Transient reduction in retinal function revealed by multifocal electroretinogram after photodynamic therapy

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.

Comparison of efficacy and safety between half-fluence and full-fluence photodynamic therapy for chronic central serous chorioretinopathy

PURPOSE

To compare the efficacy and safety of half-fluence photodynamic therapy (PDT) and conventional PDT in chronic central serous chorioretinopathy.

METHODS

A multicenter retrospective comparison study. Retrospective review of 60 patients including 29 patients (34 eyes) who received half-fluence PDT and 31 patients (33 eyes) who received conventional PDT for the treatment of chronic central serous chorioretinopathy. Best-corrected visual acuity, central fovea retinal thickness and resolution of subretinal fluid on optical coherence tomography, and choroidal perfusion decrease on indocyanine green angiography were assessed. Choriocapillaris perfusion decrease was quantified as mean gray value ratio of treated and nontreated areas using commercial imaging software.

RESULTS

Treatment success without recurrence was achieved in 32 of 34 eyes (94.1%) treated with half-fluence PDT and 33 of 33 eyes (100%) treated with conventional PDT (P = 0.493). There was no difference in final best-corrected visual acuity (logarithm of the minimal angle of resolution) between the 2 groups (0.17 ± 0.32 vs. 0.21 ± 0.39; P = 0.603). Choriocapillaris perfusion decrease quantified from post-PDT indocyanine green angiography was significantly more severe in the conventional PDT group (P = 0.006), and it showed a positive correlation with retinal thinning after PDT (R = 0.380; P < 0.001).

CONCLUSION

Half-fluence PDT is as effective as conventional PDT, while minimizing the deleterious effect on choriocapillaris perfusion and retinal thickness.

Fluorescein angiography-guided photodynamic therapy with half-dose verteporfin for chronic central serous chorioretinopathy

PURPOSE

The purpose of this study was to evaluate the results of fluorescein angiography-guided photodynamic therapy with half-dose verteporfin in the treatment of chronic central serous chorioretinopathy with focal leakage areas.

METHODS

Eight cases with a history of central serous chorioretinopathy of ≥6 months were included. All eyes had one or more focal areas of active retinal pigment epithelial leak. Photodynamic therapy was applied with half-dose verteporfin (3 mg/m²), and the spot size was set limited to the area of active leakage shown on fluorescein angiography.

RESULTS

The mean duration of the last central serous chorioretinopathy episode was 12.50 months. The mean best-corrected visual acuity improved from 20/122 to 20/60 the first month (P = 0.017) and to 20/55 the first year after treatment (P = 0.018). Seven eyes (87.5%) had improved vision 1 year after treatment, and 1 eye (12.5%) had stable vision with a mean number of 3.61 gained lines. The mean central macular thickness was reduced from 366 ± 95 μm to 217 ± 32 μm the first month (P = 0.006).

CONCLUSION

Fluorescein angiography-guided photodynamic therapy with half-dose verteporfin seems to be a rational and effective alternative to other methods in the treatment of chronic central serous chorioretinopathy with focal leakage on fluorescein angiography.

Focal macular electroretinograms after photodynamic therapy combined with intravitreal bevacizumab

BACKGROUND

Retinal function is transiently depressed after photodynamic therapy (PDT) alone. One of the reasons for this functional impairment is a reduction of choroidal circulation caused by the PDT. The purpose of this study was to determine whether PDT combined with intravitreal bevacizumab (PDT+IVB) can reduce or prevent the transient impaired macular function. In addition, we examined whether a significant correlation existed between the changes in the focal macular electroretinograms (FMERGs), optical coherence tomography (OCT)-determined morphology, and changes in choroidal circulation.

METHODS

Thirty-eight eyes that were treated by full fluence PDT+IVB were studied. FMERGs, OCT, and indocyanine green angiography (ICGA) were performed before and after the PDT. The intensity of the diffuse fluorescence within the PDT site was measured by densitometry (I/N ratio).

RESULTS

The macula was significantly thinner 1 week after PDT+IVB (P < 0.01). The mean a- and b-wave amplitudes of the FMERGs were not significantly decreased 1 week after PDT+IVB. The mean b-wave amplitudes 3 months after PDT+IVB were significantly increased (P < 0.01). The I/N ratio of ICGA 3 months after PDT+IVB was 0.88 ± 0.1. The correlation between the FMERGs and I/N ratio was not significant.

CONCLUSION

The use of IVB with PDT mitigates the reduction of the FMERGs and reduces the macular thickness soon after PDT, regardless of the degree of impairment of choroidal circulation caused by PDT. Finally, the macular retinal function 3 months after PDT+IVB were better than that before the treatment.

Combined photodynamic therapy and intravitreal bevacizumab for idiopathic polypoidal choroidal vasculopathy: one-year follow-up

OBJECTIVE

To report the efficacy and safety of combined photodynamic therapy (PDT) and intravitreal bevacizumab (IVB) injection in the treatment of idiopathic polypoidal choroidal vasculopathy (IPCV).

