Outcomes of Chandelier-Assisted Scleral Buckling in Rhegmatogenous Retinal Detachments: Systematic Review and Meta-analysis

Introduction

Rhegmatogenous retinal detachment (RRD) is the most common type of RD and can be blinding if left untreated. ¹ The major modern surgical approaches for RRD are pneumatic retinopexy, scleral buckling, and pars plana vitrectomy (PPV). ¹ Scleral buckling is often performed in younger, phakic patients who have an attached posterior hyaloid because it allows for preservation of the vitreous. ² In addition, cataractogenesis is less likely to occur with scleral buckling than with PPV, making scleral buckling more palatable for the patient.^2–4 However, compared with PPV, scleral buckling has disadvantages of longer operative times, a more difficult learning curve, and a higher risk for missing additional retinal breaks.^1,2

In standard scleral buckling, an indirect ophthalmoscope is typically used to view the retina. It generates an inverted image and can be tedious to wear and remove repeatedly. ⁵ Standard scleral buckling is also ergonomically challenging, and with the high rates of musculoskeletal injuries in ophthalmologists, it is important to search for new techniques that can reduce ergonomic strain.^6,7 In addition, standard scleral buckling has limitations in certain patient populations. For example, pseudophakic patients have been found to have worse outcomes after standard scleral buckling, possibly as a result of the increased difficulty of visualization using the indirect ophthalmoscope through an opacified peripheral capsule and the risk for missing potential tears.^4,6,8 This is supported by studies reporting that a history of posterior capsulotomy was associated with lower primary standard scleral buckling success.^6,9

Recently, a new technique involving chandelier endoillumination for scleral buckling (chandelier scleral buckling) was introduced. Initially described by Aras et al, ¹⁰ this technique involves inserting a 4.0 mm chandelier light through the pars plana to allow for visualization through the surgical microscope. Since then, several studies have examined the efficacy of chandelier-assisted scleral buckling surgery, with some studies also comparing it to standard scleral buckling.^{2,5,6,8,10–35} The advent of chandelier scleral buckling has helped improve the identification of retinal breaks that may have been previously missed in the preoperative examination when performing standard scleral buckling. ⁶ Chandelier scleral buckling also has the added benefit of potentially improving visualization in pseudophakic eyes. ⁶ Although several primary studies have reported on the efficacy of chandelier scleral buckling, at present no higher level evidence is available. ³⁶ To our knowledge, this is the first meta-analysis to pool data on the outcomes of chandelier scleral buckling and compare them against those of standard scleral buckling.

Methods

Article Selection

Two authors (D.Z., G.J.) independently screened and reviewed articles in 2 phases as follows: title and abstract screening and full-text screening. During the title and abstract screening phase, articles were included if they reported the primary retinal reattachment rate after chandelier-assisted scleral buckling in the title or abstract. These articles proceeded to phase 2 of the article selection process. If the content of the article was unclear based on the title or abstract, the study was selected for full-text screening.

During phase 2 (full-text screening), the independent authors screened full-text articles based on predetermined inclusion and exclusion criteria. Inclusion criteria were as follows: (1) reports on the efficacy of chandelier-assisted scleral buckling for primary repair of RRDs in adult patients; (2) reports on complication rates; (3) full-text publication; (4) English language; (5) clinical trial, cohort, case-control, case series. Exclusion criteria were (1) case reports, conference proceedings, letters, commentaries, and reviews/meta-analyses; (2) animal or laboratory studies; (3) duplicate literature or duplicate data. Disagreements were resolved via consensus and with a third review (A.W.).

Figure 1 shows the PRISMA flowchart of this meta-analysis. ³⁸ The initial search performed using the search strategy obtained an initial 345 results that were then imported into Covidence, a systematic review manager. One additional study was identified through hand searching. Covidence merged duplicates, consolidating the number to 291. After screening the titles and abstracts, the number of results was reduced to 48. In the full-text screening phase, 18 studies were excluded. Thirty studies remained, from which data were extracted.

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Figure 1.

PRISMA flowchart.

