First and second-order kernel multifocal electroretinography abnormalities in acute 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.

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.

Macular Integrity Assessment and Fixation Analysis in Chronic Central Serous Chorioretinopathy

Purpose

To investigate retinal sensitivity characteristics associated with morphologic changes in the eyes exhibiting chronic central serous chorioretinopathy (CSC), using macular integrity assessment (MAIA) microperimetry.

Methods

A retrospective, cross-sectional, observational study was constructed. The eyes of patients classified as chronic CSC, according to the onset of subjective symptoms with serous retinal detachment, as confirmed by optical coherence tomography examination, were included in the study. Retinal sensitivity and fixation were analyzed by performing microperimetry examinations using the MAIA instrument.

Results

We reviewed microperimetry examinations of 15 eyes of 15 patients (age: 28-51 years) with chronic CSC and mean best-corrected visual acuity of -0.2 logMAR units. The mean retinal integrity in the chronic CSC group was 49.0 ± 27.6, which was significantly different from the control eyes. The mean average threshold in the eyes with chronic CSC was 24.7 ± 5.8 dB, which also was significantly different from the control eyes. Fixation stability was significantly different between the CSC and control eyes for the P1 parameter (90.1 ± 13.7 versus 99.3 ± 1.5), and for the P2 parameter (97.4 ± 4.0 versus 100.0 ± 0.0).

Conclusion

New microperimetry technology may provide valuable information regarding the visual status of chronic CSC cases. Our findings suggest that retinal sensitivity and fixation stability in chronic CSC eyes may serve as useful indicators for assessing the effectiveness of clinical treatments.

What is new in central serous chorioretinopathy?

Central serous chorioretinopathy (CSCR) is considered a benign, self-limiting disease. However, as many as third of the patients have recurrent episodes or chronic disease that may cause significant functional impairment. New diagnostic tools and new treatment modalities are emerging in order to improve the functional outcomes of these patients. Spectral domain optical coherence tomography (SD-OCT) has the ability to image individual layers of the retina and choroid. SD-OCT images in CSCR patients have demonstrated increased subfoveal thickness measurements, high reflective deposits in areas of subretinal precipitates and changes in the Retinal pigment epithelium layers of the asymptomatic eyes of patients with supposedly unilateral CSCR. A positive correlation was found between the level of distribution to the layer of inner segment/outer segment junction of the photoreceptors and the visual impairment. Fundus autoflouresence images show a wide variety during different stages of the disease in CSCR patients. Minimal abnormalities during the early stages are followed by hyperautofluoresence in the detached area in later stages, often in a manner of inferior gravitation and at the borders of the detachments. The chronic phase is characterized by varying degrees of atrophy and areas of decreased autofluorescence surrounding areas of chronic leaks. These changes help differentiate an active disease from an inactive state. Multifocal electroretinography (mfERG) has the ability to demonstrate a persistent depression despite the resolution of subretinal detachments. It is therefore being investigated as a follow up tool for patients with chronic CSCR. An excellent correlation was found between changes in mfERG and visual function. Macular microperimetry, measuring retinal sensitivity within the central visual field, is intended to compensate for the underestimation of visual impairment in patients with macular diseases. Reduced retinal sensitivity was found in areas of previous subretinal fluids in CSCR patients. The device can also serve as a follow up tool in these patients. Regarding treatment in CSCR patients, focal argon laser photocoagulation treatment may be applied to small extrafoveal leaks. However, the main purpose of this treatment is to shorten disease duration, with no advantage over observation regarding final visual outcome, rate of progression to chronic CSCR or number of recurrences. Photodynamic therapy (PDT) with verteporfin has been shown to completely resolve serous detachment in 60%-80% of patients and to have a partial affect in the remaining patients. Reduced-fluence treatment is replacing full-fluence therapy in order to minimize side effects with no accompanying reduced effectiveness. Visual acuity is also improved following reduced-fluence PDT compared to placebo. It has also been found that patients with intense hyperfluorescence are more likely to show resolution of accumulating fluid compared to patients with mild or no leakage observed on indocyanine-green angiography prior to treatment. Regarding newer treatment modalities, intravitreal injections of anti-vascular endothelial growth factor agents have a limited effect in patients with CSCR. Recent reports have not demonstrated an advantage for this treatment in regards to anatomic and functional outcome. Micropulse diode laser was not proven to be safer or more effective than argon laser or PDT. Corticosteroid antagonists, not tested in controlled trials, may have a beneficial effect in patients with CSCR. Aspirin may also play a role in treating these patients, with rapid recovery of visual acuity and reduced number of recurrences observed. In conclusion, imaging is evolving rapidly while the clinical implications of these new imaging modalities are less clear. Large randomized trials investigating different treatment modalities are still lacking.

