Purpose
To investigate the relationship between the changes of the thickness of retina in macula and the abnormalities in multifocal electroretinog rams (mERG) in diabetic retinopathy.
Methods
mERG and optical coherence tomography (OCT) examination were performed in 38 patients (60 eyes) with DR (phase Ⅲ～Ⅳ). The data were processed with software SPSS and line relation analysis was done.
Results
The response densities of N1, P1 and N2 in central 5deg; area was significantly negative related to the thickness of neuroretina in macular fovea (correlation efficient -0.252～-0.266，Plt;0.05). The response density of N2 in central 10deg; area was also significantly negative related to the thickness of neuroretina in macular fovea (correlation efficient -0. 332，P=0.01).There was no significant relationship between the latencies of N1 in central 5deg;, 10deg; area and the thickness of macula, whereares the latenc ies of P1 and N2 in central 5deg; were negatively related to the thickness of retinal pigment epithelium in the macular fovea (correlation efficient-0.271～ - 0.322，Plt;0.05).
Conclusion
The changes of the thickness of neuroretina in macula may affect the local retinal function in macula, which may be revealed by the reduction of response densities in mERG in patients with diabetic retinopathy.
(Chin J Ocul Fundus Dis, 2001,17:257-259)
Objective To assess the effects of 670nm LED (lightemitting diode) to protect the photoreceptor from the lightinduced damage in a rat model. Methods 32 SD rats were randomly assigned to one of eight groups: untreated control group, the LEDtreated control group, three groups of lightinduced damage，and three groups of lightinduced damage treated with LED. Lightinduced damage result from exposing to constant light for 3 hours of different illuminations of 900，1800 and 2700 lx, respectively. The LED treatment (50 mW) was delivered for 30 minutes at 3 hours before the light damage and 0，24 and 48 hours after the light damage. Retinal function and morphology were measured by electroretinogram (ERG) and histopathology assay. Results The illumination of 900 lx for 3 hours did not damage the rat retina. The illumination of 1800 lx for 3 hours resulted in thinner ONL and no OS and IS. The ratio of damaged area/total retinal area was 048plusmn;012， the damaged thickness of ONL/normal ONL (L5 ) was 039plusmn;007，and the amplitude of ERG b wave was (431plusmn;120) mu;V. With the LED treatment the ratio of damaged area decreased (M6=017plusmn;0.12, P5/6=0.002), and the ratio of the damaged thickness of ONL also decreased (L6=0.22plusmn;0.09, P5/6lt;0.01), and the amplitude of ERG b wave increased to (1011plusmn;83) mu;V（P5/6lt;0.001）. The illumination of 2700 lx for 3 hours caused severed damage to the rat retina and the LED could not protect them significantly. Conclusions 670 nm LED treatment has an evident protective effect on retinal cells against light-induced damage, which may be a simple and effective therapy to prevent or to delay agerelated macular degeneration.
Objective
To investigate the effects of myopia on first-order kernels six ring responses of multifocal electroretinogram (mfERG).
Method
We continuously selected 80 subjects aged from 13 to 20 year-old and divided four groups into normal, mild myopia, moderate myopia and high myopia. Each group had 20 subjects that were examined with mfERG of 103 stimuli locations. The amplitude and latency of N1, P1, N2 waveforms of six-ring first-kernel responses in mfERG were analyzed.
Result
With increasing of myopia degree, the response density of N1, P1, N2 waveforms of six-ring first-kernel responses in mfERG was decreased gradually (all Plt;0.05). However, latency of N1, P1, N2 waveforms of six-ring first-kernel responses in mfERG didnrsquo;t change significantly (all Pgt;0.05).
Conclusion
Myopia can decrease the response density of first-order kernels six ring responses of mfERG, which is very important to determine the abnormality of mfERG in the clinic.
(Chin J Ocul Fundus Dis, 2006, 22, 103-105)
Objective
To explore the clinical application value of multifocal oscillatory potentials (MOPs) in retinal vein occlusion (RVO).
