Primary vitrectomy for rhegmatogenous retinal detachment in pseudophakic eyes: 20-gauge versus 25-gauge vitrectomy

Clinical features of retinal detachment treated with segmental scleral buckling

PURPOSE

Our study aims to evaluate the surgical outcomes and clinical features of retinal detachment (RD) cases treated with segmental scleral buckling (SB), elucidating the role of segmental SB as a vital option in specific situations during the current era.

METHODS

We retrospectively reviewed 128 eyes with primary rhegmatogenous RD that underwent segmental scleral buckling between November 2008 and December 2020. Clinical features and success rates were recorded and analyzed.

RESULTS

A total of 128 eyes were included. The patient's ages ranged from 12 to 72 years, with a median age of 45. Most of the eyes were phakic (97%). Regarding the type of break, 47% were holes, and flap tears were found in 68 cases (53%). The break locations were superior-temporal (54%), inferior-temporal (31%), superior-nasal (9.5%), and inferior-nasal (5.5%). The length of the SB applied ranged from 3.5 to 8.0 clock hours, with a median of 6.0. Primary success was achieved in 121 eyes, and recurrence occurred in 7 eyes. All recurrent RD cases reattached after undergoing secondary VT. The causes of failure included 2 break reopens, 1 missed break, and 4 eyes with proliferative vitreoretinopathy. The single-surgery anatomic success (SSAS) rate for segmental SB was 94.5%. The final success rate was 100%.

CONCLUSIONS

For phakic, low complexity retinal detachment in our study, segmental scleral buckling emerges as a surgical option with a high primary success rate and a lower incidence of complications.

The Role of Preoperative Case Selection in the Training of Surgical Repair of Primary Rhegmatogenous Retinal Detachment

Purpose

To analyse single-operation anatomical success (SOAS) of primary rhegmatogenous retinal detachment (RRD) repair by junior vitreoretinal surgeons guided by preoperative individual case selection by an experienced mentor vitreoretinal surgeon.

Methods

Retrospective, single institute, observational study, included all patients who underwent standard pars plana vitrectomy (PPV) or combined encircling band (CB) and PPV and gas tamponade in the treatment of RRD from November 2021 to December 2022 were included. Preoperative selection for the surgery decision, whether standard PPV or combined CB & PPV was undertaken through the senior surgeon; according to the location and extensions of the RRD, number of retinal tears (RT) and lens status. We excluded patients with tractional retinal detachment, RD with proliferative vitreoretinopathy stage C, giant tears, trauma, previous scleral buckle, schisis RD and RD requiring silicone oil. The primary outcome measure was to evaluate the single-operation anatomic success (SOAS). Secondary outcome measures evaluated whether there was a statistical significant difference between both procedures.

Results

Eighty-two eyes were included in the study. Forty-five eyes were selected for combined CB&PPV and 37 eyes for standard PPV. SOAS was achieved in 40 eyes (88.8%) in combined group and 35 eyes (94.5%) in standard PPV group. There was no statistically significant difference in the success rate between both operations, p = 0.65.

Conclusion

Structured preoperative selection of standardized surgical techniques according to the degree of complexity of RD together with close supervision enables junior vitreoretinal surgeons in training to achieve re-attachment rates of more than 80% with both types of surgeries.

Design and Conduct of Randomized Clinical Trials Evaluating Surgical Innovations in Ophthalmology: A Systematic Review

PURPOSE

Surgical innovations are necessary to improve patient care. After an initial exploratory phase, novel surgical technique should be compared with alternative options or standard care in randomized controlled trials (RCTs). However, surgical RCTs have unique methodological challenges. Our study sought to investigate key aspects of the design, conduct, and reporting of RCTs of novel surgeries.

DESIGN

Systematic review.

METHODS

The protocol was prospectively registered in PROSPERO (CRD42021253297). RCTs evaluating novel surgeries for cataract, vitreoretinal, glaucoma, and corneal diseases were included. Medline, EMBASE, Cochrane Library, and Clinicaltrials.gov were searched. The search period was January 1, 2016, to June 16, 2021.

