To assess the functional and anatomical outcome of primary vitrectomy without scleral buckling for rhegmatogenous retinal detachment (RRD) in highly myopic eyes with axial length over 30 mm.
In this retrospective, interventional case series, we evaluated the outcome of primary vitrectomy without scleral buckling in 67 highly myopic patients (67 eyes) with RRD. Anatomical success rate was defined as complete reattachment of the retina without definitive silicone oil tamponade.
Retinal reattachment was achieved with a single surgery in 49 of 67 eyes (73.1%) and after 2 or 3 surgeries in 54 eyes (80.6%). The characteristics of retinal tears did not influence the final outcome. Multivariate analysis revealed that a longer axial length was the only factor associated with a higher failure rate, p = 0.0061. Mean preoperative visual acuity significantly increased after surgery, p = 0.0003.
The study demonstrated fair efficacy of vitrectomy and fluid–gas exchange in the treatment of retinal detachment in highly myopic eyes with an axial length over 30 mm.
Eur J Ophthalmol 2013; 23(4): 564 - 570
Article Type: ORIGINAL RESEARCH ARTICLE
AuthorsBrice Dugas, Alain M. Bron, Grégoire Minoyan, Serge Aho, Jean-Paul Berrod, Catherine P. Creuzot-Garcher
- • Accepted on 26/02/2013
- • Available online on 28/03/2013
- • Published in print on 31/05/2013
This article is available as full text PDF.
Scleral buckling (SB) and pars plana vitrectomy (PPV) are the main surgical procedures used to treat retinal detachment (RD). The latter procedure has gained popularity over the past 20 years and has proven to be effective in the treatment of various types of RD (1-2-3). Moreover, SB may lead to postoperative complications such as refractive change, diplopia, explant erosion or infection, and a risk of decreased retinal blood flow and anterior segment ischemia (4, 5). The prognosis of RD in highly myopic eyes has long been considered very poor. The challenge comes from the diversity of lesions at the origin of the RD. These lesions can be peripheral retinal tears, posterior paravascular tears (PVT), and macular hole (MH). Moreover, the vitreous base and consequently peripheral tears are more posterior in high-myopic eyes. These features make indentation location more difficult and hazardous.
In 1982, Gonvers and Machemer proposed a new treatment for RD with MH consisting of combined PPV, partial fluid–gas exchange, and face-down positioning for 12 hours (6). Recently, it was shown that epiretinal membrane (ERM) and inner limiting membrane (ILM) were the cause of tangential traction leading to the formation and enlargement of MH and to the reopening of MH and relapsing RD (7). Additional ILM removal proved to be essential in achieving reattachment and macular closure according to some authors (8-9-10-11). Very few articles concerning RD with PVT of the postequatorial region have been published. In 1984, Benson and Tasman successfully treated 3 cases of shallow posterior rhegmatogenous RD caused by tiny paravascular breaks using vitrectomy without thermal adhesion (12). Pars plana vitrectomy with gas tamponade has been proven to be an effective treatment for RD with rhegmatogenous peripheral retinal tears, whatever their location (13, 14). In this study, we retrospectively analyzed the characteristics of RD treated in highly myopic eyes, defined as having an axial length (AL) over 30 mm, and focused on the anatomical and functional results of the cases treated with PPV without SB.
