Citation: Saleh OA,
Al-Dwairi RA, Mohidat H, Jusufbegovic D, Nesmith B, Barak Y, Mimouni M, Schaal
S. International multi-center study of iatrogenic retinal tears in pars plana
vitrectomy. Int J Ophthalmol 2019;12(6):996-1000
DOI:10.18240/ijo.2019.06.19
·Clinical Research·
International multi-center study of iatrogenic retinal
tears in pars plana vitrectomy
Omar A. Saleh1, Rami
A. Al-Dwairi1, Hasan Mohidat1, Denis Jusufbegovic2,
Brooke Nesmith2, Yoreh Barak3, Michael Mimouni3,
Shlomit Schaal4
1Department of Ophthalmology, Jordan University of Science
and Technology, Irbid 22110, Jordan
2Department of Ophthalmology and Visual Sciences,
University of Louisville, Louisville, Kentucky 40202, United States
3Department
of Ophthalmology, Rambam Health Care Campus, Haifa 3109601, Israel
4Department
of Ophthalmology and Visual Sciences, University of Massachusetts Medical
School, Worcester, Massachusetts 01605, United States
Correspondence to: Omar A. Saleh. Department of Ophthalmology, Jordan University of Science
and Technology, 3030 Ramtha Str, Irbid 22110, Jordan. omarsaleh80@yahoo.com
Received:
Abstract
AIM: To study and compare the effect
of different surgical settings on the development of iatrogenic retinal tears
(IRT) in conventional (20-gauge) and microincisional vitrectomy.
METHODS: An international retrospective
comparative study of 394 patients who had simple vitrectomy at three tertiary
centers. Surgeries were performed by four retina surgeons using different
viewing systems. Two groups of eyes were compared: microincisional vitrectomy
(327 eyes) and conventional (67 eyes) vitrectomy. An iatrogenic tear was
defined as the occurrence of one or more peripheral retinal tears during
surgery or at any visit in the first 6wk postoperatively.
RESULTS: Mean age was 67±12y and 55%
were female. Iatrogenic tears occurred in 11/394 (2.8%) of eyes. The rate of
tears was similar among different surgeons and viewing systems (P=0.93
and P=0.76, respectively). Surgical indication, preexisting
pseudophakia/aphakia, induction of posterior vitreous detachment (PVD) during
surgery, and the use triamcinolone acetonide didn’t significantly affect the
rate of tears (P>0.1 for all factors). A higher rate of tears was
found in the conventional group compared to the microincisional group
(respectively, 7.5%, 1.8%, P=0.02).
CONCLUSION: The rate of IRT in vitrectomy
is not significantly affected by surgical indication, preexisting PVD or
pseudophakia, or use of triamcinolone or different viewing systems but is
significantly higher in conventional vitrectomy. Microincisional platforms
improve the safety of vitrectomy regardless of the viewing system used.
KEYWORDS: microincisional; vitrectomy; iatrogenic; retinal tear; 20-gauge
DOI:10.18240/ijo.2019.06.19
Citation: Saleh OA, Al-Dwairi RA, Mohidat H, Jusufbegovic D,
Nesmith B, Barak Y, Mimouni M, Schaal S. International multi-center study of
iatrogenic retinal tears in pars plana vitrectomy. Int J Ophthalmol
2019;12(6):996-1000
INTRODUCTION
Pars plana vitrectomy (PPV) has evolved over the past few decades and is
the standard surgical procedure for the management of a wide range of
vitreoretinal pathologies including retinal detachment, proliferative diabetic
retinopathy (PDR), and macular conditions such as epiretinal membranes (ERMs)
and macular holes (MHs). Iatrogenic retinal tears (IRT) may complicate PPV and
may lead to rhegmatogenous retinal detachment (RRD) which necessitates further
surgical management and may substantially affect the final visual outcome and
patient satisfaction. Thus, understanding the circumstances and risk factors
that may affect the development of IRTs in PPV can help surgeons make certain
modifications in the surgical platform, technique, and instrumentation in order
to minimize the chance of occurrence of retinal tears.
The documented incidence of IRTs after PPV is variable among studies and
ranges from less than 1% to approximately 24%[1-2]. This inconsistency may be attributed to the lack of
standardization of surgical technique among different surgeons and to other
factors including surgical indication, type and location of the retinal breaks
reported, instrument gauge, use of dyes during surgery, lens status, and the
presence of preexisting posterior vitreous detachment (PVD) at time of surgery[1-3].