RESULTS

A total of 52 ophthalmic surgery RCTs were identified in the fields of glaucoma (n = 12), vitreoretinal surgery (n = 5), cataract (n = 19), and cornea (n = 16). A description defining the surgeon's experience or level of expertise was reported in 30 RCTs (57%) and was presented in both control and intervention groups in 11 (21%). Specification of the number of cases performed in the particular surgical innovation being assessed prior to the trial was reported in 10 RCTs (19%) and an evaluation of quality of the surgical intervention in 7 (13%). Prospective trial registration was recorded in 12 RCTs (23%) and retrospective registration in 13 (25%); and there was no registration record in the remaining 28 (53%) studies.

CONCLUSIONS

Important aspects of the study design such as the surgical learning curve, surgeon's previous experience, quality assurance, and trial registration details were often missing in novel ophthalmic surgical procedures. The Idea, Development, Exploration, Assessment, Long-term follow-up (IDEAL) framework aims to improve the quality of study design.

Effect of Changes in Surgical Strategies for the Treatment of Primary Rhegmatogenous Retinal Detachment on Functional and Anatomical Outcomes: A Retrospective Analysis of 812 Cases from the Years 2004 to 2012

Background: At the Department of Ophthalmology and Optometry at the MUV surgical method (scleral buckling, vitrectomy, combined vitrectomy/scleral buckling) and timing (daytime, nighttime) for the treatment of primary rhegmatogenous retinal detachment (RRD) changed continuously in the years 2004 to 2012. This study aims to evaluate changes in surgical strategies over time including their impact on functional and anatomical outcomes. Methods: Retrospective evaluation of patients operated on primary RRD between the years 2004 and 2012. Baseline demographic data, month 3 best-corrected visual acuity (BCVA), surgical method, single success surgery, surgical timing, and intraoperative complications were analyzed. Results: Overall, 812 eyes of 812 patients with a mean (±SD) age of 58.1 ± 13.3 years were included. A total of 413 (51%) patients presented with macula-on and 359 (44%) with macula-off RRD. Month 3 BCVA increased over time, both in macula-on or macula-off groups (p < 0.001). The rate of complete retinal reattachment 3 months postoperatively increased significantly from 65% in 2004 to 83% in 2012 in both groups. Scleral buckling surgeries decreased continuously from 95% to 16% with an appropriate increase in vitrectomies as well as a decrease in surgeries during nighttime (68% in 2004, 6% in 2012) with equal or better visual and functional outcomes. Conclusion: Our data showed that improving functional and single-success surgery outcomes in patients operated on for primary RRD. In the years 2004 to 2012, surgical techniques shifted from scleral buckling to primary vitrectomy and were increasingly scheduled during the daytime.

Advances in Vitreoretinal Surgery

Advances in vitreoretinal surgery provide greater safety, efficacy, and reliability in the management of the several vitreoretinal diseases that benefit from surgical treatment. The advances are divided into the following topics: scleral buckling using chandelier illumination guided by non-contact visualization systems; sclerotomy/valved trocar diameters; posterior vitrectomy systems and ergonomic vitrectomy probes; chromovitrectomy; vitreous substitutes; intraoperative visualization systems including three-dimensional technology, systems for intraoperative optical coherence tomography, new instrumentation in vitreoretinal surgery, anti-VEGF injection before vitrectomy and in eyes with proliferative diabetic retinopathy, and new surgical techniques; endoscopic surgery; the management of subretinal hemorrhages; gene therapy; alternative techniques for refractory macular hole; perspectives for stem cell therapy and the prevention of proliferative vitreoretinopathy; and, finally, the Port Delivery System. The main objective of this review is to update the reader on the latest changes in vitreoretinal surgery and to provide an understanding of how each has impacted the improvement of surgical outcomes.

Pars Plana Vitrectomy Port Sizes: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND OBJECTIVE

The uptake of small-gauge (SG; ie, 23-gauge [23-G], 25-gauge [25-G], and 27-gauge [27-G]) pars plana vitrectomy (PPV) has grown. We aim to investigate the advantages and disadvantages of various PPV port sizes in a meta-analysis of randomized controlled trials (RCTs).

MATERIALS AND METHODS

A systematic literature search was performed for RCTs comparing PPV port sizes for any indication. Weighted mean differences (WMDs) and risk ratios (RRs) were calculated, and meta-analysis was performed with random-effects models.

