Seventy eyes of 69 patients were identified. After propensity score matching, 21 eyes of 21 patients in the peeling group were matched against 21 eyes of 21 patients in the flap group.
The baseline characteristics before and after propensity score matching of the flap group and the peeling group are shown in Table 1. There were no significant differences in age, preoperative BCVA, minimum MH diameter, base diameter, axial length, or duration of symptoms between the two groups before and after propensity score matching. The percentage of stage 3/4 MH eyes was higher in the flap group before propensity score matching, but this difference was not present after the matching, indicating that the two groups were successfully matched. Three eyes were already pseudo phakic in each group. Seventeen eyes in the flap group and 18 eyes in the peeling group underwent cataract surgery.
Table 1
Preoperative baseline characteristics before and after propensity score matching of the flap group and the peeling group
|
Pre matching
|
|
|
Flap n=22
|
Peeling n=48
|
|
|
(SD)
|
(IQR)
|
(SD)
|
(IQR)
|
|
Age, median, y
|
65.8 (10.6)
|
66.5 (57.8 to 74.0)
|
66.1 (7.6)
|
66.0 (62.0 to 70.8)
|
|
Pre-op BCVA, logMAR
|
0.69 (0.3)
|
0.70 (0.40 to 1.00)
|
0.66 (0.3)
|
0.70 (0.43 to 0.82)
|
|
Snellen
|
20/98
|
20/100
|
20/91
|
20/100
|
|
Minimum MH diameter, μm
|
272.6 (83.6)
|
281.5 (216.3 to 346.8)
|
252.3 (90.2)
|
269.0 (168.0 to 326.0)
|
|
Base diameter, μm
|
678.7 (194.0)
|
675.5 (514.8 to 803.5)
|
667.0 (257.6)
|
644.5 (505.3 to 763.0)
|
|
Axial length, mm
|
23.9 (1.2)
|
23.8 (22.7 to 25.2)
|
23.4 (1.3)
|
23.4 (22.5 to 24.2)
|
|
Stage 3 or 4 (%)
|
20 (90.9)
|
20 (90.9)
|
32 (66.7)
|
32 (66.7)
|
|
Duration of symptoms, m
|
3.7 (6.5)
|
2.0 (1 to 2.5)
|
2.1 (1.3)
|
2.0 (1.0 to 2.0)
|
|
|
Post matching
|
|
|
Flap n=21
|
Peeling n=21
|
Standardized
|
|
(SD)
|
(IQR)
|
(SD)
|
(IQR)
|
difference
|
Age, median, y
|
66.2 (10.6)
|
68.0 (59.5 to 74.0)
|
66.6 (7.0)
|
67.0 (64.5 to 69.5)
|
0.045
|
Pre-op BCVA, logMAR
|
0.71 (0.3)
|
0.70 (0.46 to 1.0)
|
0.73 (0.3)
|
0.70 (0.52 to 0.91)
|
0.098
|
Snellen
|
20/102
|
20/100
|
20/107
|
20/100
|
Minimum MH diameter, μm
|
278.6 (80.7)
|
288.0 (224.0 to 348.5)
|
276.0 (84.5)
|
288.0 (224.5 to 339.0)
|
0.031
|
Base diameter, μm
|
686.0 (195.7)
|
704.0 (511.5 to 811.0)
|
708.1 (276.6)
|
629.0 (570.0 to 764.5)
|
0.092
|
Axial length, mm
|
23.8 (1.2)
|
23.7 (22.6 to 25.0)
|
23.6 (1.4)
|
23.6 (22.7 to 24.5)
|
0.178
|
Stage 3 or 4 (%)
|
19 (90.5)
|
19 (90.5)
|
19 (90.5)
|
19 (90.5)
|
0
|
Duration of symptoms, m
|
2.4 (3.6)
|
2.0 (1.0 to 2.0)
|
2.3 (1.5)
|
2.0 (1.0 to 2.8)
|
0.061
|
Wilcoxon’s rank-sum test, Fisher’s exact test.
