Multifocal electroretinogram in patients with central serous chorioretinopathy

Central Serous Chorioretinopathy: An Update on the Current State of Management

Central serous chorioretinopathy (CSCR) is a relatively common retinal disorder that leads to central vision impairment, often with a high recurrence rate. The exact etiology and pathogenetic mechanisms have not been fully elucidated but are likely to be associated with hyperpermeability of the choroidal capillaries and failure of the retinal pigment epithelium (RPE), leading to serous detachment of the neurosensory retina. Multimodal imaging plays a critical role in the diagnostic approach and monitoring of CSCR. Fortunately, the natural course of the disease is usually self-limiting, with spontaneous resolution and total fluid reabsorption. However, some patients may exhibit recurrences or persistent subretinal fluid (chronic CSCR), leading to progressive and irreversible RPE atrophy or photoreceptor damage. Thus, to prevent permanent visual loss, individualized treatment should be considered. Recent developments in the diagnostic and therapeutic approach have contributed to better outcomes in patients with CSCR. More studies are required to improve our understanding of epidemiology, pathogenesis, diagnosis, and treatment, with a significant impact on the management of this challenging clinical entity. The purpose of this review is to summarize the current knowledge about the clinical features, diagnostic workup, and therapeutic approach of CSCR.

Functional Outcomes and Safety Profile of Trans-Foveal Subthreshold Micropulse Laser in Persistent Central Serous Chorioretinopathy

Our study evaluated visual function changes after subthreshold micropulse laser (SML) treatment in persistent central serous chorioretinopathy (CSC) and SML safety profile. We conducted a prospective study including 31 fovea-involving CSC patients. The natural course was observed for the first 3 months, SML was performed at 3 months, and SML effectiveness was observed at 6 months. At all three clinical visits, optical coherence tomography (OCT), best corrected visual acuity (BCVA), contrast sensitivity (CS) in five spatial frequencies (1.5, 3.0, 6.0, 12.0, and 18.0 cycles per degree (cpd)), microperimetry (MP), and multifocal electroretinography (mfERG) were performed. The SML safety profile was evaluated with functional and morphological parameters. In the cohort of all CSC patients treated with SML, the statistically significant average improvement was observed in BCVA (p = 0.007), CS-1.5 (p = 0.020), CS-3.0 (p = 0.050), CS-12.0 (p < 0.001), CS-18.0 (p = 0.002), CS (CS-A) (p < 0.001), MP in the central ring (MP-C) (p = 0.020), peripheral ring (MP-P) (p = 0.042), and average retinal sensitivity (MP-A) (p = 0.010). After the SML treatment, mean changes in mfERG amplitudes and implicit times in our cohort were not statistically significant. No morphological or functional adverse effects of SML treatment were observed. SML treatment in persistent CSC episodes leads to significant functional improvement and has an excellent safety profile.

Multifocal Electroretinography Changes over 12 Months after Resolution of Central Serous Chorioretinopathy: Prospective Observational Study

INTRODUCTION

This prospective observational study aimed to evaluate the changes in retinal function after the anatomical resolution of central serous chorioretinopathy by multifocal electroretinography.

METHODS

Thirty-two eyes of 32 patients with unilaterally resolved central serous chorioretinopathy were prospectively studied. Serial multifocal electroretinography examinations were performed at the initial visit for active central serous chorioretinopathy, the time of anatomical resolution (resolved central serous chorioretinopathy), and 3, 6, and 12 months after resolution. The peak amplitudes of the first kernel responses were analysed and compared with those in 27 age-matched normal controls.

RESULTS

Compared with controls, the N1 amplitudes of rings 1-4 and P1 amplitudes of rings 1-3 showed statistically significant reductions at 12 months after the resolution of central serous chorioretinopathy (p < 0.05). The multifocal electroretinography amplitude substantially increased at the time of resolution and gradually improved until 3 months after the resolution of central serous chorioretinopathy.

CONCLUSION

Serial examinations with multifocal electroretinography showed that retinal responses increased mostly after the resolution of central serous chorioretinopathy, and this improvement slowly progressed until 3 months; however, the multifocal electroretinography amplitudes remained statistically reduced 12 months after the anatomical resolution of central serous chorioretinopathy, indicating the residual functional deficits detected by multifocal electroretinography.

Electrophysiological and anatomical outcomes of subthreshold micropulse laser therapy in chronic central serous chorioretinopathy

BACKGROUND

To evaluate short-term efficacy of subthreshold micropulse laser therapy on chronic central serous chorioretinopathy (CSC) electrophysiologically and anatomically.

METHODS

This prospective study included 18 eyes with chronic CSC. Subthreshold micropulse laser therapy was applied to the eyes using Endpoint Management System (EpM). The efficacy of the treatment was evaluated with optical coherence tomography (OCT) and multifocal electroretinography (mfERG) measurements before and after one month of the treatment.

