rod and cone pathways.  相似文献   

7.

Purpose

Vigabatrin (VGB), a treatment for the childhood epilepsy, infantile spasms (IS), is implicated in visual field constriction. Electroretinograms (ERGs) are used as a substitute for visual field testing in infants. We use the VGB-associated ERG reduction (VAER), defined as reduction in age-corrected light adapted 30 Hz flicker amplitude from a pre-treatment measurement in the absence of other retinal defects, as an indicator of retinal toxicity resulting from VGB use. The d-wave ERG response is predominantly the result of OFF-bipolar cell depolarization response to light offset. The purpose of this study is to evaluate the ERG d-wave response as a marker for VAER toxicity in an infant population.

Methods

One hundred children with IS treated with VGB (median age at baseline: 7.6 months; range 1.7–38.4) were tested for the cone-OFF response elicited to a 250 cd s m2 flash with 200 ms duration (long flash ERG). Diagnosis of VAER requires baseline testing of the flicker ERG and at least one follow up ERG; Fifty-one patients fulfilled this criteria. Fifty-eight children received the long flash ERG at baseline. Thirteen retinally normal controls with a median age of 32 months (5.7–65) were also tested. Amplitude and implicit time of the d-wave response were measured manually.

Results

Longer duration of treatment was associated with reduced d-wave amplitude (ANOVA p < 0.05) in patients taking VGB. Nine patients demonstrated VAER during the course of the study. D-wave amplitude was reduced in the IS group with VAER compared to those without VAER (p < 0.05).

Conclusions

Vigabatrin associated retinal defects may be reflected in reduction of the cone d-wave amplitude.  相似文献   

8.

Purpose

To evaluate the nature and extent of changes in the fundamental and harmonic components of the 31-Hz flicker electroretinogram (ERG) during light adaptation.

Methods

Full-field ERGs were recorded from five visually normal subjects (ages 21–60 years). Following 30 min of dark adaptation, the subjects were exposed to a uniform adapting field of 50 cd/m2. The field, which was presented for approximately 15 min, was intermittently modulated sinusoidally at 31.25 Hz. The ERG was recorded during the sinusoidal modulation, and Fourier analysis was used to obtain the amplitude and phase of the fundamental (F), second (2F), and third (3F) harmonic response components.

Results

F amplitude increased by almost a factor of two over approximately 6 min (time constant, τ, of 3.0 min). The 2F amplitude increased by a smaller amount, a factor of 1.4, and the time-course was approximately eight times faster than that of F (τ = 0.4 min). The 3F amplitude increased by a factor of 4.6, an increase that was larger than F or 2F, with a time-course that was between that of F and 2F (τ = 1.4 min). F phase was unaffected by light adaptation, whereas the 2F and 3F phases both increased by approximately 45° over similar time-courses (τ = 2.0 min).

Conclusions

Light adaptation had different effects on the fundamental, second, and third harmonic components of the 31-Hz flicker ERG, which resulted in a change in waveform shape during light adaptation. The previously reported flicker ERG amplitude growth is driven primarily, but not entirely, by changes in the fundamental.  相似文献   

9.

Purpose

To evaluate rod and cone a-waves in cases with unilateral central retinal vein occlusion (CRVO).

Methods

Scotopic and photopic flash electroretinograms (ERGs) were recorded in seven patients aged 54–84 with unilateral hemorrhagic CRVO. Rod and cone a-waves were analyzed using photoreceptor models, and Rm p3 (maximum a-wave amplitude) and S (sensitivity) were calculated.

Results

Decreased rod log?S was found in all seven cases, and decreased cone log?S was found in five cases. In only one case, rod log?S in the fellow eye was decreased. The alterations in rod and cone log Rm p3 were smaller than those in rod and cone log?S. Of three cases in which ERGs could be recorded again after a certain follow-up period, rod log?S and cone logS became larger in two cases and smaller in one case.

Conclusions

The change in the phototransduction cascade was confirmed not only in rods but also in cones in five of our seven cases of CRVO. The ERG findings might reflect the functional change in the photoreceptor layer after the onset of CRVO. Jpn J Ophthalmol 2005;49:402–410 © Japanese Ophthalmological Society 2005  相似文献   

10.

