Are the submacular surgery trials still relevant in an era of photodynamic therapy?

Submacular hemorrhage in neovascular age-related macular degeneration: A synthesis of the literature

Large submacular hemorrhage, an uncommon manifestation of neovascular age-related macular degeneration, may also occur with idiopathic polypoidal choroidal vasculopathy. Submacular hemorrhage damages photoreceptors owing to iron toxicity, fibrin meshwork contraction, and reduced nutrient flux, with subsequent macular scarring. Clinical and experimental studies support prompt treatment, as tissue damage can occur within 24 hours. Without treatment the natural history is poor, with a mean final visual acuity (VA) of 20/1600. Reported treatments include retinal pigment epithelial patch, macular translocation, pneumatic displacement, intravitreal or subretinal tissue plasminogen activator, intravitreal anti-vascular endothelial growth factor (VEGF) drugs, and combinations thereof. In the absence of comparative studies, we combined eligible studies to assess the VA change before and after each treatment option. The greatest improvement occurred after combined pars plana vitrectomy, subretinal tissue plasminogen activator, intravitreal gas, and anti-vascular endothelial growth factor treatment, with VA improving from 20/1000 to 20/400. The best final VA occurred using combined intravitreal tissue plasminogen activator, gas, and anti-vascular endothelial growth factor therapy, with VA improving from 20/200 to 20/100. Both treatments had an acceptable safety profile, but most studies were small, and larger randomized controlled trials are needed to determine both safety and efficacy.

Contrast sensitivity as an outcome measure in patients with subfoveal choroidal neovascularisation due to age-related macular degeneration

PURPOSE

Although visual acuity is the most frequently used primary outcome measure in clinical trials of treatments for choroidal neovascularisation (CNV) due to age-related macular degeneration (AMD), contrast sensitivity may provide valuable additional information. This paper reviews the evidence for using contrast sensitivity as a measure of visual function and as an outcome measure in clinical trials in patients with subfoveal CNV due to AMD.

METHODS

Medline database searches were performed to retrieve relevant articles on contrast sensitivity. In addition, articles were included from the authors' knowledge of the literature and from the reference lists of retrieved articles.

RESULTS

The published literature demonstrates that contrast sensitivity is an important measure of visual function in patients with subfoveal CNV due to AMD. Most clinical trials of treatments for CNV due to AMD have reported visual acuity as the primary outcome. However, there is evidence that treatment (such as verteporfin therapy) may also provide additional benefits in terms of contrast sensitivity. These benefits may not be completely characterised by measurement of visual acuity alone.

CONCLUSIONS

The inclusion of contrast sensitivity as an outcome measure in studies of patients with CNV due to AMD may provide a more complete understanding of the effects of treatment on visual function and the likely benefits for patients.

Photodynamic Therapy for Choroidal Neovascularization Associated With Submacular Hemorrhage in Age-Related Macular Degeneration

BACKGROUND AND OBJECTIVE

To describe visual acuity results after photodynamic therapy (PDT) with verteporfin for choroidal neovascularization in age-related macular degeneration (AMD) associated with large submacular hemorrhage (SMH).

PATIENTS AND METHODS

Eyes that had AMD, at least 12 months' follow-up, and SMH of at least 2.5 mm2, and had received no other treatment modality in conjunction with PDT, were divided into two groups: eyes with spontaneous SMH that was treated with PDT and eyes with SMH that occurred following PDT treatment. The presence of SMH did not preclude the patients from undergoing further PDT.

RESULTS

Mean acuity of the spontaneous SMH group was 20/294 initially and 20/252 after 12 months. Mean acuity of the post-PDT SMH group was 20/336 initially and 20/406 after 12 months. Initial and 12-month acuities in both groups were not statistically different. Mean size of the hemorrhage was 11.5 mm2 in the spontaneous SMH group and 17.8 mm2 in the post-PDT SMH group. Subgroup analysis showed no statistically significant difference between initial and final visual acuities, regardless of the presence of blood under the fovea. Analysis by size of the SMH showed only the spontaneous SMH group with hemorrhages over 10 mm2 to have a statistically significant difference in visual acuity at 12 months (P= .0001; initial acuity, 20/230; 12-month acuity, 20/456).

CONCLUSION

Eyes treated with PDT for choroidal neovascularization associated with submacular hemorrhage and AMD maintained stable vision over 12 months.

Incidence of laser photocoagulation and photodynamic therapy with verteporfin at a tertiary retinal center

PURPOSE

To examine the influence of photodynamic therapy (PDT) with verteporfin on the indication and frequency of conventional thermal krypton laser photocoagulation in choroidal neovascularization.

METHODS

A retrospective chart review was performed comparing laser indication and frequency 1 year before and 2 years after PDT started to be used routinely following the guidelines of the Treatment of Age-Related Macular Degeneration with Photodynamic Therapy Study Group and the Verteporfin in Photodynamic Therapy Study Group.

RESULTS

Similar frequencies of laser treatment were seen in the year before and during the first year after PDT was commenced (301 [7.1% of all patients] to 281 [6.9%]). In the year thereafter, however, there was a marked decrease in laser treatments (174 [3.9%]). Interestingly, there was a steady increase in the relative frequency of laser treatments of extrafoveal and parapapillary lesions in the years after PDT was commenced (29.2%, year 1; 30.6%, year 2; and 39.6%, year 3).

CONCLUSION

PDT has led to a decrease in conventional laser photocoagulation at one large tertiary retinal center in Austria. Moreover, it is our belief that patients are now referred at earlier stages of the disease, which has resulted in a shift in thermal laser indications.

Autologous peripheral retinal pigment epithelium translocation in patients with subfoveal neovascular membranes

AIM

To evaluate the possibility of translocating autologous peripheral retinal pigment epithelial (RPE) cells and enhance their adhesion to improve functional outcome after choroidal neovascular membrane extraction in patients with subfoveal neovascular membranes.

METHODS

A prospective, non-controlled surgical study in eight consecutive patients operated between February and July 2001 with final data monitoring in July 2002. All patients had mixed subfoveal membranes of 2-4 disc diameters. Functional tests included Snellen vision and central fixation testing. During vitrectomy, after the extraction of the neovascular complex, 8 x 10(4)-16 x 10(4) RPE cells were removed from the periphery and translocated under the macula following the submacular injection of 2 microg of poly-L-lysine to promote adhesion of the cells.

RESULTS

With a follow up ranging from 3 months to 16 months, a pigmented area was seen in the extraction bed of the neovascular membrane in only one patient. Fixation was at the edge of the extraction bed in three patients. Vision remained the same in five patients and deteriorated in three (all with retinal detachment). Retinal detachment due to proliferative vitreoretinopathy occurred in three patients.

CONCLUSIONS

The translocation of autologous peripheral RPE cells after membrane extraction was technically possible in a sterile manner, but was associated with a high proliferative vitreoretinopathy rate and in the present series had no measurable positive effect on functional outcome.