Morpho-Functional Evaluation of Full-Thickness Macular Holes by the Integration of Optical Coherence Tomography Angiography and Microperimetry

Abstract

(1) Objective: To use optical coherence tomography angiography (OCTA) and microperimetry (MP) to evaluate the correlation between retinal structure and function in patients with idiopathic, full-thickness macular holes (FTMHs) (2) Methods: This prospective, observational study included 11 eyes of 10 patients with FTMHs evaluated before surgery using OCTA and MP. MP sensitivity maps were superimposed and registered on slabs corresponding to superficial capillary plexus (SCP) and deep capillary plexus (DCP) on OCTA, and on the outer plexiform layer (OPL) and the Henle fiber layer (HFL) complex in en face OCT. On these maps, mean retinal sensitivity was calculated at 2° and 4°, all centered on the FTMH. Cystic cavity extension was assessed on the slab corresponding to the OPL + HFL complex in en face OCT and DCP in OCTA using the Image J software (Version 1.49v; National Institutes of Health, Bethesda, MD, USA); (3) Results: Absolute scotomas were observed corresponding to the FTMH. Additionally, rings of relative scotoma in the perilesional area were detected and correlated to the cystic spaces on en face OCT and OCTA. There was a significant correlation between reduced retinal sensitivity at 2° and 4° diameters around the FTMH and the extension of cystic areas (p < 0.01). There was a significant correlation between the extension of cystic cavities and BCVA (p < 0.01). (4) Conclusions: Morpho-functional analysis of FTMH using OCTA and MP, and the correlation between vascular abnormalities and impaired retinal sensitivity, may provide new, useful information. This integrated evaluation of FTMH may be useful to determine the function-structure correlation before and after vitreoretinal surgery, in order to gain a better understanding of the functional consequences induced by the morphological alterations, assessing outcomes in a more objective way, and potentially adding new surgical prognostic factors.

Keywords: OCT Angiography; full-thickness macular hole; microperimetry.

Figure 1

An eye with full thickness macular hole analyzed using en face optical coherence tomography (OCT) (A) and OCT angiography (B). In the lower part the corresponding segmentation is visible.

Figure 2

The ETDRS-based vessel density [%], with division of the macular area into the nine ETDRS subfields (on the left). On the right, a scheme showing the rings centered around the fovea. The fovea is defined as the area within the central 1-mm ring of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid. The surrounding ring with an inner diameter of 1 mm and an outer diameter of 3 mm is considered as the inner ring. The ring with an inner diameter of 3 mm and an outer diameter of 6 mm is considered as the outer ring. The whole ring includes the fovea and the inner and outer rings.

Figure 3

(A) The B-scan OCT shows a full-thickness macular hole. (B) The central absolute scotoma corresponding to the FTMH and rings of relative scotoma extending in the perilesional area are shown in microperimetry map. These relative scotomas correlate with the cystic alterations detected by OCT angiography at the level of deep capillary plexus (B) and by en face OCT in the outer plexiform layer (OPL) and the Henle fiber layer (HFL) complex (C).

Figure 4

(A) 1. En face scan of the OPL + HFL complex of a large MH. 2. The extension of cystic cavities measured on the slab corresponding to OPL + HFL complex assessed by OCT en face, using the Image J software. In the lower part the corresponding cavity area in mm² and the Best Corrected visual Acuity in LogMAR are indicated. 3. Overlay of the microperimetry (2° retinal sensitivity) on the slabs corresponding to the deep capillary plexus on OCTA. (B) 1. En face OCT (OPL + HFL complex) of a smaller macular hole. 2. The extension of cystic cavities measured on the slab corresponding to OPL + HFL complex assessed by OCT en face, using Image J software. 3. Overlay of the microperimetry (2° retinal sensitivity) on the slabs corresponding to the deep capillary plexus on OCTA.

Figure 5

Scatterplot shows the statistically significant correlation (p = 0.01; R² = 0.53) between macular hole diameter (μm) and microperimetry 2 degree sensitivity (dB).

Figure 6

Scatterplot shows the statistically significant correlation (p = 0.0027; R² = 0.65) between cavity areas in OPL + HFL complex (mm²) and microperimetry 2 degree sensitivity (dB).

Figure 7

Scatterplot shows the statistically significant correlation (p = 0.0148; R² = 0.50) between cavity areas on OPL + HFL complex (mm²) and microperimetry 4 degree sensitivity (dB).

Figure 8

(A) Area of peak of flow in the choroidal slab (also named “choriocapillary transparency”) due to visibility of choroidal vessels caused by lack of neuroepithelium. (B) Scatterplot shows the statistically significant correlation (p = 0.04, R² = 0.36) between the area of peak of flow in the choroidal slab (mm²) and microperimetry 2 degree sensitivity (DB).