RESULTS

A total of 1,678 eyes from 22 RCTs were included. Risk-of-bias assessment found some concerns in 13 studies. Compared with 20-gauge PPV, there was no significant difference in the final or change in best-corrected visual acuity (BCVA; five studies analyzed each) relative to that of SG PPV. SG PPV was associated with a significantly greater incidence of hypotony (RR = 3.79; 95% confidence intervals [CI], 2.02 to 7.10; P < .0001; six studies) and choroidal detachment (RR = 5.65; 95% CI, 1.01 to 31.71; P = .05; three studies). Compared with 25-G PPV, there was no significant difference in BCVA at any time point with 23-G (two studies), and significantly more frequent port suturing was required with 23-G (RR = 0.46; 95% CI, 0.25 to 0.84; P = .01; two studies). Compared with 25-G PPV, 27-G was associated with a significantly better final BCVA (WMD = -0.06 logMAR; 95% CI, -0.11 to -0.01; P = .02; five studies) and a significantly lengthened surgery (WMD = 4.11 minutes; 95% CI, 0.18 to 8.05; P = .04; three studies).

CONCLUSIONS

There was no significant difference in visual or surgical outcomes following 20-gauge PPV relative to SG PPV (Grading of Recommendations, Assessment, Development, and Evaluation recommendation: low certainty), and there was an increased risk of postoperative complications with SG PPV (moderate certainty). Compared with 25-G PPV, 23-G required more frequent port suturing (moderate certainty), whereas 27-G may be associated with a better final BCVA but longer surgery (low and moderate certainty, respectively). [Ophthalmic Surg Lasers Imaging Retina. 2022;53:152-158.].

Reporting of Complications in Retinal Detachment Surgical Trials: A Systematic Review Using the CONSORT Extension for Harms

IMPORTANCE

Knowledge on the frequency and severity of complications in surgical trials for rhegmatogenous retinal detachment (RRD) is essential to determine whether surgical procedures are developed and compared adequately, taking into account not only efficacy but also harms.

OBJECTIVE

To review standards of reporting of complications in recent randomized clinical trials of RRD surgery.

EVIDENCE REVIEW

This systematic review included randomized clinical trials on RRD surgery published between January 2008 and January 2021 in Embase, MEDLINE, and Web of Science Core Collection databases. Titles, abstracts, and full-text articles retrieved were reviewed for eligibility by 2 independent authors. Eligible studies were evaluated against checklist items from the Consolidated Standards of Reporting Trials Extension for Harms criteria by 2 independent authors, and discrepancies were resolved by discussion with a third author.

FINDINGS

Fifty studies were included. The median number of checklist items fulfilled was 8 (range, 0-15), of a possible total of 18. Frequently reported items were discussions balanced with regard to efficacy and adverse events (42 studies [84%]) and inclusions of harm-associated timing of data collection (41 studies [82%]). The least frequently reported items were distinctions between expected and unexpected adverse events (1 study [2%]) and mentions of the use of a validated instrument to report adverse event severity (4 studies [8%]). Frequency of complications was commonly reported (29 studies [58%]) in contrast with complication severity (10 studies [20%]).

CONCLUSIONS AND RELEVANCE

This review suggests that severity of complications of RRD surgery has been infrequently quantified and reported in randomized clinical trials and potentially represents an important area of improvement in future RRD surgical trials.

Montgomery and informed consent during Covid-19: Pneumatic retinopexy versus pars plana vitrectomy or scleral buckling for retinal detachment repair

Recent reports suggest that the use of an outpatient-based procedure (pneumatic retinopexy, PR) for retinal detachment repair should be encouraged within the UK, especially in light of Covid-19 and possible restrictions/competing demands on access to operating theatres. It is therefore essential that patients receive comprehensive information about the risks and benefits of this approach compared with a formal surgical repair either by pars plana vitrectomy (PPV) and/or scleral buckling (SB). We report a retrospective case series of retinal detachments (RD) satisfying the strict selection criteria for PR but who were managed with formal surgery. Single-operation success rate for PPV/SB at six months follow-up was 93.8% in our study, higher than published primary success rates for PR (60-80%). When counselling patients for possible PR, the ease, speed and potentially reduced co-morbidity of an outpatient-based procedure needs to be balanced against its significantly higher failure rate in comparison with primary PPV/SB.

Comparison of safety and effectiveness between 23-gauge and 25-gauge vitrectomy surgery in common vitreoretinal diseases

PURPOSE

To assess and compare safety and effectiveness between 23-gauge and 25-gauge vitrectomy systems for the treatment of common vitreoretinal diseases in non-vitrectomized eyes.

