Dr Piergiacomo Grassi MD is a Consultant Ophthalmologist specializing in vitreoretinal surgery, complex cataract surgery and glaucoma surgery. Italy.
During the EURETINA 2021 meeting, I was honoured to present, as a free paper, the results of our study reporting anatomical and functional outcomes; and structural and functional macular changes in a large series of non-primary retinectomies performed for rhegmatogenous retinal detachments (RRD) complicated by proliferative vitreoretinopathy (PVR) grade C. This was a retrospective single-centre cohort study lead by myself and Mr Anand Chawla FRCOphth MD. The cases were collected from a large dataset from the Royal Hallamshire Hospital in Sheffield, a busy supraregional tertiary referral centre in the UK. Relaxing retinectomies and the use a silicone oil intraocular tamponade are useful for complex retinal detachments with PVR when other procedures including membrane peeling and scleral buckling are insufficient.
In our study, one hundred and one consecutive retinectomies of 101 eyes affected by RRD with PVR-C between January 2014 – February 2020 were included. Cases were identified using the institutional ophthalmology electronic patient database. All eyes previously vitrectomized for RRD which then underwent retinectomies (non-primary retinectomies) for retinal redetachments related to PVR-C were included. Eyes operated on with a retinectomy for other surgical indications were excluded, as well as eyes having already received a previous retinectomy at a different hospital and/or in which the retinectomy was performed as a primary adjunct procedure during the first pars plana vitrectomy performed for RRD (primary retinectomies for RRD). Final anatomical success was defined as an attached retina after retinectomy with the absence or presence of intraocular silicone oil tamponade. In patients who achieved anatomical success, macular spectral domain OCT was retrospectively reviewed in order to evaluate the final macular status after successful retinectomy. The subsequent analysis of all retinal layers of the macular OCT allowed us to identify the location of cystoid macular oedema and to distinguish between exudative intraretinal cystoid spaces (exudative maculopathy) and tractional intraretinal cystoid spaces (tractional maculopathy), as described in previous literature.
The mean follow-up duration was 36.18±19.53 months. Anatomical success was achieved in 79 cases after one retinectomy procedure (78.2%), and 84 cases (83.1%) after two retinectomies. Reasons for anatomical failure was PVR-C development under silicone oil in 50% of failures, reoccurrence of PVR after removal of silicone oil (ROSO) in 27%, retinectomy extension of 3 clock hours or less in 14%, and PVR development after ROSO in 9%. Final best corrected visual acuity (BCVA) ≥ 20/200 was achieved in 29% of cases; 8% gained ≥ 20/80. Final mean postoperative BCVA of successes with oil in situ was 1.68±0.59 compared with 1.07±0.63 logMAR of successes after oil removal; the difference was statistically significant (p=0.00005).
Post-operative macular OCT was obtained from 60/84 anatomical successes (71%). A normal macular profile was found in 3%, while majority demonstrated exudative maculopathy (51.5%), macular atrophy (22%), tractional maculopathy (21.5%) and macular disciform scar (2%). Final central foveal thickness (CFT) was significantly lower in eyes with normal macular profile when compared to exudative maculopathy (p=0.019) and tractional maculopathy (p=0.037), but not macular atrophy (p=0.560). The bivariate linear relationship between final CFT and BCVA was statistically significant(p=0.000013).
In conclusion, our results bring evidence that a satisfactory anatomical and functional outcome is possible following secondary retinectomy for retinal redetachment due to PVR-C. Also, we show that recurrent RRD due to ongoing PVR is the primary reason for failure, and that a normal macular profile is a rare event after successful retinectomy, since it was found only in 3% of cases, with the majority demonstrating exudative maculopathy (51.5%), macular atrophy (22%) and tractional maculopathy (21.5%). To our knowledge, this study is the first to assess macular changes after successful retinectomy for recurrent RRD due to PVR in a large cohort of patients with a long follow-up period, and to describe the anatomic distribution of the cystoid spaces in the context of exudative and tractional maculopathy. Positive prognostic factors include removal of oil without redetachment, normal macular status and lower CFT. Functional outcome was influenced by macular changes, as final BCVA and CFT correlated.