OBJECTIVE:To investigate the value of psychophysical testing for the macular function in the diegnosis of diabetic retinopathy(DR). METHODS:To compare the testing results of macular light sensitivity and pattern visual evoked potential(P-VEP)of 30 eyes of 15 normal person with those of 82 eyes of 41 diabetic patients(27 eyes without DR,55 eyes with simple type DR ). RESULTS:The macular light sensitivity of diabetic patients is much lower than that of normal Control group(plt;0.05). In the diabetic group, 62.19% is abnormal in macular light sensitivity, 69.51% in P-VEP. CONCLUSION: Testing of macular light sensitivit y is helpful in finding of diabetic retinopathy and early deterioration of macular visual function in diabetics. （Chin J Ocul Fundus Dis,1996,12: 223-224）
One eye each in 3 groups of 12 pigmented rabbits after bilateral vitrectomy received 0.5mg, 1mg or 2mg triamcinolone acetonide (TA), respectively. The fellow eye received only balance saline solution as control. Ophthalmoscopy and electroretinography were performed during 1 day to 38 days after vitrectomy and drug injection. Light and electronmicroscopic studies were done on the 28th day. The particles of drug were visible on day 28 in all TA-treated eyes. Administration of 0. 5rug and 1mg TA did not result in different changes in ERG b-wave amplitudes compared with those in control eyes(P＞0. 05). There were significant elevations of ERG b-wave in 2mg TA eyes compared to the control eyes(Plt;0.05), Both ligbt and electronmicroscopy of the retina in these groups were almost normal. The results showed no Toxielties in TA treated eye up to 2mg after vitrectomy. This offers the experimental evidence as a baseline for combining TA with vitrectomy to reduce recurrence of proliferative vitreoretinopathy. （Chin J Ocul Fundus Dis,1996,12: 105- 107）
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 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 study the response of the retinal neuronal adaptive system to changes of background illumination (BG) by measuring the oscillatory potentials (OPs) and the a- and b-waves of the electroretinogram (ERG) in different BG illuminations. Methods The a- and b-wave and the digitally filtered OPs were simultaneously recorded from Wistar Fu rats aged from 25 to 29 days during dark adaptation (DA) and during 6~8 minutes of BG illuminations at four levels increased successively by steps of two log units, i.e., ldquo;low scotopicrdquo; level of 1.43times;10-6cd/m2, ldquo;high scotopicrdquo; of 1.43times;10-4cd/m2 , ldquo;low mesopicrdquo; of 1.43times;10-2cd/m2 and ldquo;high mesopicrdquo; of 1.43times;10-2cd/m2. Full field stimulus flashes of 75 msec duration and 1.43times;10-2cd/m2intensity was delivered at an interval of 1 minute. Results Five OP wavelets were recorded in DA and during scotopic BG illuminations. The number of wavelets was reduced to three as the eyes were exposed to mesopic BG levels. However, the sum of OPs amplitudes (SOPs) increased as the BG was intensified, except at ldquo;high mesopicrdquo; level, by which a significant decrease of SOPs occurred. The amplitudes of the a-and b-waves remained unchanged at the two scotopic BG and decreased as the BG intensity increased to mesopic levels. Conclusion The response of retinal neural adaptive system of the Albino rat to changes of BG light is more sensitive and robust than the slow components of the ERG. The enhancement of the oscillatory responses at ldquo;low mesopicrdquo; illumination level suggests that using proper BG light may be conducive to reducing the variation of OPs. (Chin J Ocul Fundus Dis, 2001,17:286-288)
Purpose To measure and compare the difference of multifocal electroretinogram in normal subjects and patients with age-related macular degeneration. Methods Seventeen cases(20 eyes)of normal subjects,7 cases(10 eyes)of dry form AMD(age-related macular degeneration),8 cases(8 eyes)of wet-form AMD and 11 cases(11 eyes)of idiopathic macular hole(IMH)were tested with VERIS SciencesTM 4.0 made by EDI company of America.The latencies and average response densities of 6 ring retinal regions in normal subjects were compared with those in various types of age-related maculopathies. Results The N1 and P1 wave latencies of all 6 rings in wet-form AMD and the N1 wave latencies of 3～6 rings in dry-form AMD were delayed statistically.The N1 and P1 wave average response densities of 1～4 rings in and the P1 wave average response densities of 1-6 rings wet-form AMD and the N 1 wave average response densities of 1～5 and the P1 wave average response densties of 1-6 rings in dry-form AMD were decreased statistically.The N1 and P1 wave average response densities of 1～2 and the P1 wave average esponse densities of 1～3 rings were decrease statistically in IMH. Conclusion Multifocal electroretinogram can be used to quantitate the visual function of the affected location in age-related macular degeneration. (Chin J Ocul Fundus Dis,2000,16:224-226)
