MyVisionTest News Archive
Nov 12, 2008
Safety-enhanced photodynamic therapy protocol for central serous chorioretinopathy
A new study reports good success treating acute central serous chorioretinopathy with a novel safety-enhanced photodynamic therapy protocol.
Central serous chorioretinopathy (CSCR) is characterized by the accumulation of subretinal fluid at the macula and is a common condition in young adults, especially in men with a so-called type A personality. The use of indocyanine green angiography (ICGA) has demonstrated that CSCR primarily affects the choroidal circulation, resulting in multifocal areas of choroidal vascular hyperpermeability.
Although CSCR generally is considered a self-limiting and benign condition, some patients may experience significant visual impairment caused by recurrent attacks of CSCR, persistent chronic neurosensory retinal detachment, or RPE atrophy. Most episodes of CSCR usually resolve spontaneously within 3 to 4 months. Traditional management has been observation alone. Laser photocoagulation and pharmacological agents have been attempted for treating CSCR. These treatment options serve only to shorten the duration of symptoms and have no effect on the recurrence rate or the final visual acuity.
Photodynamic therapy (PDT) with verteporfin recently has been used for treating CSCR. The mechanism of action of PDT for treating CSCR is postulated to be caused by short-term choriocapillaris hypoperfusion and long-term choroidal vascular remodeling. However, the application of conventional PDT in CSCR can result in potential complications such as RPE atrophy, choroidal ischemia, and secondary choroidal neovaascularization.
In this study 63 eyes of 63 patients with acute symptomatic CSCR 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/m2) verteporfin and 21 eyes were randomized to placebo.
To enhance the efficacy of PDT in treating CSCR while minimizing its side effects, the investigators reduced the dosage of verteporfin and shortened the interval between infusion and laser application. Studies have shown that the maximal concentration of verteporfin within the choroidal circulation is achieved at 10 minutes after infusion, whereas the concentrations at the outer retina and RPE are still relatively low. Shortening the interval between the infusion and laser application therefore may minimize collateral damage to the adjacent retinal structures.
Thirty-nine patients in the verteporfin group and 19 patients in the placebo group completed 12 months of follow-up.
Complete resolution of subretinal fluid at 1 year was achieved in 94.9% of eyes treated with verteporfin, compared with 57.9% in the placebo group.
The mean logMAR visual acuity of patients in the verteporfin-treated group also was significantly better compared with that of the placebo group at 12 months. Moreover, none of the patients experienced visual loss in the verteporfin group, compared with 21.1% in the placebo group. All 39 (100%) verteporfin-treated eyes had stable or improved vision, compared with 15 (78.9%) eyes in the placebo group.
The mean OCT central foveal thickness for the verteporfin group also was significantly lower compared with the placebo group at 12 months.
In terms of safety profile, the development of secondary CNV or RPE atrophy was not observed in any patients.
The authors conclude that PDT with half-dose verteporfin is an effective treatment option for acute CSCR, and no adverse events were associated with the treatment. The researchers state that their safety-enhanced PDT protocol is among the best of the currently available treatment options for patients with acute symptomatic CSCR.
WHAT IT MEANS TO YOU: This paper offers very encouraging results using a modified PDT protocol that may decrease the risk of adverse effects of the procedure. Others have employed different modifications to the standard PDT protocol in an attempt to decrease the risk of vision loss associated with PDT. Currently, we do not have any evidence that any of these modifications actually do any good. I would not recommend PDT for patients with CSCR until we have studies demonstrating long-term benefit.
Read more...
Ophthalmology 2008;115:1756–1765
Tags: central serous chorioretinopathy, photodynamic therapy, clinical trial
A new study reports good success treating acute central serous chorioretinopathy with a novel safety-enhanced photodynamic therapy protocol.Central serous chorioretinopathy (CSCR) is characterized by the accumulation of subretinal fluid at the macula and is a common condition in young adults, especially in men with a so-called type A personality. The use of indocyanine green angiography (ICGA) has demonstrated that CSCR primarily affects the choroidal circulation, resulting in multifocal areas of choroidal vascular hyperpermeability.
Photodynamic therapy (PDT) with verteporfin recently has been used for treating CSCR. The mechanism of action of PDT for treating CSCR is postulated to be caused by short-term choriocapillaris hypoperfusion and long-term choroidal vascular remodeling. However, the application of conventional PDT in CSCR can result in potential complications such as RPE atrophy, choroidal ischemia, and secondary choroidal neovaascularization.
In this study 63 eyes of 63 patients with acute symptomatic CSCR 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/m2) verteporfin and 21 eyes were randomized to placebo.
To enhance the efficacy of PDT in treating CSCR while minimizing its side effects, the investigators reduced the dosage of verteporfin and shortened the interval between infusion and laser application. Studies have shown that the maximal concentration of verteporfin within the choroidal circulation is achieved at 10 minutes after infusion, whereas the concentrations at the outer retina and RPE are still relatively low. Shortening the interval between the infusion and laser application therefore may minimize collateral damage to the adjacent retinal structures.
Thirty-nine patients in the verteporfin group and 19 patients in the placebo group completed 12 months of follow-up.
Complete resolution of subretinal fluid at 1 year was achieved in 94.9% of eyes treated with verteporfin, compared with 57.9% in the placebo group.
The mean logMAR visual acuity of patients in the verteporfin-treated group also was significantly better compared with that of the placebo group at 12 months. Moreover, none of the patients experienced visual loss in the verteporfin group, compared with 21.1% in the placebo group. All 39 (100%) verteporfin-treated eyes had stable or improved vision, compared with 15 (78.9%) eyes in the placebo group.
The mean OCT central foveal thickness for the verteporfin group also was significantly lower compared with the placebo group at 12 months.
In terms of safety profile, the development of secondary CNV or RPE atrophy was not observed in any patients.
The authors conclude that PDT with half-dose verteporfin is an effective treatment option for acute CSCR, and no adverse events were associated with the treatment. The researchers state that their safety-enhanced PDT protocol is among the best of the currently available treatment options for patients with acute symptomatic CSCR.
WHAT IT MEANS TO YOU: This paper offers very encouraging results using a modified PDT protocol that may decrease the risk of adverse effects of the procedure. Others have employed different modifications to the standard PDT protocol in an attempt to decrease the risk of vision loss associated with PDT. Currently, we do not have any evidence that any of these modifications actually do any good. I would not recommend PDT for patients with CSCR until we have studies demonstrating long-term benefit.
Read more...
Ophthalmology 2008;115:1756–1765