Methods
MOPs were tested using VERIS 4.0 visual evoked response imaging system for 19 cases (19 eyes) of RVO，among them 8 cases of central retinal vein occlusion (CRVO) and 11 cases of branch retinal vein occlusion (BRVO). Twenty normal subjects were as normal control group. The stimulative visual angles subtended ±26.6°horizontally and ±22.1°vertically. The filter setting was bandpass 100～1000 Hz. The retinal responses from 103 hexagons were recorded in 4 min (8 segments).
Results
In normal control group, OP-1, OP-2 and OP-3 were recorded during 37 ms for first order and 47 ms for second order first slice in whole test field and 5 ring retinal regions, the oscillatory wave shapes of second order were clearer than those of first order. In RVO groups, 91.6% latencies of OP-1, OP-2 and OP-3 were delayed, and 70.8% amplitudes of OP-1, OP-2 and OP-3 were reduced. The delay of the latencies and the decrease of the amplitude in CRVO were more markedly than those in BRVO.
Conclusion
MOPs can be effectively and quantitatively used to evaluate the retinal function of the different location in RVO.
(Chin J Ocul Fundus Dis,2002,18:20-22)
ObjectiveTo observe the electroretinogram (ERG) photopic negative response (PhNR) of idiopathic macular hole (IMH) in stage 2 by vitrectomy with or without internal limiting membrane peeling (ILMP).MethodsTwenty-three stage 2 IMH patients (23 eyes) were enrolled in this prospective study. All patients received the best corrected visual acuity (BCVA), optical coherence tomography and flash-ERG examinations. The patients were randomly divided into group A (11 eyes, vitrectomy) and B (12 eyes, vitrectomy with ILMP). There was no significant difference in BCVA (t=0.96, P=0.350), diameter of macular hole (MH) (t=3.21, P=0.580) and the PhNR amplitude (t=0.98, P=0.353) in group A and B. All patients underwent 25G vitrectomy, ILMP was carried out in group B. The follow-up time was 3 to 6 months, with the mean follow-up time of 4.3 months. BCVA, MH closure rate and PhNR amplitude in group A and B were analyzed before and after surgery.ResultsThree months after surgery, 10 eyes (90.9%) gained MH closure but 1 eye (9.1%) failed in group A. In group B, 12 eyes (100.0%) gained MH closure. There was no significant difference in MH closure rate between the two groups (P=0.462). The mean BCVA of group A and B was 0.69±0.24 and 0.65±0.22, there was no significant difference between the two groups (t=0.49, P=0.722). The amplitude of PhNR in group A was (36.6±7.4) μV, which was lower than the pre-surgery PhNR, but the difference was not significant (t=0.73, P=0.472). The amplitude of PhNR in group B was (27.1±12.4) μV, which was lower than that the pre-surgery PhNR, and the difference was significant (t =3.56, P =0.002). The difference of PhNR amplitude in group A and B was statistically significant (t=2.17, P=0.042).ConclusionCompared with non-ILMP, vitrectomy combined with ILMP will significantly reduce the PhNR amplitude of IMH in stage 2.
Objective
To evaluate the variability of four parameters of multi-focal electroretinogram (mERG) a-wave amplitude, b-wave amplitude, awave latent period, b-wave latent period.
Methods
Sixty normal eyes of 46 volunteers were divided into 3 groups of different ages. RETIscan 3-12 system was used to carry out mERG examination. The stimulus matrix of 61 hexagonal elements spanning the central 24deg;of the visual field. These hexons were scaled with eccentricity and divide d into 5 rings. First-order kernel was selected.
Results
The variability of four parameters of mERG was great. The variability of b-wave latent period was the smallest, its coefficient of variatian was 4.52%～15.62%；that of a-wave latent period held the second place:10.29%~48.67%；that of b-wave amplitude was greater:25.92%~76.11%；that of a-wave amplitude was the greatest:43.82%~88.23%. The results of three groups showed that b-wave amplitude of ring 1 had the smallest variability.
Conclusions
The variability of latent period is smaller than that of amplitude; the variability of b-wave was smaller than that of a-wave. The longer the centrifugal distance, the lower the amplitude density of a-wave and b-wave. Physiological and anatomical factors might be important for the variability of parameters of multi-focal electroretinogram.
