Retinal Displacement After Scleral Buckle Versus Combined Scleral Buckle And Vitrectomy For The Management Of Rhegmatogenous Retinal Detachment : ALIGN SB Vs PPV-SB
Authors: Aditya Bansal1, Sumana C. Naidu1, JAMES M. Kohler2, Shilpa In3, Garima Garima3, Priyanka A. Mahendrakar3, Himanshu Kashyap3, Samara B. Marafon1, Pradeep Susavar4, Muna Bhende3, Edwin H. Ryan5, Rajeev Muni1. 1St Michael's Hospital, 2VitreoRetinal Surgery in Minneapolis, USA, 3Sankara Nethralaya, 4Sanakara Nethralaya, 54.VitreoRetinal Surgery in Minneapolis.
Author Disclosures: A. Bansal: None. S.C. Naidu: None. J.M. Kohler: None. S. In: None. G. Garima: None. P.A. Mahendrakar: None. H. Kashyap: None. S.B. Marafon: None. P. Susavar: None. M. Bhende: None. E.H. Ryan: None. R. Muni: None.
Abstract Body:
Purpose: Low-integrity retinal attachment (LIRA) is characterized by retinal displacement on fundus autofluorescence (FAF) imaging. Recent evidence suggests LIRA occurs more commonly with pars plana vitrectomy (PPV) compared to RPE-pump based procedures such as pneumatic retinopexy. This is likely related to the full-gas fill during PPV that exerts a buoyant force on the retina and residual subretinal fluid leading to retinal stretching and worse functional outcomes. We set out to assess the risk of LIRA following RRD repair with scleral buckle (SB), also an RPE-pump based procedure, versus combined PPV-SB.
Study Design: Multicenter prospective non-randomized comparative trial.
Methods: Patients (age >18 years) presenting with primary macula-off RRD undergoing SB or PPV-SB were included. Patients with significant media opacity or proliferative vitreoretinopathy grade B or worse were excluded. Patients were recruited at St. Michael’s Hospital in Toronto, Canada, VitreoRetinal Surgery PA in Minneapolis, Minnesota and Sankara Nethralaya in Chennai, India. All patients had FAF imaging and assessment of functional outcomes. Metamorphopsia was assessed with MCHARTs and aniseikonia was assessed with the New Aniseikonia Test at 3 months post-operatively. FAF images were assessed for retinal vessel printings (RVPs) by two masked graders with any differences adjudicated by consensus.Patients with poor quality ungradable FAF images were excluded from the study. The primary outcome was the risk of LIRA following SB vs PPV-SB.
Results: Ninety-one eyes were included in this study out of which 46.2% (42/91) had SB and 53.8 (49/91) underwent PPV-SB as the primary procedure. As expected, SB group had younger and phakic patients but otherwise both the groups were comparable in terms of baseline characteristics. The agreement between graders was 78.1% (Kappa=0.49). 16.7% (7/42) in the SB group and 38.8% (19/49) in the PPV-SB group had RVP at 3 months post operatively ( difference, 22.1%; Odds Ratio, 3.2; 95% confidence interval [CI] = 1.2-8.6, P=0.02 ). This difference was statistically significant even after multivariate analysis (p=0.01). 22.5% (6/27) who had external subretinal fluid drainage performed during the scleral buckle procedure noted to have retinal displacement while only 6.7% (1/15) had a nondrainage procedure (Odds Ratio 4, 95% CI 0.4-36.9, p = 0.19). There wasn’t any statistical difference for functional outcomes between eyes undergoing SB vs PPV-SB.
Conclusions: SB, an RPE-pump based procedure, is associated with less retinal displacement/LIRA compared to PPV-SB. There were no significant differences in functional outcomes between the groups. Further prospective studies with a larger sample size are required to assess the impact of retinal displacement on functional outcomes in patients undergoing SB or PPV-SB.