Purpose

The purpose of this study is to describe the relationships between full-field stimulus threshold (FST), electroretinography (ERG), and visual field (VF) outcomes in retinitis pigmentosa (RP).

Methods

Data from 47 patients with RP (n = 94 eyes) were evaluated. Patients were submitted to comprehensive ophthalmological examination including measurement of best-corrected visual acuity (BCVA), 30-2 threshold static VF, and microperimetry. Full-field ERG (ISCEV standard) was recorded, and achromatic FST was measured using a Diagnosys Espion system with the ColorDome? LED full-field stimulator (Diagnosys LLC, Lowell, MA, USA).

Results

BCVA mean ± SD was 0.31 ± 0.03 logMAR, and FST mean ± SD was ?18.45 ± 9.53 dB. No significant correlation was found between BCVA and FST. In contrast, statistically significant correlations were found between FST and static 30-2 VF mean deviation (r = ?0.389; P < 0.01), microperimetry mean threshold (r = ?0.607; P < 0.01). Dark and light-adapted ERGs were detectable in 28 and 48 eyes, respectively. Nevertheless, considering only the eyes with recordable ERG responses, moderate correlations were found between combined dark-adapted a-wave amplitude (r = ?0.560; P < 0.01), b-wave amplitude (r = ?0.643; P < 0.001), 30-Hz flicker response (r = ?0.501; P < 0.01), and FST, and high correlation with FST for cone b-wave amplitude (r = ?0.715; P < 0.01).

Conclusions

FST could be successfully determined in RP patients with a wide range of vision loss. FST results showed stronger correlations with full-field ERG amplitude than with sensitivity measured with visual field tests. FST is as an alternative to VF or ERG for assessment of retinal function in patients unable to do visual fields or with non-detectable ERGs.  相似文献   

11.

Purpose

To investigate the relation between psoriasis and vitiligo with the electrophysiologic function of the retinal photoreceptors.

Methods

Patients with psoriasis or vitiligo referred for PUVA therapy were enrolled. Complete eye examination was performed. Patients with any drug or familial history or abnormal eye examination that might affect the retinal function were excluded. Standardized full-field electroretinogram (ERG) elicited with Ganzfeld stimuli using the commercial ERG system (Retiport32; Roland Consult) according to International Society for Clinical Electrophysiology of Vision guidelines was performed. The outcome measures were the difference between the mean rod response, standard combined response, single-flash cone response and 30-Hz flicker wave amplitudes of the patients and normal population.

Results

Seventy-six eyes of 38 patients (vitiligo: 21; psoriasis: 17) and 40 eyes of 20 normal subjects were enrolled in this study. The mean age of patients was 31.3 ± 11.3 years (range 16–54 years). Twenty-two patients (58 %) were female. The mean rod response b-wave, standard combined a- and b-waves, single-flash cone response b-wave and the 30-Hz flicker (N1-P1) amplitudes were significantly lower than the normal population in the same range of age as the study group. There was no significant difference between the patients with vitiligo and those with psoriasis in all wave amplitudes (P = 0.094).

Conclusion

This study showed that overall retinal electrophysiologic function in patients with vitiligo or psoriasis is significantly impaired compared with normal population, independent of age and sex.  相似文献   

12.

Purpose

To determine the electroretinogram (ERG) changes in eyes manipulated in the course of local ablative therapy (transpupil thermotherapy (TTT), cryotherapy or both) or scleral depression and in un-manipulated fellow, healthy eyes.

Methods

This prospective observational report summarizes 73 ERG studies in 42 patients with retinoblastoma; a study consisted of ERGs of one or both eyes (if present) followed by ocular manipulation (scleral depression, cryotherapy, transpupillary thermotherapy, pressure applied to orbital implant in an anophthalmic socket, or a 5- or 10-min delay without mechanical manipulation) followed by a repeat of the ERGs. Each patient was studied with only a single manipulation modality on any given date: 23 patients were studied only once, and 19 patients were included in more than one study occasion.

Results

Following local ablative treatment of patients with unilateral retinoblastoma, the photopic response decreased significantly in both the treated eye and the untouched fellow, healthy eye. Following scleral depression of the diseased eye, the photopic response immediately decreased in the diseased eye by a mean of 16 μV (21 %, p = .006) and, in the fellow, healthy eye by 40 μV (23 %, p = .0005). Following scleral depression of the fellow, healthy eye, the photopic response immediately decreased by a mean of 11 μV (4 %, p = .37) in the fellow, healthy eye, and by 16 μV (28 %, p = .01) in the diseased eye.