(Chin J Ocul Fundus Dis, 2001,17:277-279)
Objective To measure the macular function of the fellow eye in patients with unilateral retinal vein occlusion (RVO). Methods A total of 24 cases of unilateral RVO were diagnosed by fundus fluorescein angiography (FFA), and multifocal ERG (mfERG) was recorded by RETI scan. The mfERG data of 24 fellow eyes of those RVO patients, and 18 normal control eyes were analyzed and compared. The parameters included the amplitude density, latency of the P1 and N1 wave in 6 concentric circles and 4 quadrants of the mfERG graphics. Results The amplitude densities of P1 and N1 wave in first and second concentric circles of RVO fellow eyes were significantly lower than normal eyes (t=4.520, 2.147; P＜0.05). There was no significant difference (P＞0.05) of P1/N1 latency in any concentric circles or quadrants between RVO fellow eyes and normal eyes. Conclusion The central fovea of the RVO fellow eyes was functionally impaired.
Acute zonal occult outer retinopathy (AZOOR) is an acquired retinal diseases. The majority of patients who develop AZOOR are women characterized by an acute onset of visual blurred and scotoma with photopsias. The fundus examination is often normal or appeared mild abnormal. The RPE atrophy of fundus is similar with white syndrome. Although FFA and ICGA features are either unremarkable or unrelated to AZOOR, there are still important in differential diagnosis. The characteristic abnormalities appearance of FAF (complicated and varied), OCT (regional anomaly of ellipsoid zone), visual field (visual field defect) and ERG (decreased amplitude and prolonged latency of rod reaction, maximum reaction, cone reaction and scintillation reaction) are considered critical examinations to the diagnosis of AZOOR. Although there is no effective therapy for AZOOR, it has some self-limitation.
Objective
To investigate the early effects of intervention with tanakan on retinal function in diabetic retinopathy(DR) after laser photocoagulation.
Methods
Prospective random controlled study was performed on 60 Patients (60 eyes) from 23 to 69 years old with DR(phase Ⅲ～Ⅳ). The multifocal electroretinograms (MERG) were tested with VERIS Ⅳ before, the 3rd day and the 7th day after photocoagulation.
Results
No significant differences were found in the latencies and response densities of N1,P1 and N2 between the two groups before photocoagulation. Compared with that before photocoagulation, three days after photocoagulation the latencies in tanakan group had no significant change. The response densities of N1,P1 and N2 reduced and the changes were much smaller than that in control. Three days after photocoagulation, the response densities of P1 and N2 in the central macula 5°area were much higher and the latencies of P1 and N2 were significantly shorter than that in control group. There were no significant differences in the response densities in the 7th day and the differences in the latencies between two groups still existed.
Conclusion
Tanakan may be effective in preventing the retina from damage of retinal photocoagulation in some degree in DR.
(Chin J Ocul Fundus Dis, 2002, 18: 208-211)
Objective To observe the changes of visual acuity and multifocal electroretinogram （mfERG）before and after pars plana vitrectomy (PPV) combined with internal limiting membrane（ILM）peeling with ICG on idiopathic macular hole surgery. Methods The clinical data of 19 patients (19 eyes) with idiopathic macular hole（IMH） who had undergone PPV combined with ILM peeling assisted by 0.25% ICG from Zhongshan Ophthalmic Center were retrospectively analyzed. The closure of macular holes was confirmed by OCT two months after surgery. VERIS Science 4.9 visual evoked response image system was used to record the amplitude density of P1 waves according to six concentric rings before and two,six,twelve months after surgery, meanwhile compared and analyzed best corrected visual acuity（BCVA）before and after surgery. Results The results of OCT showed that 16 eyes (84.21%) had anatomic closure of the macular hole two months after the surgery while three eyes (15.79%) failed in the closure. The BCVA after surgery improved significantly which was more obvious at the second month (F=6.389，Plt;0.05). Compared with before surgery, the responses were depressed severely in P1 wave amplitude densities in six rings, the differences were statistically significant (t=6.140，Plt;0.05). Conclusion The postoperative BCVA of IMH patients improved but the amplitude densities of P1 wave depressed compared with before surgery.
