Multifocal electroretinogram in non-pathological myopic subjects:correlation with optical coherence tomography

AIM： To investigate the changes of retinal function in non-pathological myopic subjects using multifocal electroretinography （mfERG） and to correlate the data with the central macular thickness obtained using optical coherence tomography （OCT）. ~ METHODS： One hundred and thirteen subjects （113 eyes） with age range from 18 to 35y were enrolled in the study. The subjects were divided into four groups according to spherical equivalent （SE） and axial length （AL）： emmetropia group （EG, n=31; SE： ＋0.75 to -0.50 D; AL： 22 to 24 mm）, low and medium myopia group （LMMG, n=26; SE： 〉-0.50 to -6.00 D; AL： 〉24 to 26 ram）, high myopia group （HMG, n--34; SE： 〉-6.00 to -10.00 D; AL： 〉26 to 28 mm） and super high myopia group （SHMG, n =22; SE： 〉-10.00 D; AL： 〉28 mm）. The P1 amplitude density, P1 amplitude, and P1 implicit time of the first- order kernel mfERG responses were obtained and grouped into five rings. The central subfield macular thickness （CST） was obtained using macular cube 512x218 scan of Cirrus HD-OCT. RESULTS： With the increasing of eccentricity, the first positive peak （P1） amplitude density （P=0.0000, 0.0001, 0.0021 in ring 1-3 respectively） and P1 amplitude （all P= 0.0000 in ring 1-5） of each group decreased. With the increasing of myopia, P1 implicit time gradually extended （all P=0.0000 in ring 1-3）. The average CST in four diagnostic groups was 241.56±12.72um, 244.56±12.19um, 254.33±11.61um, 261.75±11.83um respectively. With the increasing of myopia, CST increased （P〈0.001）. There was negative relationship between CST and P1 amplitude, P1 amplitude density （r =-0.402, P〈0.001; r= -0.261, P =0.003）. There was positive relationship between CST and P1 implicit time （r=0.34, P〈0.001）.~ CONCLUSION： With the increasing of myopia, P1 amplitude density and P1 amplitude of the first-order reaction gradually reduced. This showed potential decline in retinal function in myopia. To some extent it may reflect the functional disorder or depression of the visual cells, The exact mechanism needs further study,

Effect on multifocal electroretinogram in persistently elevated intraocular pressure by erigeron breviscapus extract

AIM: To observe the effect on multifocal electroretinogram (mfERG) in persistently elevated intraocular pressure (TOP) by erigeron breviscapus extract (also named Dengzhanhua in Chinese) in rat models. METHODS: The rat models with persistently elevated TOP were established by the method of Akira. Then, erigeron breviscapus extract was given for one month to observe the effect on mfERG in persistently elevated TOP in rats. RESULTS: As elevated TOP went on, the mfERG changes were mainly in weaken of reaction density with progressive development. After intervention of erigeron breviscapus extract, the total peak latency of 131 wave had recovered to some extent and the difference was significant when compared with control group (P <0.05); the total response density and P1 wave response density in second circle had risen noticeably, which had significant differences than those of control group (P <0.05). CONCLUSION: Erigeron breviscapus extract can improve the impaired visual function of persistently elevated TOP in rats, suggesting that this extract is the effective part of erigeron breviscapus for optic neuroprotection.

Evaluating role of bone marrow-derived stem cells in dry age-related macular degeneration using multifocal electroretinogram and fundus autofluorescence imaging

AIM：To evaluate the role of bone marrow-derived stem cells in the treatment of advanced dry age-related macular degeneration（AMD）using multifocal electroretinogram（mf-ERG）and fundus autofluorescence imaging.METHODS：Thirty patients（60 eyes）with bilateral central geographic atrophy（GA）were recruited.Worse eye of each patient received autologous bone marrow-derived hematopoietic stem cells（BM-HSCs）（group 1）and the fellow eye with better visual acuity served as control（group2）.The effect of stem cell therapy was determined in terms of visual acuity,amplitude and implicit time in mf-ERG and size of GA on fundus autofluorescence imaging.These tests were performed at presentation and first,third and sixth month follow up.Adverse events（if any）were also monitored.RESULTS：At 6mo follow-up there was no statistically significant improvement in median log MAR best corrected visual acuity（BCVA）in either group.Mf-ERG revealed significant improvement in amplitude and implicit time in the intervention group.A significant decrease was also noted in greatest linear dimension（GLD）of GA in the eyes receiving stem cells[6.78±2.60 mm at baseline to 6.56±2.59 mm at 6mo（P=0.021）].However,no such improvement was noted in the control group.CONCLUSION：Electrophysiological and anatomical improvement in the intervention group sheds light on the therapeutic role of BM-HSCs.Further studies are required to determine the stage of disease at which the maximal benefit can be achieved and to standardize the dose andfrequency of stem cell injection.

Efficiency analysis by mfERG and OCT of intravitreal injection with ranibizumab on diabetic macular edema

AIM: To analyze the clinical efficacy of intravitreal injection of ranibizumab(IVR) on diabetic macular edema(DME) with multifocal electroretinography(mf ERG) and optical coherence tomography(OCT).METHODS: A total of 41 patients(41 eyes) with DME were treated with IVR. The best corrected visual acuity(BCVA), mf ERG results, and OCT were analyzed to compare to the baselines at 1 wk, 1, and 3 mo after operation.RESULTS: The BCVA was significantly improved in all eyes at each time point(P<0.001). The macular area leakage and edema were reduced 1 wk and 1 mo after IVR, and the central fovea thickness(CFT) was significantly reduced compared to baseline(P<0.001). The mf ERG, twodimensional and three-dimensional images all showed that the macular fovea(1 ring) response density decreased, and the fovea and macular area spikes significantly decreased or disappeared. The amplitude density of the P1 wave was increased, and the latency of the P1 wave was shortened than preoperation(P<0.001). At 1 wk and 1 mo after the operation, there was a negative correlation between the amplitude density of P1 waves and CFT.CONCLUSION: OCT and mf ERG fully demonstrate the importance of IVR for DME patients from the macular morphology and function, especially the significance of mf ERG in this disease.