Retinal Choroidal Anastomoses and Occult Choroidal Neovascularization in Age-related Macular Degeneration

Objective: This study was designed to identify the incidence of retinal choroidal anastomoses in patients with occult choroidal neovascularization (CNV) and focal hot spots on indocyanine green (ICG) angiography, to identify the clinical and angiographic features that would assist in their identification, and to determine if the presence of these anastomotic lesions affect the outcome of laser therapy.

Design: Combined prospective and retrospective cross-sectional study.

Participants: One hundred fifty consecutive patients with newly diagnosed occult CNV secondary to exudative age-related macular degeneration and focal hot spots on ICG angiography were evaluated prospectively. In addition, a retrospective review was performed on 79 eyes previously reported to have undergone laser photocoagulation treatment with ICG guidance. METHODS AND TESTING: In all cases, stereo color and red-free photographs, and stereo fluorescein and digital ICG angiograms were obtained for evaluation.

Main Outcome Measures: Images obtained by all four techniques were evaluated for the presence of a retinal choroidal anastomosis. Associated clinical and angiographic findings were noted. In the retrospective review, the success rate of laser treatment was correlated with the presence or absence of a retinal choroidal anastomosis.

Results: Of the 150 eyes evaluated prospectively, 31 (21%) were found to have a retinal choroidal anastomosis. Retinal choroidal anastomoses were found in 27% of patients with associated serous pigment epithelial detachment (PED), whereas 13% were found in those without an associated elevation of the retinal pigment epithelium. Seventy-one percent of eyes had multiple anastomotic connections. Ninety percent of eyes had at least one retinal vein involved in the anastomotic connection. Clinical evidence of preretinal and intraretinal hemorrhage and cystic edema coupled with angiographic evidence of intraretinal dye leakage were key features of retinal choroidal anastomoses. In the retrospective review, seven patients were found to have retinal choroidal anastomoses with associated serous PED and demonstrated a very low (14%) success rate for laser treatment.

Conclusions: Retinal choroidal anastomoses can present as a primary manifestation of the exudative process in age-related macular degeneration. They may be seen in eyes with and without detachment of the retinal pigment epithelium. Specific clinical and angiographic features have been identified that can aid in the diagnosis of these vascular anomalies. Their presence represents a poor prognostic sign for successful ICG-guided laser treatment.