Objective To investigate the degree of retinal developmen t in pret erm infants and compare the electroretinograms between preterm and fullterm in fants. Methods Flash electroretinogram (ERG) were obtained wit h contact lens el ectrodes in one eye from ten preterm infants (10 eyes) and twenty full-term inf a nts (20 eyes) in seven days after birth. The rod cell, cone cell, maximal combi nation, oscillatory potentials, and 30 Hz flicker responses were recorded. Results Compared with the full-term infants, the implicit time of rod cell respon s e (t=3.216，P=0.003) was longer and the amplitudes were lower (t=6.0 50，P=0.000) in the preterm infants; the difference of implicit time of maximal response was not significant (t=0.465，P=0.650; t=1.068，P=0.295), while th e amplitudes dec reased (t=6.584, P=0.000; t=6.649, P=0.000). The a- and b-wav e implicit time of cone response was not differed much between the two groups (t=0.077, P=0.939; t=0.935,P=0.358); the amplitudes was obvious lower in preterm group (t =3 .417，P=0.002；t=6.310，P=0.000); the difference of implicit t ime of 30 Hz flic ker betw een the two groups was not significant (t=3.745，P=0.001). The difference of b/a value of maximal combination response was not obvious between the two groups ( t=0.215, P=0.831). Conclusions The development of retinal function is slower in preterm infants than that in full-term ones．
ObjectiveTo observe the effect of simulated microgravity on the photopic negative response (PhNR) of full-field flash ERG in adult mice.MethodsIn an experimental study, forty-eight adult male C57BL/6J mice (48 eyes) were randomly divided into model and control groups. Model mice were further divided into three subgroups of 8 each: tail-suspended for 15 days (subgroup A), tail-suspended for 30 days (subgroup B), and tail-suspended for 30 days followed by returning to normal position for 30 days (subgroup C). The three control subgroups were similarly fixed with a harness but kept in the normal position for corresponding periods of 15, 30, and 60 days. The mice were immediately examined using ERG-PhNR, flash VEP, OCT and visually-guided behavior in vivo, and subsequently sacrificed to analyze the retinal histology in vitro. PhNR amplitude was measured from baseline to PhNR trough. N1 peak-time and N1-P1 amplitude of VEP was analyzed. The escape duration was used to quantitatively evaluate the visual function of mice. In addition, inner retinal thickness was analyzed by OCT imaging. Data were compared by the independent sample t-test.ResultsPhNR amplitude in the model subgroup A was obviously lower than the corresponding control subgroup, the difference was statistically significant (t=?3.196, P＜0.01). There was no significant difference in PhNR amplitude between the model subgroup B or C and the corresponding control subgroup (t=?1.976, 0.285; P＞0.05). There was no significant difference in FVEP N1 peak-time or N1-P1 amplitude between any of the three model subgroups and the corresponding control subgroup (P＞0.05). There was no significant difference in OCT-measured inner retinal thickness between any of the three model subgroups and the corresponding control subgroup (t=?0.461, 2.073, ?0.402; P＞0.05). The three model subgroups showed almost normal retinal structure, including the retinal ganglion cell, inner pexiform layer, inner nuclear layer, outer plexiform layer, outer nuclear layer, ellipsoid zone and RPE. There was no significant difference in visually-guided escape time between any of the three model subgroups and the corresponding control subgroup (t=?0.637, ?0.955, 1.297; P＞0.05).ConclusionVia tail-suspension, short-term simulated microgravity can affect the PhNR of flash ERG; however, the change is reversible and does not affect visual function of mice.