Conclusions

Following physical ocular manipulation, the amplitude of the photopic response decreased in the manipulated, but also the untouched healthy, fellow eyes. These findings may account for some of the variation in clinical ERG recordings, particularly that observed following ocular manipulation by TTT, laser or even scleral depression.  相似文献   

13.

Purpose

To analyse the effects of long-term memantine treatment on the retinal physiology and morphology of DBA/2J mice.

Methods

DBA/2J (D2J) mice received i.p. injections of the NMDA receptor antagonist memantine, which protects neurons from abnormally elevated glutamate levels, twice a day over a period of 7 months. At the age of 2, 6 and 10 months, the intraocular pressure (IOP) and electroretinograms (ERGs) were measured in all treated D2J mice, in untreated D2J controls and in C57Bl/6 (B6) wild-type mice. After the last measurement at the age of 10 months, the mice were killed and the retinae and the optic nerves were analysed morphologically.

Results

The IOP increased with age in both D2J and B6 mice with a larger increase in the D2J strain. IOPs were not influenced by memantine treatment. The response amplitude of the scotopic flash ERG decreased with age in the D2J strain. This amplitude decrease, particularly that of the b-wave, was smaller in treated D2J mice. The retinae of treated D2J mice exhibited less peripheral degeneration of cone photoreceptors, and optic nerve neuropathy was less frequent.

Conlcusions

Application of the NMDA receptor antagonist memantine diminished retinal neurodegeneration in the D2J mice and had a protective effect on the b-wave amplitude of the scotopic flash ERG. This protection may occur secondarily as memantine primarily acts on retinal ganglion cells.  相似文献   

14.

Purpose

To analyze neurovascular coupling in the retina of untreated primary open-angle glaucoma (POAG) and ocular hypertension (OHT) patients.

Patients and methods

Maximal vessel dilation in response to flicker light was analyzed with Retinal Vessel Analyzer (RVA) in temporal superior/inferior arterioles and veins in 51 POAG patients, 46 OHT and 59 control subjects. RVA parameters were compared between groups, between contralateral POAG eyes, and correlated to intraocular pressure, visual field mean defect and retinal nerve fiber layer thickness.

Results

POAG eyes demonstrated generally smaller response of all vessels to flicker light than the other two groups (ANOVA p?=?0.026; mean arterial flicker response in percent of baseline, averaged superior and inferior was 3.48?±?2.22 % for controls , 2.35?±?2.06 % for POAG patients , and 2.97?±?2.35 % for OHT patients; corresponding values for venules were 3.88?±?1.98 %, 2.89?±?1.72 %, 3.45?±?2.77 %). There was no difference in flicker response between the eye with more and less advanced damage in each patient of the POAG group (ANOVA p?=?0.79). Correlation of flicker response to intraocular pressure (IOP) was borderline at best, correlations to the level of glaucomatous damage were not significant. Correlation of flicker response of superior and inferior vessels of the same eye was significant for the arteries (Pearson r?=?0.23, p?=?0.004), as well as venules (r?=?0.52, p?<?0.001).

Conclusion

General vessel response to flicker light was decreased in POAG patients, compared to normal controls and OHT patients. In contrast to significant correlation between the two contralateral eyes of the flicker response itself, only its borderline correlation to IOP was seen. There was no correlation to the level of damage, altogether indicating a systemic dysregulation phenomenon.

Grants

Swiss National Foundation Grant 3200B0-113685, Velux Stiftung Grant, Freie Akademische Gesellschaft (FAG) Grant, Pfizer Inc. Grant

Clinical trial registration reference number

ClinicalTrials.gov NCT00430209  相似文献   

15.

Purpose

To investigate mutations of causal genes in two affected male siblings of a Japanese family with suspected Leber congenital amaurosis (LCA) and to characterize the related clinical features.

Methods

After obtaining informed consent, genomic DNA was extracted from peripheral blood of the proband and his family members. Mutation screening was initially performed with microarrays. The PCR and direct sequencing were successively done for confirmation of mutation detected by microarray, and the two patients who are the subjects of this study were also clinically examined.

