Epiretinal proliferation seen in association with lamellar macular holes: a distinct clinical entity
PURPOSE: To describe the prevalence and imaging characteristics of a distinct entity of epiretinal proliferation seen predominantly in association with lamellar macular holes (LMH), termed lamellar hole-associated epiretinal proliferation (LHEP). METHODS: Retrospective observational case review of 2,030 eyes of 1,104 patients with diagnoses including LMH, full-thickness macular hole, and epiretinal membrane (ERM) imaged with spectral domain optical coherence tomography (SD-OCT) from 2008 to 2013. Lamellar hole-associated epiretinal proliferation, defined on SD-OCT imaging as an epiretinal material of homogenous medium reflectivity, was identified and its features were qualitatively compared against conventional ERM using the SD-OCT data. RESULTS: Lamellar hole-associated epiretinal proliferation was found in 68 of 2,030 eyes (3.3%), of which 88.2% had LMH and 11.8% had full-thickness macular hole. Lamellar hole-associated epiretinal proliferation was found in 60 of 197 eyes (30.5%) with LMH and 8 of 99 eyes (8.0%) with full-thickness macular hole. Lamellar hole-associated epiretinal proliferation was not seen in 1,734 eyes with ERM, which had no inner retinal defects detectable on SD-OCT. Lamellar hole-associated epiretinal proliferation appeared as a substantial material of homogenous medium reflectivity on the epiretinal surface that demonstrated contiguity with the middle retinal layers and conformed to the adjacent retinal anatomy. Of the eyes with LHEP and LMH, 98% had splitting of the retina in the region of Henle's fiber layer in the area immediately around the partial thickness hole, whereas 88% had visible connecting tissue from the base of the lamellar hole to the proliferating epiretinal tissue. In contrast to ERM, LHEP did not induce tractional effects such as distortion or edema of the underlying normal retinal tissue. Morphologic stability was demonstrated in 97% of eyes containing LHEP in serial eye-tracked SD-OCT images for up to 63 months of retrospective follow-up. CONCLUSION: Spectral domain optical coherence tomography imaging showed that a subset of patients with LMH had an epiretinal proliferation with medium reflectivity and no evidence of contractile properties that was contiguous with layers of the mid-retina. This phenotype differs from conventionally described ERMs in appearance and induced changes of the underlying retina. Given these distinct anatomical relationships, the presence of LHEP could affect surgical outcomes.