Results

Study Characteristics

The meta-analysis included 30 studies published between 2012 and 2023 with sample sizes ranging from 6 patients to 282 patients. Table 1 shows the characteristics of the studies. The published studies were conducted in 12 countries. Two studies were prospective randomized clinical trials (RCTs), 3 were prospective nonrandomized studies, and the remainder were retrospective cohort studies and case series. All studies reported on the primary anatomic success rates and complications of chandelier scleral buckling. Seven studies directly compared chandelier scleral buckling and standard scleral buckling.

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Table 1.

Summary of Included Studies.

Study	Year	Country	Study Design	Age (Y)	Follow-up Time	Eyes a (n)	Primary Anatomic Success in CSB (n/N)
AlAkeely et al 11	2020	Saudi Arabia	CS	20 to 60	6 mo d	6	5/6
Albalkini et al 2	2022	Egypt	RCT	36.61 c	6 mo	23	18/23
Ali et al 12	2022	Pakistan	RCT	44.3 ± 12.1 c	3 mo	20	19/20
Alkabes et al 13	2021	Italy	RCS	61.8 c	12 mo	121	111/121
Aras et al 10	2012	Turkey	PNRS	53.6 c	13.4 mo c	16	13/16
Assi et al 14	2018	Lebanon	PNRS	26.7 ± 11.5 c	12 mo	23	20/23
Caporossi et al 15	2019	Italy	CS	61.5c	6.4 mo d	28	27/28
Cohen et al 16	2019	Israel	RCS	35.73	6 mo	22	18/22
Gogia et al 17	2014	India	CS	46d	24 mo	23	22/23
Gomaa and Elbaha 18	2017	Egypt	PNRS	49.8 c	3 mo	30	25/30
Haug et al 19	2016	USA	CS	52 c	6 mo c	7	6/7
Hong et al 20	2020	Korea	CS	36.38 c	16.19 mo	21	19/21
Hu et al 5	2017	China	RCS	12 to 67	6–27 mo	61	57/61
Ilhan et al 21	2022	Turkey	RCS	59 to 45	14.93 mo c	20	17/20
Imai et al 22	2015	Japan	CS	43.7 c	11.8 mo c	79	73/79
Jeon and Han 23	2019	Korea	CS	43.5 c	10.4 mo c	29	27/29
Jo et al 24	2017	Korea	CS	26.8 ± 10.2 c	7.3 ± 3.1 mo c	17	16/17
Kita et al25, b	2019	Japan	CS	33.4 c	11.3 mo c	15	15/15
La Spina et al 26	2021	Italy	CS	59 ± 8 c	3 mo	107	101/107
Li et al 27	2016	China	RCS	37	12 mo	47	44/47
Li et al 28	2021	China	CS	49.3 ± 18.9 c	6 y c	10	9/10
Nagpal et al 29	2013	India	CS	Not reported	6 mo	10	9/10
Narayanan et al 30	2016	India	RCS	34.28 ± 18.41	115.63 d	14	13/14
Nossair et al 8	2019	Egypt	CS	Not reported	24.09 mo c	21	19/21
Roca et al 31	2020	Multicenter	CS	42.6 c	13.5 mo c	282	240/282
Savastano et al 32	2023	Italy	CS	59.7 ± 6.9 c	6 mo	20	19/20
Seider et al 6	2016	USA	CS	52 c	234.6 d c	12	10/12
Tayyab et al 33	2014	Pakistan	CS	45.3 c	2 mo	11	9/11
Tomita et al 34	2015	Japan	RCS	41.3 ± 14.0 c	8.6 ± 3.2 mo c	16	15/16
Yan 35	2017	China	CS	49.23 ± 15.19 c	9.59 ± 2.24 mo c	22	22/22

Abbreviations: CS, case series; CSB, chandelier endoillumination–assisted scleral buckling; PNRS, prospective nonrandomized study; RCS, retrospective cohort study; RCT, randomized controlled trial.

a

Number of eyes that had chandelier endoillumination–assisted scleral buckling.

b

This study included 3 pediatric patients who were excluded from the analyses.

c

Reported mean.

d

Reported median.