BCVA = best-corrected visual acuity, MH = macular hole, logMAR = logarithm of minimum angle of resolution, pre-op = pre-operative,
SD = standard deviation, IQR = interquartile range (25th to 75th percentiles)
|
The MH was closed in all cases (21/21) in the peeling group. Though anatomical closure was not achieved in 2 eyes (9.5%) in the flap group, they underwent re-operation and achieved closure. There was no significant difference in the MH closure rate between the groups (P = 0.49).
The visual outcome is shown in Table 2 and Figure 2.
Table 2
Postoperative changes in BCVA and the MH closure rate of the flap group and the peeling group
|
Flap
|
Peeling
|
|
|
n=21
|
n=21
|
P
|
MH closure rate (%)
|
19 (90.5)
|
21 (100)
|
0.49
|
Post-op BCVA
|
logMAR (SD)
|
Snellen
|
logMAR (SD)
|
Snellen
|
|
1M
|
0.49 (0.33)
|
20/62
|
0.43 (0.21)
|
20/54
|
0.81
|
3M
|
0.42 (0.30)
|
20/53
|
0.32 (0.17)
|
20/42
|
0.29
|
6M
|
0.36 (0.26)
|
20/46
|
0.27 (0.18)
|
20/37
|
0.27
|
12M
|
0.28 (0.24)
|
20/38
|
0.24 (0.24)
|
20/35
|
0.48
|
Wilcoxon’s rank-sum test, Fisher’s exact test.
BCVA = best-corrected visual acuity, MH = macular hole, logMAR = logarithm of minimum angle of resolution, SD = standard deviation, post-op = postoperative
|
In the flap group, a significant improvement was noted at 3 months after the surgery and thereafter. Meanwhile, the peeling group showed significant improvement of vision as early as one month after surgery. Nonetheless, there was no significant difference between the two groups in the postoperative BCVA at each time point (P = 0.81, P = 0.29, P = 0.27, and P = 0.48, respectively).
Recoveries of the ELM and EZ were evaluated using OCT images. Though both groups showed gradual recovery, the peeling group showed better anatomical status at 3 and 6 months after surgery (Figure 3). The score for the ELM was higher in the peeling group at 3 months after surgery (P = 0.02), and the score for the EZ was higher in the peeling group at 3 and 6 months after surgery (P = 0.03, P = 0.04, respectively).
To investigate the reason for the delayed ELM and EZ recovery in the flap group, a subgroup analysis was performed by the invert method (cover : 5 eyes or fill : 17 eyes). There was no significant difference between the cover group and the fill group in the MH closure rate (80.0% vs 94.1%, P = 0.41). Meanwhile, improvement of BCVA was better in the cover group than in the fill group at 3 and 6 months after surgery (-0.53 vs -0.21, P = 0.045 and -0.60 vs -0.27, P = 0.049, respectively); this difference was not observed at 12 months after surgery (P = 0.14) (Table 3). The morphological changes of the ELM and EZ in the subgroups are shown in Figure 4. The cover group had significantly higher scores for ELM and EZ recovery than the fill group at 3 months after the surgery (P = 0.02 and 0.01, respectively).
Table 3
Postoperative changes in BCVA and the MH closure rate of the cover group and the fill group
|
Cover
|
Fill
|
|
|
n=5
|
n=17
|
P
|
MH closure rate (%)
|
4 (80.0)
|
16 (94.1)
|
0.41
|
BCVA change
|
logMAR (SD)
|
letters
|
logMAR (SD)
|
letters
|
|
1 M-pre
|
-0.40 (0.3)
|
20
|
-0.16 (0.3)
|
8
|
0.08
|
3 M-pre
|
-0.53 (0.3)
|
27
|
-0.21 (0.3)
|
11
|
0.045
|
6 M-pre
|
-0.60 (0.3)
|
30
|
-0.27 (0.3)
|
14
|
0.049
|
12 M-pre
|
-0.65 (0.3)
|
33
|
-0.32 (0.3)
|
16
|
0.14
|
Wilcoxon’s rank-sum test, Fisher’s exact test.
BCVA = best-corrected visual acuity, MH = macular hole, logMAR = logarithm of minimum angle of resolution, pre = pre-operative, SD = standard deviation
|