Negative scotopic ERG and photopic ERG ON response impairment in a patient with normal dark adaptation.

PURPOSE: To present ocular findings in a patient who showed negative scotopic electroretinogram (ERG) and reduced ON response, but normal dark adaptation. CASE: An 18-year-old Japanese male patient who complained of severe asthenopia. His corrected visual acuities were 1.2 in both eyes. His fundi were normal. He had normal contrast sensitivity and normal dark adaptation. METHODS: The patients underwent ERG (including the standard protocol and photopic long flash recordings). RESULTS: The amplitudes of the rod ERG b-wave were reduced. The scotopic standard combined ERG response showed negative configuration. The photopic response to long flash revealed the reduced b-wave (ON response), while the amplitude of the first peak of the d-wave (OFF response) was within the normal range. CONCLUSIONS: Postsynaptic abnormalities in both the rod and cone ON-pathways, which are often found in patients with night blindness, were suggested in the ERG findings, but the dark adaptation of our patient was normal. Neuromuscular evaluation of the patient and ophthalmological evaluation, including ERG, of his parents were normal. To our knowledge, the ophthalmological and electrophysiological findings of our patient cannot be attributed to any known clinical entity.

PIII and derived PII analysis in a patient with retinal dysfunction with supernormal scotopic ERG.

PURPOSE: To present electroretinographic (ERG) findings in a patient with retinal dysfunction with supernormal scotopic ERG, and to analyze rod and cone PIII components and rod inner nuclear layer (derived PII) responses. PATIENT: A Japanese 11-year-old girl complained of poor visual acuity. There was no parental consanguinity in her family. The corrected visual acuity was 0.7 in both eyes. No abnormal finding was observed in both fundi. METHODS: The patient underwent full-field ERGs. Rod and cone a-waves were analyzed using photoreceptor models. The derived PII responses were analyzed using a technique described by Hood and Birch. RESULTS: In the photopic ERG, responses to single flash and 30-Hz flicker were attenuated. In the scotopic ERG, b-wave was supernormal in amplitude in response to intense flashes, but smaller than normal and markedly delayed over a lower range of flash intensities. By the PIII analysis, phototransductions (values of S) of both rod and cone were remarkably decreased. The derived PII responses for this patient were larger than the responses for normal subjects, and the onset of the PII responses in this patient are significantly delayed compared to those in normal subjects. CONCLUSIONS: The ophthalmological findings in this patient are consistent with previous publications of this disease. Although it has been reported that the sites of disease action were beyond the outer segment (values of S were within the normal range), our results suggest that photoreceptors could be involved in sites of disease action in at least some patients with this disease.

Rod and cone a-waves in central retinal vein occlusion.

PURPOSE: To evaluate rod and cone a-waves in cases with unilateral central retinal vein occlusion (CRVO). METHODS: Scotopic and photopic flash electroretinograms (ERGs) were recorded in seven patients aged 54-84 with unilateral hemorrhagic CRVO. Rod and cone a-waves were analyzed using photoreceptor models, and Rm(p3) (maximum a-wave amplitude) and S (sensitivity) were calculated. RESULTS: Decreased rod log S was found in all seven cases, and decreased cone log S was found in five cases. In only one case, rod log S in the fellow eye was decreased. The alterations in rod and cone log Rm(p3) were smaller than those in rod and cone log S. Of three cases in which ERGs could be recorded again after a certain follow-up period, rod log S and cone logS became larger in two cases and smaller in one case. CONCLUSIONS: The change in the phototransduction cascade was confirmed not only in rods but also in cones in five of our seven cases of CRVO. The ERG findings might reflect the functional change in the photoreceptor layer after the onset of CRVO.

Ocular fundus images by scanning laser ophthalmoscopy in a patient with enhanced S-cone syndrome.

PURPOSE: To present ocular fundus images in a patient with enhanced S-cone syndrome by scanning laser ophthalmoscopy. A 34-year-old Japanese woman whose parents were consanguineous showed mismatched electroretinographic responses to photopically balanced single-flash stimuli, with a larger signal to blue light than to red light. The central macula lacked a foveal reflex, and the surface was dull. Yellowish flecks and retinal pigment epithelium atrophy were evident in a ring at and around the vascular arcades. Faint black pigmentation was deposited in the mid peripheral retina. METHODS: The ocular fundus of the patient was observed by scanning laser ophthalmoscopy with the use of an argon blue laser (wavelength, 488 nm), a helium-neon laser (633 nm), and an infrared laser (780 nm). RESULTS: The argon blue laser showed numerous black spots of pigment, which were observed as faint pigmentation by conventional ophthalmoscopy. The spots were more enhanced with the argon blue laser than with the helium-neon laser. The white spots, which corresponded to the yellowish flecks in a ring at and around the vascular arcades, were more enhanced with the helium-neon laser than with the argon blue or infrared laser. Hypopigmentation of the retinal pigment epithelium was best shown with the infrared laser. CONCLUSION: An abnormality of the retinal structure in enhanced S-cone syndrome may exist in the inner and outer retinal levels, in at least some patients.

