Outcome of primary rhegmatogenous retinal detachment using microincision vitrectomy and sutureless wide-angle viewing systems
To evaluate the efficacy of micro-incision vitrectomy surgery (MIVS) using Lumera and Resight non-contact sutureless wide-angle viewing systems (WAVS) for primary rhegmatogenous retinal detachment (RRD), and to analyze the anatomical and visual outcomes.
The retrospective, non-comparative, interventional case series reported here was conducted from June 2014 through November 2016. Enrolled patients presented with primary RRD and received MIVS with/without cryopexy by one surgeon using the Lumera and Resight non-contact sutureless WAVS. All patients were followed-up for a minimum of 12 months. Variables collected included patient demographics, best-corrected visual acuity, and macular status. The number and position of retinal break(s), and the use of cryopexy, were also recorded. Outcome measures included operative time, single-operation anatomical success rate, final anatomical success rate, recurrent rate, postoperative best-corrected visual acuity, and surgical complications. The end points were operative time, anatomical outcome, and functional outcome.
In total, 110 eyes from 110 patients (68 men and 42 women) were treated. Of these, 103 (93%) eyes were reattached after primary vitrectomy. One hundred ten eyes (100%) reached final anatomical success. The mean operative time was 50.55 min. Multivariate analyses were performed with best model selection principle based on general linear model by Akaike Information Criteria for detecting possible factors related to operation time, and with multivariate logistic regression analysis for revealing probable clinical parameters which might influence the anatomical outcome after first operation and final visual outcome. Intraoperative cryopexy and multiple breaks increased operative time significantly. More favorable BCVA was significantly correlated with shorter operation time and the preoperative macula-on status. Multivariate logistic regression on the group of patients who have received the cataract surgery revealed that the pre-operative BCVA is a significant factor which can predict the visual outcome after MIVS.
The outcome of primary RRD repaired by MIVS using the Lumera and Resight sutureless WAVS was not inferior to any other published method. This instrument combination resulted in a relatively rapid and comfortable procedure without serious postoperative complications. Cryopexy and multiple breaks affected operative time significantly. Shorter operative times and preoperative macula-on status are associated with better final visual outcomes.
KeywordsNon-contact wide angle viewing system Sutureless Micro-incision vitrectomy surgery Rhegmatogenous retinal detachment
Best-corrected visual acuity
Micro-incision vitrectomy surgery
Pars plana vitrectomy
Rhegmatogenous retinal detachment
Wide angle viewing systems
A rhegmatogenous retinal detachment (RRD) occurs when at least one retinal tear allows vitreous humor to penetrate into the subretinal space and separate the neurosensory retina from the underlying retinal pigment epithelium. RRD incidence has been reported to be between 6.3 and 17.9 per 100,000 population and demonstrates significant geographical variation . Retinal specialists have long sought to improve methods for repairing the detached retina successfully while causing less damage. The developments of scleral buckling techniques, laser, and intraocular gases have been critical for improved outcomes in the repair of RRD [2, 3, 4]. The first pars plana vitrectomy (PPV), which allows vitreous removal via a closed-system vitreous infusion section cutter, was performed in 1972 [5, 6]. Since then, the instrumentation has evolved from the original 17-gauge cutter to micro-incision vitrectomy surgery (MIVS) [6, 7]. Smaller sutureless sclerotomy wounds result in less postoperative inflammation, greater postoperative patient comfort, and possibly faster postoperative visual recovery [8, 9]. On the other hand, innovations to the viewing system have included the contact lens and noncontact lens wide angle viewing systems (WAVS). The RESIGHT WAVS contains two fixated lenses (128D and 60D) that could be rotated into the light beam easily. Noncontact sutureless WAVS, unlike contact WAVS, do not require either sutures or the aid of skilled assistants to hold the lens in place during surgery [10, 11]. However, the surgeon has to adjust the focus and field of view more frequently during the operation when using noncontact sutureless WAVS than when using contact WAVS. Therefore, whether the noncontact sutureless WAVS shorten the operation is a matter of debate. In Taiwan, retinal detachment is very common, possibly due to the high incidence rate of myopia. The number of patients requiring surgery exceed the capacity of hospitals that can perform pars plana vitrectomy. In order to arrange PPV as soon as possible, a safe and faster method of operation is necessary for these patients. To our best knowledge, there have been few publications reporting the operation time of MIVS using noncontact sutureless WAVS. In the present study, we therefore set out to assess the operation time, analyze influencing factors, and offer a compatible data for MIVS using noncontact sutureless WAVS. In addition, we recorded and discuss the anatomical and visual outcomes.