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.

Electrophysiology and glaucoma: current status and future challenges

Visual electrophysiology allows non-invasive monitoring of the function of most processing stages along the visual pathway. Here, we consider which of the available methods provides the most information concerning glaucomatous optic nerve disease. The multifocal electroretinogram (ERG), although often employed, is less affected in glaucoma than two direct measurements of retinal ganglion cell function, namely the pattern ERG (PERG) and the photopic negative response (PhNR) of the ERG. For the PERG, longitudinal studies have been reported, suggesting that this method can be used for the early detection of glaucoma; for the PhNR, no longitudinal study is available as yet. The multifocal PERG can spatially resolve ganglion cell function but its glaucomatous reduction is typically panretinal, even with only local field changes and so, its topographic resolution is of no advantage in glaucoma. The multifocal visual evoked potential promises objective perimetry and shows sensitivity and specificity comparable with standard automated perimetry but has not been established as a routine tool to date.

An Update on the Diagnosis and Management of Central Serous Chorioretinopathy

Central serous chorioretinopathy (CSC) is a complicated disease with still unclear causes, pathogenesis and management strategy despite active research. CSC has been traditionally considered as a self-limiting disease where spontaneous recovery occurs in 90% of the patients within a few months. This proclaimed "benign" nature of CSC, however, has been queried by increasing scientific evidence that permanent photoreceptors damage and neurosensory-cystoid degeneration of macula occur in the event of chronic CSC. CSC is probably not a benign disease. Treatments for CSC are still evolving. It is very difficult to define the proper timing for active treatment of CSC because it is not easy to define a universally accepted cut-off time point for active intervention. There is a recent suggestion that active CSC treatment should be considered if symptoms last longer than 3 months as atrophy of photoreceptors may occur as early as 4 months after initial presentation. The CSC patients may be stratified into two groups based on the initial presenting visual acuity and duration of symptom: the good visual prognosis group and the dubious visual prognosis group. The management may then be tailor-made based on the visual prognosis group. "Safety-enhanced'" photodynamic therapy (PDT) using lower doses and reduced fluence is still the mainstay of treatment. Newer treatment modalities like intravitreal anti-VEGF therapy, micropulsed diode laser treatment, and the use of corticosteroid antagonists do warrant further investigation. Combination therapies involving two or more of the above modalities of treatments may have a role to play in this actively researched area.

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.

Correlation between functional and anatomical assessments by multifocal electroretinography and optical coherence tomography in central serous chorioretinopathy

To evaluate the correlation between functional and anatomical assessments with multifocal electroretinography (mfERG) and optical coherence tomography (OCT) in patients with acute central serous chorioretinopathy (CSC). Thirty-four eyes of 34 patients with acute CSC underwent mfERG and OCT examinations. First-order mfERG N1 and P1 response amplitudes and latencies were analyzed.OCT parameters measured included central subretinal fluid (SRF) thickness, central retinal thickness, total central foveal thickness, vertical, and horizontal diameters of SRF, and macular volume. Correlation analyses were performed between best-corrected visual acuity (BCVA), mfERG parameters, and OCT measurements. Correlation analysis showed that logMAR BCVA was significantly correlated with mfERG N1 amplitudes of rings 1 and 2 (P = 0.006), N1 latency of ring 4 (P = 0.012), and P1 latency of ring 1 (P = 0.036). No significant correlation was observed between logMAR BCVA and any of the OCT measurements. For the correlation between mfERG parameters and OCT measurements, mfERG N1 and P1 latencies of the paracentral rings were significantly correlated with the central SRF thickness (P < or = 0.024), diameters of the SRF (P < or = 0.018), and macular volume (P < or = 0.030). MfERG responses but not OCT measurements correlated with logMAR BCVA in patients with acute CSC. The amount of SRF nonetheless correlated with the mfERG N1 and P1 latencies of the paracentral rings, suggesting that impairment in the conduction of electrical responses in the paracentral macula is proportional to the severity of serous macular detachment in CSC. MfERG and OCT can complement each other in the functional and anatomical assessments in CSC.