METHODS

Retrospective evaluation of patients who underwent pars plana vitrectomy from April 2018 to December 2019 at the Department of Ophthalmology and Optometry at the Medical University of Vienna (MUV) for the following indications: macular epiretinal membrane, macular hole, macular lamellar hole, vitreous hemorrhage, vitreous opacities, vitreomacular traction syndrome and macular edema.

RESULTS

201 eyes of 195 patients that underwent 23-gauge (n = 105 eyes) or 25-gauge (n = 96 eyes) vitrectomy were included in this study. The mean best-corrected visual acuity (BCVA) improved at 1-3 months postoperatively and beyond 3 months in both gauge groups. Risk of any complication within 1 month postoperatively was lower in the 25-gauge group, but the difference was statistically not significant (HR [95% CI]: 0.95 [0.53; 1.70], p = 0.85). Intraocular pressure less than 5 mmHg was observed in 2 eyes (2%) in the 23-gauge group at the first postoperative day. Intraocular pressure elevation over 25 mmHg occurred in 5 eyes (2 eyes, 2%, in 23-gauge and 3 eyes, 3%, in 25-gauge group) at postoperative day 1, between 7 and 28 days in 5 cases (2 eyes, 2%, in 23-gauge and 3 eyes, 3%, in 25-gauge group), and in 2 eyes (2%) of the 23-gauge group at postoperative day 145 and 61, respectively. Retinal detachment occurred in 1 eye (1%) in the 23-gauge and in 3 eyes (3%) in the 25-gauge group. We did not observe any cases of endophthalmitis.

CONCLUSION

Results in terms of safety, surgical success and visual outcomes for the treatment of common vitreoretinal surgery indications seem to be comparable between 23-gauge and 25-gauge vitrectomy systems, indicating that the two gauge systems can be used equally in the clinical routine.

INCIDENCE AND RISK FACTORS FOR HYPOTONY AFTER 25-GAUGE PARS PLANA VITRECTOMY WITH NONEXPANSILE ENDOTAMPONADE

PURPOSE

The purpose of this study was to assess the incidence and risk factors for early postoperative hypotony after 25-gauge pars plana vitrectomy with nonexpansile endotamponade.

METHODS

A retrospective study of consecutive patients who underwent 25-G pars plana vitrectomy. Hypotony was defined as an intraocular pressure of 5 mmHg or less after surgery and ocular hypertension as an intraocular pressure greater than 21 mmHg.

RESULTS

Overall, 307 eyes of 307 patients with a mean age of 61.7 ± 14.3 of which 56.7% were males were included. Hypotony was identified in 5.2% of cases (n = 16) at Day 1 and 0.7% (n = 2) at Week 1 with no hypotony-related complications. The hypotony group had a higher number of previous vitreoretinal surgeries (1.5 ± 1.1 vs. 0.4 ± 0.7, P < 0.001) and a higher prevalence of preoperative ocular hypertension (22.2% vs. 4.8%, P = 0.02), pseudophakia (77.8% vs. 48.4%, P = 0.01), silicone oil removal (61.1% vs. 8.3%, P < 0.001), and external diathermy performed (55.6% vs. 20.1%, P = 0.001). In stepwise multivariate analysis, significant parameters were silicone oil removal (R = 16.34%, odds ratio 13.45, P < 0.001), pseudophakia (R = 5.69%, odds ratio 3.65, P = 0.03), and younger age (R = 2.68%, odds ratio 0.96, P = 0.04).

CONCLUSION

Silicone oil removal is a significant risk factor for early postoperative hypotony after 25-G pars plana vitrectomy.

Multicenter survey of sutureless 27-gauge vitrectomy for primary rhegmatogenous retinal detachment: a consecutive series of 410 cases

PURPOSE

To evaluate the surgical outcomes of the 27-gauge (G) vitrectomy system for the treatment of primary rhegmatogenous retinal detachment (RRD).

METHODS

This retrospective consecutive series multicenter study involved a total of 410 eyes of 406 patients who underwent 3-port transconjunctival 27G pars plana vitrectomy (PPV) for RRD between November 2014 and December 2016 and who were followed for a minimum of 3 months postoperative. The main outcome measure was primary reattachment, with the secondary outcome measures being final reattachment, improvement of visual acuity (VA), intraocular pressure (IOP), intraoperative and postoperative complications, and surgery time.

