General characteristics
A total of 332 patients (343 eyes) were included in this study. The mean age of the patients was 49.2 ± 10.4 years (range: 18 to 78 years). The mean duration of follow-up was 18.4 ± 9.1 months (range: 12 to 43 months). The mean time between symptom onset and surgery was 12.5 days ± 7.4 days (range: 3 to 110 days). In total, 321 (93.6%) eyes were phakic and 22 (6.4%) eyes were pseudophakic. Retinal detachment was macula-on in 134 eyes (39.1%) and macula-off in 209 eyes (60.9%). Retinectomy was conducted in 38 eyes (11.1 %). Following retinal reattachment, the recurrence of RD after PPV for primary RRD was observed in 42 of the 343 eyes (12.2%) during the follow-up period. The mean time from the recurrence of RD to initial RRD repair was 5.3 months ± 2.7 months (range: 2 to 13 months). Twenty-nine cases (69%) were diagnosed with recurrent RD within 6 months of the initial PPV for RRD.
The effect of various perioperative factors on the recurrence of RD
In order to compare the effects of various factors on the recurrence of RD, we divided our patient population into a recurrence group and reattachment group. A comparison of the perioperative characteristics of the two groups of patients are shown in Table 1. The two groups showed similar perioperative characteristics, except for the presence of PVR ≥ Grade C. Univariate analysis demonstrated that the presence of PVR ≥ Grade C was a risk factor that was significantly associated (P = 0.003) with the recurrence of RD. Both groups of patients showed a similar distribution of age, gender, lens status, number of breaks, duration of detachment, extent of retinal detachment, high myopia, macula status, PVD, giant retinal tears, choroidal detachment, use of perfluorocarbon liquid, retinectomy, and combined cataract surgery. The BCVA did not differ statistically between the groups at baseline (P = 0.342). We also performed logistic regression analysis in a step-by-step manner to evaluate confounding variables. Logistic regression revealed that PVR ≥ Grade C (odds ratio [OR]: 9.421; 95% confidence interval [CI]: 2.432 - 56.39, P=0.020) was a significant predictor for the recurrence of RD.
Table 1. A comparison of perioperative characteristics between the recurrence group and reattachment group
Parameter
|
Overall
(n = 343 eyes)
|
Recurrence group (n = 42 eyes)
|
Reattachment group (n = 301 eyes)
|
P-value
|
Gender, n (%)
|
|
|
|
|
Male
|
172 (50.1)
|
20 (47.6)
|
152 (50.5)
|
0.727a
|
Female
|
171 (49.9)
|
22 (52.4)
|
149 (49.5)
|
|
Age, mean ± SD
|
49.2± 10.4
|
49.9 ± 11.7
|
48.7 ± 11.3
|
0.268b
|
Laterality, n (%)
|
|
|
|
|
Right eye
|
184 (53.6)
|
23 (54.8)
|
161 (53.5)
|
0.877a
|
Left eye
|
159 (46.4)
|
19 (45.2)
|
140 (46.5)
|
|
Lens status, n (%)
|
|
|
|
|
Phakic
|
321 (93.6)
|
38 (90.5)
|
283 (94.0)
|
0.38a
|
Pseudophakic
|
22 (6.4)
|
4 (9.5)
|
18 (6.0)
|
|
Detachment duration (days), mean ± SD
|
12.5 ± 7.4
|
12.1 ± 9.1
|
12.9 ± 8.5
|
0.607b
|
Quadrants of RRD, mean ± SD
|
2.8 ± 0.79
|
2.7 ± 0.69
|
2.8 ± 0.61
|
0.478b
|
High myopia, n (%)
|
24 (7.0)
|
3 (7.1)
|
21 (6.9)
|
0.968a
|
BCVA (logMAR) at baseline, mean ± SD
|
1.07 ± 0.51
|
1.04 ± 0.59
|
1.1 ± 0.53
|
0.342b
|
Macular status
|
|
|
|
|
On
|
134 (39.1)
|
18 (42.9)
|
116 (38.5)
|
0.591a
|
Off
|
209 (60.9)
|
24 (57.1)
|
185 (61.5)
|
|
PVD (%)
|
238 (69.4)
|
29 (69.0)
|
209 (69.4)
|
0.959a
|
Giant retinal tears, n (%)
|
13 (3.8)
|
2 (4.8)
|
11 (3.6)
|
0.725a
|
Number of breaks, n (%)
|
|
|
|
|
Single breaks
|
243 (70.8)
|
31 (73.8)
|
212 (70.4)
|
0.652a
|
Multiple breaks
|
100 (29.2)
|
11 (26.2)
|
89 (29.6)
|
|
Choroidal detachment
|
23 (6.7)
|
3 (7.1)
|
20 (6.6)
|
0.904a
|
PVR≥Grade C, n (%)