[Multifocal electroretinograms in patients with retinal vein occlusion].

PURPOSE: To investigate waveform changes of multifocal electroretinograms(mERG) in patients with retinal vein occlusion(RVO). METHODS: Nine eyes of 8 patients with RVO and 29 eyes of 29 normal subjects were examined using mERG. An array of 103 hexagonal elements was displayed on a monitor. mERG latencies(ms) and response densities (nV/deg2) were measured for center area(Ct) and for each of four quadrant areas. The peak and troughs were named N1, P1 and N2, consecutively. RESULTS: In pathological quadrants, although the response densities were abnormal in only one eye, latencies of the N2 and P1 were prolonged in 7 eyes and in 2 eyes, respectively(over 1 SD-2 SD). The latencies were significantly prolonged compared with those of normal eyes(p < or = 0.03, U-test). On the other hand, in the central area, although the latencies were abnormal in 3 eyes, the response densities were reduced in 6 eyes(over 1 SD-2 SD). The response densities were significantly reduced compared with those of normal eyes(p < or = 0.024, U-test). CONCLUSIONS: Both peak latencies in pathological quadrants and response densities in the central retinal area can be sensitive indicators of retinal dysfunction caused by RVO. The mERG system is useful for detecting local retinal dysfunction in patients with RVO.

Surgical management of retinal detachment associated with myopic macular hole: anatomic and functional status of the macula.

PURPOSE: To evaluate the postoperative status of the macula after vitreous surgery with internal limiting membrane removal for macular hole related retinal detachment in patients with severe myopia. DESIGN: Interventional case series. METHODS: We prospectively examined 10 eyes with retinal detachment associated with a myopic macular hole from 10 consecutive patients, and performed pars plana vitrectomy with internal limiting membrane peeling. Macular buckling was performed in one eye during the initial treatment and in three eyes during subsequent operations. The main outcome measures were the anatomic reattachment rate and the postoperative status of the macular hole. We examined the macular area pre- and postoperatively with slit-lamp biomicroscopy and with a scanning laser ophthalmoscope. Cross-sectional imaging of the macular area was conducted with optical coherence tomography. RESULTS: Successful retinal reattachment was achieved in seven eyes (70%) after the initial surgery and in three eyes (30%) after additional procedures. Visual acuity remained unchanged in two eyes (20%), and improved by two or more logarithmic units of minimum angle of resolution (logMAR) measurement in eight eyes (80%). The macular hole was anatomically closed in only one eye (10%). Postoperative enlargement of the macular hole was observed in seven eyes. CONCLUSIONS: In highly myopic eyes with macular hole related retinal detachment, closure of the macular hole is difficult to attain despite the complete relief of tangential traction by internal limiting membrane peeling. Results indicate the presence of a possible imbalance between the retina and the choroid-sclera complex associated with axial elongation and posterior staphyloma in highly myopic eyes.

Severe hypotony after macular translocation surgery with 360-degree retinotomy.

PURPOSE: To report a case of severe hypotony after macular translocation with 360-degree retinotomy. DESIGN: Interventional case report. METHODS: A 50-year-old woman with myopic neovascular maculopathy underwent macular translocation with 360-degree retinotomy in her left eye. RESULTS: After the second procedure of silicone oil removal, severe hypotony developed. No clear sign of leakage was found. Pure perfluoropropane gas tamponade was then performed, which resulted in temporal resolution of severe hypotony, but the hypotony recurred as the gas bubble was absorbed. Ten weeks after the second surgery, the hypotonous eye was refilled with silicone oil. No apparent cyclitic membrane was observed intraoperatively. After this procedure, the choroidal and retinal folds regressed; intraocular pressure has been between 5 and 7 mm Hg for more than 4 months thereafter. CONCLUSION: Severe hypotony can occur as a complication of otherwise uneventful macular translocation with 360-degree retinotomy.

Multifocal electroretinogram in patients with central serous chorioretinopathy.

PURPOSE: To assess local retinal function of macula in patients with central serous chorioretinopathy (CSC). METHODS: Multifocal electroretinograms (ERGs) were recorded in 5 patients with unilateral CSC and 20 normal subjects. The waveforms from the central retina within 5 degrees of visual angle were analyzed. The first negative trough was designated as N1, the first positive peak as P1, and the second trough as N2. RESULTS: The multifocal ERG amplitudes were significantly reduced at the first attack of CSC in all patients compared with the values in the normal controls, for P1-N1 (P <.01) and for P1-N2 (P <.01). Multifocal ERG latencies of the patients significantly increased compared with normal controls, for P1 (P <.01) and N2 (P <.01). After the resolution of retinal detachment, although the multifocal ERG amplitudes increased markedly, they did not improve to the normal level during the follow-up period (4-23 months). CONCLUSIONS: Persistent functional impairment of the retina was found by multifocal ERGs in patients with CSC after the resolution of subretinal fluid. A topographical analysis of the multifocal ERG is useful in the clinical observation of CSC.