RESULTS

Of the 410 treated eyes, primary reattachment was achieved in 392 (95.6%) and final reattachment was achieved in 410 (100%). In 226 eyes (55.1%) with macula-on RRD, the mean logarithm of the minimum angle of resolution (logMAR) VA improved from 0.16 ± 0.51 pre-surgery to 0.02 ± 0.14 post-surgery (P = 0.11). In 184 eyes (44.9%) with macula-off RRD, logMAR VA improved from 1.06 ± 0.77 pre-surgery to 0.26 ± 0.35 post-surgery (P < 0.001). Following surgery, the mean IOP was highest at 1 day (15.7 ± 7.0 mmHg) postoperative. In all eyes, surgery was concluded without the use of sutures or the need of conversion to a larger-gauge instrument. Although hypotony was observed in 14 (3.4%) of the 410 treated eyes at 1 day postoperative, it spontaneously resolved within 1 week without additional surgical intervention. No postoperative complications such as infectious endophthalmitis were observed throughout the follow-up period.

CONCLUSION

Our findings show that 27G PPV is both safe and effective for the treatment of primary RRD.

Long-Term Outcome of Patients Operated with Pars Plana Vitrectomy for Primary Rhegmatogenous Retinal Detachment

PURPOSE

To determine the long-term outcome of patients operated with pars plana vitrectomy (PPV) for primary rhegmatogenous retinal detachment (RRD) and to identify potential predictors for poor visual outcome.

METHODS

Prospective, observational 30-month study of patients operated for primary RRD with PPV. Examinations were performed preoperatively and after months 2, 6, and 30.

RESULTS

Eighty-four patients (84 eyes) were included and 73 (86.9%) participated at month 30. The macula was attached in 30 (35.7%) patients at primary operation. The majority of patients (n = 59, 80.8%) achieved a good final best corrected visual acuity (BCVA ≤0.3 logMAR, ≥0.5 Snellen) with a better outcome in patients with the macula attached than detached (0.02 vs. 0.17 logMAR, p = 0.007). Variables associated with poor visual outcome were baseline BCVA >0.3 logMAR (p = 0.03), female gender (p = 0.02), silicone oil (p = 0.03), and larger areas of retinal detachment (p = 0.01). In multivariable regression analysis, female gender (OR = 8.5 [95% CI 1.8-39.8]) was the strongest risk factor for poor visual outcome.

CONCLUSION

The majority of patients operated for primary RRD achieved a reasonable long-term visual outcome. Notably, female gender was associated with poor visual outcome, indicating a need for closer follow-up.

[Treatment of retinal detachment of the pseudophak: vitrectomy without episcleral indentation versus ab externo surgery]

Several factors predispose to the occurrence of rhegmatogenous retinal detachment, including cataract surgery, myopia, and degenerative lesions of the peripheral retina as well as eye trauma. This study aims to compare the anatomical and functional outcome of the two surgical techniques (AB interno vs AB externo) in our Hospital. We conducted a descriptive, retrospective study in the Department of Ophthalmology at the University Hospital Mohamed VI in Marrakech, over a period of 3 years, ranging from January 2013 to December 2015. During the study period we compared two groups of people: the first group undergoing surgery by an external approach (cryoapplication of the dehiscences with episcleral indentation) while the second undergoing surgery by endo-ocular approach. Group A or AB externo group included 26 eyes (26 patients) while Group B or vitrectomy with internal tamponade group included 22 eyes (22 patients). In the AB externo group, the average age was 54.92 years against 51.64 years in the AB interno group, with a slight predominance of males in both groups. After the first surgery, retinal reapplication was obtained in both groups with no significant difference, (about 80.76% in Group A versus 81.82% of the second group). In both groups failure was caused advanced vitreoretinal proliferation (4 cases), de novo breaks (3 cases) and breaks which had not been detected on first examinations (2 cases). All these cases underwent reoperation by AB interno approach: patients of group A underwent complete vitrectomy with revision of the indentation +/- internal limiting membrane peeling with internal gas tamponade while patients of group B underwent complementary vitrectomy with dissection of proliferative vitreoretinopathy (PVR) and an internal tamponade with silicone oil. After a mean follow-up period of 12 months, there was no significant difference in visual acuity between the 2 groups, with more than one third of the patients who had regained visual acuity between 1/10 and 5/10 (about 34,61% in AB externo group and 36,36% in AB interno group). Given the technological advances in vitrectomy, the current trend is the endo-ocular surgery however ab-externo surgery is mainly used in the treatment of retinal detachment with visible breaks which can be easily treated with indentation without advanced vitreoretineal proliferation (PVR A-B).

