Masanori Hayashi

Morphological and functional analyses of diabetic macular edema by optical coherence tomography and multifocal electroretinograms

Abstract.Purpose: To determine the correlation between the tomographic features and the visual functions of eyes with diabetic macular edema. Methods: Optical coherence tomographic (OCT) images and multifocal electroretinograms were obtained from 45 eyes of 25 patients with diabetic macular edema and from 21 eyes of 21 normal subjects. Results: The OCT images showed cystoid macular edema in 18 eyes and diffuse retinal swelling without cystoid edema in the other 27 eyes. The fovea was significantly thicker in eyes with cystoid macular edema and in those with diffuse retinal swelling than in normal eyes. The fovea of eyes with cystoid edema was significantly thicker than the fovea of eyes with diffuse swelling. The best-corrected visual acuity and the electrical response density from the macular area were significantly reduced in eyes with diabetic macular edema, particularly in those with cystoid edema. The best-corrected visual acuity and macular response density of the multifocal ERGs were inversely correlated, and the implicit times were directly correlated with foveal thickness. Conclusion: The visual acuity was correlated significantly with morphological changes revealed by OCT and with multifocal ERGs. The combination of OCT and multifocal ERGs may provide objective criteria for the evaluation and assessment of diabetic macular edema.

Morphological and functional analyses of adult onset vitelliform macular dystrophy

Aim: To evaluate the morphology and visual function of the macula in eyes with adult onset vitelliform macular dystrophy (AVMD). Methods: 12 eyes of six patients with AVMD were examined by ophthalmoscopy, scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT), and multifocal electroretinography (mfERGs). The macular lesions were bilateral in all patients and varied from the typical vitelliform (five eyes), faded vitelliform changes with retinal pigment epithelium (RPE) atrophy (five eyes), and a normal fovea associated with small flecks around the macula (two eyes). Results: SLO demonstrated small abnormal bright spots in the deep retina throughout the posterior retina in all cases. OCT showed a highly reflective fusiform thickened layer at the level of the RPE and choriocapillaris in patients with a submacular yellow vitelliform lesion. A well circumscribed, optically clear space was observed beneath the retinal layer in the macular lesions with RPE atrophy. The mfERGs were significantly reduced not only in the macular area but also in the outermost ring (20–30°) of the mfERGs. Conclusions: The submacular materials that accumulate within the RPE or subepithelial layers reported in previous histopathological studies of vitelliform lesions can be detected by OCT. In the macular lesions with RPE atrophy, the material may have disappeared leaving a subretinal or subepithelial optical clear space. These SLO and mfERG observations suggest that the morphological and functional abnormalities may not be localised just in the macular area but may be present throughout the posterior pole in eyes with AVMD.

Early postoperative macular morphology and functional outcomes after successful macular hole surgery.

Purpose: To investigate the relationship between early postoperative macular morphology and postoperative visual acuity in eyes that had undergone successful macular hole (MH) surgery. Methods: Pars plana vitrectomy and internal limiting membrane peeling were performed during surgery for idiopathic MHs on 25 eyes. The macular configuration was determined by optical coherence tomography, and best-corrected VA (BCVA) was measured postoperatively. Results: Eleven eyes had nearly normal foveal morphology (normal group) and 14 eyes had subretinal fluid or intraretinal cysts (abnormal group) at 1 month. Among the 14 eyes in the abnormal morphology group, normal foveal morphology was confirmed in 9 eyes 3 months and in the remaining 5 eyes 6 months after surgery. Mean BCVA improved significantly from the preoperative values in both groups 6 months after surgery. Conclusions: The morphology of the macular area was abnormal in more than one half of eyes that had successful MH surgery 1 month after surgery. However, by 6 months, all eyes had normal macular configuration, and BCVA was not significantly different in the two groups. We conclude that an abnormal morphologic appearance of the macular area in the early postoperative period does not predict the final visual outcome.

S-cone electroretinograms in multiple evanescent white dot syndrome

Cone electroretinograms (ERGs), elicited by different color flashes under Ganzfeld conditions, were recorded from 6 patients with multiple evanescent white dot syndrome (MEWDS). All of the patients had normal color vision as determined by the Farnsworth Panel D-15 except for one who showed non-specific errors. The b-waves elicited from short wavelength sensitive (S-) cones were reduced more than the mixed long (L-) and middle (M-) wavelength sensitive cones in the affected eyes. The ratio of the S-cone b-wave amplitude of the affected eyes to that of the normal fellow eyes was significantly lower than the comparable ratio for the L- and M-cone ERG b-waves (p= 0.012). The S-cone ERGs recorded from 2 patients recovered to normal levels after their symptoms abated. These ERG results indicate that the S-cone system is more impaired than the L- and M-cone systems in the acute stage of MEWDS, and the changes in the S-cones may be reversible.

Selective reduction of S-cone response and on-response in the cone electroretinograms of patients with X-linked retinoschisis.