PATIENTS AND METHODS
The protocol of this retrospective study was approved by the local ethics committee of Burgundy, France, and followed the tenets of the Declaration of Helsinki. A total of 840 cases of RD consecutively treated with PPV from October 1, 1999, to February 28, 2005, were reviewed in 2 academic centers. All patients underwent near and far visual acuity measurements using projected-light Snellen charts converted to the logarithm of minimal angle of resolution (logMAR) and intraocular pressure (IOP) measurement with a Goldmann tonometer. A careful peripheral retina examination before the surgical procedure was done with a Goldmann 3-mirror lens (three-mirror lens 903, Haag-Streit, Köniz, Switzerland) and a wide-field lens (SuperQuad 160, Volk Optical, Mentor, Ohio, USA) to locate tears. Axial length was measured by A-mode echography (Aviso, Quantel Medical, Les Ulis, France). On the basis of AL greater than 30 mm, 67 eyes of 67 patients with at least 24-month follow-up in our department were selected, including RD secondary to peripheral breaks (retinal tears, atrophic retinal hole) and those secondary to posterior breaks (MH, PVT). Two surgeons performed the surgical procedures (J.-P.B. and C.P.C.-G.). Exclusion criteria included RD secondary to severe eye injury, diabetic retinopathy, retinopathy of prematurity, uveitis, or hereditary disease.
Preoperative data recorded for the patients included age, sex, side, duration of symptoms, AL, visual acuity, lens status, extent of the RD, and its proliferative vitreoretinopathy (PVR) degree using the PVR classification according to Machemer (15).
Patient visits took place at 1 week, 1 month, 3 months, and 6 months. Visual acuity, IOP, fundus examination results, and postoperative complications were reported. Anatomical success was defined as complete reattachment without definitive silicone oil tamponade. The total number of operations to obtain retinal reapplication and their nature were also recorded.
Anesthesia consisted of general anesthesia or peribulbar anesthesia with sedation depending on the patient’s and anesthesiologist’s preferences. A standard 3-port 20-gauge vitrectomy under a wide-angle viewing contact lens (Oculus, Wetzlar, Germany) was performed. Peripheral vitreous shaving was completed under slit-lamp illumination without a contact lens by gentle scleral indentation. Posterior hyaloid detachment was checked with a prepapillary suction with the vitreotome and completed in most cases. Epiretinal membrane removal or internal limiting membrane (ILM) peeling was performed without dye when it was present. In general, the latter procedure was not conducted for RD secondary to peripheral retinal tears without PVR or ERM but was done in almost all cases related to posterior break. Subretinal fluid was aspirated through the retinal tear, the MH, the PVT, or through a retinotomy to obtain complete intraoperative retinal reattachment. Retinopexy was performed with cryotherapy and/or laser photocoagulation after complete fluid–air exchange. When retinopexy was done, only the retinal breaks (RB) were treated with transscleral cryopexy or endophotocoagulation. The MH rim was not photocoagulated. Tamponade was chosen among 3 long-acting gases: sulfur hexafluoride (SF6), hexafluoroethane (C2F6), or perfluoropropane (C3F8). In a few cases, a silicone oil tamponade was used momentarily at the third surgery. Combined cataract surgery was performed when lens opacities restricted proper fundus examination and posterior surgical maneuvers. Cataract surgery consisted of clear corneal incision, continuous curvilinear capsulorhexis, phacoemulsification, and intracapsular lens implantation according to preoperative biometry.
Visual acuity was measured using Snellen charts and was then transformed into logMAR units for statistical analysis (16). Data are reported as median, range, interquartile range (IQR) since the continuous variables were not normally distributed (Kolmogorov-Smirnov test) (17). Comparisons were made with the Fisher exact test for dichotomous data. Nonparametric tests were used for continuous variables, the Mann-Whitney test or the Wilcoxon test for nonpaired and paired variables, respectively. The relationship between outcome (success) and each of the explanatory variables was modeled as a logistic regression with a robust variance estimator. The multinomial explanatory variables were used as such or transformed into dummy variables. Fractional polynomials were used to examine the log-linearity assumption. Model fit was assessed using the Hosmer-Lemeshow goodness-of-fit test. Exact logistic regression was used to confirm the final model. Odds ratios (OR) and 95% confidence intervals were reported for the surgical outcome associated with patient age, AL, baseline visual acuity, PVR, number and type of retinal tears, the type of the surgery, and the surgeon (J.-P.B. or C.P.C.-G.). All analyses were conducted using STATA version 12.0 (STATACORP, College Station, TX, USA). The level of statistical significance was set at p<0.05 and the tests were 2-tailed.
