Clinical science 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. RESULTS OCT scans of the 92 eyes were analysed and categorised into three different subgroups of lamellar macular defects: MPH, LMH and FP. Thirty-nine eyes had OCT features of well- defined, punched out defects corresponding to MPH; 26 eyes were in the LMH subgroup, and 27 eyes had FP. Figure 2 shows the varied presentations of the three types of lamellar macular defects, with examples of each subtype showing varying diameters and depths. The VA of the 92 eyes with lamellar macular defects at initial presentation ranged from 20/15 to 20/200. The VA differed significantly between the three subtypes of lamellar macular defects (F2,89 = 8.272, p = 0.001). The MPH group had the best VA of 0.1 (0.15) logMAR (equivalent to 20/25 Snellen acuity) compared with that of the LMH group (0.28 (0.25) logMAR; p = 0.005) and the FP group (0.30 (0.26) logMAR; p = 0.002) (table 1). The VA of LMH and FP was similar (p = 1.00). The difference in central foveal thickness of the three subtypes of lamellar macular defects followed the same pattern as the difference observed in VA (F2,89 = 10.747, p,0.0001; table 1). MPH had the thickest central foveal thickness measurement (141 (26) mm), which was significantly greater than LMH (122 (36) mm, p = 0.047) and FP (104 (34) mm; p,0.0001). The differences in central foveal thickness of LMH and FP were not significantly different (p = 0.128). There was a statistically significant correlation between VA and central foveal thickness (r = 22.33, p = 0.025), that is, the thicker the central foveal thickness, the better the VA. There were also significant differences in the base diameter of the lamellar defects for the three groups (F2,89 = 15.184, p,0.0001; table 1). LMH had the widest base diameter (1022 (632) mm), which was significantly greater than that of the MPH group (452 (178) mm; p,0.0001) and the FP subgroup (707 (377) mm, p = 0.019). The difference between MPH and FP was 1344 also statistically significant (p = 0.044). The opening (mini- mum) diameter of LMH was similar to the width of MPH (442 (173) mm, cf. 452 (178) mm; p = 1.00). In addition to having defects of larger base diameters, LMH also had deeper defects compared with MPH and FP (F2,89 = 12.757, p,0.0001; table 1). The average depth of LMH was 216 (54) mm, which was significantly greater than that of MPH (182 (54) mm, p = 0.033) and FP (144 (47) mm; p,0.0001). The depth of MPH was significantly greater than FP (p = 0.014). There was also a statistically significant correlation between VA and depth of the lamellar macular defect (r = 0.222, p = 0.034), that is, the deeper the lamellar defect, the poorer the VA. Perifoveal thickness measurements of MPH and LMH were similar (322 (54) mm cf. 338 (57) mm; p = 0.593). The perifoveal thickness of FP (281 (22) mm) was significantly less than that of MPH and LMH (p = 0.002) (table 1). Fifty per cent of all lamellar defects had associated ERM. The presence of ERM was associated with the depth of lamellar defects; lamellar defects with ERM had an average defect depth of 205 (61) mm compared with 156 (44) mm of defects without ERM (t90 = 4.417, p,0.0001). When the depth of the lamellar defect was expressed as a percentage of perifoveal thickness, over 60% of lamellar defects with greater than a third of retinal thickness involvement were associated with ERM (fig 3). This was significantly different to that observed for the shallower lamellar defects; less than 20% of lamellar defects with less than a third of retinal thickness depth involvement were associated with ERM (fig 3). The presence of ERM alone did not have any significant effect on VA (t90 = 0.670, p = 0.505). DISCUSSION The varied presentation of lamellar macular defects presented in the study shows the wide clinical spectrum of macular disorders that may simulate a macular hole on clinical examination. Br J Ophthalmol 2008;92:1342–1346. doi:10.1136/bjo.2007.133041