|
31 (9.0)
|
9 (21.4)
|
22 (7.3)
|
0.003a
|
Retinectomy, n (%)
|
38 (11.1)
|
6 (14.3)
|
32 (10.6)
|
0.480a
|
Perfluorocarbon liquid, n (%)
|
56 (16.3)
|
8 (19.0)
|
48 (15.9)
|
0.611a
|
Cataract surgery, n (%)
|
28 (8.2)
|
4 (9.5)
|
24 (8.0)
|
0.731a
|
Abbreviations: BCVA: best-corrected visual acuity; logMAR: logarithm of minimal angle of resolution; PVD: posterior vitreous detachment; RRD: rhegmatogenous retinal detachment; SD: standard deviation; PVR: proliferative vitreoretinopathy
aP values according to chi-square tests.
bP values according to t-tests.
P values that are statistically significant (<0.05) are given in bold.
Causes and visual outcomes of patients with recurrent RD
We found that PVR was the main cause of RD recurrence. Overall 25 eyes (59.5%) were shown to have posterior PVR, 6 eyes (14.3%) had anterior PVR, and 3 eyes (7.1%) had a combination of anterior and posterior PVR. In other cases of RD, 5 eyes (11.9%) showed missed and/or new retinal breaks, 2 cases (4.8%) were caused by reopening of the primary retinal breaks, and one eye (2.3%) had a macular hole. In 34 cases, we performed another vitrectomy and used silicone oil to repair RD. A further 8 cases received scleral buckling (SB) surgery.
Silicone oil is usually removed 3 months after primary RRD repair if the retina was attached. In our present series, 12 (28.6%) cases showed re-detachment while the silicone oil was still retained in the eye. Of these 12 patients, 5 patients presented with an inferior RD, which was treated with a second round of SB surgery. Six cases presented with partial RD caused by PVR and underwent a second vitrectomy and oil procedure, while 3 cases underwent retinectomy. One case developed recurrent RD because of a new retinal break; this condition was treated with vitrectomy and oil. Anatomic reattachment was achieved in all of these patients. Thirty cases (71.4%) developed recurrent RD following the removal of the silicone oil. The mean duration of time to recurrent RD following the removal of silicone oil removal was 2.9 ± 1.2 months. With regards to the eyes that developed recurrent RD after the removal of silicone oil, 3 eyes achieved anatomical reattachment following the SB procedure, while a further 24 eyes underwent a second PPV and endolaser photocoagulation. If necessary, we also performed membrane peeling (epiretinal or subretinal), internal limiting membrane peeling, vitrectomy, and silicone oil endotamponade.
Of the 42 patients in which primary PPV failed, we successfully attached the retina in 39 (92.9%) cases during the second round of surgery. Three cases required a third round of surgery. At the final follow-up visit, the retina had successfully reattached in 41cases. One of these patients had silicone oil and tamponade at the final follow-up. In one further case, RD persisted, despite the eye being filled with oil. However, this patient did not wish to undergo further surgery because vision was light conception only.
Recurrent RD resulted in a significant reduction in BCVA at the last follow-up visit when compared with the group of patients without recurrent RD. The mean BCVA at the last follow-up visit was 0.45 ± 0.32 logMAR in the reattachment group, and 0.71 ± 0.22 logMAR in the recurrence group. Visual acuity at final the final follow-up visit was worse in the recurrence group than in the reattachment group (P=0.000). Eyes with PVR prior to primary surgery, or those diagnosed with re-detachment, showed a worse BCVA at the last follow-up visit. The mean final LogMAR BCVA was 0.89 ± 0.27 in cases of PVR, whereas the mean final LogMAR BCVA was 0.63 ± 0.29 in eyes without PVR (P=0.002).