MATERIAL AND METHODS

A prospective case series of 10 eyes of 10 consecutive patients affected by IPCV with subfoveal involvement. PDT plus IVB (1.25 mg/0.05 mL) injection two weeks later was performed in all patients. Two adjunctive injections of bevacizumab were scheduled at four and eight weeks after the initial treatment. Best-corrected visual acuity (BCVA), fluorescein and indocyanine green angiographies, and optical coherence tomography were obtained at baseline, and at one, three, six, nine, and 12 months.

RESULTS

The combined treatment led to an improvement of both neurosensory detachment and pigmented epithelial detachment in all eyes, with a decrease of exudation and regression of macular thickness, which remained stable to the end of follow-up. However, BCVA remained stable over the 12 months of follow-up.

CONCLUSION

These findings demonstrate that PDT/IVB combined therapy is able to achieve morphologic stabilization of the IPCV lesion, through a rapid decrease of macular thickness and regression of the size of polypoidal vascular lesion.

Central serous chorioretinopathy: an update on pathogenesis and treatment

Central serous chorioretinopathy (CSC) is a chorioretinal disease, incompletely understood with systemic associations, a multifactorial aetiology, and a complex pathogenesis. Increased permeability from the choriocapillaris leads to focal or diffuse dysfunction of the retinal pigment epithelium causing a detachment of the neurosensory retina. CSC has been described in patients with endogenously high levels of corticosteroids as well as in patients with hypercortisolism due to the treatment of ocular or systemic diseases. It is therefore the only 'inflammatory' choroiditis, not proven to be associated with infection that is precipitated or worsened by glucocorticoids. Foveal attenuation, chronic macular oedema, and damage of the foveal photoreceptor layer have been reported as causes of visual loss in CSC. Photoreceptor atrophy in the fovea, despite successful retinal reattachment, typically occurs after a duration of symptoms of approximately 4 months. Treatment should therefore be considered after 3 months if there is angiographic evidence of ongoing foveal leakage in recurrent chronic CSC or in a single CSC episode accompanied by signs of chronic CSC alterations. Based on results of trials conducted so far, it appears that photodynamic therapy with verteporfin is effective and safer than argon laser treatment and should be considered as the treatment of choice, whereas micropulse diode laser photocoagulation seems to be an effective alternative. Glucocorticoid inhibitors are an interesting alternative treatment. Clinical trials are ongoing to test their efficacy. In addition, it is important, where possible, to discontinue any corticosteroid treatment. The possible association of CSC with stress should also be discussed with patients.

Development and recovery of laser-induced retinal lesion in rats

PURPOSE

Laser-induced retinal lesions undergo primary and secondary degeneration followed by a partial reduction of the lesion size. To evaluate treatment effects, detailed data regarding the changes of the lesion over time are essential. The purpose of the study is to describe the histologic changes in an argon laser-induced retinal lesion over a period of 60 days.

METHODS

Argon laser lesions were produced in retinas of pigmented rats. The lesions were examined by light microscopy 1 hour and 1, 2, 3, 20, and 60 days after the exposure.

RESULTS

The diameter of the lesion increased 24 hours after photocoagulation and then decreased by day 20. Most pyknotic nuclei seen in the outer nuclear layer 1 hour after lasering disappeared 3 days later. Remodeling began 3 days after lasering. By day 60, partial filling in of the empty area with sliding of adjacent nuclei was observed. Recovery was also seen in the other retinal layers.

CONCLUSION

The course of a laser-induced retinal lesion is gradual: the photoreceptors are damaged first and the damage then spreads to other layers and to the adjacent retina. By day 3, the damage spreading stops, and adjacent cells begin to fill in and remodel the area of the lesion.

Development of novel drugs for ocular diseases: possibilities for individualized therapy

In clinical ophthalmology, new and old drug regimens are available for the treatment of major eye diseases, including potentially blinding conditions, such as glaucoma, and various macular diseases. In glaucoma, therapeutic treatment mainly deals with control of intraocular pressure at low levels but the clinical courses of patients can be very variable. Very often, specific drug combinations and dosages have to be formulated for individual glaucoma patients. In neovascular age-related macular degeneration, choroidal neovascularization can lead to progressive and irreversible visual impairment if not treated early. In recent years, clinical trials using photodynamic therapy with verteporfin and various anti-VEGF antibodies, such as ranibizumab and bevacizumab, have enhanced the treatment outcomes of neovascular age-related macular degeneration. In diabetic macular edema, intravitreal triamcinolone acetonide and anti-VEGF therapy are effective in some patients. Again, responses to treatment are not uniform in all macular patients. Traditional herbal medicine has long been known to play a role in the practice of personalized formulations in Asia. Potential preventive and therapeutic effects have been claimed in individual eye patients. Meanwhile, advanced technologies in molecular biology have led to identification of genes associated with many eye diseases and development of the concept of individual medicine, in which the genotype of a person can be used as a basis for disease prediction or prophylactic treatments. Moreover, pharmacogenomic studies have demonstrated the association of various genotypes or haplotypes with responses to drug therapies, providing hope for tailormade personalized treatments. The combination of genotypic information with clinical features for the prescription of treatment modes in eye diseases is under vigorous research.