Results

Results of the microarray suggested deletion of exon 17 of RPGRIP1. Confirmation by PCR and direct sequencing following microarray analysis revealed that both siblings had homozygous deletion of exon 17 of the RPGRIP1 gene, while their unaffected parents were heterozygous carriers. Length of the deletion was 1339 bp including exon 17 at the position of c.2710+372_2895+76del1339. Clinical features of the two siblings showed nystagmus, poor visual acuity, hyperopia, and photophobia since early childhood; but there was no oculo-digital sign, vessel attenuation or RPE mottling from the mid-retina to the periphery. Full-field single flash ERG was recordable but 30 Hz flicker ERG was not detectable.

Conclusions

Although the present patients did not show sufficient clinical findings as LCA, PCR findings and direct sequencing following microarray analysis confirmed that they were LCA. Genetic analyses are helpful for confirmation of clinical diagnosis.  相似文献   

16.
We have used the post-bleach recovery of the ERG a-wave to estimate the time-course of regeneration of cone pigment, following bleaching exposures far stronger than in a previous study. We recorded the photopic electroretinogram a-wave from two subjects, in response to dim red flashes delivered following 1-min exposures to intensities ranging from 1.1 × 104 to 1.3 × 105 photopic cd m?2. The measured response amplitudes were “linearized” to derive estimates of pigment level. These estimated pigment levels were found to increase at an initially linear rate, consistent with a “rate-limited” model of photopigment regeneration. The extracted time-course was similar to that previously reported in densitometric studies of cone pigment regeneration after similarly intense exposures. On the other hand, the rate of regeneration was slower than measured in the same subjects following less intense bleaches. These results are consistent with the notion that cone pigment regeneration is slowed following very strong bleaching exposures, possibly as a result of depletion of a pool of retinoid.  相似文献   

17.

Purpose

To quantify the direct contribution of retinal ganglion cells (RGCs) on individual components of the mouse electroretinogram (ERG).

Methods

Dark- and light-adapted ERGs from mice 8 to 12 weeks after optic nerve transection (ONTx, n = 14) were analyzed through stimulus response curves for a- and b-waves, oscillatory potentials (OPs), positive and negative scotopic threshold response (p/n STR), and the photopic negative response (PhNR) and compared with unoperated and sham-operated controls, as well as to eyes treated with 6-cyano-7-nitroquinoxaline-2,3-dion (CNQX).

Results

We confirmed in mice that CNQX intravitreal injection reduced the scotopic a-wave amplitude at high flash strength, confirming a post-receptoral contribution to the a-wave. We found that ONTx, which is more specific to RGCs, did not affect the a-wave amplitude and implicit time in either photopic or scotopic conditions while the b-wave was reduced. Both the pSTR and nSTR components were reduced in amplitude, with the balance between the two components resulting in a shortening of the nSTR peak implicit time. On the other hand, amplitude of the PhNR was increased while the OPs were minimally affected.

Conclusion

With an intact a-wave demonstrated following ONTx, we find that the most robust indicators of RGC function in the mouse full-field ERG were the STR components.  相似文献   

18.

Purpose

To investigate whether macular pigment optical density (MPOD) is related to dark adaptation in healthy subjects.

Methods

Dark adaptation was measured after a minimum 30 % pigment bleach in 33 subjects (aged 15–68), using a white 1° stimulus presented 11° below fixation on a cathode ray tube monitor. The luminance range of the monitor was extended using neutral density filters. A heterochromatic flicker photometry based instrument (MPS 9000) was used to measure MPOD.

Results

The average MPOD for the whole group was 0.37 ±0.21 optical density units. Subjects with lighter irides had on average 40 % lower MPOD compared to those with darker irides (0.3 ± 0.20 vs 0.5 ± 0.19). Group mean MPOD was weakly associated with second (r?=?0.32, p?=?0.07) and third rod-mediated recovery rates (r?=?0.31, p?=?0.08) and with the rod threshold (r?=??0.24, p?=?0.18) 30 min after the onset of bleach. MPOD was unrelated to cone time constant (r?=??0.02, p?=?0.91), cone threshold (r?=??0.01, p?=?0.96), rod–cone break (r?=?0.13, p?=?0.45) or the rod–rod break (r?=?0.11, p?=?0.52). The second rod-mediated recovery rate (S2) for the lower 10th percentile of MPOD (n?=?4) was 0.18 log cd.m-2.min-1 and 0.24 log cd.m-2.min-1 for the upper 10th percentile (n?=?4). The two groups were significantly different (t?=??2.67, p?=?0.037).