ObjectiveTo observe the features of the full field electroretinogram (FF-ERG) in type 1 diabetes (T1D) children without diabetic retinopathy (DR). MethodsRetrospective case study. Forty-one T1D children and 25 age-matched normal controls underwent a complete ophthalmic examination, including best-corrected visual acuity, refraction, intraocular pressure, slit lamp, fundus photography, indirect ophthalmoscopy, and spectral domain optical coherence tomography to exclude DR. All FF-ERG tests were performed by an experienced technician. The ERG series includes six protocols: dark-adapted 0.01 ERG (r-b 0.01); dark-adapted 3 ERG (mix-a 3.0, mix-b 3.0); dark-adapted 10 ERG (mix-a 10.0, mix-b 10.0); dark-adapted oscillatory potentials (OPS); light-adapted 3 ERG (c-a 3.0, c-b 3.0); light-adapted 30 Hz flicker (30 Hz FP) ERG. To compare the amplitudes and implicit times of the FF-ERG between the T1D and control group children. ResultsCompared with the control subjects, the FF-ERG amplitudes decreased and the implicit times increased in T1D. Except for r-b 0.01 (t=-0.228, P > 0.05), the amplitudes of other FF-ERGs were all significantly attenuated (t=-1.664, -3.645, -4.324, -6.123, -5.846, -12.9, -14.4, -5.23; P < 0.05) in T1D children. The implicit times of mix-b 3.0, mix-b 10.0, c-b 3.0 and OP2 significantly increased (t=5.242, 2.879, 5.378, 3.506; P < 0.05). The implicit times of r-b 0.01, mix-a 3.0, mix-a 10.0, c-a 3.0 and 30Hz FP changes were not significantly (t=2.331, 1.677, 0.557, 0.84, 0.064; P > 0.05). ConclusionThe FF-ERG amplitudes decreased and implicit times increased in T1D children compared with the control normal subjects.
Objective To observe the changes of visual acuity、multifocal electroretinogram (mfERG) and optical coherence tomogram（OCT）before and after successful idiopathic macular hole (IMH) surgery, and evaluate the efficiency of the IMH surgery. Methods A total of 28 eyes of 28 patients with IMH who underwent vitrectomy during February 2001 and May 2002 in our hospital were collected. visual acuity, mfERG, and OCT were examined preoperatively and 1, 3, 6, and 12 months postoperatively, respectively. The results were analyzed statistically compared with 33 eyes in control group. Results (1) OCT showed that 27 eyes (96.43%) had anatomic closure of the macular hole 1 month after the surgery without recurrence in 12 months. Just 1 eye (3.57%) failed in the closure within 1 year. (2) The visual acuity was much higher in the eyes 1 year after surgery, especially within 6 months postoperatively, than that before the vitrectomy（P＜0.01）. (3) Before the operation, the mfERG topographies of IMH eyes seem like volcanoes becase the response densities of wave P1 of ring 1 and ring 2 were lower than control group while the other three rings kept in normal. The central peaks of mfERG topographies reappeared little by little during 1 year after the surgery, and the response densities of wave P1 of ring 1 and ring 2 were higher than before, which was still lower than the control group（P＜0.05）. (4) The thickness of neuroepithelial layer (NEL) of fovea measured by OCT of 27 eyes with anatomic closure was no longer varied and kept lower than control group throughout the follow-up time （P＜0.05）. (5) One year after the operation, there were positive correlations among visual acuity, mfERG and NEL（P＜0.05）. Conclusions Vitrectomy is useful for IMH, which could be evaluated by visual acuity mfERG and OCT efficiently. The three factors had consistency. (Chin J Ocul Fundus Dis，2004，20：221-225)