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

Abstract

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.

Fig. 1. Follow up mode OCT B scan sections showing spontaneous closure of a degenerative LMH during a 4 year follow up.

The right column displays unprocessed OCT images while the left column shows processed OCT images. The red arrow highlights a zone of HIB in the area most interested by the process. In this case, image processing evidenced an HIB that was almost imperceptible in unprocessed image, showing an example of how the processing technique increased sensitivity to the sign. First row: the last acquisition before the beginning of LMH closure process (T1); Second row: intermediate acquisition (2 years follow up); Third row: first acquisition after LMH closure (T2). HIB Hyperreflective inner border, LMH Lamellar macular hole; OCT Optical coherence tomography.

Fig. 2. Follow up mode OCT B scan sections showing spontaneous closure of a mixed-type LMH during a 4 year follow up.

The left column displays unprocessed OCT images; the white circles highlight a zone of LHOP mostly visible at 1-year follow up acquisition. The left column shows processed OCT images; LHOP is highlighted with a red arrow. First row: the last acquisition before the beginning of LMH closure process (T1); Second row: intermediate acquisition (1 years follow up); Third row: intermediate acquisition (3 years follow up); Forth row: first acquisition after LMH closure (T2). LHOP Linear hyperreflectivity in the outer plexiform layer, LMH Lamellar macular hole, OCT Optical coherence tomography.