Focal Macular Electroretinography Research Articles

ASSESSMENTS OF MACULAR FUNCTION BY FOCAL MACULAR ELECTRORETINOGRAPHY AND STATIC PERIMETRY IN EYES WITH RETINITIS PIGMENTOSA.

To assess the macular function by focal macular electroretinography and static perimetry in eyes with retinitis pigmentosa. Eighty-eight eyes of 88 retinitis pigmentosa patients were analyzed. The relationships between the focal macular electroretinography components and the mean deviations (MDs) of the Humphrey Field Analyzer 10-2 were determined. Spectral-domain optical coherence tomography was used to determine the integrity of the ellipsoid zone (EZ) and the interdigitation zone. Forward-backward stepwise regression analyses showed that the amplitudes (r = 0.45, P < 0.01) and implicit times (r = -0.29, P < 0.01) of the b-waves were significantly correlated with the MDs. Some of the eyes had reduced b-wave amplitudes (<1.0 µ V) and disrupted interdigitation zone, despite having a better MD (≥ -10.0 dB) and intact EZ. Subgroup analyses of eyes with better MD (≥ -10.0 dB) showed that the EZ width was correlated with the MDs but not with the b-wave amplitude. The thickness of the EZ-retinal pigment epithelium as an alternative indicator of interdigitation zone was correlated with the b-wave amplitude (r = 0.32, P = 0.04) but not with the MDs (r = -0.10, P = 0.53). The fact that the focal macular electroretinography amplitudes are reduced before the shortening of the EZ in the early stage of retinitis pigmentosa indicates that the focal macular electroretinography amplitudes are an earlier indicator of macular dysfunction than the Humphrey Field Analyzer 10-2 findings.

Macular dysfunction in patients with macula-on rhegmatogenous retinal detachments

AimsTo assess macular function in patients with macula-on rhegmatogenous retinal detachments (RRDs) using focal macular electroretinography (FMERG).MethodsThis is a prospective, observational case series of 27 patients diagnosed with a macula-on...

Short-term focal macular electroretinogram of eyes treated by aflibercept & photodynamic therapy for polypoidal choroidal vasculopathy.

To compare short-term outcomes of intravitreal aflibercept injection (IAI) with or without initial photodynamic therapy (PDT) for polypoidal choroidal vasculopathy (PCV) using focal macular electroretinography (FMERG). Observation case series. Twelve patients (6 males, 6 females; 12 eyes) with naïve PCV received 3 initial IAIs and a single session of PDT 3days after the first IAI (combination group), and 13 patients (7 males, 6 females; 13 eyes) with naïve PCV received 3 initial IAIs only (IAI group) were retrospectively observed. Changes in visual acuity, central retinal thickness (CRT), central choroidal thickness (CCT), and FMERG parameters (FMERGs) were compared. The combination group showed improved visual acuity after the second and third IAI (P = 0.040, 0.019, respectively); both groups showed reduced CRT after the first IAI (P < 0.01, each). Only the combination group showed reduced CCT after the third IAI (P = 0.031). The FMERGs of the IAI group showed improved amplitudes of a-waves after the third IAI (P = 0.026) and of b-waves after the first and third IAI (P = 0.034, < 0.01, respectively); the combination group did not show improvement. The implicit times of the a- and b-waves were not changed in either group. Combination therapy and IAI monotherapy each improved visual acuity and retinal structure to a similar degree; combination therapy reduced choroidal thickness but did not improve FMERGs in the short term.

Multimodal evaluation of macular function in age-related macular degeneration

To evaluate macular function using multimodality in eyes with age-related macular degeneration (AMD) at various stages. Macular function in 20 control eyes (20 subjects), 17 eyes (17 patients) with large drusen, 18 eyes (18 patients) with drusenoid pigment epithelial detachment (PED), and 19 eyes (19 patients) with neovascular AMD was examined using a Landolt chart for visual acuity; retinal sensitivity was measured by microperimetry; and focal macular electroretinography (fmERG) was performed. In all of these eyes, retinal morphology was examined using optical coherence tomography. Eyes with neovascular AMD showed morphologic changes in the neurosensory retina as well as marked deterioration of macular function in all parameters measured with a Landolt chart, fmERG, and microperimetry. Eyes with large drusen showed only minimal morphologic changes in the neurosensory retina. In this large drusen group, although retinal sensitivity at the central point was significantly decreased (P = 0.0063), the other parameters of macular function were well preserved. In eyes with drusenoid PED, the structure of the neurosensory retina was well preserved, while the foveal thickness was significantly increased (P = 0.013). The macular function of these eyes was significantly deteriorated, with the VA, amplitude of the a-wave and b-wave, and retinal sensitivity being markedly decreased. In addition, the area of PED correlated with the latency of the a-wave and b-wave and with the retinal sensitivity within the central 4° or 8° region. Multimodal evaluation demonstrated a significant decrease in macular function in drusenoid PED and in neovascular AMD.