All surgeries were performed after administration of retrobulbar anesthesia. The trocar and infusion cannula were inserted. 25-gauge MIVS without scleral buckling was performed using the Alcon Constellation vitrectomy system (Ft Worth, TX, USA) and Lumera 700 and Resight (Carl Zeiss Meditec) noncontact type sutureless WAVS. A 23-gauge 6 mm trocar was only used for infusion cannula in patients with hypotony. Core and peripheral vitrectomy were performed with careful attention directed toward relieving all tractional forces on the peripheral retina and on all identified retinal breaks, which were marked with endocautery. Intravitreal triamcinolone was used in all cases to identify and remove the vitreous and epiretinal membrane as completely as possible. Scleral depression was performed through the noncontact sutureless WAVS to check for possible iatrogenic breaks. Fluid–air exchange with a soft-tip extrusion needle and active suction was used to drain subretinal and posterior pole fluid. Endolaser retinopexy was performed both before and after the fluid–air exchange. Transconjunctival cryopexy was used in cases of anterior retinal breaks. Internal limiting membrane peeling was not performed in any of the surgeries. Nonexpansile mixtures of either perfluoropropane (C3F8) or sulfur hexafluoride (SF6) were used in all cases. At the conclusion of each procedure, Levofloxacin eyedrops were placed on the surface of the eye followed by a patch and shield. Patients were instructed in either face-down or one-sided post-operative positioning for 14 days.
Variables collected for the study include patient demographics, preoperative best-corrected visual acuity (BCVA), intraocular pressure (IOP), lens status, and macular status. Operation records retrospectively reviewed include the number of retinal breaks noted after scleral depression, the use of cryopexy, the type of gas tamponade used, and the operation time. The postoperative IOP and the postoperative final BCVA, defined as the BCVA during follow up in patients (or in the cases of patients who subsequently underwent cataract surgery, the BCVA after the latter surgery), were also recorded.
Outcome measures included the average operation time, single-operation anatomical success rate, final anatomical success rate, postoperative BCVA, and surgical complications. All analyses were carried out using SPSS statistics 22.0. P < 0.05 was considered statistically significant. Multivariate analyses were performed with best model selection principle based on general linear model by Akaike Information Criteria (AIC) for detecting possible factors related to operation time, and with multivariate logistic regression analysis for revealing probable clinical parameters which might influence the anatomical outcome after first operation and final visual outcome.
Baseline characteristics and intraoperative management
Out of 110 patients initially surveyed for the study, 110 eyes met the inclusion criteria. The median age of the patients was 54.77 years. Of the 110 cases, 68 (61.8%) were male and 42 (38.2%) were female. The mean preoperative BCVA was 20/224 (1.05 logMAR), and the mean preoperative IOP was 13.42 mmHg. Of the 110 eyes, 98 (89%) were phakic and the remaining (11%) were pseudophakic. The macula was attached preoperatively in 41 (37.2%) of 110 eyes, while macula detachment was present in the remaining eyes (62.8%). During the operation, single breaks were noted in 39 (35.5%) eyes, and multiple retinal breaks were found in 71 (64.5%) eyes. Transconjunctival cryopexy was applied adjuvant to laser on 40 (36.4%) eyes. C3F8 was used as gas tamponade after MIVS in 79 (71.8%) eyes, while SF6 was used in 31 (28.2%) eyes.