The purpose of this study is to report the incidence and the effect of
certain factors on the development of IRT in simple conventional (20 gauge) and
microincisional vitrectomy surgery (MIVS).
SUBJECTS AND METHODS
Ethical Approval This was an international
multicenter retrospective study with the collaboration of several investigators
affiliated to institutions in the United States, Jordan, and Israel. We were
given approval to conduct the study by the institutional review board at each
of the University of Louisville, KY, USA, the Jordan University of Science and
Technology, Irbid, Jordan, and the Technion-Israel Institute of Technology,
Haifa, Israel.
A retrospective chart review was performed on patients who underwent PPV at
the ophthalmology department in each of the institutions between 2/2013 and
4/2016. We collected existing medical data and no patients’ personal
identifiers were recorded. Data collected included patient demographics and
surgical information including indication of PPV, instrument gauge, dilated
fundoscopy before and after surgery, preexisting pseudophakia/aphakia, use of
preservative-free triamcinolone acetate (TA) to visualize the vitreous during
surgery, presence of preexisting PVD, viewing system used, name of surgeon, and
occurrence of IRT with or without RRD during surgery and up to 6wk
postoperatively. Exclusion criteria included incomplete medical records, follow
up period of less than 6wk postoperatively, history of previous PPV, and the
indication for the study PPV being RRD or a complex pathology with an inherent
risk for the development of tears including advanced PDR, uveitis, trauma, and
congenital malformations.
In all patients, standard 3-port PPV was performed by four different retina
surgeons (Barak Y, Barr C, Saleh O, Schaal S) at three different ophthalmology
centers. One type of vitrectomy machine was used (Stellaris PC®,
Bausch+Lomb, Bridgewater, NJ, USA) with vitrectomy cutting rate values ranging
from 2000-5000 cut per minute and vacuum values ranging from 150
For studying the effect of different factors on the rate of IRT, eyes were
divided into comparison groups according to the gauge of PPV surgery, the
indication for surgery, the presence of pseudophakia/aphakia, the presence of PVD,
the use of TA, the viewing system used, and the surgeon.
Statistics All data collected in the study were
recorded onto an electronic database via Microsoft Excel 2007 (Microsoft
Corporation). Statistical analyses were performed using Minitab version
RESULTS
Overall, 394 eyes of 394 patients fulfilled the inclusion criteria and were
included in the final analysis. Microincisional PPV was performed in 327 eyes
(25-gauge: 256, 23-gauge: 32, 27-gauge: 39) and 20-gauge PPV in 67 eyes. The
mean age was 67±12y and 55% (n=218) were female. As demonstrated in
Table 1, demographic parameters were similar among eyes with and without IRT.
Table 1 Demographic and baseline characteristics of all 394 patients with
comparison between eyes with and without the development of IRT
|
Parameters |
Iatrogenic tear (n=11) |
No iatrogenic tear (n=383) |
P |
|
Age (y) |
66.2±12.8 |
66.8±11.8 |
|
|
Gender, female (%) |
45.5 |
55.1 |
0.53b |
|
Ethnicity, ME/C/AA (%) |
45/55/0 |
40/55/5 |
0.98b |
|
MH (%) |
36 |
30 |
0.55b |
|
ERM (%) |
36 |
48 |
0.74b |
|
Preexisting PVD at time of surgery (%) |
64 |
45 |
0.76b |
|
Preexisting pseudophakia/aphakia at time of surgery
(%) |
63 |
73 |
0.52b |
IRT: Iatrogenic retinal tears; ME: Middle Eastern; C: Caucasian; AA:
African American; MH: Macular hole; ERM: Epiretinal membrane; PVD: Posterior
vitreous detachment. aStudent’s t-test; bChi-square
with Yates correction.
The most common indication for PPV was ERM (48%, n=189), followed by
MH (30%, n=117), vitreous hemorrhage (12%, n=47), vitreomacular
traction syndrome (5%, n=19), central retinal artery occlusion (2%, n=9),
submacular hemorrhage secondary to advanced age related macular degeneration
(1%, n=5), symptomatic floaters (1%, n=4), and dislocated or
dropped intraocular lens (1%, n=4). No significant association was found
between ERM or MH and the rate of tears (P=0.74 and P=0.55
respectively). The proportion of eyes that had preexisting PVD or preexisting
pseudophakia/aphakia at the time of surgery was similar in patients with and
without IRT (P=0.76 and P=0.52, respectively).