Photodynamic therapy with or without intravitreal triamcinolone acetonide for symptomatic polypoidal choroidal vasculopathy

PURPOSE

To evaluate the outcome of verteporfin photodynamic therapy (PDT) with or without intravitreal triamcinolone acetonide (IVTA) for the treatment of symptomatic polypoidal choroidal vasculopathy (PCV).

METHODS

Retrospective analysis of PCV patients who underwent PDT with or without IVTA with follow-up of 2 or more years. Changes in best-corrected visual acuity (BCVA), proportion of eyes with moderate visual loss (3 or more lines), and complications were compared between patients with or without IVTA.

RESULTS

Twenty-seven eyes of 27 patients were analyzed, with 12 eyes treated by PDT monotherapy and 15 eyes treated by combined PDT with IVTA. The baseline characteristics of both groups were similar. At 1 year, the mean logMAR BCVA for the PDT monotherapy group improved from 0.74 to 0.58 (P = 0.011), whereas the combined PDT and IVTA group improved from 0.84 to 0.74 (P = 0.17). At 2 years, the mean logMAR BCVA for the monotherapy and combined treatment groups were 0.62 and 0.84, respectively, and the changes compared with baseline were not statistically significant. No significant difference was found in the mean logMAR BCVA, the mean line of visual changes, and the mean number of PDT treatments between the 2 groups at 1 and 2 years. One (8.3%) and 4 (26.7%) eyes in the monotherapy and the combined groups lost 3 or more lines at 2 years, respectively. Patients who had combined PDT with IVTA were more likely to develop cataract requiring surgery and ocular hypertension (P = 0.043 and 0.046, respectively).

CONCLUSIONS

PDT reduced the risks of visual loss in patients with symptomatic PCV in the short term but the effect might not be sustained after 1 year. The adjunctive use of IVTA during PDT did not appear to result in additional benefit for treating PCV.

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.

The electroretinogram: a useful tool for evaluating age-related macular disease?

With an ageing population, the number of age-related macular disease (ARMD) cases will inevitably rise. This gives greater impetus for the need to identify the disease earlier and assess treatments to slow disease progression. Differing electroretinogram (ERG) modalities have been reviewed in relation to the objective assessment of retinal function in ARMD and for monitoring the effectiveness of clinical interventions. Conflicting results have been found with regard to the efficacy of ERG findings in the investigation of ARMD in previous years. The newer multifocal ERG paradigm provides spatial topographical information about retinal function in ARMD. It has shown promising results in monitoring effectiveness of clinical interventions and studies are continuing in this area. Better knowledge of retinal function in ARMD may lead to enhanced treatments at each phase of the disease.

Standard-fluence versus low-fluence photodynamic therapy in chronic central serous chorioretinopathy: a nonrandomized clinical trial

PURPOSE

To evaluate the efficacy of low-fluence compared with standard-fluence rate photodynamic therapy (PDT) for treating chronic central serous chorioretinopathy.

DESIGN

Prospective, multicenter, investigator-masked, nonrandomized clinical trial.

METHODS

Forty-two eyes (42 patients) with chronic central serous chorioretinopathy were enrolled; 19 eyes received indocyanine green angiography-guided standard-fluence PDT (50 J/cm(2)) and 23 eyes received indocyanine green angiography-guided low-fluence PDT (25 J/cm(2)). Primary outcome measures were the changes in mean logarithm of the minimal angle of resolution best-corrected visual acuity and the rate of eyes with complete subretinal fluid reabsorption. Secondary outcomes were the changes in central foveal thickness and choroidal perfusion.

RESULTS

Mean logarithm of the minimal angle of resolution best-corrected visual acuity improved significantly at all time points (P < .01), in the standard-fluence group from 0.43 to 0.24 at 12 months and in the low-fluence-group from 0.46 to 0.16, without significant difference between the 2 groups. At 12 months, a complete subretinal fluid reabsorption was seen in 15 standard-fluence-treated and 21 low-fluence-treated eyes (79% vs 91%; P = .5). In 1 standard-fluence eye, choroidal neovascularization developed at 3 months, and this eye received further PDT; in the other eyes, at 12 months, a moderate-significant choriocapillaris nonperfusion was seen in 8 standard-fluence-treated and 0 low-fluence-treated eyes (44% vs 0%; P = .002).

CONCLUSIONS

In most of the eyes, both standard-fluence PDT and low-fluence PDT resulted in complete subretinal fluid reabsorption with visual acuity improvement. Choroidal hypoperfusion related to PDT could be reduced by low-fluence PDT.