RESULTS

The mean patient age was 47.3 ± 5.7 years (ranged between 36 and 56). The mean symptomatic time of the disease was 12.7 ± 3.33 months. Central macular thickness, choroidal thickness, subretinal fluid height and width showed statistically significant decreases after EpM treatment (p < 0.05). P 1 amplitude of ring 1, 3, 4, and 5 in mfERG increased significantly (p <  0.05).

CONCLUSIONS

The study demonstrated that, in both OCT and electrophysiological evaluations, EpM subthreshold laser therapy resulted in anatomical and functional improvements in chronic CSC.

Visual function during and after an acute central serous chorioretinopathy episode

PURPOSE

To evaluate visual function parameters during and after an acute central serous chorioretinopathy (CSC) episode.

METHODS

A prospective study included 19 fovea involving acute CSC patients with episode resolution within 3 months from the episode onset. Optical coherence tomography, best corrected visual acuity (BCVA), contrast sensitivity (CS), microperimetry (MP), and multifocal electroretinography (mfERG) were performed at baseline, 3 and 6 months from the episode onset. In a sub analysis, patients were divided into groups with greater (gMV, N = 9) and lower (lMV, N = 10) macular volume at presentation, and functional outcomes were observed.

RESULTS

BCVA (p < 0.001), average CS (CS-A) (p < 0.001), average retinal sensitivity (MP-A) (p < 0.001), mfERG amplitude densities in the first and second ring (mfERG-A1, p < 0.001; mfERG-A2, p = 0.017), and implicit times in the first, second, and third ring (mfERG-IT1, p = 0.024; mfERG-IT2, p = 0.002; mfERG-IT3, p = 0.018) improved with episode resolution 3 months after the episode onset. From 3 to 6 months after the episode onset, only CS-A (p = 0.045) continued to improve. Patients in the gMV group had lower mfERG-A1 (p = 0.017) and central retinal sensitivity (MP-C, p = 0.05) 6 months from the episode onset.

CONCLUSIONS

Although all functional parameters mostly improve with CSC episode resolution, only CS continues to improve thereafter. Patients with greater MV at presentation have worse functional outcomes. Visual function impairment in acute CSC patients is confined to the topographical area of subretinal fluid detachment.

Longitudinal multimodal functional macular analysis after half-dose photodynamic therapy for central serous chorioretinopathy

BACKGROUND

Half-dose photodynamic therapy (HD-PDT) has been widely used for central serous chorioretinopathy (CSC) with good anatomical results. However, long-term functional outcomes after this treatment remain uncertain. This study aimed a longitudinal multimodal macular assessment, correlating functional and anatomical outcomes.

METHODS

This is a retrospective study performed in a tertiary referral center including 111 eyes from 95 CSC patients. Data on best corrected visual acuity (BCVA), central macular thickness (CMT), central retinal sensitivity (CRS) using microperimetry (MP) and multifocal electroretinography (mfERG) at baseline and 3, 6, 12, 18, 24, 36, 48 and 60 months after treatment were registered. A correlation analysis was performed.

RESULTS

Mean follow-up was 34.5 ± 26.3 months. A significant improvement in BCVA and CMT was registered in all the visits. CRS significantly improved until 24 months (p<0.001 at 12 months, p<0.05 at 24 months), worsening afterwards. The mfERG amplitude of N1 and P1 waves significantly improved in the first 12 months, aggravating afterwards. The implicit time improved until 24 months, deteriorating after 48 months. This long-term decline was also described in some inactive untreated fellow eyes CONCLUSIONS: : A multimodal longitudinal analysis of CSC patients after HD-PDT shows that, after the first 12 to 24 months, the significant sustained improvement in BCVA and CMT is not paired by a sustained improvement in macular sensitivity or electrical response. This long-term functional deterioration might result from the disease itself and not directly from the treatment.

Central serous chorioretinopathy: update on pathophysiology and treatment

Recent technological advances--new pathophysiological insights, new imaging techniques for diagnosis and management, and new treatments--have led to an improved understanding of central serous chorioretinopathy (CSC). The primary role of the choroid has become more widely accepted with widespread use of indocyanine green angiography. Optical coherence tomography (OCT), and particularly enhanced depth imaging OCT, demonstrate a thickened and engorged choroid. Adaptive optics, fundus autofluorescence, multifocal electroretinography, microperimetry, and contrast sensitivity testing reveal that patients with even a mild course suffer previously undetected anatomic and functional loss. Although focal laser and photodynamic therapy are the current standard of care for persistent subretinal fluid in CSC, they are not appropriate in all cases, and the optimal timing of intervention remains unclear.

The effect of subretinal viscoelastics on the porcine retinal function

The functional consequence of long-term retinal detachment in the porcine model is examined by multifocal electroretinography (mfERG). Retinal detachment (RD) in humans leaves permanent visual impairment, despite anatomical successful reattachment surgery. To improve treatment, adjuvant pharmaceutical therapy is needed, and can only be tested in a suitable animal model. The porcine model is promising and the mfERG is well validated in this model. RD was induced in 18 pigs by vitrectomy and healon injection of various concentrations. Preoperatively and 6 weeks postoperatively eight animals were examined by mfERG. The major component P1 was analyzed statistically. Indirect ophthalmoscopy and bilateral color fundus photography (FP) were performed. Selected animals underwent high-resolution optical coherence tomography (OCT). Examination by ophthalmoscopy and FP showed that the RDs remained detached for the 6 weeks of follow-up. The P1 amplitude of the mfERG did not differ significantly between the detached areas, the surrounding attached areas, and the healthy eye (p = 0.25). Similarly, P1 implicit time did not differ between the areas (p = 0.85). The lack of functional consequences of long-term RD makes the porcine model unsuitable for examining adjuvant pharmaceutical RD treatment. Future studies should focus on foveated primates.

