Phenomenology of spontaneous closure in degenerative and mixed type lamellar macular hole

Purpose: To the describe OCT imaging characteristics of a cohort of patients showing spontaneously closing degenerative or mixed type lamellar macular holes (LMH) and to compare them to the ones of a sex and age matched group showing stable lesions. Methods: Patients diagnosed with degenerative and mixed type LMHs showing OCT-documented spontaneous anatomical closure were retrospectively selected from 3 specialized retina centres. An equal number of age and sex matching subjects were randomly selected among patients with anatomically stable lesions. Results: Eleven (11) spontaneously closing (SC group) and 11 stable (ST group) degenerative LMH with a mean follow up of 4 years were recruited. Hyperreflective inner border (HIB) and linear hyperreflectivity in the outer plexiform layer (LHOP) at baseline were significantly more prevalent in SC group in processed images (respectively p = 0.007 and p = 0.003). A borderline significance in lamellar hole associated epiretinal proliferation (LHEP) at last follow up was detected (p = 0.085). As for mixed type LMH, 10 patients for SC group and 10 for ST group were recruited. LHOP at baseline in processed images was significantly more prevalent in SC group (p = 0.005). Conclusions: Spontaneously closing LMHs show higher prevalence of HIB and LHOP at the beginning of the closing process, a difference which is enhanced by image processing. These signs might be a signal of microglial and Muller cells coordinated activation.