Focal macular electroretinograms after photodynamic therapy combined with posterior juxtascleral triamcinolone acetonide

PURPOSE

Retinal function is commonly depressed transiently after photodynamic therapy (PDT). Additional treatment may prevent this impaired retinal function. The purpose of this study was to determine the changes in the focal macular electroretinograms (FMERGs) after PDT combined with TA for age-related macular degeneration.

METHODS

Thirty-four eyes that were successfully treated by PDT with a posterior juxtascleral injection of TA were studied. FMERGs, optical coherence tomography, and indocyanine green angiography were performed before and after the PDT.

RESULTS

The mean amplitudes of the FMERGs were not significantly decreased 1 week after PDT with TA (P > 0.05). The mean ratio of the FMERG b-wave 1 week after PDT to that before PDT was 1.09, with an indistinct hypofluorescence at the site of the PDT (18 eyes), and the ratio was 0.91 in the eyes with a distinct hypofluorescence border (16 eyes; P < 0.05).

CONCLUSION

The combined use of TA with PDT mitigated the depression of retinal function soon after PDT. However, there were cases of severe choroidal hypoperfusion corresponding to the site of the laser spot that impaired retinal function in comparison to cases with mild hypoperfusion. Even with severe choroidal hypoperfusion, the deterioration in retinal function was relatively mild, with the b-wave FMERG reduced by only 10%.

Photodynamic therapy with verteporfin in age-related macular degeneration: a systematic review of efficacy, safety, treatment modifications and pharmacoeconomic properties

Photodynamic therapy (PDT) with verteporfin has been used less comprehensively in the treatment of exudative age-related macular degeneration (AMD), and specifically of choroidal neovascularization (CNV), since the advent of antiangiogenic therapies. Recently, there has been a renewed interest in PDT as an adjunct to these and other agents in the treatment of neovascular AMD. In light of this new development and the European Medicines Evaluation Agency's (EMEA) recent labelling decision to rescind approval for the use of PDT in occult CNV lesions, the present systematic review was undertaken to revisit the evidence supporting its clinical application. Photodynamic therapy provided the first pharmacological treatment for patients suffering from subfoveal CNV, the major cause of severe vision loss in AMD. Key clinical trials evaluating efficacy and safety have examined patients with all lesion subtypes, with the primary labelled indication (i.e. lesions containing a classic component of > or = 50% ) deriving from the results of the Treatment of Age-related Macular Degeneration with Photodynamic Therapy (TAP) Study. The subsequent TAP Study Group post hoc categorization of lesions as predominantly classic is open to question, however, as it appears that the overall efficacy in this group only may have reflected the especially strong response in 100% classic lesions. Based on a subgroup analysis of the Verteporfin in Photodynamic Therapy Study, the indication for PDT subsequently was expanded in some jurisdictions, including that of the EMEA, to include occult lesions with no classic component. However, the subsequent Visudyne in Occult Study found no benefit in 100% occult lesions, resulting in the EMEA rescinding its approval for this indication.

The prognosis of cases with massive subretinal hemorrhage after photodynamic therapy

PURPOSE

To investigate cases with massive subretinal hemorrhage after photodynamic therapy (PDT).

SUBJECTS AND METHODS

We studied four cases (3 men and 1 woman, mean 80.5 years old) with massive subretinal hemorrhage after PDT about type of disease, spot size, period to the onset of hemorrhage, visual acuity (VA) before and after PDT.

RESULTS

Four cases consisted of one with age-related macula degeneration (AMD) and 3 with polypoidal choroidal vasculopathy (PCV). The average spot size of PDT was 5525microm. Two patients underwent the second PDT about 3 months after the initial PDT. Four periods to the onset of hemorrhage were 22, 27, 137, and 208 days respectively. The latter 2 cases underwent PDT twice, and the periods were the days from the initial PDT. Two patients among four underwent vitrectomy. Average VA before PDT was 0.20, and the final one was 0.02 after PDT.

CONCLUSIONS

PDT has a risk to cause massive subretinal hemorrhage leading to grave visual disturbance. Especially PDT for PCV seems to have more risk. Therefore we need to inform patients about the risk before PDT, since treating patients with massive subretinal hemorrhage is very difficult.

Half-dose verteporfin photodynamic therapy for acute central serous chorioretinopathy: one-year results of a randomized controlled trial

OBJECTIVE

To evaluate the efficacy of photodynamic therapy (PDT) with half-dose verteporfin for treating acute central serous chorioretinopathy (CSC).

DESIGN

Prospective, double-masked, placebo-controlled, randomized clinical trial.

PARTICIPANTS AND CONTROLS

Sixty-three eyes of 63 patients with acute symptomatic CSC of 3 months' duration or less were recruited. Forty-three eyes were randomized to indocyanine green angiography (ICGA)-guided PDT with half-dose (3 mg/m(2)) verteporfin and 21 eyes were randomized to placebo.

