Clinical spectrum of lamellar macular defects including pseudoholes and pseudocysts defined by optical coherence tomography

Abstract

Objective: To present the clinical spectrum of lamellar macular defects and describe the different subtypes based on their optical coherence tomography (OCT) configuration and visual prognosis.

Methods: The retrospective observational case series reviewed OCT scans of 92 eyes with lamellar macular defects. Lamellar macular defects were categorised into subtypes of macular pseudohole (MPH), lamellar macular hole (LMH) and foveal pseudocyst (FP) according to their OCT morphology. The defects were quantitatively characterised in terms of base diameter, depth and central foveal thickness, and examined for the presence of associated epiretinal membranes (ERM).

Results: Visual acuity (VA) was significantly correlated with the central foveal thickness and depth of the lamellar defect. MPH was associated with better VA compared with LMH and FP. MPH was of a smaller base diameter and had a greater central foveal thickness than that of LMH and FP. Fifty-per cent of all lamellar defects had an associated ERM.

Conclusions: Different profiles of lamellar macular defects were characterised and quantified by OCT. Deeper and wider lamellar defects were associated with poorer visual outcome. Such objective parameters lamellar macular defects are of value when explaining to patients regarding their decreased acuity. Future prospective investigations are required to study the natural history of lamellar defects of different aetiology and surgical indications.

Figure 1. Optical coherence tomography scans of lamellar macular defect measurements showing placement of calipers for base diameter, depth, central foveal and perifoveal retinal thickness measurement for the three types of defects: macular pseudohole (MPH), lamellar macular hole (LMH) and foveal pseudocyst (FP). For LMH, the opening (minimum) diameter of the lamellar hole was also measured. The blue arrows indicate the base diameter of the defects, while the yellow arrow indicates the opening diameter. The purple bar indicates the depth of the lamellar defect; the red bar indicates the central foveal thickness; and the white arrows indicate retinal thickness at points 750 μm either side of the foveal centre. The perifoveal retinal thickness was calculated as the average of the two measurements on either side from the foveal centre.

Figure 2. (A) Optical coherence tomography (OCT) scan of a sharply punched-out defect corresponding to a macular pseudohole (MPH). (B) OCT scan of an MPH of larger diameter compared with (A) and verticalisation of the foveal contour. (C) As the MPH became deeper, it also assumed a more oval shape. A thick epiretinal membrane bridging deep retinal folds was observed. (D) OCT profile of a lamellar macular hole (LMH) with small lateral cleft. (E) LMH, of larger diameter compared with (D) with lateral intraretinal split, assuming a “bilobate” contour. (F) Extensive lateral intraretinal split between the inner and outer retinal layers and irregular foveal base of the LMH. Note the detached posterior hyaloid. (G) Foveal pseudocysts (FP), which appeared as an intraretinal cystoid space occupying the inner part of the foveola. Partially detached posterior hyaloid was also evident. (H) Posterior hyaloid, which remained adherent to the foveal centre, exhibiting a biconvex linear signal and elevating the roof of the pseudocyst, suggesting vitreomacular traction. (I) Increased cystoid spaces on the edge of the cyst laterally between the inner and outer retinal layers, as the size of the FP increased.

Figure 3. (A) Number of eyes with or without epiretinal membrane (ERM) based on the depth of lamellar macular defect, expressed as a percentage of normal perifoveal retinal thickness. As the depth of the lamellar macular defect increased, the number of eyes with ERM increased. For depth over 33% of retinal involvement, over 60% of defects had associated ERM. (B) Number of vitrecomised and non-vitrecomised eyes based on the depth of lamellar macular defect, expressed as a percentage of normal perifoveal retinal thickness. The majority of shallower defects (over 80%) did not undergo a vitrectomy, while close to half of lamellar defects with more than 67% of retinal thickness involvement underwent a vitrectomy.