Clinical outcomes of endoscope-assisted vitrectomy for treatment of rhegmatogenous retinal detachment

Summary

We evaluated the clinical outcomes for ophthalmic endoscope-assisted vitrectomy in consecutive patients with uncomplicated rhegmatogenous retinal detachment (RRD). The primary success rate was 98.4% (125/127) without performing a posterior drainage retinotomy or using perfluorocarbon liquids (PFCL) for subretinal fluid drainage.

Purpose

To investigate the clinical outcomes of endoscope-assisted vitrectomy in patients with uncomplicated RRD.

Methods

We examined 127 eyes from consecutive patients who underwent repair of RRD by 23- or 25-gauge endoscope-assisted vitrectomy, with a minimum follow-up of 3 months. Eyes with the following criteria were excluded: Giant retinal tears, grade C proliferative vitreoretinopathy, dense vitreous hemorrhage, retinal detachment secondary to other ocular diseases, and prior retinal or vitreous surgery. All cases underwent subretinal fluid drainage, endolaser photocoagulation and fundus inspection were performed under ophthalmic endoscopic observation. Success rate, visual acuity, surgery time and complications were evaluated.

Results

Primary and final success rate was 98.4% (125/127) and 100% (127/127), respectively, Surgery time was 59.6±26.3 minutes. The best-corrected visual acuity significantly improved from 20/100 to 20/20 (P<0.0001). There were 2 cases (1.6%) of creation of a peripheral drainage retinotomy and 4 cases (3.1%) of using PFCL to suppress movement of the detached retina, but there were no cases of creation of a posterior drainage retinotomy or using PFCL for subretinal fluid drainage. There was 1 case of presumed endophthalmitis after surgery. There were 12 hypotonous cases at postoperative day 1 and one of them needed additional scleral sutures at postoperative day 4 for prolonged hypotony.

Conclusion

The present study demonstrated the efficacy of endoscope-assisted vitrectomy for patients with uncomplicated RRD. To perform endoscope-assisted vitrectomy safely, sufficient closure of sclerotomies is necessary at the end of surgery.

Comparison of subconjunctival scarring after microincision vitrectomy surgery using 20-, 23-, 25- and 27-gauge systems in rabbits

PURPOSE

To compare subconjunctival scarring after vitrectomy in rabbit eyes using different gauge systems by analysing anterior segment optical coherence tomography (AS-OCT) images and histological sections.

METHODS

Vitrectomy using 20-, 23-, 25- and 27-gauge systems was performed for rabbits. Anterior segment optical coherence tomography (AS-OCT) images of the incision sites were obtained before and at day 1, 7 and 1 month after surgery. We measured the thickness of conjunctival epithelium, stroma, Tenon's capsule and total conjunctiva of these three layers, then determined the preservation rates of the borderlines between each layer. Surgical invasion was estimated by histological observation.

RESULTS

The thickness of total conjunctiva, or the thickness of both conjunctival stroma and Tenon's capsule in the 20-gauge group was significantly thicker than that in the 27-gauge group at day 1 and day 7 after surgery. Preservation rates of the conjunctival stroma/Tenon's capsule borderline were significantly lower in the 20-gauge group than in the 25- and 27-gauge groups at day 1, day 7 and 1 month. Preservation rates of the Tenon's capsule/sclera borderline were significantly lower in the 20-gauge group than in the 25- and 27-gauge groups at 1 month. In the 27-gauge group, the number of α-smooth muscle actin-positive fibroblasts was significantly smaller than in the 20-gauge group at day 7.

CONCLUSION

Based on the finding of AS-OCT and histology, micro incision vitreous surgery, especially using 27-gauge, contributed to less subconjunctival scarring postoperatively. Therefore, the 27-gauge pars plana vitrectomy (PPV) may be a more effective technique for preserving the structure of conjunctiva.