Different transitions of multifocal electroretinogram recordings between patients with age-related macular degeneration and polypoidal choroidal vasculopathy after photodynamic therapy

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.

Transcranial Focused Ultrasound for Noninvasive Neuromodulation of the Visual Cortex

Currently, blindness cannot be cured and patients' living quality can be compromised severely. Ultrasonic (US) neuromodulation is a promising technology for the development of noninvasive cortical visual prosthesis. We investigated the feasibility of transcranial focused ultrasound (tFUS) for noninvasive stimulation of the visual cortex (VC) to develop improved visual prosthesis. tFUS was used to successfully evoke neural activities in the VC of both normal and retinal degenerate (RD) blind rats. Our results showed that blind rats showed more robust responses to ultrasound stimulation when compared with normal rats. ( , two-sample t-test). Three different types of ultrasound waveforms were used in the three experimental groups. Different types of cortical activities were observed when different US waveforms were used. In all rats, when stimulated with continuous ultrasound waves, only short-duration responses were observed at "US on and off" time points. In comparison, pulsed waves (PWs) evoked longer low-frequency responses. Testing different parameters of PWs showed that a pulse repetition frequency higher than 100 Hz is required to obtain the low-frequency responses. Based on the observed cortical activities, we inferred that acoustic radiation force (ARF) is the predominant physical mechanism of ultrasound neuromodulation.

Idiopathic polypoidal choroidal vasculopathy: a review of literature with clinical update on current management practices

PURPOSE

Polypoidal choroidal vasculopathy is a major cause of visual disability in a vast majority of Asian population due to exudative maculopathy. Although it is a distinctive disease entity with characteristic pathophysiology, genetics, immunology and clinical features, but it is still misdiagnosed as neovascular age related macular degeneration as both the diseases are a part of pachychoroid spectrum and have some similar features. Also, there are varied options for the management of this disease, but there are no clear recommendations. So, a detailed review of the literature has been done along with special attention to the recent therapeutic advances to help the readers get a better understanding of the disease and its current management practices.

METHOD

Detailed review of literature regarding polypoidal choroidal vasculopathy was done. The disease pathophysiology, genetics, risk factors, diagnostic modalities along with current treatment guidelines were extensively studied and compiled.

RESULT

A comprehensive clinical update on polypoidal choroidal vasculopathy was compiled with special emphasis on the recent diagnostic modalities and treatment guidelines.

CONCLUSION

Polypoidal choroidal vasculopathy is a distinct clinical entity which can be diagnosed based on indocyanine green angiography and optical coherence tomography. Treatment includes various options like photodynamic therapy, anti VEGF agents and thermal laser ablation. A review of literature has been done and recent diagnostic modalities with management practices have been compiled for the better understanding of the disease.

Polypoidal choroidal vasculopathy: Pearls in diagnosis and management

Polypoidal choroidal vasculopathy (PCV) is increasingly recognized as an important cause of exudative maculopathy in Asians as against Wet age-related macular degeneration in Caucasians. A panel of retinal experts methodically evaluated pertinent updated literature on PCV with thorough PubMed/MEDLINE search. Based on this, the panel agreed upon and proposed the current consensus recommendations in the diagnosis (clinical and imaging), management and follow-up schedule of PCV. Diagnosis of PCV should be based on the gold standard indocyanine green angiography which demonstrates early nodular hyperfluorescence signifying the polyp with additional features such as abnormal vascular network (AVN). Optical coherence tomography is an excellent adjuvant for diagnosing PCV, monitoring disease activity, and decision-making regarding the treatment. Current treatment modalities for PCV include photodynamic therapy, anti-vascular endothelial growth factor agents, and thermal laser. Choice of specific treatment modality and prognosis depends on multiple factors such as the location and size of PCV lesion, presence or absence of polyp with residual AVN, amount of submacular hemorrhage, presence or absence of leakage on fundus fluorescein angiography, visual acuity, and so on. Current recommendations would be invaluable for the treating physician in diagnosing PCV and in formulating the best possible individualized treatment strategy for optimal outcomes in PCV management.

Structure versus function: correlation between outer retinal and choroidal thicknesses measured by swept-source OCT with multifocal electroretinography and visual acuity

Background

To correlate retina-choroidal anatomy as assessed via swept-source OCT (SS-OCT) with retinal function as determined by best-corrected visual acuity (BCVA) and multifocal electroretinogram (mfERG).

