Key messages

• Pars plana vitrectomy plus scleral buckle may make little or no difference neither in primary or final reattachment rate nor in final visual acuity (low certainty evidence).
• We are uncertain if pars plana vitrectomy plus scleral buckle increases the risk of proliferative vitreoretinopathy or reduces the risk of glaucoma, as the certainty of the evidence has been assessed as very low.

What is the evidence.
See evidence matrix  in Epistemonikos later

We identified four systematic reviews [4], [5], [6], [7] including eight primary studies [8],[9],[10],[11],[12],[13],[14],[15], one of which is a randomized control trial [9].

We excluded four studies from the analysis: in three of them [12], [13], [14] the comparison was unclear according to the information provided by the systematic reviews. In one study [15], the population had an additional condition besides retinal detachment.

This table and the summary are based on the randomized trial [9] because the observational studies did not increase the certainty of the evidence nor provided additional relevant information.

What types of patients were included*

All patients included in the randomized trial [9] were pseudophakic with rhegmatogenous retinal detachment and inferior retinal tear.

The mean age was 57 years old for the pars plana vitrectomy group and 61 years for the pars plana vitrectomy plus scleral buckle group.

Patients had macular detachment (73% of the patients in pars plana vitrectomy group and 63% of the patients in pars plana vitrectomy plus scleral buckle group) and proliferative vitreoretinopathy at grade C or worse (27% of the patients from the pars plana vitrectomy group and 3% of the patients with pars plana vitrectomy plus scleral buckle group).

What types of interventions were included*

The trial [9] compared pars plana vitrectomy plus scleral buckle with pars plana vitrectomy alone.

Laser photocoagulation in 360° and silicone oil instillation were performed in all patients randomized to the pars plana vitrectomy group.

The scleral buckle was conducted using a 360° encircling band in the group which received both procedures.

The systematic review [6] did not describe the procedure used to perform pars plana vitrectomy and scleral buckle. Neither if laser photocoagulation in 360° was applied nor if instillation of air or gas was used in the pars plana vitrectomy plus scleral buckle group.

What types of outcomes 
were measured

• Primary reattachment rate (retinal reattachment after one procedure).
• Final reattachment rate (retinal reattachment after more than one procedures).
• Visual acuity in Snellen scale.
• Complications: proliferative vitreoretinopathy and increased intraocular pressure.

To whom this evidence does and does not apply

• To whom this evidence does and does not apply
  The conclusions reported in this summary are applicable to patients with cataract surgery (pseudophakic) and rhegmatogenous retinal detachment. 
• This evidence could apply to patients without an intraocular lens (aphakic) and with rhegmatogenous retinal detachment. Although the randomized trial [9] included patients with retinal detachments with an inferior retinal tear, the results of this analysis could be applied in retinal detachments with tears in another localization.
• These results can not be applied to traumatic or juvenile (age less than 18 years old) retinal detachments or associated with macular hole or retinoschisis, because these conditions have a different physiopathology and clinical features compared with rhegmatogenous retinal detachment in pseudophakic patients.

• The outcomes reported in the summary of findings table are critical for decision-making according to the opinion of the authors of this summary, which coincide in general with those identified by the systematic reviews. 
• However, it is important to note that increased intraocular pressure will not cause glaucoma necessarily, so it was considered as an indirect outcome. Moreover, the systematic reviews did not report complications such as cystoid macular oedema, epiretinal membrane, endophthalmitis or myopization.

• The benefit of adding scleral buckle to pars plana vitrectomy might be similar compared with pars plana vitrectomy in terms of primary retinal reattachment, final reattachment and visual acuity.
• In terms of adverse effects, pars plana vitrectomy plus scleral buckle may slightly decrease the risk of high intraocular pressure, but this effect could be a result of silicone oil instillation applied exclusively in the pars plana vitrectomy group [6].
• On the other hand, the risk of proliferative vitreoretinopathy is hardly estimable due to the low-certainty evidence and the differences between the groups after randomization (27% in pars plana vitrectomy and 3% in pars plana vitrectomy plus scleral buckle).
• Finally, taking into account that other surgical complications were not reported, it is not possible to make an adequate balance between benefits and risks because of the low certainty evidence.

• None of the systematic reviews included a cost-effectiveness analysis. However, the combination of pars plana vitrectomy and scleral buckle is more expensive compared with pars plana vitrectomy. According to the evidence described in this article, the balance between costs and benefits should lean towards the use of pars plana vitrectomy in pseudophakic or aphakic retinal detachments, but higher quality evidence is needed to support this decision.

• Given the low to very low certainty evidence presented in this summary, the selection of the surgical procedure for pseudophakic or aphakic retinal detachments will depend on its complexity, the available resources, patients baseline characteristics and surgeon's preference, amongst others.

Differences between this summary and other sources

• The conclusions of this article are in accordance with one systematic review which performed a sub-group analysis for pseudophakic retinal detachments [6]. It reported that pars plana vitrectomy plus scleral buckle does not produce additional benefit compared with pars plana vitrectomy. 
• We did not identify specific guidelines about the treatment of pseudophakic or aphakic rhegmatogenous retinal detachment.

• There is a high probability that future evidence changes the conclusions of this summary, given the very low to low certainty evidence and because it is based on one randomized trial [9]. 
• We identified one randomized controlled trial [16] evaluating the question of interest, but it was not included in any systematic review due to its publication date.
• We did not identify ongoing randomized trials evaluating this intervention in the International Clinical Trials Registry Platform of the World Health Organization, neither ongoing systematic reviews in the PROSPERO database.