|Year : 2016 | Volume
| Issue : 1 | Page : 42-46
Comparison between 20-, 23-, and 25-G transconjunctival sutureless vitrectomy in the surgical treatment of idiopathic macular hole and idiopathic epiretinal membrane
Ahmed M Bedda, Hesham F Elgoweini, Ahmed M Abdel-Hady, Osama R El-Naggar
Ophthalmology Department, Faculty of Medicine, Alexandria University, Alexandria, Egypt
|Date of Submission||22-Apr-2015|
|Date of Acceptance||05-Aug-2015|
|Date of Web Publication||16-Mar-2016|
Osama R El-Naggar
49 Elgeish Street, Elibrahimia, Alexandria 2026
Source of Support: None, Conflict of Interest: None
The aim of the present study was to compare 20, 23, and 25-G transconjunctival sutureless vitrectomy (TSV) systems in the management of idiopathic macular hole and idiopathic epiretinal membrane (EMM) as regards the operative time and postoperative complications such as hypotony (as shown by intraocular pressure<8 mmHg), retinal detachment, or endophthalmitis.
Patients and methods
This prospective, comparative, randomized clinical study was carried out on 60 consecutive patients undergoing TSV at a single center and by the same surgeon. Included patients were with preoperative diagnoses of idiopathic macular hole (group A) and idiopathic EMM (group B). Ten patients of each group were randomly allocated to 25-, 23-, or 20-G TSV subgroups using a table of random numbers. Three-port pars plana vitrectomy with internal limiting membrane peeling in group A with gas tamponade and EMM peeling in group B was carried out.
In group A, the mean duration of surgery in the 20-G TSV subgroup was 43.7 ± 1.89 min compared with 42.5 ± 2.01 min in the 23-G subgroup and 43.5 ± 1.84 min in the 25-G subgroup. There was no statistically significant difference between the three subgroups. In group B, there was no statistically significant difference between the three subgroups, with a mean time of surgery of 35.8 ± 1.81 min in the 20-G subgroup versus a mean time of 37.9 ± 2.33 and 37.3 ± 1.98 min in the 23-G and the 25-G subgroups, respectively. In group A, the intraocular pressure was within the normal range in all follow-up periods in the three subgroups and no reported cases of hypotony either in the early or late follow-up periods. In group B, there was a statistically significant difference only in the first follow-up period between the three subgroups, as two cases of hypotony in the 20-G subgroup and two cases in the 25-G subgroup were reported, all of which resolved without sequelae. There were no cases of postoperative endophthalmitis in any case of either group A or group B. There were no cases of postoperative retinal detachment in any case of either group A or group B in all follow-up periods.
The current study indicated no increased risk of postoperative complications such as hypotony, endophthalmitis, or retinal detachment during sutureless vitrectomy.
Keywords: 23-, 2-, 25-G, complications, sutureless, transconjunctival, vitrectomy
|How to cite this article:|
Bedda AM, Elgoweini HF, Abdel-Hady AM, El-Naggar OR. Comparison between 20-, 23-, and 25-G transconjunctival sutureless vitrectomy in the surgical treatment of idiopathic macular hole and idiopathic epiretinal membrane. Delta J Ophthalmol 2016;17:42-6
|How to cite this URL:|
Bedda AM, Elgoweini HF, Abdel-Hady AM, El-Naggar OR. Comparison between 20-, 23-, and 25-G transconjunctival sutureless vitrectomy in the surgical treatment of idiopathic macular hole and idiopathic epiretinal membrane. Delta J Ophthalmol [serial online] 2016 [cited 2021 Nov 27];17:42-6. Available from: http://www.djo.eg.net/text.asp?2016/17/1/42/178775
| Introduction|| |
Pars plana vitrectomy (PPV) is one of the most common surgical procedures performed for the treatment of various vitreoretinal diseases such as retinal detachment, vitreous hemorrhage, proliferative diabetic retinopathy, epiretinal membrane (EMM), and macular hole (MH) .
Traditionally, most vitrectomy surgical systems utilize the 20-G instruments. PPV includes multiple incisions including peritomy (opening of the conjunctiva) and sclerotomy. Since the introduction of PPV in 1971, one of the most revolutionary developments in vitreoretinal surgery over the past few years has been transconjunctival sutureless vitrectomy (TSV) .
Fujii et al. , introduced the 25-G TSV in 2002; however, many vitreoretinal surgeons use it only in limited cases because of the inborn high flexibility of 25-G instruments.
A 23-G TSV, introduced by Eckardt  in 2005, offers firmer instruments and supports easier use by the vitreous surgeon who is more familiar with the 20-G instruments rather than the 25-G instruments. This may help the surgeon to convert from 20-G vitrectomy to TSV. This offers a number of potential advantages including decreased surgical trauma, less postoperative inflammation, and faster postoperative recovery time. Eliminating suturing may also shorten total operating time ,,.
