Retinal Displacement after Idiopathic Macular Hole Surgery: Layer by Layer Analysis.

Abstract

Purpose: To measure the displacement of retinal vascular plexi and choriocapillaris after Pars Plana Vitrectomy (PPV) for idiopathic Macular Hole (MH), using Optical Coherence Tomography Angiography (OCTA) and correlate it with clinical data.

Methods: Retrospective series with 6-month follow-up. Records included best-corrected visual acuity (BCVA), M-charts, structural OCT and OCTA. Coronal displacement was calculated comparing consecutive images across the 6.4 mm x 6.4 mm field and concentric circular regions of 0.5, 1.5 and 3.0mm radii. Each circular region was further divided in four quadrans indicated as follows: ST=SuperoTemporal; SN=SuperNasal; IT=InferoTemporal; IN=InferoNasal.

Results: The study comprised 33 patients (11 males and 22 females) with 68.9 ± 10.2 years mean age, similar among sexes. MH closed in 31/33 (93.9%) of cases and BCVA improved from mean 20/62 (0.50±0.62 logMAR) to 20/47 (0.23±0.63 logMAR; p=0.0064). Vertical and horizontal metamorphopsia decreased from 0.98±0.68 to 0.51±0.59 degrees (p=0.0028) and 0.84±0.63 to 0.29±0.45 degrees (p<0.001), respectively. The average retinal displacement was 81.2±44.1 μm for the superficial plexus and 79.4±45.7 μm for the deep one, both greater than the choriocapillaris displacement (60.9±20.2 μm; p<0.05). The temporal and superior quadrants displaced more than the others (p<0.05). MH size correlated to retinal displacement within the central 0.5 mm radius area at all layers (p<0.05 in all cases).

Conclusion: MH closure is associated with significant retinal displacement of all retinal layers as well as choriocapillaris remodelling. Surgical peeling removes the constraining effect of the Internal Limiting Membrane and promotes a multi-layered displacement that fills the retinal defect, likely due to a change in the equilibrium of forces between the contractile retinal structures: the larger superficial retinal vessels and the Retinal Nerve Fiber Layer.