Methods

Thirty-three eyes from 33 patients including 16 with neovascular AMD (nvAMD) and 17 controls were included. Patients were included in the present study after a complete ophthalmologic examination, including BCVA, slit-lamp study, intraocular pressure measurement, dilated fundus examination after tropicamide instillation, SD-OCT, SS-OCT, fundus photographs and mfERG. Age, sex, BCVA, number of anti-VEGF intravitreal injections in the nvAMD group, were recollected. Outer retinal and choroidal thickness were determined at the fovea and 500 μm temporal, superior, nasal and inferior. First-order response from mfERG was collected. P1 amplitude was recorded in R1, R2 and the average of R1 + R2. The measurements recollected from the SS-OCT, mfERG and BCVA were compared.

Results

Better BCVA was found with thicker outer retina foveal thickness (r = 0.349; P = 0.047), with thicker subfoveal choroidal thickness (r = 0.443; P = 0.010), and with higher amplitude in P1 at R1 (r = 0.346; P = 0.037). Outer retina foveal thickness did not correlate with P1 amplitude at R1 (r = 0.072; P = 0.692), R2 (r = 0.265; P = 0.137) either with the average P1 amplitude at R1 + R2 (r = 0.253; P = 0.156). A thicker subfoveal choroidal thickness was related with higher amplitude in P1 at R1 (r = 0.383; P = 0.028), R2 (r = 0.409; P = 0.018) and the average of R1 + R2 (r = 0.419; P = 0.015).

Conclusions

Choroidal thickness demonstrated a positive correlation with retinal function in the sample studied, so a thicker choroid is related to a better retinal function measured with mfERG and BCVA.

COL1A2 polymorphic markers confer an increased risk of neovascular age-related macular degeneration in a Han Chinese population

PURPOSE

We have previously documented that neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV) have multiple different clinical and genetic characteristics. In this study, we investigated the association of rs42524 in the alpha-2 type I collagen (COL1A2) gene, which has been identified as a risk variant for intracranial aneurysm, with nAMD and PCV in a Han Chinese population.

METHODS

The study prospectively recruited 195 patients with PCV, 136 patients with nAMD, and 181 control individuals. We genotyped the rs42524 polymorphism of COL1A2 using the Multiplex SNaPshot System and direct DNA sequencing. Genotype and allele frequencies were evaluated with PLINK software.

RESULTS

The rs42524 polymorphism was modestly significantly associated with nAMD [minor allele: G, p(allelic)=0.04253, odds ratio=0.5285 (95% confidence interval: 0.2832-0.9866)], but not with PCV [minor allele: G, p(allelic)=0.4164, odds ratio=1.2110 (95% confidence interval: 0.7631-1.9210)]. The pvalues for the additive model were significant for nAMD but not for the dominant or recessive models. None of the models for PCV were statistically significant. The size of our sample cohort resulted in a post hoc power of more than 80% to detect associations of rs42524 with nAMD and PCV.

CONCLUSIONS

The rs42524 polymorphism is a risk allele for nAMD in a Han Chinese population. rs42524 in COL1A2 confers different levels of susceptibility to nAMD and PCV.

Combination therapy with focal laser photocoagulation and intravitreal ranibizumab for polypoidal choroidal vasculopathy: a case series

PURPOSE

The study aim is to describe the clinical outcomes of patients with polypoidal choroidal vasculopathy (PCV) treated with focal argon laser photocoagulation and ranibizumab combination therapy.

METHODS

This study is a retrospective case series of 6 patients (6 eyes) diagnosed with PCV who received combination therapy with argon laser photocoagulation and ranibizumab and have at least 12 months follow-up. Argon laser photocoagulation was applied directly to the polypoidal lesions as identified on indocyanine green angiography and followed by a course of intravitreal ranibizumab injections. The primary outcome measures were the mean change in logMAR visual acuity and the mean change in central macular thickness (CMT) at final follow-up.

RESULTS

The mean (SD) duration of follow-up was 1.09 (0.22) years. At the final follow-up the difference (95% confidence interval [CI]) in logMAR acuity was 0.48 (0.10-0.74) (p=0.01) and the difference (95% CI) in CMT was 207 µm (35-490) (p=0.02) on optical coherence tomography. The mean (SD) number of ranibizumab injections per eye was 4.83 (3.6). The mean (SD) number of laser treatments per eye was 1.16 (0.4).

CONCLUSIONS

In this study, combination therapy with focal argon laser photocoagulation and intravitreal ranibizumab resulted in improved visual acuity and clinical outcomes for patients with PCV for up to 1 year.