Efficacy of Chandelier-Assisted Scleral Buckling

A meta-analysis of data extracted from 30 studies found that the primary anatomic success rate of chandelier scleral buckling was 91.7% (95% CI, 89.6%-93.6%). No heterogeneity was detected (I² = 7%; P = .36). Figure 2 shows the forest and funnel plots. A linear regression test of funnel plot asymmetry did not detect any publication bias (P = .96).

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Figure 2.

(A) Forest plot meta-analysis of proportions of the pooled primary anatomic success rates. Each study is shown by the last name of the first author and the proportion with the 95% CI. The summary proportion and 95% CI are also shown. (B) Funnel plot of the studies included in the meta-analysis.

Efficacy of Chandelier-Assisted vs Standard Scleral Buckling

The meta-analysis of data extracted from 7 studies comparing the primary anatomic success rates between chandelier scleral buckling and standard scleral buckling found no statistically significant difference between the 2 methods, with a risk ratio of 1.01 (95% CI, 0.94-1.08; P = .80). No heterogeneity was detected (I² = 0%; P = .99). Figure 3 shows the forest plot. Leave-one-out sensitivity analysis did not significantly alter the pooled results.

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Figure 3.

Forest plot of the risk ratio meta-analysis comparing success rates between chandelier scleral buckling and standard scleral buckling. Each study is shown by the last name of the first author and the risk ratio with the 95% CI. The combined effect and 95% CI is also shown (according to random-effect estimations).

Surgical Duration of Chandelier-Assisted vs Standard Scleral Buckling

A meta-analysis was performed from data extracted from the 3 studies that compared the surgical durations between chandelier scleral buckling and standard scleral buckling. The average chandelier scleral buckling durations ranged from 77.85 to 107 minutes, and the average standard scleral buckling durations ranged from 95.71 to 130 minutes. The mean difference between the 2 techniques was 18.83 minutes, with chandelier scleral buckling being significantly shorter (mean difference, −18.83; 95% CI, −30.88 to −6.79; P = .002). No heterogeneity was detected (I² = 0%; P = .95). Figure 4 shows the forest plot. One additional study reported operative times for segmental buckles and encircling buckles separately but did not report an overall time for the 2 treatment groups. ²⁷ The authors were contacted; however, the data could not be obtained and this study was excluded from this portion of the analysis. Leave-one-out sensitivity analysis did not significantly alter the pooled results.

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Figure 4.

Forest plot meta-analysis comparing the mean surgical durations of chandelier scleral buckling and standard scleral buckling. Each study is shown by the last name of the first author and the mean difference with the 95% CI. The summary mean difference and 95% CI are also shown (according to random-effect estimations).

Outcomes of Chandelier-Assisted Scleral Buckling in Pseudophakic Eyes and Phakic Eyes

A meta-analysis of data extracted from 5 studies comparing the primary anatomic success rates between pseudophakic eyes and phakic eyes having chandelier scleral buckling showed that there was no statistically significant difference between the 2 groups, with a risk ratio of 0.99 (95% CI, 0.91-1.08; P = .89). No heterogeneity was detected (I² = 0%; P = .66). Figure 5 shows the forest plot. Leave-one-out sensitivity analysis did not significantly alter the pooled results.

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Figure 5.

Forest plot of the risk ratio meta-analysis comparing success rates between pseudophakic eyes and phakic eyes having chandelier scleral buckling. Each study is shown by the last name of the first author and risk ratio with the 95% CI. The combined effect and 95% CI are also shown (according to random-effect estimations).

Conclusions

The popularity of scleral buckling has been declining, possibly as a result of the significant advances in vitrectomy visualization systems and instruments as well as the technical challenges in performing standard scleral buckling. ⁶ However, with the incorporation of chandelier endoillumination, there could be a resurgence in the use of scleral buckling to treat primary RRDs. In this meta-analysis, chandelier endoillumination–assisted scleral buckling was found to have a high success rate of 91.7%. There was no difference in the primary anatomic success rates between the chandelier scleral buckling and standard scleral buckling techniques, and chandelier scleral buckling was found to have an added benefit of a shorter surgical duration. Chandelier scleral buckling was also found to have similar efficacy in pseudophakic eyes and phakic eyes, in contrast to standard scleral buckling where pseudophakic eyes tend to have worse outcomes.^4,6,8,9 There was low heterogeneity, and no significant publication bias was noted.