The registration number of our trial is NCT01480505 and the registration information is available at
Sixty-seven eyes of 67 patients were included in our study. Their characteristics are displayed in
PREOPERATIVE CHARACTERISTICS OF THE PATIENTS PRESENTING WITH RETINAL DETACHMENT IN HIGHLY MYOPIC EYES WITH AN AXIAL LENGTH OVER 30 MM (N = 67)
|characteristics||Values (total n = 67)|
|IQR = interquartile range.|
|aGrade A: vitreous haze, vitreous pigment clumps, vitreous clusters on inferior retina. Grade B: wrinkling of inner retinal surface, retinal stiffness, vessel tortuosity, rolled and irregular edge of retinal break, decreased mobility of vitreous. Grade CP 1-12: posterior to equator: focal, diffuse, or circumferential full-thickness folds; subretinal strands. Classification of retinal detachment from Machemer et al (34).|
|No. (%) of eyes|
|Age, y, median (range), IQR||50 (13-80), 16|
|Sex, n (%)|
|Duration of symptoms, d, median (range), IQR||7 (1-120), 9|
|Median axial length, mm, median (range), IQR||31.6 (30.1-37.9), 2.4|
|Laser treatment history, n (%)||6 (8.9)|
|Lens status, n (%)|
|Peripheral breaks, n (%)||31 (46.3)|
|Round retinal hole||3 (4.5)|
|Horseshoe tear||25 (37.3)|
|Horseshoe tear + macular hole||1 (1.5)|
|Giant retinal tear||2 (3.0)|
|Posterior breaks, n (%)||31 (46.3)|
|Macular hole||15 (22.4)|
|Paravascular tear||11 (16.5)|
|Paravascular tear and macular hole||5 (7.4)|
|No breaks found, n (%)||5 (7.4)|
|Extent of retinal detachment, n (%)|
|1 quadrant||4 (6.0)|
|2 quadrants||15 (22.4)|
|3 quadrants||17 (25.4)|
|4 quadrants||31 (46.2)|
|Proliferative vitreoretinopathy, n (%)a|
|Grade A||4 (6.0)|
|Grade B||15 (22.4)|
|Grade CP||0 (0)|
SURGICAL PROCEDURES USED AT THE FIRST INTERVENTION IN PATIENTS PRESENTING WITH RETINAL DETACHMENT IN HIGHLY MYOPIC EYES WITH AN AXIAL LENGTH OVER 30 MM (N = 67)
|Procedures||Values, n (%)|
|By a retinal break||58 (86.6)|
|By a retinotomy||9 (13.4)|
|Cryotherapy and laser||8 (12)|
Anatomical success, defined as complete reattachment of the retina without definitive silicone oil tamponade, was achieved in 49 (73.1%) of 67 eyes after the first surgery and 52 (77.6%) after the second surgery. Two RDs were successfully treated after a temporary use of silicone (9 and 10 months, respectively) with a third surgery. The overall final success as defined above was obtained in 54 eyes (80.6%). Among our 13 failures, 11 eyes needed definitive silicone tamponade and 2 eyes were not further operated. In the group of RD secondary to peripheral RB, anatomical success was achieved in 25 out of 31 eyes (80.6%) after the first surgery and 27 (87.1%) after subsequent surgeries. In the group of RD secondary to posterior RB, anatomical success was achieved in 21 out of 31 eyes (67.7%) after the first surgery and 23 (74.2%) after subsequent surgeries. In the group without any RB, anatomical success was achieved in 3 out of 5 eyes (60%) after the first surgery and 4 (80%) after subsequent surgeries. The different success rate was similar among groups after one or several surgeries (p = 0.41 and p = 0.35, respectively). We also considered separately the outcome of cases with MH and giant retinal tears (n = 23) and did not find any statistical difference when compared to the other cases (p = 0.55 and p = 0.53) after a single surgery and after 2 or 3 surgeries, respectively.