IRTs were detected in 2.8% of the eyes (n=11). All tears were flap
(horse-shoe) tears of variable sizes. In one eye, three IRTs developed (at 5,
7, and 11 o’clock positions) while a single tear occurred in the rest. Eight
tears (62%) were within 2 clock hours of the sclerotomy sites while two
occurred at the 6 o’clock position, and one at each of the 5 o’clock, 7
o’clock, and 12 o’clock positions. The IRTs were detected before the conclusion
of surgery in 7 eyes (64%), a week after surgery in 3 eyes (27%) and about a
month after surgery in 1 eye (9%). A significantly higher rate of tears was
found in the 20-gauge PPV group (5 tears, 7.5%) than in the MIVS group (6
tears, 1.8%; P=0.02). One eye with a single tear progressed to RRD (0.3%
of all eyes). The IRT was detected along with the RRD one week following
20-gauge PPV. The RRD was successfully treated with PPV and silicone oil
tamponade. Table 2 depicts the intraoperative variables of eyes with and
without IRT.
Table 2 Intraoperative variables in all 394 patients with comparison
between eyes with and without the development of IRT %
|
Parameters |
Iatrogenic tear (n=11) |
No iatrogenic tear (n=383) |
Pa |
|
20-gauge PPV |
45 |
16 |
0.02 |
|
Triamcinolone acetonide used |
64 |
71 |
0.74 |
|
Viewing system, BIOM/AVI/RESIGHT/EIBOS |
46/18/18/18 |
38/32/19/12 |
0.76 |
|
Retina surgeons (Barak Y, Barr C, Saleh O, Schaal
S) |
36/27/18/18 |
43/26/17/14 |
0.93 |
IRT: Iatrogenic retinal tears; PPV: Pars plana vitrectomy; BIOM: BIOM®
(OCULUS Surgical, Inc., Wetzlar, Germany); AVI: A.V.I.® (Advanced
Visual Instruments, Inc., NY, USA); RESIGHT: Resight 700® (Carl
Zeiss Meditec AG, Jena, Germany); EIBOS: EIBOS® (HAAG-STREIT
SURGICAL, Wedel, Germany). aChi-square with Yates correction.
Triamcinolone was used to visualize the vitreous in the majority of our
patients (70%, n=277) but that didn’t significantly affect the rate of
IRT (P=0.74). Surgeries were performed by four retina surgeons each
using a different type of contact or non-contact binocular panoramic indirect
fundus viewing system (Table 2). The BIOM® platform was used in 38%
of cases, the A.V.I.® in 32%, the Resight 700® in 19%,
and the EIBOS® in 12%. The rate of IRT was similar among the
different surgeons and the different viewing systems (P=0.93 and P=0.76,
respectively).
DISCUSSION
The overall rate of IRT in PPV was found to be 2.8% in our study, which is
similar to rates documented by some studies of IRTs in conventional and MIVS[4-5], but is considered relatively low
when compared to other similar studies in the literature[1,3,6-7]. It is possible
that such variability among studies may be partly attributed to differences in
surgical techniques and settings or patient demographics. Additionally, the
definition of an IRT may differ from one study to another. For example, Ehrlich
et al[3] reported IRT in 29 out of 184 eyes
which underwent PPV (15.7%) but included tears that occurred posterior to the
equator, which accounted for almost half of the documented tears. Similarly,
Tan et al[7] reported IRT in 28 out of 177
PPV cases (16%) but only 9 tears were sclerotomy-related. In our study, we
excluded retinal tears posterior to the equator as such tears are usually a
result of direct retinal injury during surgical manipulations in the macula and
included in our statistical analysis only IRTs located anterior to the equator,
which are usually attributed to peripheral mechanical traction on the retina
close to the vitreous base during exit and entry of instruments through the
sclerotomies or vitreous incarceration within the sclerotomies[3,8]. Accordingly, our documented rates
of 1.8% in MIVS and 7.5% in conventional PPV are in keeping with other similar
reports from groups who adopted this definition of IRT. In addition, the
distribution of our observed IRTs, with the majority being
sclerotomy-associated, and the rest occupying both superior and inferior
locations appears compatible with similar studies[4-5,9].