Multifocal electroretinograms in age-related macular degeneration before and after photodynamic therapy

Purpose

To evaluate multifocal electroretinograms (mfERG) and macular retinal thickness before and after photodynamic therapy (PDT) for predominantly classic choroidal neovascularization (CNV) (classic type) and occult with no classic CNV (occult type).

Methods

Recording of mfERG and measurement of macular retinal thickness were performed before and after PDT in 19 patients (19 eyes) with the classic type and 24 (26 eyes) with the occult type. The evaluation items were the amplitude of the first negative wave (N1), the amplitude from the peak of the negative wave to that of the following positive wave (P1), and the peak latencies of the negative and positive waves.

Results

Compared with mfERG before PDT, that after PDT showed a significant decrease in the P1 latency in the central area (31.1±1.9 ms before and 29.6±1.6 ms after PDT) for the classic type and significant decreases in both the central (32.0±2.0 ms before and 30.5±2.4 ms after PDT) and peripheral (30.2±2.0 ms before and 29.5±2.0 ms after PDT) areas for the occult type. Optical coherence tomography showed significant decreases in macular retinal thickness in both groups (464 and 314 μm before and after PDT, respectively, for the classic type and 516 and 340 μm for the occult type).

Conclusions

After PDT, retinal function evaluated by mfERG improved for both the classic and occult types, and the recovery of P1 latency may be due to improvement in retinal edema.

Polypoidal choroidal vasculopathy: a review

More than a quarter century has passed since the original description of polypoidal choroidal vasculopathy (PCV) in 1982 as a peculiar hemorrhagic disorder involving the macula characterized by recurrent subretinal pigment epithelial bleeding. In the ensuing years, numerous reports have described the expanded clinical spectrum of this entity. PCV is the principal vascular composition of patients of pigmented races experiencing neovascular maculopathies, particularly African Americans and Asians. This form of neovascularization is now known to occur in white patients with or without concomitant drusen, and the site of involvement has extended from the peripapillary area to the peripheral fundus. Indocyanine green angiography has made detection of these abnormal vascular changes more reliable and definitive. More precise diagnosis has also led to a better understanding of specific clinical features that distinguish PCV from more typical proliferations of abnormal choroidal vessels. We review the nature of PCV, including its genetic basis, demographic features, histopathology, clinical manifestations, natural course, response to treatments, and the histopathological and genetic bases. We emphasize multimodal ophthalmic imaging of these vessels, in particular fluorescein and indocyanine green angiography and optical coherence tomography.

Transitions of multifocal electroretinography in patients with age-related macular degeneration after combination therapy with photodynamic therapy and intravitreal bevacizumab

To compare the differences in color Doppler imaging (CDI) and pattern visual evoked potential (P-VEP) examinations between normal tension glaucoma (NTG) and hypertension primary open angle glaucoma (HTG) patients, and investigate the relation between flow velocities measured by CDI and P-VEP examination in NTG and HTG patients. Sixty NTG patients, 66 HTG patients and 44 control subjects underwent CDI evaluation of the ophthalmic artery (OA), short posterior ciliary artery (SPCA) and central retinal arteries (CRA). The peak systolic velocities (PSV) and end-diastolic velocities (EDV) and resistive index (RI) of all retrobulbar vessels were measured. The latency and amplitude of P100 in P-VEP were recorded from the three groups. The differences of CDI and P-VEP parameters among NTG group, HTG group and control group were compared by one-way analysis of variance. The correlations between CDI parameters and visual field indices, P-VEP and visual field indices, P-VEP and CDI parameters in NTG and HTG patients were evaluated by Pearson's correlation analysis. NTG and HTG patients had the lower EDV and higher RI in the OA, CRA and SPCA comparing with that of control subjects. NTG and HTG patients also had lower PSV in OA and CRA comparing with that of control subjects. There was no significant difference in the blood flow velocities and RI of all retrobulbar vessels between NTG and HTG patients. The latency of P100 in VEP delayed and the amplitude of P100 decreased in the NTG and HTG patients comparing with that of the control group. There was no significant difference in the latency and amplitude of P100 between the NTG and HTG patients. The RI of OA and SPCA were negatively correlated with the mean deviation (MD) values in the NTG and HTG patients. The RI of OA was positively correlated with the PSD value in the NTG and HTG patients. The MD values in the NTG and HTG patients were negatively correlated with the latency time of P100. The RI of OA was positively correlated with the latency time of P100 in NTG and HTG patients. The RI of OA was negatively correlated with the amplitude of P100 in HTG patients. No significant difference was found in the parameters of CDI and P-VEP between NTG and HTG patients. The certain parameters of CDI were correlated with P-VEP parameters in NTG and HTG patients.