There has been a continuous expansion in the clinical indications for the 23-G vitrectomy system. With the increase in the spectrum of various 23-G instruments and improved surgical techniques, the indications for any 23-G system are now almost identical to the conventional 20-G system ,.
Twenty-three-gauge vitrectomy has also been successfully applied in the treatment of retinal detachment, and the primary anatomical success rate appeared to be comparable to the conventional 20-G PPV .
The main drawback of this is that an unsutured wound would not hold at the end of the surgery and may leak postoperatively, causing hypotony, as the sclerotomy could remain open for some time or require a vitreous plug to seal the eye. Postoperative hypotony has been described with different incidence rates ,.
Moreover, since the conjunctiva is covering the incision, it is difficult to visualize whether some vitreous fibers are trapped inside the scleral opening, thus increasing the risk of endophthalmitis .
In 2007, a new 20-G transconjunctival trocar system (DORC, Zuidland, Holland), which allowed the use of the conventional 20-G vitrectomy in sutureless surgeries, was introduced. It is analogous to the 23-G system; a tangential tunnel is made with a bend stiletto and the trocars are introduced with a blunt inserter in a two-step technique .
| Aim|| |
The aim of the present study was to compare 20-, 23-, and 25-G TSV systems in the management of idiopathic MH and idiopathic EMM as regards the operative time and postoperative complications such as, hypotony [defined as intraocular pressure (IOP) <8 mmHg], retinal detachment, or endophthalmitis.
| Patients and methods|| |
A prospective, comparative, and randomized clinical trial was carried out on 60 consecutive patients undergoing transconjunctival microincision sutureless vitrectomy at a single center and by the same surgeon (A.M.B.).
Patients were given full information on the study, and were informed about its benefits and risks, and then a written consent was obtained from them before the surgery.
Included were patients with preoperative diagnoses of idiopathic full-thickness MH (group A) and idiopathic epimacular membrane (EMM) (group B).
Ten patients of each group were randomly allocated to 25-, 23-, or 20-G TSV subgroups using a table of random numbers.
Preoperative evaluation included history-taking, preoperative refraction, and best-corrected visual acuity, anterior segment examination, IOP measurement, biomicroscopic fundus examination, and colored fundus photography, fluorescein angiography, and optical coherence tomography.
- The conjunctiva was displaced 2 mm laterally and an angled tunnel incision 15-30° was made parallel to the limbus through the conjunctiva, sclera at the pars plana 3.5 or 4 mm from the limbus.
- PPV, internal limiting membrane peeling with intraocular gas tamponade was carried out in all cases with idiopathic MH (group A), whereas in eyes with idiopathic EMM (group B), the membrane was removed and the internal limiting membrane was peeled off when needed.
- At the end of the surgery, the microcannulas were withdrawn from the scleral tunnel incision without suturing of the sclera or the conjunctiva.
- Using a cotton tip applicator gentle pressure was applied on the sclerotomy site to enhance the sealing of sclerotomy, and to return the displaced conjunctiva to its original position.
Intraoperative and postoperative complications such as sclerotomy site wound leakage, hypotony, retinal tear, retinal detachment, or endophthalmitis were recorded.
| Results|| |
A total of 60 eyes of 60 patients were included in the current study.
[Table 1] shows the operative time for eyes with the MH (group A); the mean duration of surgery in the 20-G sutureless vitrectomy subgroup was 43.7 ± 1.89 versus 42.5 ± 2.01 min in the 23-G subgroup and 43.5 ± 1.84 min in the 25-G subgroup. There was no statistically significant difference in the three subgroups as regards the operative time.
|Table 1: Comparison between the studied subgroups regarding operative time|
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[Table 2] shows the operative time for the eyes with epimacular membrane (group B). There was no statistically significant difference in the three subgroups as regards the operative time, with a mean time of surgery 35.8 ± 1.81 min in the 20-G subgroup versus mean time of 37.9 ± 2.33 and 37.3 ± 1.98 min in the 23- and 25-G subgroups, respectively.
[Table 3] shows the incidence of hypotony in the MH group (group A). The IOP was within the normal range in all follow-up periods in the three subgroups and there were no reported cases of postoperative hypotony either in the early or late follow-up periods. In addition, there were no reported cases of IOP elevation that needed IOP-lowering measures.
|Table 3: Comparison between different studied subgroups in group A regarding incidence and mean value of hypotony at different period of follow-up|
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In the epimacular membrane group (group B), there were two cases of hypotony in the 20-G subgroup and two cases in the 25-G subgroup; all of them resolved without sequelae. There was a statistically significant difference only in the first follow-up period (first day after surgery) between the three subgroups, as shown in [Table 4].
|Table 4: Comparison between different studied subgroups in group B regarding incidence and mean value of hypotony at different period of follow-up|
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There were no cases of postoperative endophthalmitis in any case of either group A or group B. There were no cases of postoperative retinal detachment in any case of either group A or group B in all the follow-up periods.
| Discussion|| |
The aim of the current study was to compare 20-, 23-, and 25-G TSV systems in the management of idiopathic MH and idiopathic EMM as regards the time of the surgery, intraoperative, and postoperative complications.
