Iris pigment epithelial cell translocation in exudative age-related macular degeneration - A pilot study in patients

Background. This prospective, non-controlled pilot study investigates the practicability of IPE translocation and functional outcome in ARMD patients. Removal of submacular choroidal neovascularization (CNV) in age-related macular degeneration (ARMD) is usually associated with RPE damage and poor visual prognosis. Homologous RPE transplants fail to preserve macular function, possibly due to immune rejection. Instead of homologous RPE, we suggest translocating autologous iris pigment epithelium (IPE), building on earlier evidence from animal and in vitro investigations that IPE can substitute RPE functions in the experimental animal. Immunological cell rejection is avoided. Methods: Four eyes with well-defined and eight eyes with ill-defined subfoveal CNV were submitted to operation and followed up for a minimum of 6 months. IPE cells were harvested from a peripheral iridectomy. A vitrectomy was performed. Submacular membranes were removed, and isolated IPE cells were injected into the subretinal space. Examinations included ETDRS visual acuity, fluorescein angiography, and SLO microperimetry. Results: All patients underwent successful surgical removal of CNV and subretinal IPE injection. Compared to preoperative visual acuity (20/400-20/100) no significant change was observed after 6 months (20/320-16/80). A change of more than two ETDRS chart lines was de fined as significant. One eye with preoperative ill-defined CNV developed a recurrence, leading to reduced visual acuity. In all patients, postoperative fluorescence angiography revealed early hyperfluorescence (window defect) in the surgically denuded area. Central fixation was demonstrated in 50% of eyes. Conclusions: Preliminary data suggests that IPE translocation in submacular surgery for ARMD can preserve but not improve preoperative visual acuity over 6 months. Functional results are promising compared to submacular membrane extraction alone and RPE transplantation. Continued research on improvement of IPE translocation seems justified.