Polypoidal choroidal vasculopathy: an angiographic discussion

The understanding of polypoidal choroidal vasculopathy has evolved rapidly in the past three decades. The hallmark of the disease is the presence of typical hyperfluorescent nodules in the early phase of indocyanine green angiography. Although the classical clinical presentation is recurrent serosanguinous detachment of the retinal pigment epithelium, it may present with clinical features indistinguishable from exudative age-related macular degeneration secondary to choroidal neovascularization. Some cases may present initially with submacular haemorrhage, but later with features of exudative age-related macular degeneration. Studying the associated network of vessels using confocal scanning laser ophthalmoscopy indocyanine green dynamic angiography revealed in many cases feeder vessels, branching pattern, and leakage similar to choroidal neovascularization. Owing to the overlap of clinical and angiographic features, it may be considered as a vascular subtype of exudative age-related macular degeneration. However, having seemingly better natural history, better response to photodynamic therapy, and incomplete response to anti-vascular endothelial growth factor therapy suggests that it should be studied as a separate entity from choroidal neovascularization. Combining angio-occlusion of the polyps using photodynamic therapy and anti-permeability effect of anti-vascular endothelial growth factor therapy on the branching vascular network may provide a synergistic effect. We await the result of EVEREST trial, a multi-centre randomized controlled trial comparing photodynamic therapy, with or without ranibizumab, with ranibizumab monotherapy.

Polypoidal choroidal vasculopathy and treatments

PURPOSE OF REVIEW

This review assesses the current knowledge of the clinical characteristics of polypoidal choroidal vasculopathy and treatments.

RECENT FINDINGS

Polypoidal choroidal vasculopathy is a disease with characteristic choroidal vascular abnormalities. Indocyanine green angiography is essential for diagnosis. The prevalence is higher in Asian people than in Caucasians. Photodynamic therapy is efficacious for treating polypoidal choroidal vasculopathy; 1-year results have shown greater benefit of photodynamic therapy than choroidal neovascularization secondary to age-related macular degeneration. Recurrence, however, seriously affects vision long term during follow-up after photodynamic therapy. The lower efficacy of bevacizumab- a full-length antibody of vascular endothelial growth factor- has been shown for polypoidal choroidal vasculopathy.

SUMMARY

Although the polypoidal choroidal vasculopathy and age-related macular degeneration have been known to share common genetic factors, its clinical characteristics including the different responses to photodynamic therapy suggest that polypoidal choroidal vasculopathy is a separate clinical entity from age-related macular degeneration. The results of photodynamic therapy for polypoidal choroidal vasculopathy are encouraging; however, recurrence may affect vision over time. Therapeutic modalities to inhibit development of the exudative choroidal vasculature of polypoidal choroidal vasculopathy are desirable.

Central retinal sensitivity measured with the micro perimeter 1 after photodynamic therapy for polypoidal choroidal vasculopathy

PURPOSE

To evaluate central retinal sensitivity and its relation to the symptomatic change noted in central visual disturbance shortly after photodynamic therapy (PDT) in eyes with polypoidal choroidal vasculopathy (PCV).

DESIGN

Retrospective interventional case series.

METHODS

We reviewed retrospectively 20 eyes of 20 patients who underwent PDT for the treatment of subfoveal PCV. Microperimetry in the macular area was performed with Micro Perimeter 1 (MP1) [Nidek, Vigonza, Italy] before and at one, three, and six months after PDT. Forty measurement points were located within the central 10 degree of the macula.

RESULTS

After PDT, although most eyes showed a reduction in exudation, the mean posttreatment visual acuity did not change significantly. At one month after PDT, however, retinal sensitivities within the central 2 degree, 6 degree, and 10 degree fields, which were 3.6 +/- 3.1, 5.1 +/- 3.4, and 6.2 +/- 3.6 dB [decibels] at baseline, improved to 5.9 +/- 3.8 (P = .003), 7.1 +/- 3.6 (P = .003), and 8.1 +/- 3.5 dB (P = .004). At one month after treatment, 14 patients (70%) noted subjective improvement of the central visual disturbance and mean retinal sensitivity within the central 2 degree, 6 degree, and 10 degree fields had improved more than 2 dB in 11, 10, and eight eyes, respectively. At three and six months after PDT, however, postoperative improvement of the retinal sensitivities was diminished.

CONCLUSIONS

Retinal sensitivity in the macular area of eyes with subfoveal PCV improved shortly after PDT, and may account, at least in part, for the immediate subjective improvement in central vision after PDT.