AbstractPurpose. To examine the electroretinograms (ERGs) of the short-wavelength-sensitive (S-) and the mixed long- and middle-wavelength-sensitive (L,M-) cones, and the ON- and OFF-responses of the cone ERGs in three patients with X-linked juvenile retinoschisis (XLRS). Methods. Cone ERGs elicited by different color flashes and those elicited by long duration stimuli under Ganzfeld conditions were recorded from three patients with XLRS. Results. The S-cone b-waves were undetectable to short-wavelength stimuli in all three XLRS patients, while the L,M-cone ERG b-waves were within the normal range. To long-duration white stimuli, the ON-response (b-wave) was reduced and delayed in all patients compared with that of the normal subjects, while the d-wave or OFF-response appeared normal in amplitude and implicit time. Conclusions. These results support the hypothesis that the normal S-cone ERG arises primarily from the ON-pathway of the cone ERGs and the hypothesis that ON-bipolar cells are predominant in the S-cone system.

Electroretinograms and Visual Evoked Potentials Elicited by Spectral Stimuli in a Patient With Enhanced S-Cone Syndrome

PURPOSE To evaluate the properties of the retina of a Japanese patient with enhanced S-cone syndrome by analyzing electroretinograms (ERGs) and visual evoked potentials (VEPs) elicited by different spectral stimuli. METHODS Ganzfeld spectral flashes in the presence of strong white adapting background illumination were used to elicit cone ERGs and VEPs. RESULTS The cone ERG elicited in the patient by short wavelength stimuli was distinctly different from the normal S-cone ERG. The action spectrum of the cone ERG confirmed its relative hypersensitivity to short wavelengths. The action spectrum of the VEP for the patient showed a similar relative hypersensitivity to short wavelengths. The response of the VEPs to short wavelength stimuli was different in waveform from the VEP response to longer wavelength stimuli observed in a normal subject. CONCLUSIONS These results indicate that the hypersensitivity to short wavelengths is transmitted to the central nervous system and that there is a short wavelength transducing photopigment in many of the photoreceptors, either abnormal S-cones or photopic rods.

S-cone electroretinogram to Ganzfeld stimuli in patients with retinitis pigmentosa

Cone electroretinograms (ERGs) elicited by different chromatic stimuli were recorded from patients with typical retinitis pigmentosa (RP) younger than 50 years of age. Ganzfeld color flashes on a bright white background illumination were used to elicit short-wavelength-sensitive (S-), and mixed long- (L-) and middle- (M-) wavelength-sensitive cone ERGs. Three patients with dominant inheritance, 22 patients with non-dominant inheritance, and 27 age-similar normal subjects were compared. Although the b-wave amplitudes of both the S- and L,M-cone ERGs were reduced in the RP patients, the S-cones were reduced to a greater degree than the L,M-cones. No significant difference in the S-cone reduction was observed between patients with dominant inheritance and those with non-dominant inheritance. The selective reduction of the S-cone system, reported previously in psychophysical studies, may be attributable not only to the macular region but also to the entire retina.

Surgically removed submacular nematode

Editor,—Intraocular filariasis is an uncommon disease in civilised countries. In only a few cases has the worm been surgically removed from the posterior portion of the eye and identified.1 In this report we describe a patient who had a filaria-like worm in an epimacular and/or submacular lesion, which was successfully removed surgically. ### CASE REPORT A 38 year old woman complained of decreased visual acuity in her left eye of 5 days’ duration. Her medical history was unremarkable. The patient had two pet dogs, and she had not travelled to foreign countries in recent years. On examination, her corrected visual acuity was 20/20 in the right eye and 20/100 in the left. No inflammation was present in the anterior segment or vitreous cavity bilaterally. Ophthalmoscopic examination disclosed a white worm, approximately 3 disc diameters in length, equivalent …

Cone Electroretinograms in Response to Color Stimuli After Successful Retinal Detachment Surgery

Cone electroretinograms (ERGs) in response to different color flashes were examined using a Ganzfeld stimulus in 19 eyes after successful retinal detachment surgery. In the operated eyes, the short wavelength sensitive (S-) cone b-wave was reduced more than the mixed long (L-) and middle (M-) wavelength sensitive cone b-waves. The ratio of the S-cone ERG b-wave amplitude between operated eyes and fellow eyes was significantly lower than the L- and M-cone ERG b-waves (P < .01). These ERG results indicated that the S-cone system is more impaired than the L- and M-cone systems after retinal detachment surgery.

Built-in LED contact lens electrode for S-cone electroretinographic recordings

Purpose:To characterize the cone electroretinograms (ERGs) elicited by chromatic stimuli obtained from a newly-developed contact lens electrode with built-in light-emitting diodes (LEDs) emitting different colors. Methods:Cone ERGs were recorded from normal subjects with a contact lens electrode with built-in blue (430 nm), red (644 nm), and white LEDs. These LEDs have a wide range of luminance intensities (3 log units), and can be used as either the background illumination or the stimulus in any combination. The stimulus duration was fixed at 1 ms. For comparison, cone ERGs were recorded with Ganzfeld color flash stimuli using Wratten color filters on a bright white background. Results:With a bright background illumination provided by the white LED (2.0 log cd/m2), the blue LED stimulus elicited an ERG with two positive peaks similar to that recorded with conventional Ganzfeld blue flashes. The peak time of the early b-wave was 24 to 28 ms, and that of the later one was 43 to 48 ms, and these values were identical to the L,M-cone and S-cone b-wave, respectively, elicited by Ganzfeld flashes. The ERGs elicited by the red LED lacked the second peak. Conclusion:These results indicate that the S-cone and L,M-cone ERGs can be recorded simultaneously under the same background with this contact lens electrode. This relatively simple technique can be used to examine the human S-cone system in a routine clinical setting.