Conclusions

We report a statistically significant difference between subjects falling in the 10th percentile extremes of MPOD and rod-mediated but not cone-mediated sensitivity recovery. Further investigation into the relationship between MPOD and rod function is warranted, particularly extending the work to encompass those with low MPOD and poor night vision.  相似文献   

19.

Background

To present a case of melanoma-associated retinopathy (MAR) which manifested 26 months prior to a formal diagnosis of melanoma.

Methods

Case report.

Results

A 72-year-old female presented with bilateral continuous photopsia consistent with MAR of 7-months duration. At this point, visual function appeared normal with the exception of mildly impaired colour vision (10/17 Ishihara plates). The flash electroretinographic (ERG) revealed extinguished rod responses, a normal a-wave and reduced b-wave (electronegative ERG) on the maximal combined response, absent oscillatory potentials and broadened a-wave trough on the cone response. Multifocal ERG (mfERG) responses were delayed and demonstrated atypical morphology. Nineteen months after the initial presentation, her visual symptoms had progressed significantly with constant debilitating photopsia in combination with 13 kg weight loss. Biopsy of a now evident left axillary mass demonstrated a metastatic high-grade malignant melanoma. No primary was detected, and an axillary lymph node clearance was undertaken. Subsequently, visual symptoms resolved with corresponding improvement in the ERG over the next 18 months. Rod responses recovered such that the amplitude was at the lower limit of normal and the mfERG response delay lessened. Unfortunately, the melanoma recurred and the patient passed away 6 months later. Visual symptoms did not recur.

Conclusion

We present a case which demonstrates MAR may precede the formal diagnosis of melanoma by up to 26 months. The potential for improvement in the rod visual function persists over a period of years with normalisation of an electronegative waveform. In this case, cytoreductive surgery resulted in complete resolution of the MAR, which did not return even with a recurrence of the tumour.  相似文献   

20.

Purpose

To evaluate intravitreal bevacizumab (IVB) treatment in patients with central retinal vein occlusion (CRVO) by spectral domain optical coherence tomography (OCT) and electroretinography (ERG).

Methods

Twenty-two CRVO patients were treated with IVB injections and followed for 1 year. Morphological effect of treatment was observed with fluorescent angiography and OCT. Functional effect was followed with best corrected visual acuity (BCVA) and ERG: combined rod-cone response of the standard full-field ERG (dark adapted 3.0 ERG), photopic negative response (PhNR), and pattern ERG (PERG).

Results

Best corrected visual acuity (BCVA) improved by 18.2 letters after 6 months (p ≤ 0.001) and additional 4.7 letters by the 12th month (p ≤ 0.001). The central retinal thickness of 829.8 ± 256.7 μm decreased to 398.8 ± 230 μm (p ≤ 0.001) after 6 months and to 303.7 ± 128.9 μm during the following 6 months (p ≤ 0.001). The total macular volume (14.4 ± 4.2 mm3) decreased to 9.6 ± 3.2 mm3 and 8.5 ± 2.0 mm3 after 6 months and 1 year of treatment, respectively (p ≤ 0.001). Electrophysiological measures improved significantly after 6 months and 1 year of treatment: the a-wave implicit time of dark adapted 3.0 ERG from 25.6 ± 2.3 to 24.1 ± 2.1 and 24.1 ± 2.0 ms (p ≤ 0.01); the PhNR from ?5.9 ± 6.6 to ?9.4 ± 6.1 and ?10.4 ± 4.6 µV (p ≤ 0.05); the PERG P50 amplitude from 0.2 ± 0.3 to 0.9 ± 0.6 and 1.1 ± 0.6 µV (p ≤ 0.001); and N95 amplitude from 0.4 ± 0.6 to 1.2 ± 0.9 and 1.6 ± 0.9 µV (p ≤ 0.001).

Conclusions

Intravitreal bevacizumab (IVB) treatment of macular edema due to CRVO improved standard morphological measures and the electrophysiological function of outer and inner retinal layers, which was most evident in central retina.  相似文献   

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