Potential Factors Affecting Operation Time
Number of Cases
Mean operation time (mins)
Age ≤ 50
Age > 50
Number of breaks
Potential Factors Affecting Anatomical Outcomes
Potential Factors Affecting the Final BCVA
Multivariate analysis. a) Model of prediction for operation time by general linear model (GLM). b) Model of prediction for visual acuity improvement by multivariate logistic regression. c) Model of prediction for visual acuity improvement by multivariate logistic regression only in group of patients who have received cataract surgery
Pr > F
Use of Cryopexy
Pr > ChiSq
Odds Ratio (95% CI)
C statistics (AUC)
Pre-operative VA (logMar)
Pr > ChiSq
Odds Ratio (95% CI)
C statistics (AUC)
Pre-operative VA (logMar)
Post-PPV cataract formation can considerably decrease vision even the function of retina is well improved. In order to identify the factors affecting visual outcome after the single operation, we further excluded the preoperative phakic eyes that did not undergo cataract surgery after MIVS, as well as the eyes with recurrent RRD. Sixty eyes remained, and visual outcome was analyzed with respect to preoperative measures and surgical factors. The results are summarized in Table 3. More favorable BCVA was significantly correlated with shorter operation times (p < 0.05) and the preoperative macula-on status (p < 0.05). Focusing on improvement of BCVA, multivariate logistic regression on the group of patients who have received the cataract surgery revealed that the pre-operative BCVA is a significant factor which can predict the visual outcome after MIVS (for every 0.1 logMAR increase of pre-operative VA, the odds of successful operation will increase 30.4%, c statistics = 0.91, Table 4c).
No expulsive choroidal hemorrhages, hypotony or endophthalmitis occurred during or after any of the operations.
In this study, we report the results of a retrospective analysis on the repair of primary RRD through sutureless MIVS with the use of a noncontact sutureless WAVS. The noncontact sutureless WAVS have several advantages over the hand-held irrigating lens systems or the self-irrigating fixed contact lens retaining ring system . The noncontact sutureless WAVS does not require an experienced assistant to hold the lens in place, thus the risk of excessive pressure on the cornea, causing corneal epithelial defect or edema, is avoided. Furthermore, fixation sutures for the lens ring, which may induce subconjunctival hemorrhage, are not necessary.
However, corneal surface dehydration and lens condensation could significantly decrease the visibility of the fundus image, and this requires occasional irrigation of the corneal surface or cleaning of the front lens [12, 13]. With BIOM (Oculus Surgical, Inc), Merlin (Volk Optical, Inc.) and OFFISS (Topcon Medical Inc.) noncontact WAVS, focus is achieved by moving entire lens support system up and down to adjust the distance between the cornea and front lens. With Resight noncontact sutureless WAVS, focusing is done internally, using a vario lens system. The distance between the wide-angle lens and the cornea remains constant. Through the 60D lens, epiretinal membrane removal can be done clearly.
Owing to this, it was a common assumption that the operation time of sutureless MIVS using noncontact sutureless WAVS is not decreased despite the high anatomical success rate reported (between 74 and 92.9%) [7, 8]. There have been no previous studies describing the operation time of transconjunctival sutureless MIVS using Resight noncontact sutureless WAVS. We report the average operation time to be 50.55 min, and anticipate this to be used as a data of comparison between different kinds of viewing systems.
Furthermore, we noted that the operation time was not influenced by the preoperative factors of patients, including age, lens status, and macula status. In other words, MIVS can be performed smoothly and widely using a Resight noncontact sutureless WAVS even if the patient has a mild to moderate cataract or intraocular lens. The presence of macular detachment, i.e., the arrangement of subretinal fluid that needs to be drained, did not affect the operation time. However, the relationship of age and operation time calls for careful explanation because of the trend noted (p = 0.051). In our study, operation times were longer for patients younger than 50 years old, though not significantly. This may be a result of the additional time spent to induce posterior vitreous detachment in younger patients.
Cryopexy and multiple breaks were only two significant factors which influenced operation time, confirmed by multivariate analysis. The use of adjuvant transconjunctival cryopexy increased operation time significantly (p < 0.05), because cryopexy was performed in extremely peripheral retinal breaks in which attempts with focal laser coagulation were tried but ceased in order to avoid touching the lens with the laser probe. RRD with multiple breaks also increased the operation time significantly (p < 0.05), as more laser spots were applied around the breaks.
