Evidence of Carotenoid in Surgically Removed Lamellar Hole-Associated Epiretinal Proliferation

Abstract To determine the constituents and origin of the yellow pigment in surgically removed lamellar hole-associated epiretinal proliferation (LHEP) in patients with lamellar macular hole (LMH). This prospective case series comprised nine eyes with LMH in patients aged 41 to 83 years. The presence of LHEP was confirmed by preoperative optical coherence tomography; the distribution of macular pigment was observed by two-wavelength fundus autofluorescence technique before and after surgery. The subjects underwent a 25-gauge vitrectomy, and the surgically removed epiretinal membranous tissue was fixed with formalin. The specimens were examined using resonance Raman microscopy, and paraffin sections were stained with antiglial fibrillary acidic protein. Seven cases presented with LHEP, and the presence of yellow pigment was confirmed using an operating microscope. Carotenoid-specific Raman signals with three major Raman peaks could be identified in the specimens with LHEP. These specimens were positive for glial fibrillary acidic protein staining. Using the fundus autofluorescence technique, a central defect in the distribution of the macular pigment was noted in the exact area of the lamellar hole. This type of defect was no longer visible after surgical repair of the lamellar hole. The constituents of the yellow pigment in the removed LHEP were carotenoids that typically originate from the macular xanthophyll pigments at the fovea. Since LHEP is reported to be composed of Muller cells, we hypothesize that xanthophyll carotenoids at the fovea are contained in the Muller cells.