INTERVENTION

Patients in the verteporfin group received an infusion of half-dose verteporfin over 8 minutes, followed by ICGA-guided PDT 10 minutes from the start of infusion. Laser was applied for 83 seconds covering the choroidal abnormalities observed in ICGA, with a maximum laser spot size of 4500 mum.

MAIN OUTCOME MEASURES

The primary outcome measure was the proportion of eyes with absence of subretinal fluid at the macula at 12 months. Secondary outcome measures included changes in mean logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA), subjective symptoms, optical coherence tomography (OCT) results, central foveal thickness (CFT), and angiographic findings during the 12-month study period.

RESULTS

Thirty-nine patients in the verteporfin group and 19 patients in the placebo group completed 12 months of follow-up. Thirty-seven (94.9%) eyes in the verteporfin group compared with 11 (57.9%) eyes in the placebo group showed absence of subretinal fluid at the macula at 12 months (P = 0.001). The mean logMAR BCVA at 12 months was significantly better in the verteporfin group compared with the placebo group: -0.05 and 0.05, respectively (P = 0.008). All 39 (100%) verteporfin-treated eyes had stable or improved vision, compared with 15 (78.9%) eyes in the placebo group (P = 0.009). The mean OCT CFT for the verteporfin group also was significantly lower compared with the placebo group at 12 months (P = 0.001). No ocular or systemic adverse event was encountered in the study.

CONCLUSIONS

Photodynamic therapy with half-dose verteporfin is effective in treating acute symptomatic CSC, resulting in a higher proportion of patients with absence of exudative macular detachment and better visual acuity compared with placebo.

Use of intravitreal injection of triamcinolone acetonide in the treatment of age-related macular degeneration

Age-related macular degeneration (AMD) is now considered an important and leading cause of blindness among elderly patients in developed and developing countries. AMD has two forms, dry and wet; both can lead to visual loss. However, occurrence of subfoveal choroidal neovascular (CNV) membrane in the wet form results in severe visual impairment.

Treatment options for choroidal neovascularization are available in order to maintain and in some cases improve vision. Photodynamic therapy (PDT) has been used to treat both classic and occult membranes. It has known to cause choroidal hypoperfusion and production of vascular endothelial growth factor.

Intravitreal steroid can possibly reduce the damage caused due to these undesirable effects. In the recent past, intravitreal injection of triamcinolone acetonide (IVTA) has been used extensively as an adjunct to PDT in AMD in order to reduce the number of PDT sessions and evaluate possible beneficial effects on vision.

This article reviews the pharmacological attributes of triamcinolone, available evidence of its use as monotherapy or combination therapy to treat AMD, ocular side-effects thereof and ongoing clinical trials on IVTA.

Deficits in the electroretinogram in neovascular age-related macular degeneration and changes during photodynamic therapy

PURPOSE

To describe the deficits in four electroretinography (ERG) modalities in patients with neovascular age-related macular degeneration (AMD). To describe the changes in these parameters during a course of verteporfin photodynamic therapy (PDT).

METHODS

Pattern (PERG), multifocal (mfERG) (19 segment simplified test protocol), flash ERG and flicker ERG were performed in patients with active neovascular AMD before PDT and compared to fellow eye controls using paired t-tests. Changes in ERG parameters during the 12 month treatment course were visualised using 95% confidence intervals of the median difference. The statistical significance of any changes was quantified using Wilcoxon signed ranks tests.

RESULTS

Fifty patients were recruited and followed. At presentation all ERG amplitudes were reduced with greater reductions in focal as opposed to global test protocols (P < 0.05). Over the 12 month course of PDT, PERG P50 amplitude showed a general downward trend and latency remained unchanged. mfERG p1 amplitude density showed an upward trend at six months before returning to baseline by 12 months. mfERG ring 2 amplitude density was significantly increased at 12 months compared to baseline (P = 0.010). Flicker ERG latency was significantly increased at six months compared to baseline (P = 0.015).

DISCUSSION

The simplified mfERG protocol was tolerated by this patient group, however, they found the full test protocol demanding. Large deficits in the retinal ERG function occur in neovascular AMD and involve retinal locations adjacent to as well as overlying choroidal neovascularisation (CNV). After PDT there is an improvement in electro-retinal function in retinal locations overlying the CNV.

Indocyanine green angiography: guided photodynamic therapy for polypoidal choroidal vasculopathy

PURPOSE

To report the 12-month follow-up results of subfoveal polypoidal choroidal vasculopathy (PCV) patients treated with indocyanine green angiography (ICGA)-guided photodynamic therapy (PDT).

DESIGN

Interventional, noncomparative cases series.

METHODS

A retrospective analysis of the clinical and angiographic data related to 47 PCV eyes that were followed up for 12 months was carried out. The greatest linear dimension (GLD) for PDT was determined based on the ICGA findings. Optical coherence tomography (OCT) also was used to evaluate the therapeutic effects.