Visual functions after laser photocoagulation in central serous chorioretinopathy

The authors evalute the visual functions of patients with unilateral central serous chorioretinopathy (CSC) and compare them with their non-affected eye and with a control group. Fourteen patients with CSC treated with direct laser-photocoagulation were examined preoperatively and followed-up, up to 2 years postoperatively. Baseline best corrected visual acuity (BCVA) and contrast sensitivity (CS) of both eyes of patients was significantly lower in comparison with the controls. BCVA and CS in affected eyes were significantly lower compared to the fellow eye of patients. The final BCVA and CS of patients did not differ significantly from the controls, except CS of affected eyes in the spatial frequency of 3.69 c/deg. Two years after laser treatment, there were only nonsignificant differences of both photopic full-field electroretinography (phERG) and multifocal electroretinography (mfERG) responses between the treated, the nonaffected eye of the patients and the control group with exception of a significantly longer P1 implicit time in the parafoveolar region in affected eyes. Colour discrimination was normal in 85.8% of affected eyes of the patients. Despite a significant improvement of macular function in CSC eyes, functional examination methods do not prove complete resolution of function 2 years after laser-treatment.

Electroretinographic findings in transplant chorioretinopathy

Aim:

Transplant chorioretinopathy is a rare complication following solid organ or bone marrow transplantation and can result in severe vision loss. This series presents electroretinogram (ERG) results in patients with this condition.

Methods:

Patients who presented with bilateral vision loss following bone marrow or solid organ transplantation were identified. A complete ophthalmologic examination, fundus photography, and fluorescein angiography (FA) were performed. Full-field ERG was obtained in all patients and a multifocal ERG (mfERG) was obtained in two patients.

Results:

Four patients were identified. All patients had bilateral vision loss and displayed a characteristic pattern of mottled hyperfluorescence on FA. Three patients developed progressive vision loss ranging from 20/60 to hand motions whereas one retained 20/40 vision. All patients exhibited moderate to severe cone dysfunction, while the degree of rod abnormalities was varied. Two patients with severe cone dysfunction showed mild clinical changes initially, but later developed progressive vision loss and chorioretinal atrophy.

Conclusion:

Transplant chorioretinopathy patients undergoing ERG testing show cone dysfunction with a variable degree of rod dysfunction. ERG abnormalities preceded the visual acuity and clinical changes in two patients, suggesting that ERG may be a helpful predictor of the clinical course in this rare disease.

The clinical applications of multifocal electroretinography: a systematic review

Multifocal electroretinography (mfERG) is an investigation that can simultaneously measure multiple electroretinographic responses at different retinal locations by cross-correlation techniques. mfERG therefore allows topographic mapping of retinal function in the central 40-50 degrees of the retina. The strength of mfERG lies in its ability to provide objective assessment of the central retinal function at different retinal areas within a short duration of time. Since the introduction of mfERG in 1992, mfERG has been applied in a large variety of clinical settings. This article reviews the clinical applications of mfERG based on the currently available evidence. mfERG has been found to be useful in the assessment of localized retinal dysfunction caused by various acquired or hereditary retinal disorders. The use of mfERG also enabled clinicians to objectively monitor the treatment outcomes as the changes in visual functions might not be reflected by subjective methods of assessment. By changing the stimulus, recording, and analysis parameters, investigation of specific retinal electrophysiological components can be performed topographically. Further developments and consolidations of these parameters will likely broaden the use of mfERG in the clinical setting.

Comparison of achromatic and blue-on-yellow perimetry in patients with resolved central serous chorioretinopathy

Central serous chorioretinopathy (CSCR) is a disorder characterized by the serous detachment of the sensory retina in the posterior pole. Although CSCR usually resolves spontaneously, the patients may notice residual visual deficits, despite recovering normal visual acuity. The aim of this study is to compare the blue-on-yellow perimetric parameters with conventional automated perimetric parameters in the detection of visual deficits in patients with resolved CSCR. Eighteen patients who had spontaneous recovered from CSCR were enrolled this study. All subjects were examined twice with each type of perimetry. Wilcoxon test was used for statistical analysis. The achromatic perimetric mean deviation values were significantly higher in patients with CSCR than in the control group, while statistically a significant difference was determined for all of blue-on-yellow perimetric values. In conclusion the loss of central retinal sensitivity remains after resolution of the CSCR even if the visual acuity has recovered to normal. Blue-on-yellow perimetry is more sensitive than achromatic perimetry to reveal this central sensitivity loss.