A Correlation with Retinal Thickness Using Retinal Thickness Analyzer and the Responses of Multifocal Electroretinogram in Patients with Diabetic Macular Edema

PURPOSE: To assess the correlation between retinal thickness determined with a retinal thickness analyzer (RTA) and the responses of multifocal electroretinogram (mfERG) in patients with diabetic macular edema. METHODS: RTA and mfERG were performed in patients with diabetic macular edema (20eyes, 10 patients) and normal subjects (10eyes, 10 patients). The measured retina of RTA and mfERG overlapped based on the anatomical landmarks of the fundus. The center of macula was defined as "Area 1", and the central 5 degree retina including the center of macula was defined as "Area 2". The correlations between retinal thickness and the local responses in each area were assessed. RESULTS: The mean retinal thickness of patients with diabetic macular edema was significantly greater than that of normal subject, and the results of mfERG typically represented decreased amplitudes and delayed latencies. In the matching of retinal thickness and local responses in Area 2, amplitudes of N1 & P1 decreased and latency of P1 delayed as the retinal thickness increased. The correlation was prominent in patients with diabetic macular edema. CONCLUSIONS: In the matching of RTA and mfERG of patients with diabetic macular edema, retinal thickness and local responses were significantly correlated.

The Classification and Multifocal ERG Findings of Congenital Stationary Night Blindness

PURPOSE: To report on the classification of congenital stationary night blindness (CSNB) and multifocal ERG findings. METHODS: We studied three patients (case 1-3) with night blindness but normal fundus and one patient (case 4) with decreased vision after trauma with respect to the patients' medical history, familial history, refraction, slit lamp examination, fundus examination, FAG, ERG, and multifocal ERG. RESULTS: The ERG in case 1 showed a decreased rod response, and this patient was diagnosed with Riggs-type CSNB. The typical "negative ERG" was found in all three cases of ERG (except case 1), and these cases were diagnosed with Schubert-Bornschein-type CSNB. Based on Miyake's classification, case 2 was incomplete, and cases 3 and 4 were complete. The mfERG of the cases with complete Schubert-Bornschein type had delayed implicit times of the first-order kernel and decreased amplitudes of the second-order kernel. The delayed implicit times and the decreased amplitudes of the first- and second-order kernels were found in the cases of Riggs- type and incomplete Schubert-Bornschein-type.

Normal values of Positive wave in the Multifocal Electroretinography in Korean

PURPOSE: To obtain normal values of positive wave (b-wave) in the multifocal ERG in terms of age and sex of Koreans. METHODS: The multifocal ERGs by using RETIscan visual evoked response imaging system were tested for 80 eyes. 61 retinal locations were stimulated concurrently. We analyzed the average responses of 5 concentric rings. RESULTS: In the amplitudes of b-wave, ring 1, 84.1 5.4 nV/deg, was the largest of all the other rings and ring 5, 23.1+/-1.5 nV/deg, was the smallest of all the other rings (P<0.05). No statistically significant difference was observed in amplitude between sexs. The implicit time of b-wave was the longest in the ring 1, 40.8 1.6 ms, and shortest in the ring 4, 36.7+/-0.9 ms (P<0.05). CONCLUSIONS: The amplitude of b-wave was the largest in the fovea, and became smaller with eccentricity. The largest amplitude of b-wave was observed in the age of twenties. The amplitude of b-wave was decreased with age in the ring 3, 4, and 5. The interindividual variation of the amplitude of b-wave was greatest in the fovea. The implicit time of b-wave in the fovea was the longest, and that in the ring 4 was the shortest. It became longer from the ring 5, again.

Multifocal Electrophysiologic Findings in MEWDS: Multiple Evanescent White Dot Syndrome

PURPOSE: To evaluate the relationship between the lesions of the MEWDS, retinal dysfunction and the cause of decreased visual acuity. METHODS: A patient with a medical history, retinal finding, and the fluorescein angiographic findings consistent with the diagnosis of MEWDS is described. Full field ERG and mfERG were performed and the results was analyzed to find the relationship the visual acuity and the fluorescein angiographic findings. RESULTS: mfERG of the involved eye shows diffuse depression of the amplitude accentuated by focal areas of steep depression thought to correspond to white spot and full field ERG shows generalized depressed signal. The mfERG abnormalities seen at the presentation resolved with the resolution of visual symptoms after 1 month. CONCLUSIONS: The major symptoms of the patient is due to the decreased retinal function and the mfERG is seem to be the useful and safe tool for evaluation of the retinal function and the relationship between the symptoms and the white dots.

Clinical Applications of Multifocal Electroretinography (mfERG)

PURPOSE: To compare the multifocal electroretinography (mfERG) system to full-field ERGs obtained from patients with known retinal diseases in order to assess its clinical applicability. METHODS: Full-field ERGs, mfERG, fluorescein angiography, visual field examination were performed in normal person and in patients with retinitis pigmentosa, nonischemic central retinal vein occlusion, branch retinal vein occlusion, Vogot-Koyanagi-Harada syndrome, central serous chorioretinopathy, macular degeneration or retinal detachment. RESULTS: The dysfunctional areas measured by mfERG were well compatible to those assumed by findings of full-field ERGs. However, the results of mfERG in the retina with central serous chorioretinopathy were shown abnormal response despite of normal response of full-field ERGs. The results of mfERG in the retina with macular degeneration showed abnormal response although other findings (e.g. Full-filed ERGs, FAG, Fundus ) were normal. CONCLUSIONS: The mfERG system is useful for electroretinographic field mapping and evaluating retinal function clinically.