RESULTS

The mean logarithm of the minimum angle of resolution visual acuity (VA; 0.58 +/- 0.37) significantly improved to 0.53 +/- 0.38 at three months (P = .04) and to 0.46 +/- 0.40 at 12 months (P = .02). The average ICGA GLD (2682.3 +/- 1026.9 mm) was significantly (P = .0001) smaller than the presumed fluorescein angiography (FA) GLD (4043.6 +/- 1914.8 mm). In more than 80% of cases, complete resolution of retinal exudative changes was observed. Although polypoidal vascular lesions disappeared in 82.2% of eyes, the branched vascular networks showed little change. The initial VA and GLD had little correlation with the VA outcome.

CONCLUSIONS

ICGA-guided PDT reduces the size of laser exposure and is an effective treatment for PCV. Because PCV may appear as occult choroidal neovascularization (CNV) on FA, PCV should be diagnosed using ICGA before treatment because PCV may respond differently than CNV to appropriate treatment.

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.

Functional deficits resulting from laser-induced damage in the rat retina

BACKGROUND AND OBJECTIVES

To determine the threshold for electrophysiological detection of functional changes after laser photocoagulation in rats, and to correlate the functional damage with retinal morphology.

STUDY DESIGN/MATERIALS AND METHODS

Argon-laser lesions, covering a quarter or half of the retina, were produced in the right eyes of 25 rats. Eyes were evaluated by flash electroretinography (ERG) and histologically at 3, 21, and 60 days after lasering.

RESULTS

Lasering of half the retina, but not of a quarter, produced a significant decrease in signals at all time points. Some functional recovery was evident 60 days after injury, and was consistent with concurrent morphological healing.

CONCLUSIONS

In rats, lasering of half the retina, but not a quarter, leads to significant deficits in outer retinal functions over a 2-month period. Thereafter some recovery occurs, presumably as a result of migration of photoreceptors from undamaged areas and their retinal remodeling.

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

AIM

To compare and evaluate the transitions in retinal function after photodynamic therapy (PDT) between age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV) using multifocal electroretinograms (mfERGs).

METHODS

10 eyes with choroidal neovascularisation (CNV) secondary to AMD and 11 eyes with CNV secondary to PCV were included in the study. mfERGs were recorded before PDT, and 1 week and 3 months after PDT. mfERG recordings were acquired by a Veris system (V.3.1.3) using a 103 hexagon stimulus. The first-order kernel was used to calculate amplitudes and latencies. Mean amplitudes and latencies from two central rings rated 0-4 degrees of visual angle were analysed and compared with each disease.

RESULTS

In AMD, the mean first negative peak (N1) amplitudes tended to decrease, and the mean first positive peak (N1P1) amplitudes reduced to significant levels (p = 0.047) 1 week after PDT. 3 months after PDT, there were no significant differences in the mean N1 and N1P1 amplitudes compared with pre-PDT values. In PCV, there were no significant changes in the mean N1 and N1P1 amplitudes 1 week after treatment. However, 3 months after PDT, mean amplitudes showed significant increases in N1 (p = 0.008) and N1P1 (p = 0.006) amplitudes compared with pre-PDT values.

CONCLUSIONS

mfERG recording transitions are different between patients with AMD and those with PCV. In patients with AMD, these results may show transient impairments in retinal function 1 week after PDT, but in those with PCV, the efficacy of PDT is superior to the impairment after PDT.

Safety enhanced photodynamic therapy with half dose verteporfin for chronic central serous chorioretinopathy: a short term pilot study

AIM

To evaluate short term safety of an enhanced photodynamic therapy (PDT) protocol with half dose verteporfin for treating chronic central serous chorioretinopathy (CSC).

METHODS

20 eyes of 18 patients with symptomatic chronic CSC underwent PDT using 3 mg/m2 verteporfin. Verteporfin was infused over 8 minutes followed by indocyanine green angiography guided laser application 2 minutes later. Serial optical coherence tomography (OCT) and multifocal electroretinography (mfERG) recordings were performed before PDT, at 4 days, 2 weeks, and 1 month after PDT. The best corrected visual acuity (BCVA), OCT central retinal thickness, and mean mfERG response amplitudes and peak latencies were compared longitudinally. Subgroup analysis was further performed for eyes with or without pigment epithelial detachment (PED).

RESULTS

At 1 month after PDT, the median BCVA improved from 20/40 to 20/30 (p = 0.001). The mean central retinal thickness also reduced from 276 microm to 158 microm (p < 0.001) and 17 (85%) eyes had complete resolution of serous retinal detachment and/or PED. MfERG showed no significant changes in the mean N1 and P1 response amplitude and latency for all eyes. Subgroup analysis demonstrated that eyes without PED had a significant increase in the mean central mfERG P1 response amplitude with reduction in P1 peak latency at 1 month post-PDT. For eyes with PED, transient reduction in the mean central P1 response amplitude was observed at 4 days post-PDT.