The single-operation success rate in this study was 93.6%, which is comparable to rates in previous reports of either contact or noncontact WAVS. In our experience, MIVS using noncontact sutureless WAVS is a surgical procedure with consistent anatomical outcomes independent of preoperative variables and surgical factors, including age, BCVA, IOP, refraction, lens status, macular status, the use of adjuvant cryopexy, the type of gas tamponade used, and the operation time. Further analysis of recurrent cases is limited due to small case numbers. Nevertheless, among the 7 eyes with recurrent RRD, 5 eyes had more than 2 breaks (up to 8 breaks) and at least one break located inferiorly.
Multivariate logistic regression model revealed the pre-operation VA is the only factor might predict the improvement of VA compared to pre-operative level. Because there is the best level, 20/20, about the visual acuity, patients with poor pre-operation VA have more possibility of VA improvement. Therefore, PPV with WAVS is still worth to perform on patients with poor VA and macula-off status although final BCVA may not good.
Focusing on the patients who were pseudophakic before MIVS and who underwent cataract operation after MIVS, final BCVA was significantly superior in the pre-MIVS macula-on group and was proportional with shorter operation time. That patients with macula-on RRD will have better visual outcomes is a well-documented event [14, 15, 16, 17], and our study supports this observation. That a shorter operation time is correlated with less tissue damage, sooner recovery time, and better outcomes, is another observation in our daily clinical practice. However, to our best knowledge, this is the first study to quantify the relationship between operation time and final BCVA. Even though sutureless transconjunctival MIVS using noncontact sutureless WAVs is a surgery involving very small wounds and without contact with the cornea, there are still possible factors that generate stress to intraocular tissue. The illuminator may cause phototoxicity to the photoreceptor and retinal pigment epithelium in the macula area . Lower temperatures of infusion fluid potentially exert unknown effect on cell metabolism . The turbulent flow of the infusion tube could induce direct mechanical trauma to the retinal tissue . Shorter operation time minimized these retinal damage-causing factors and presumably improved visual outcome. Our study offered evidence of the clinical experiences of a medical center in Taiwan.
There are several limitations to this study. This study was retrospective and the sample size was relatively small. There was no control group of contact WAVS for the operation time because Dr. CJ Lin only uses non-contact sutureless WAVS at China Medical University Hospital. Nevertheless, the comparison between preoperative and intraoperative variables was made and showed significant results.
Although these factors limit the strength of our conclusions, this study nonetheless demonstrates that sutureless MIVS using the Lumera and Resight sutureless noncontact WAVS is an effective method for primary repair of RRD. The single-operation anatomical success rate is 93.6%, comparable to those of previous studies. BCVA improved significantly after MIVS. The mean operation time is 50.55 min, and is prolonged when adjuvant cryopexy is performed or in cases of RRD with multiple breaks. Finally, shorter operation time and pre-MIVS macula-on status are associated with better final visual outcomes.
LCT, KWH, LCJ, BH, LJM, CWL, TPT and TYY were responsible for substantial contributions to the conception or design of the work, and acquisition of data. LCT, KWH, LCJ and CHS were responsible for interpretation of results. LCT, KWH and LCJ participated in the design, and were major contributors in writing the manuscript. LCT, KWH, LCJ and BH were responsible for final approval of the version to be published. All authors reviewed and approved the final manuscript.
Ethics approval and consent to participate
The need for approval was waived due to deidentification.
This study was approved by the Institutional Review Board of the China Medical University Hospital (IRB No. CMUH 106-REC2–054), Taiwan, and complied with the principles outlined in the Declaration of Helsinki.
Consent for publication
The authors declare that they have no competing interests.
- 3.Ahmadieh H, Moradian S, Faghihi H, Parvaresh MM, Ghanbari H, Mehryar M, et al. Anatomic and visual outcomes of scleral buckling versus primary vitrectomy in pseudophakic and aphakic retinal detachment: six-month follow-up results of a single operation--report no. 1. Ophthalmology. 2005;112(8):1421–9.CrossRefGoogle Scholar
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