Peripheral RB were divided according to their size: break size less than 3 optic disc diameters (ODD) and break size over 3 ODD including giant retinal tears. In the former group, the success rate at the first operation was significantly higher, with 18 reattachments out of 21 eyes (86%), than in the latter group, with 4 reattachments out of 10 eyes (40%) (p = 0.02). The location of the retinal tears did not affect the outcome of the surgery since the rate of success was 63.6% and 77.8% (p = 0.25) for superior and inferior locations, respectively.
The lens status of the eyes, the type of surgery performed (combined surgery vs PPV alone), the PVR, and the type of retinopexy did not influence the results (p = 0.76, p = 0.71, p = 0.52, and p = 0.16, respectively). The AL was significantly higher in failure cases than in success cases (32.2 [30.2-37.9], 3.43 mm vs 31.5 [30.0-35.1], 1.9 mm, respectively, p = 0.03). In our logistic regression model, the only variable statistically associated with failure was the AL (OR = 1.51, 95% confidence interval 1.12-2.03, p = 0.0061). Mean preoperative visual acuity significantly increased from 3.00 (0.22-3.00), 1.7 logMAR to 0.70 (0.22-3.00), 2.48 logMAR at the last follow-up (p = 0.0003).
The major cause of failure was the reopening of the initial break and among the 18 relapses at first surgery, 8 eyes were treated with new gas tamponade. We observed several intraoperative complications including 7 cases of iatrogenic retinal tears during PPV, 1 case of luxation of the intraocular lens in the anterior chamber, 1 case of subfoveal hemorrhage, and 1 case of subchoroidal hemorrhage. Postoperatively, one MH without RD developed in a patient who did not have any ILM peeling and was successfully treated with a second fluid–gas exchange, a tamponade with C2F6, and ILM peeling. Eleven cataract extractions were done with no complications during the follow-up, with a mean delay of 8 months. We observed an IOP elevation in 8 cases, treated with topical IOP-lowering agents in 7 cases and 1 case needed transscleral diode laser cyclophotocoagulation. Silicone oil migration into the anterior chamber of an aphakic eye led to an enlargement of the initial inferior iridectomy performed during the surgery.
The treatment of RD in highly myopic eyes is particularly challenging due to the diversity of initial RB, the presence of chorioretinal atrophy precluding laser treatment, poor retinal adhesion to the underlying pigment epithelium, and posterior staphyloma. Moreover, the posterior location of the RB limits SB use. In our series, we found an overall anatomical success rate of 73.1% after the first surgery (defined as complete reattachment without definitive silicone oil tamponade), 77.6% and 80.6% after 2 and 3 surgeries, respectively. This primary anatomic success rate is comparable to the results published in most studies for nonmyopic patients (18). Morita et al found refractive error, myopic choroidal change, and posterior staphyloma as risk factors for MH developing into RD (19). As shown in different studies, posterior staphyloma is one of the main causes of MH evolving into RD in highly myopic eyes and of relapse in this type of RD (9, 20, 21). In our study, with univariate analysis, the size of RB in the peripheral RB group and the AL in the overall group were found to be correlated with the anatomical success rate. However, when using a logistic regression model, the AL was the only statistically significant parameter associated with RD failure: each additional millimeter from 30 mm led to a 51% increased risk of failure. Similar observations were published recently in patients undergoing MH surgery in MH without RD; the outcome was less favorable in eyes with high myopia than in non-high myopia (22, 23).