CONCLUSIONS

The modified safety enhanced PDT protocol with half dose verteporfin appeared to be a beneficial treatment option for patients with chronic CSC, especially in eyes without serous PED. Further controlled study is warranted to demonstrate the long term safety and efficacy of this treatment option.

Photodynamic Therapy in Macular Diseases of Asian Populations: When East Meets West

PURPOSE

We reviewed the indications, safety, and efficacy of photodynamic therapy with verteporfin in various macular diseases and vasculopathies, which are common in Asian populations, and compared the outcomes of photodynamic therapy in Asian patients with the outcomes in Caucasian patients.

METHODS

Relevant clinical and laboratory original articles, case reports, and review articles that have been published in the literature between January 1999 and October 2004 were searched in Medline. The potential differences in the response to photodynamic therapy between Asian and Caucasian patients were evaluated. Articles in foreign languages with English abstracts were included.

RESULTS

Macular diseases commonly seen in Asian populations, including choroidal neovascularization (CNV) of age-related macular degeneration, secondary to pathologic myopia or from an idiopathic cause, and choroidal vasculopathies such as central serous chorioretinopathy and polypoidal choroidal vasculopathy were included in the review. The results were tabulated and the differences with Caucasian populations were compared and highlighted.

CONCLUSION

Photodynamic therapy has been found to be an effective and noninvasive treatment for various subfoveal CNV and choroidal vasculopathies of the macula. Diverse behavior in different ethnic groups is observed.

Combined photodynamic therapy and intravitreal triamcinolone injection for the treatment of subfoveal choroidal neovascularisation in age related macular degeneration: a comparative study

AIM

To evaluate the outcomes of combined intravitreal triamcinolone (IVTA) and photodynamic therapy (PDT) with verteporfin in the treatment of subfoveal choroidal neovascularisation (CNV) caused by age related macular degeneration (AMD).

METHODS

48 eyes from 48 patients with subfoveal CNV caused by AMD were prospective recruited, with 24 eyes treated with combined PDT with IVTA and compared with a control group of 24 eyes which received PDT monotherapy. In the combined treatment group, IVTA was performed immediately after PDT as an outpatient procedure. The mean number of treatments, mean logMAR best corrected visual acuity (BCVA), mean line of visual acuity changes, and proportion of patients without moderate visual loss at 1 year were compared between the combined and monotherapy groups.

RESULTS

At 1 year the logMAR BCVA for the PDT with IVTA group changed from 0.88 to 0.95 (p = 0.32 compared with baseline), whereas the logMAR BCVA for the monotherapy group reduced from 0.74 to 1.09 (p<0.001 compared with baseline). A significantly higher proportion of patients who had PDT with IVTA did not develop moderate visual loss at 1 year compared with the monotherapy group (70.8% and 33.3% respectively, p = 0.009). Eyes which had combined treatment had significantly fewer lines lost compared with monotherapy alone (0.7 and 3.5 lines respectively, p = 0.015). Subgroup analysis showed that PDT with IVTA is effective in preventing visual loss in both predominately classic and occult CNV groups. The mean number of treatments for the combined and monotherapy groups was 1.5 and 1.96 respectively (p = 0.076).

CONCLUSIONS

Combined PDT with IVTA appeared more effective statistically at 12 months for stabilisation of vision (<3 logMAR lines change) compared with PDT monotherapy. Further randomised control trials might be justified to conclude the efficacy of PDT with IVTA.

Choroidal vein and artery occlusion following photodynamic therapy in eyes with pathologic myopia

PURPOSE

To describe highly myopic patients in which either the large choroidal veins or arteries were occluded following PDT treatment.

METHODS

Demographic features of two highly myopic patients in which large choroidal vessels were occluded at 1 week following PDT, among a total of 23 patients who received PDT due to choroidal neovascularization (CNV) caused by high myopia, were demonstrated.

RESULTS

In case 1, ICG angiography demonstrated the complete occlusion of several large choroidal veins within the laser-applied area at 1 week after PDT. In case 2, ICG angiography demonstrated an occlusion of choroidal artery emanating from beneath the CNV. One month after PDT, re-perfusion of the occluded choroidal vessels was noted in both patients.

CONCLUSION

Occlusion of choroidal veins has never been reported in eyes with CNV treated by verteporfin therapy. Although further studies are necessary, occlusion of large choroidal vessels might happen in highly myopic eyes more commonly than expected. ICG angiography at 1 week after PDT was useful to evaluate the impact of PDT on large choroidal vessels.

Dynamics of Retinal Function after Multiple Photodynamic Therapies in Age-Related Macular Degeneration: A Report of Cases

PURPOSE

To monitor retinal function after multiple laser treatments by photodynamic therapy (PDT) with the multifocal electroretinogram (mfERG) in age-related macular degeneration (AMD).