In a previous meta-analysis comparing scleral buckling and PPV, ⁴² the 2 techniques had similar success rates of 80% to 90%, similar to the success rate of chandelier scleral buckling reported in this study. Furthermore, when comparing rates of primary anatomic success between chandelier scleral buckling and standard scleral buckling, we found no statistically significant difference. These findings suggest that chandelier scleral buckling is a promising technique that provides efficacies similar to those of traditional methods.

The most commonly cited intraoperative complication in chandelier scleral buckling was vitreous prolapse or leak. Although the risk for this complication is still present with standard scleral buckling if subretinal drainage is performed, it may be higher in chandelier scleral buckling given the additional sclerotomy site for the chandelier. ⁴³ Untreated vitreous prolapse risks development of vitreous incarceration and endophthalmitis. ⁴⁴ Vitreous prolapse occurred at the chandelier site during trocar removal and would necessitate excision with scissors.^2,8,18,24 Six studies reported this complication, with incidences ranging from 5% to 48%.^{2,8,10,18,24,30} Sutures at the sclerotomy site were also needed in some of the reported cases.^10,30

Authors have proposed methods to reduce the risk for vitreous prolapse, including using valved cannulas, paracentesis, or subretinal fluid drainage to lower IOP before trocar removal; inserting the trocar obliquely; or plugging the cannula during episcleral procedures as well during removal of the trocar.^2,6,8,14 Albalkini et al ² found that 12 of 23 eyes that had chandelier scleral buckling developed vitreous entrapment, identified on ultrasonic biomicroscopy, including eyes that did not have intraoperative vitreous prolapse. Their findings suggest that patients are still at risk for vitreous incarceration despite the absence of vitreous prolapse intraoperatively. It is necessary to monitor for the development of vitreous incarceration because it may be associated with an increased risk for RD. ⁴⁵ Although surgeons should be aware of this theoretical risk, there was no significant difference in the primary success rate. Future studies are needed to better evaluate the risk for late redetachment in patients with postoperative development of vitreous incarceration.

Chandelier scleral buckling has been reported to have intraoperative risks similar to those of standard scleral buckling with regard to choroidal and subretinal hemorrhages and scleral perforations.^43,46 The most common postoperative complications of chandelier scleral buckling were also similar to those of standard scleral buckling, including redetachment, PVR, and elevated IOP. ⁴⁶ These complications are more related to the scleral buckle technique itself rather than the implementation of the chandelier viewing device. Unfortunately, our analysis was unable to directly compare complication rates between chandelier scleral buckling and standard scleral buckling because the majority of studies only reported complications for chandelier scleral buckling. Although endophthalmitis, the most dreaded potential complication of chandelier scleral buckling, was not reported in any of the studies included in this analysis, it has been reported in single case reports.^47,48 It is hypothesized that the increased risk for endophthalmitis in chandelier scleral buckling vs standard scleral buckling is the result of the additional sclerotomy site and entry into the vitreous cavity.^2,48

It can be hypothesized that introduction of the chandelier endoilluminator would increase the risk for lens touch and subsequent cataract formation not typically seen in standard scleral buckling. However, no study reported a significant number of cases in which lens touch and subsequent cataract progression occurred. Imai et al ²² reported a single case of lens touch by the chandelier endoilluminator during cryoretinopexy; however, cataract progression was not observed at subsequent follow-ups. The same authors reported another case in which cataract progression was observed. Cohen et al ¹⁶ reported 2 cases in which eyes undergoing repair using chandelier scleral buckling had progression of nuclear cataract without evidence suggesting that lens touch had occurred intraoperatively.