We used a longer-acting gas tamponade (C2F6, C3F8) in RD secondary to breaks in the posterior region (MH or PVT) or in relapses than in RD related to peripheral RB. The aim was to allow longer contact of the macula with the choroid by countering the stretching force caused by the inadequacy between the posterior curvature and the retina surface. Hence laser photocoagulation and cryopexy produced less consistent and permanent adhesion on atrophic and pale areas. Uemoto et al found C3F8 to be more effective than SF6 in the treatment of MH-related RD in highly myopic eyes (24). The high prevalence of choroidal atrophic areas led us to prefer cryopexy when possible. In contrast with previous reports, we did not face an increased risk of PVR when using cryopexy, probably because cryopexy was performed after fluid–air exchange without remaining subretinal fluid, avoiding any migration of retinal pigment epithelial cells into the vitreous cavity. The rate of PVR at initial presentation was quite low, with only 22.4% of the patients exhibiting grade B PVR. Indeed, cryopexy was not related to the worst anatomical outcomes in RD with grade B PVR when used adequately (25). In our series we did not find a statistically significant difference in the outcome no matter which technique was used, cryopexy or laser photocoagulation (p = 0.16).
Tangential tractions exerted by vitreous cortex, ERM, or ILM increase the centrifugal stretching force; this was proposed as a causative factor of MH-related RD and of MH reopening. Pars plana vitrectomy with removal of these structures as initial treatment was reported (7, 26). In our study, ERM and ILM were systematically removed as completely as possible, especially when preretinal fibrosis was noted. Sometimes the ERM was friable and firmly adherent to the retina and could be difficult to remove as a single sheet. In case of relapse, the macular area was closely checked for the presence of any overlying structure to be peeled. In our experience, epiretinal structures are sometimes more easily peeled off during a second surgery required by RD relapse. At the time of our study (1999-2005), retinal dyes were not commonly used (27). However, since 2008, we have systematically used triamcinolone acetonide to identify and cut the vitreous cortex and Brilliant Blue G for ILM peeling to avoid indocyanine green’s potential toxicity (28-30). These dyes facilitate and shorten the procedure and increase the quality and the peeling area. Therefore the outcome should be improved by means of dyes to better identify preretinal fibrosis.
In MH-related RD, the major cause of relapse was a reopening of the MH. When long-acting gas tamponade was used and ERM and ILM removed, recurrence was treated with a permanent and stable tamponade such as silicone oil, which ensured sufficient glial membrane development across the area of the MH (31). In our study, silicone tamponade was definitively left in the vitreous cavity in 5 cases of MH-related RD. Complementary photocoagulation of the macular rim was done intraoperatively in one case and postoperatively in another case under silicone tamponade. This may be proposed as the last attempt to reattach the retina (32). One-third of phakic eyes undergoing RD surgeries also had their cataract removed at the same time. The advantage of a combined procedure lies in a more complete vitrectomy and more convenience for the patient (33). Most of the phakic eyes developed cataract within the year following vitrectomy. Cataract surgery in these eyes may be difficult due to the deepness of the anterior chamber and greater zonule fragility.
We acknowledge several important limitations to our study. The relative rarity of RD in highly myopic eyes leads investigators to include RD secondary to diverse RB ranging from MH to peripheral horseshoe tear. The characteristics of the retinal tears did not influence the final outcome in our series. This unexpected finding could be related to the small sample in each group. Other weaknesses are the study’s retrospective nature and the lack of a control group.
The present study demonstrates fair efficacy of vitrectomy and fluid–gas exchange without SB in the treatment of RD in highly myopic eyes with AL over 30 mm. Longer ALs were associated with an increased rate of RD surgery failure in these eyes.
- Dugas, Brice [PubMed] [Google Scholar] 1
- Bron, Alain M. [PubMed] [Google Scholar] 1
- Minoyan, Grégoire [PubMed] [Google Scholar] 1
- Aho, Serge [PubMed] [Google Scholar] 2
- Berrod, Jean-Paul [PubMed] [Google Scholar] 1
- Creuzot-Garcher, Catherine P. [PubMed] [Google Scholar] 1, * Corresponding Author (email@example.com)
Department of Ophthalmology, University Hospital, Dijon - France
Department of Epidemiology, University Hospital, Dijon - France