METHODS

Five eyes of five subjects with AMD were investigated before the first and 1 month after each of three PDT treatments. Function was assessed using the cone- and rod-mediated mfERG, high-contrast distance visual acuity, central visual fields and contrast sensitivity. For each subject the local first-order mfERG results before treatment were used as a template and fitted against the local post-treatment results (Matlab, Mathworks).

RESULTS

We found transient reduction of the cone- and rod-mediated amplitudes between the first and second treatments but stable or improved mfERG function in four of five eyes for the cone-mediated mfERG and in all eyes for the rod-mediated mfERG after three treatments. Visual acuities and contrast sensitivities remained stable between treatments in four and two eyes respectively, whereas visual fields showed substantially higher mean defects in two subjects after all treatments.

CONCLUSION

As found in previous studies of the cone-mediated mfERG after one PDT treatment, objective function was stabilized after multiple treatments in this case report. Similarly, although poor at baseline, rod-mediated function was not further compromised. Transiently reduced amplitudes after 1 month possibly reflected choroidal hypoperfusion. A larger sample size is needed to confirm if additional evaluation using electrophysiological criteria might be helpful in re-treatment decisions during PDT.

Electrooculography After Photodynamic Therapy

PURPOSE

To evaluate the changes in electrooculography (EOG) after photodynamic therapy (PDT).

METHODS

Thirty-eight eyes of 38 patients (21 males, 17 females) with choroidal neovascularization secondary to age related macular degeneration were included in this study. Standart PDT with verteporfin was performed on each patient. Serial EOG recordings were performed before, 1 week, and 1 month after PDT.

RESULTS

Mean age of the patients was 69.8+/-9.7 years (range 56 and 90 years). Seven days after PDT the visual acuity improved in 17 eyes, remained unchanged in 16 eyes and deteriorated in 5 eyes. One month after PDT the visual acuity findings were the same as the first week. New hemorrhages were seen in three eyes in the first week after PDT and visual acuity was decreased in those patients. No other patient complained of ocular and systemic adverse events. There was a statistically significant reduction in the Arden ratio of the EOG 1 week after PDT and the reduction persisted in the first month recordings.

CONCLUSIONS

The reduction in Arden ratio of EOG findings may indicate that retina pigment epithelium function could be affected after PDT.

The Changes of Pattern Electroretinography at the Early Stage of Photodynamic Therapy

PURPOSE

To evaluate the short-term changes in pattern electroretinography (PERG) after photodynamic therapy (PDT).

METHODS

Thirty eyes of 30 patients (17 males, 13 females) with choroidal neovascularization secondary to age related macular degeneration were included in this study. Standard PDT with verteporfin was performed on each patient. Serial PERG recordings were performed before, 1 week, and 1 month after PDT.

RESULTS

Mean age of the patients was 69.6+/-8.4 years (range 56 and 90 years). One month after PDT, the visual acuity improved in 16 eyes, remained unchanged in 12 eyes and deteriorated in two eyes. New hemorrhages were seen in two eyes in the first week after PDT and visual acuity was decreased in those patients. No other patient complained of ocular and systemic adverse events. There was a statistically significant reduction in the amplitudes of P50 and N95 waves at the first week recordings after PDT. At 1 month after PDT, no significant differences in the P50 and N95 amplitudes were observed compared with pre-PDT PERG recordings. There were no significant changes in the latencies of P50 and N95 at the first week and first month recordings when compared with pre-treatment PERG values.

CONCLUSIONS

Reduction in P50 and N95 amplitudes suggests that transient impairments in macular function occur at the first week after PDT.

Choroidal neovascularisation in pathological myopia: an update in management

Choroidal neovascularisation (CNV) secondary to pathological myopia is an important cause of significant visual impairment in young and middle aged adults globally and is particularly prevalent in Asian populations. In the past few years, there have been rapid advancements in the different treatments for myopic CNV. The purpose of this perspective is to give an overview of the natural history of myopic CNV and the various treatment options including laser photocoagulation, photodynamic therapy, sub-macular surgery, and macular translocation surgery. Future directions in the management of myopic CNV are also discussed.

Objective functional assessment of age‐related maculopathy: a special application for the multifocal electroretinogram

This paper gives a brief review of methods that assess objectively function in age-related maculopathy (ARM) with emphasis on a newer method, the multifocal electroretinogram (mfERG). In contrast to other electrophysiological tests, such as the full-field and focal electroretinogram (ERG) or the electro-oculogram (EOG), which measure summed responses from various cells from larger areas of the retina, the multifocal electroretinogram maps function locally with a resolution as small as four degrees within the central 30 degrees. By using different paradigms it can measure local cone- and rod-mediated functional impairment at early and late stages of ARM. This improved mapping and higher resolution of the posterior pole compared to other objective methods might lead to earlier detection of ARM. Its usefulness has been demonstrated in documenting the effects of treatment after established laser treatments, such as photodynamic therapy (PDT) and in documenting function after retinal pigment epithelial transplantation, a possible future treatment in late neovascular ARM.