Autosomal Dominant Occult Macular Dystrophy with an RP1L1 Mutation (R45W)

To characterize clinical features in occult macular dystrophy (OMD) patients with the RP1L1 gene mutation (p.R45W), one of two previously described mutations in Japanese OMD patients. Mutational screening of the RP1L1 gene was performed via polymerase chain reaction and direct sequencing for seven unrelated probands (one autosomal dominant and six sporadic probands) with OMD. A comprehensive ophthalmic examination was performed, including Cirrus optical coherence tomography. Full-field electroretinography (ERG), multifocal ERG, and focal macular ERG were performed. The heterozygous mutation (p.R45W) was found in only one female proband with autosomal dominant OMD, whose mother was also diagnosed with OMD and carried the mutation. Ophthalmoscopy showed bilateral normal fundi in the proband but subtle retinal pigment epithelium mottling in the mother. Both the proband and her mother had typical OMD findings: decreased visual acuity and markedly reduced central responses in the multifocal ERG and focal macular ERG. Although full-field ERG revealed normal rod and standard combined responses, photopic and 30-Hz flicker responses were slightly reduced in both the proband and her mother. Optical coherence tomography revealed that the external limiting membrane and inner segment-outer segment boundary were disorganized despite normal macular thickness in the proband, whereas the mother exhibited macular thinning with discontinuous reflectivity of the external limiting membrane and inner segment-outer segment boundary. The clinical phenotypes differed between the proband and her mother and were indistinguishable from other sporadic or RP1L1-unassociated OMD patients, suggesting that mutation-dependent clinical features may not be present.

Improvement of central visual function following steroid pulse therapy in acute zonal occult outer retinopathy

The purpose of this study was to report a patient with acute zonal occult outer retinopathy (AZOOR) unilaterally, who received steroid pulse therapy. A 42-year-old woman presented with photopsias and severe vision loss in her left eye. Visual acuity was 0.04, and Humphrey visual field testing showed overall depression with a mean deviation (MD) value of -25.78 dB in the left eye. Fundus and angiographic examinations found no specific abnormal findings, leading to a diagnosis of AZOOR. Optical coherence tomography showed attenuation of the photoreceptor inner segment/outer segment junction (IS/OS) line. Focal macular electroretinography (fmERG) demonstrated that there were non-detectable responses at 5°, 10° and 15° (in diameter). Following steroid pulse therapy, her visual acuity was 1.0, her MD value improved to -16.08 dB, and there were both partial recovery of the IS/OS line and apparent improvements of fmERG responses (at 10° and 15°). The present findings suggest that steroid pulse therapy might potentially be an effective treatment in some AZOOR patients.

Evaluation of Macular Function Using Focal Macular Electroretinography in Eyes with Macular Edema Associated with Branch Retinal Vein Occlusion

To study the usefulness of focal macular electroretinography (fmERG) for evaluation of macular function in eyes with macular edema (ME) associated with branch retinal vein occlusion (BRVO). The authors prospectively performed fmERG on 34 patients with untreated unilateral BRVO at the initial visit and 12 months later. Amplitudes and latencies of the a-wave, b-wave, and photopic negative response (PhNR) were compared with visual acuity, with retinal sensitivity measured by microperimetry, and with measurements obtained by optical coherence tomography. In eyes with ME from BRVO, amplitudes of the a-wave, b-wave, and PhNR were reduced significantly and latencies were prolonged significantly compared with those of healthy fellow eyes (P < 0.05). Relative amplitudes and latencies were not correlated with visual acuity but, rather, tended to be correlated with retinal sensitivity within the macular area. Among all parameters studied by fmERG, relative amplitude of the PhNR was most strongly correlated with central foveal thickness (r = -0.465; P = 0.007). In addition, the height of the serous retinal detachment showed a correlation with the relative amplitude of the PhNR (r = -0.376; P = 0.034). At 12 months, the amplitude of the b-wave and the PhNR improved significantly, in parallel with resolution of the ME (P = 0.015; P = 0.033). In eyes with ME from BRVO, amplitudes and latencies seen by fmERG were correlated with other biological parameters. Based on findings of the present study, fmERG appears to be useful as a functional examination within the macular area affected by BRVO.