As regards the operative time, both 25- and 23-G vitreous cutters were slower in performing vitrectomy than was the 20-G cutter, but this did not significantly influence the total operating time. On the contrary, the operative duration was reduced, since the time for conjunctival dissection, fixation of the infusion line, and suturing of both sclerotomies and conjunctiva was avoided.
In a randomized trial of 67 patients with EMMs, the total operating time in the 20-G group was 34.1 min, as opposed to 24.3 min in the 25-G group .
In their comparative study in the MH surgery with 25- and 20-G instruments, Shinoda et al.  reported that the operative time was significantly shorter in the 25-G group (56 ± 16 min) than in the 20-G group (85 ± 28 min).
Two other randomized studies reported no difference in total operating times between the two techniques. They found that any time saved in wound opening and closure was lost because of the longer duration of vitrectomy ,.
In the current study, the authors did not compare the sutured 20-G vitrectomy with the sutureless technique, as all the cases were sutureless. In the eyes with MH (group A) the mean duration of surgery for the 20-G sutureless vitrectomy subgroup was 43.7 ± 1.89 versus 42.5 ± 2.01 min for the 23-G subgroup and 43.5 ± 1.84 min for the 25-G subgroup, and there was no statistically significant difference in the three subgroups as regards the operative time.
In the epimacular membrane group (group B), there was no statistically significant difference in the three subgroups as regards the operative time, with a mean time of surgery of 35.8 ± 1.81 min in the 20-G subgroup versus a mean time of 37.9 ± 2.33 and 37.3 ± 1.98 min in the 23- and 25-G subgroups, respectively.
As regards postoperative hypotony, in the original description of 25-G TSV, an IOP less than 8 mmHg was observed in the first postoperative day in four out of 35 (11%) eyes, although normal pressures were reported at the end of the first week in all cases .
Other authors have reported higher rates of hypotony, and in one recent series of 111 eyes following 25-G vitrectomy with straight incisions, the hypotony rate at 2 h after the operation was 26.12%, decreasing to 17.11% at the first postoperative day, and to 8.10% at the end of the first week .
In the vast majority of reported cases, the hypotony resolved without any sequelae. A rate of choroidal effusion of 3.8% was reported in one series of 140 eyes on day 1, but all cases had resolved without additional treatment by the end of the first postoperative week .
In the study by Eckardt , no hypotony occurred, showing the self-sealing property of the technique.
In the current study, there were four cases of postoperative hypotony with IOP less than 8 mmHg in the first postoperative day, two cases in the 20-G subgroup, and the other two cases in the 25-G subgroup in epimacular membrane cases (group B) in the first postoperative day and this was statistically significant.
No cases of retinal detachment were reported at any of the follow-up periods. In their study, Oshima et al.  reported 0.7% of retinal detachments after a series of 150 eyes undergoing combined 25-G vitreous and cataract surgery.
In a series of 75 eyes, Okuda et al.  found 5.3% of the cases where retinal peripheral breaks had occurred without causing a retinal detachment. They seemed to be free of vitreous traction, and therefore, were successfully managed by using laser-photocoagulation.
Scartozzi et al.  performed a single-institution review of 347 consecutive eyes having undergone pars plana 20- or 25-G vitrectomy for MH and macular pucker repair, and found a slightly lower trend for peripheral sclerotomy-related retinal breaks in the 25-G vitrectomy group (3.1 vs. 6.4% in the 20-G group); Eckardt  presented similar retinal findings after surgery compared with those after 20-G vitrectomy, and did not mention any breaks or detachment in his series.
The first reported case of endophthalmitis following 25-G surgery was published in 2005 . The concept that angled rather than straight incisions are protective against infection is further supported by a study by Shimada et al. , who were the first to find no difference in endophthalmitis rates between 20-G (one per 3592) and 25-G TSV (one per 3343). Eckardt  did not report any case of endophthalmitis in his series.
In this current study, there were no cases of postoperative endophthalmitis in any case of either group A or group B.
| Conclusion|| |
TSV demonstrated favorable anatomic results and early visual rehabilitation, and there was no increased risk of postoperative complications such as hypotony, endophthalmitis, or retinal detachment during sutureless vitrectomy.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]