Which Reparative Surgery for Retinal Detachment Has Superior Outcomes?

Retinal displacement may be more severe and occurs more frequently in patients who undergo pars plana vitrectomy (PPV) as opposed to pneumatic retinopexy (PR) for rhegmatogenous retinal detachment repair, according to a study published in JAMA Ophthalmology.

Debate persists around which surgical technique is optimal to repair rhegmatogenous retinal detachments. PR involves “reabsorption of subretinal fluid by the retinal pigment epithelium after occlusion of the retinal break by an intravitreal gas bubble,” whereas PPV consists of internal drainage, air-fluid exchange, and near complete gas tamponade.

Researchers set out to determine which surgical technique yields the best patient outcomes by blindly assessing retinal vessel printing on fundus autofluorescence imaging. In the multicenter retrospective case series, 238 patients (238 eyes) with rhegmatogenous retinal detachments were treated with either PR or PPV. The average patient age was 62 years, and 114 individuals underwent PR (47.9%) while 124 underwent PPV (52.1%).

All eyes included in the study had similar baseline characteristics including age, lens status, macular status, and quadrants of detachment between groups (>2 quadrants: PR success, 38 [33.9%]; PR failure, 12 [52.2%]; and primary PPV, 41 [43.6%]).

The study yielded the following results:

• The proportion of eyes with retinal vessel printing on fundus autofluorescence imaging was 7% for PR (8 of 114) and 44.4% for PPV (55 of 124) (37.4 percentage point difference; 95% CI, 27.4-47.3; P&thinsp;<.001)
• Among small detachments (1-2 quadrants), retinal displacement occurred in 3 of 74 eyes (4.1%) in the PR group versus 22 of 64 eyes (34.4%) in the PPV group (30.3 percentage point difference; 95% CI, 17.8-42.8; P&thinsp;<.001)
• Among large detachments (3-4 quadrants), displacement occurred in 5 of 38 eyes (13.2%) that underwent PR versus 29 of 53 eyes (54.7%) that underwent PPV (41.5 percentage point difference; 95% CI, 24.4-58.7; P&thinsp;<.001)
• Patients with high-integrity retinal reattachment are less likely to experience vertical metamorphopsia compared with those with low-integrity retinal reattachment

The researchers defined high-integrity retinal reattachment as achieved when the retina is “reapposed as close as possible to its original location with no retinal vessel printing shown on fundus autofluorescence imaging.”

Because some PR procedures faill and PPV must be performed, researchers carried out additional analyses that included only primary PPVs in the PPV cohort. In this analysis, data showed 99 eyes underwent primary PPV and 139 underwent primary PR. Researchers found, “42.4% (42 of 99) of the eyes in the PPV group versus 15.1% (21 of 139) of the eyes in the PR group (including 13 PR failures with subsequent PPV) had displacement (27.3 percentage point difference; 95% CI, 15.9-38.7; P&thinsp;<.001).”

The differences in each procedure may be the reason outcomes vary among patients. The investigators hypothesize that the natural reabsorption of subretinal fluid in PR, along with other factors, causes less displacement of subretinal fluid and less retinal displacement overall. In PPV, the exertion of a larger buoyant force on a larger area of mobile retina may result in greater subretinal fluid flux and retinal displacement.

“Retinal displacement and low-integrity retinal reattachment appear to occur more frequently and are more severe with PPV versus PR,” the researchers concluded. “Recognition of the importance of retinal displacement and integrity of retinal reattachment…may lead to further refinements in vitreoretinal surgery techniques for primary rhegmatogenous retinal detachment repair and potentially improved functional outcomes for patients.”

Reference

Brosh K, Francisconi CLM, Qian J, et al. Retinal displacement following pneumatic retinopexy vs pars plana vitrectomy for rhegmatogenous retinal detachment [published online April 23, 2020]. JAMA Ophthalmol. doi: 10.1001/jamaophthalmol.2020.1046.