The difference in the rate of IRTs between MIVS and conventional PPV in our
study was statistically significant, which is consistent with many recent
studies which compared these two surgical platforms[1-2,4-5,10-11]. It is postulated that the smaller sclerotomies and
the cannulated ports used in MIVS offer safer passage for instruments with less
tractional forces exerted on the vitreous base and may therefore reduce the
incidence of sclerotomy-associated retinal tears[2,4,10,12].
It is interesting to note that among the different conditions in our study
the rate of IRT was similar. Most related investigations in this regard found
increased rates of IRT in PPV for MH relative to PPV for ERM[1,6,13-16]. Based on
the fact that most cases of MH repair require PVD induction during surgery, it
is not surprising to find a parallel trend for a higher rate of IRT in numerous
studies that investigated intraoperative induction of PVD[2,6-7,9-10,16-17]. Several reports, on the other
hand, found no difference in the rate of IRT for ERM or MH surgeries and no
increased risk with intraoperative PVD induction[7,10,15].
Most retinal breaks occur just posterior to the vitreous base and may not
be readily visible to the surgeon especially in cases of macular surgery where
the field of view is focused in the center. It is possible to improve
visualization of the vitreous gel as well as other ocular transparent tissues
by the use of vital dyes during PPV, a technique called chromovitrectomy[18]. One example of such a dye is TA. We wanted to
investigate if such visual facilitation in the surgical technique may possibly
play a role in reducing the likelihood of IRTs. Several case series have shown
the intraoperative usefulness of TA in PPV[19-20]. Yamakiri et al[21]
studied the effect of use of TA on the rate of complications, including IRTs,
in 774 cases of PPV in Japan, and found that retinal tears were significantly
less likely to occur in TA-assisted PPV. Covert et al[10],
in contrast, didn’t find a statistical difference in the rate of IRT with the
use of TA. Although more than two thirds of our PPV cases were TA-assisted, we
found no lowered incidence of IRT in these eyes.
The last parameters we looked at were the viewing systems used in PPV and
the operating surgeons. Each of our four different qualified retina surgeons
used a different indirect viewing system. We found that neither the type of
viewing system nor the surgeon who performed the surgery had a statistically
significant effect on the rate of IRT. Varying conclusions exist in the
literature in that regard. Some suggested that the operating surgeon may be a
crucial factor in that rate of IRT, even more important than the preoperative
diagnosis, whereas others found no significant connection[4,21].
To the best of our knowledge, our report is the first to study the type of
viewing system used in PPV as a potential factor affecting the rate of IRTs. In
addition, our report is the first to include in the analysis all available
gauges of vitrectomy platforms, including 39 cases of 27-gauge surgeries.
Limitations to our study include its retrospective nature with its inherent
risks of bias, lack of randomization of patients to the gauge of surgery or
viewing system, lack of standardization of the surgeon and surgical techniques,
and method used for detection of the peripheral retinal tears. Nonetheless,
several points of strength in our study can be mentioned including the extended
follow up period of 6wk after surgery for detection of IRTs and/or RRD which,
as reported by Wimpissinger and Binder[22], may
well develop after surgery, on average 37d postoperatively. We also excluded
from analysis complex-pathology cases with inborn tendency for IRT such as
proliferative retinopathies and uveitis to produce more accurate results. In
addition, the number of cases in our series is reasonably high and the
inclusion of almost forty cases of 27 gauge PPV is considered new.
To summarize, we investigated the development of iatrogenic peripheral
retinal tears in 394 cases of simple vitrectomy surgeries indicated mostly for
macular disease and found that the rate is significantly higher in 20-gauge
compared to MIVS (7.5% vs 1.8%). We also report no significant
association between the rate of tears and any of the following factors:
indication for surgery, preexisting PVD, use of TA, the surgeon performing the
surgery, and the viewing system used.
ACKNOWLEDGEMENTS
All authors substantially
contributed to the work and fulfilled the authorship criteria including concept
and design, data acquisition, manuscript drafting, data analysis and
interpretation, technical and administrative support, critical revision, and
supervision.
Conflicts of Interest: Saleh OA, None; Al-Dwairi RA, None; Mohidat
H, None; Jusufbegovic D, None; Nesmith B, None; Barak Y, None;
Mimouni M, None; Schaal S, None.
REFERENCES