Insertion of the endoilluminator is also thought to increase the risk for retinal breaks caused by traction during eye manipulation; however, only 1 case of intraoperative retinal tears has been reported. It may be difficult to ascertain whether a newly discovered tear was caused by endoilluminator insertion or if its presence had been missed preoperatively. It has been suggested that fixing the silicone band to the sclera before trocar and cannula insertion allows better control of the endoilluminator and minimizes the risk for lens touch and creation of new retinal breaks. ¹⁸

In pseudophakic patients, PPV is performed more often than standard scleral buckling. ⁸ Factors such as poor pupil dilation, cortical remnants, capsule opacification, and intraocular lens optical aberrations in pseudophakic patients make it difficult to obtain a satisfactory view with the indirect ophthalmoscope. ⁴⁹ Studies have compared PPV and standard scleral buckling in pseudophakic patients and found PPV to be better in achieving reattachment.^4,50 However, to our knowledge no study has yet reported on whether chandelier scleral buckling is as efficacious as PPV in achieving anatomic success in pseudophakic eyes. When comparing success in phakic eyes and pseudophakic eyes in chandelier scleral buckling, Alkabes et al ¹³ found similar anatomic success rates between the 2 techniques.

Although a limited number of studies have compared surgical duration in standard scleral buckling and chandelier scleral buckling, results in the 3 studies in our analysis suggest that the operative time in chandelier scleral buckling is significantly shorter than in standard scleral buckling. Benefits of a shorter surgical duration include decreased patient morbidity, decreased use of anesthesia, and decreased costs. These findings should be interpreted with caution given the limited sample size and factors such as surgeon experience with the 2 techniques. For example, the surgeons in these studies are likely very comfortable with chandelier scleral buckling and therefore are able to perform the procedure with operative times similar to the findings in this study. However, surgeons who are starting to adopt chandelier scleral buckling techniques are likely to require more time and may not find operative times in chandelier scleral buckling to be shorter than in standard scleral buckling. ⁵¹ Future studies with a larger sample could further explore differences in operative times between standard scleral buckling and chandelier scleral buckling to better determine whether there is a significant difference.

Our analysis included a large number of eyes and independent studies, despite chandelier scleral buckling being a relatively new surgical technique. In addition, these studies were conducted across 12 countries, making the sample analyzed more diverse and therefore more applicable. Thus, the results of this analysis are also more likely to be representative of the true rate of success across diverse populations given the low heterogeneity and no publication bias.

Despite these findings, there are limitations to this analysis. The majority of included studies had small samples and were retrospective. Only a few studies directly compared standard scleral buckling and chandelier scleral buckling, and only 2 of them were RCTs. This in itself makes each study subject to bias because surgeons may have selectively chosen eyes that would ensure the greatest chance for primary anatomic success after chandelier scleral buckling. To minimize skewing the data based on the studies with small samples, our meta-analysis model weighed these studies less, which would then have a smaller effect on the final findings.

The chandelier scleral buckling technique in all included studies was not completely standardized. There was variation in methodology, such as the gauge size used for the sclerotomy, length of follow-up, and location and number of RRDs. Studies also had varying definitions of success rates, ranging from retinal reattachment after initial surgery to RD after initial surgery by a specified follow-up date. For our analysis, we used an inclusive definition of primary anatomic success, which might have overestimated the immediate success rate after surgery but underestimated the long-term success. However, in studies that defined primary anatomic success after a specified follow-up period, the success rates were similar to those in studies with more inclusive definitions of success rates.

Reporting bias must also be considered in the documentation of complications. Additional prospective randomized studies with more standardized techniques, reporting, and larger samples are needed to better compare the efficacy and complication rates between chandelier scleral buckling and standard scleral buckling. Finally, as with any published study, it is possible that studies with higher success rates are more likely being published, falsely inflating the success rate. However, we hope this is less likely given that we did not find any statistically significant publication bias in our analysis.

Chandelier endoillumination–assisted scleral buckling not only provides a high primary anatomic success rate that is similar to that of traditional standard scleral buckling, it also may provide an additional advantage in pseudophakic cases in which standard scleral buckling may be less ideal. Complications seen in chandelier scleral buckling and standard scleral buckling, such as vitreous prolapse, can be adequately managed with no increased risk for endophthalmitis. Further prospective randomized studies are needed to better compare the efficacy of chandelier scleral buckling with that of standard scleral buckling.

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