Focal Macular Electroretinogram in Macular Edema Secondary to Central Retinal Vein Occlusion

To evaluate the usefulness of focal macular electroretinography (fmERG) for evaluation of macular function in eyes with central retinal vein occlusion (CRVO). fmERG recordings were made prospectively in 24 patients with unilateral CRVO. The amplitudes and latencies of the a-wave, b-wave, and photopic negative response (PhNR) were compared with other biological parameters, including visual acuity (VA), retinal sensitivity measured with a microperimeter, and optical coherence tomography. In eyes affected by CRVO, amplitudes of the a-wave, b-wave, and PhNR were reduced significantly, and latencies were prolonged significantly compared with those of healthy fellow eyes (P < 0.001). Relative amplitudes (affected eye/fellow eye) of each wave showed a cross correlation with VA. Furthermore, both relative amplitudes and latencies of each wave tended to correlate with retinal sensitivity within the macular area. Central foveal thickness showed a correlation with both relative amplitude and relative latency. Among all parameters, relative amplitude of the PhNR correlated most strongly with central foveal thickness (r = -0.598, P = 0.0042). In addition, sensory retinal thickness showed a correlation with relative latencies, and height of the retinal detachment (when present) showed a correlation with relative amplitudes. In ischemic CRVO, relative amplitudes were reduced more severely than were those in nonischemic CRVO. In eyes with CRVO, amplitudes and latencies of the fmERG correlated with other biological parameters. Based on the present study, fmERG appears to be useful for the examination of the macular edema that accompanies CRVO.

Focal macular photopic negative response in patients with optic neuritis

To investigate, by focal macular electroretinography (ERG), the change of photopic negative response (PhNR) in the recovery of visual function in patients with optic neuritis. Focal macular ERG was recorded from nine patients with acute optic neuritis (38.6 ± 10.2 years). The photostimulator device projected 15° visual angle spotlight onto the macula. Focal macular ERG recording was performed at the onset and at 1 month and 6 months after the onset of optic neuritis. The results were compared between each recording for seven of the patients. All patients decreased in the vision below 20/100 and had central scotoma. Vision improved more than 20/20 within 1 month and full-visual field recovered within 6 months after the onset in all patients. The amplitude of the a-wave, b-wave, and PhNR of focal macular ERG at the onset was significantly attenuated in eyes with optic neuritis (66.8 ± 15.5, 65.8 ± 17.7, and 65.2 ± 14.4% of normal control, respectively). The amplitude of the a-wave and b-wave increased gradually after steroid pulse therapy. The increase in a-wave amplitude was significant at 6 months (P = 0.046), whereas the PhNR amplitude did not show any significant change over 6 months after the onset of optic neuritis. Our results suggest that inflammation at the onset of optic neuritis leads to functional deficits that extend to at least the inner nuclear layers of the retina, and that all but the ganglion cell layers of retina recover.

Abnormal focal macular electroretinograms in eyes with idiopathic epimacular membrane

PURPOSE: To study the functional state of the retina beneath an epimacular membrane by means of focal macular electroretinography. METHODS: Focal macular electroretinograms of 30 consecutive patients (age 25 to 75 years) with unilateral idiopathic epimacular membrane were recorded prospectively. The amplitudes and implicit times of the a and b waves and the oscillatory potentials (O1, O2, O3) recorded from the eye with idiopathic epimacular membrane were compared with those of the normal fellow eye. RESULTS: There was a statistically significant reduction in the amplitude of the a wave ( P < .001), the b wave ( P < .001), and the oscillatory potentials (O1 + O2 + O3; P < .001) of the affected eyes. The reduction of the b-wave amplitude was significantly greater than that of the a wave, resulting in a lower b/a wave ratio ( P = .003) in the affected eyes. The reduction in the amplitude of the oscillatory potentials was significantly greater than that of the other two components ( P < .001). The implicit times were significantly prolonged for the a wave ( P < .001), the b wave ( P = .004), and O3 ( P < .001). There was a significant correlation between relative b-wave amplitude (affected/normal fellow eye) and the visual acuity (r = −0.50, P = .007). These findings were similar to those we reported for eyes with aphakic cystoid macular edema. CONCLUSIONS: The focal macular electroretinograms in eyes with epimacular membrane disclosed abnormalities that were similar to those of eyes with cystoid macular edema. This suggests that the epimacular membrane probably induced damage to the neurons in the inner retinal layers. Dysfunction of these neurons is one possible cause of visual impairment in this disease.